Patent Publication Number: US-11043768-B1

Title: Power adapter configured to provide power to a load and method of implementing a power adapter

Description:
PRIORITY CLAIM 
     Applicant claims priority to U.S. Application 62/869,002, filed on Jun. 30, 2019, U.S. Application 62/877,784 filed on Jul. 23, 2019, and U.S. application Ser. No. 16/560,822 filed on Sep. 4, 2019, the entire applications of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     An embodiment of the present invention relates generally to power adapters, and methods of implementing power adapters and control attachments. 
     BACKGROUND 
     Power adapters, such as switches which control the application of power to a load (e.g. a light or other appliance for example), are an important part of any residential or commercial building, and can provide beneficial control of a load attached to the power adapter, such as timing control, motion detection, and dimming for example. As power adapters continue to advance, additional functionality may be available to a user. However, replacing a power adapter can come with significant expense. In addition to the cost of the replacement power adapter, it may be necessary to pay for the professional installation of the replacement power adapter, such as in the case of an in-wall installed power adapter that is coupled to wires in a wall of a building, such as a residential building or a commercial building. For many homeowners who attempt to replace a power adapter rather than have an electrician replace the power adapter, the homeowner may face a risk of shock or other bodily harm during the installation process, or improperly install a power adapter that may pose a risk to a user of the power adapter in the future. 
     In the case of new construction, and particularly a new residential construction, a purchaser (or a builder in the case of a home that is built without input from a purchaser of the home) may not know where the different types of power adapters should be initially placed. Further, it may not be until after living in the home for a period of time that a homeowner may have a better idea where certain types of power adapters should be placed. The homeowner would then have to change some power adapters, and therefore incur additional time and effort (or incur additional time and cost if the homeowner relies upon an electrician) to change the power adapters. Such a need to change power adapters may be particularly frustrating for the homeowner, who, having spent money in the purchase of the new home and spent considerable time during the planning and move-in process, may now have to spend additional money and time to fix a problem. That is, a homeowner may not appreciate the additional cost and time to make improvements to a home that they may have already invested considerable money and time in planning. While the homeowner may decide to delay any changes of power adapters in their home to avoid the additional cost and time, such a delay may lead to dissatisfaction with their homebuilder or the purchase of their new home. 
     Accordingly, circuits, devices, arrangements and methods that enable a user such as a homeowner or other building owner to easily and efficiently implement different power adapters are beneficial. 
     SUMMARY 
     A power adapter configured to provide power to a load is described. The power adapter may comprise a first plurality of contact elements comprising a first contact element configured to receive power and a second contact element configured to provide power to a load; and a recess adapted to receive a control attachment and comprising a second plurality of contact elements; wherein a third contact element of the second plurality of contact elements is configured to receive power by way of the first contact element of the first plurality of contact elements, and a fourth contact element of the second plurality of contact elements is configured to receive power by way of the control attachment. 
     According to another implementation, a power adapter configured to provide power to a load may comprise a first plurality of contact elements comprising a first contact element configured to receive power and a second contact element configured to provide power to a load; a recess adapted to receive a control attachment and comprising a second plurality of contact elements; and a switch configured to control the application of power to a load; wherein a third contact element of the second plurality of contact elements is configured to receive power by way of the first contact element of the first plurality of contact elements, and a fourth contact element of the second plurality of contact elements is configured to receive power by way of the control attachment. 
     A method of implementing a power adapter to provide power to a load is also described. The method may comprise configuring a first contact element of a first plurality of contact elements to receive power, configuring a second contact element of the first plurality of contact elements to provide power to a load; providing a recess adapted to receive a control attachment and comprising a second plurality of contact elements; configuring a third contact element of the second plurality of contact elements to receive power by way of the first contact element of the first plurality of contact elements; and configuring a fourth contact element of the second plurality of contact elements to receive power by way of the control attachment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of a power adapter arrangement having a basic control attachment; 
         FIG. 2  is another block diagram of a power adapter arrangement having a control attachment with additional features; 
         FIG. 3  is another block diagram of a power adapter arrangement having dimming functionality; 
         FIG. 4  is another block diagram of a power adapter arrangement having dimming functionality and a control attachment with additional features; 
         FIG. 5  is another block diagram of a power adapter arrangement having dimming functionality and a control attachment with both dimming capability and an interface for transmitting or receiving communication signals; 
         FIG. 6  is a block diagram of a dimmer control circuit that may be implemented in a power adapter or in a control attachment; 
         FIG. 7  is a block diagram of an interface between a power adapter and a control attachment; 
         FIG. 8  is another block diagram of an interface between a power adapter having a dimmer control circuit and a control attachment. 
         FIG. 9  is another block diagram of an interface between a power adapter and a control attachment having a dimmer control circuit. 
         FIG. 10  is another block diagram of an interface between a power adapter and a control attachment having a wireless connection. 
         FIG. 11  is an example of a switch configuration enabling a connection by shorting contacts of a connector of a power adapter. 
         FIG. 12  is block diagram of a data block having a plurality of fields enabling the transfer of signals between a power adapter and a control attachment. 
         FIG. 13  is a flow chart showing a method of enabling the control of a power adapter using a control attachment. 
         FIG. 14  is an example of a signal transfer protocol for transferring signals between a power adapter and a control attachment. 
         FIG. 15  is a front and side view of a power adapter; 
         FIG. 16  is a cross-sectional view of the power adapter of  FIG. 15  taken at lines  16 - 16 ; 
         FIG. 17  is a front and side view of a control attachment having a portion that extends through recess of a wall plate and a portion including attachment elements that are located behind the wall plate; 
         FIG. 18  is a front and side view of a control attachment that extends through recess of a wall plate, where the attachment elements are accessible when the wall plate is attached to the power adapter or the control attachment; 
         FIG. 19  is a side view of a control attachment having a movable toggle element; 
         FIG. 20  is a side view of the control attachment of  FIG. 19  having the movable toggle element in a first position; 
         FIG. 21  is a side view of the control attachment of  FIG. 19  having the movable toggle element in a second position; 
         FIG. 22  is a front and side view of a power adapter having a single toggle actuator and an optional dimmer control element; 
         FIG. 23  is a side view of the power adapter of  FIG. 22 ; 
         FIG. 24  is a side view of a control attachment that may be implemented with the power adapter of  FIG. 22  and having a toggle element in a first state; 
         FIG. 25  is a side view of the control attachment of  FIG. 24  where the toggle element is a second state; 
         FIG. 26  is a front and side view of a control attachment having a hinged toggle element; 
         FIG. 27  is a side view of the control attachment of  FIG. 26 ; 
         FIG. 28  is a front and side view of the control attachment of  FIG. 26  with the hinged toggle element in an open position and exposing a control module and optional user interfaces; 
         FIG. 29  is a front and side view of the control attachment of  FIG. 26  with the control module of  FIG. 28  removed; 
         FIG. 30  is another front and side view of the control attachment of  FIG. 26  with the control module of  FIG. 28  removed; 
         FIG. 31  is a front and side view of a control module that could be implemented in the control attachment of  FIG. 26 ; 
         FIG. 32  is a front and side view of a control attachment having a control module that is accessible through a recess in a toggle element, such as a hinged toggle element; 
         FIG. 33  is a side view of the control attachment of  FIG. 32  having a toggle element in a closed position; 
         FIG. 34  is a front and side view of the control attachment of  FIG. 32  having the toggle element in an open position; 
         FIG. 35  is a front and side view of the toggle element of  FIG. 32  that may be removed; 
         FIG. 36  is a view of an attachment element of the control attachment which is adapted to receive corresponding attachment element of the toggle element of  FIG. 32 ; 
         FIG. 37  is a block diagram showing an example of circuit elements and interface elements that could be implemented in the power adapter  102  and control attachment  104 ; 
         FIG. 38  is a diagram showing a control element adapted to control both a light and a fan; 
         FIG. 39  is an arrangement of a power adapter and a control attachment having a power switch; 
         FIG. 40  is a front and side view of the power adapter  3902  of  FIG. 39 ; 
         FIG. 41  is a cross-sectional view of the power adapter  3902  taken at lines  41 ; 
         FIG. 42  is a side view of a control attachment that could be coupled to the power adapter  3902  of  FIG. 39 ; 
         FIG. 43  is a flow chart showing a method of enabling a wiring fault detection; 
         FIG. 44  is a block diagram of an expanded view of elements of an in-wall power adapter and control attachment that is adapted to be installed in a junction box and to receive a wall plate; 
         FIG. 45  is a front view of the arrangement of  FIG. 44  when combined; 
         FIG. 46  is another front view of the arrangement of  FIG. 44  when combined and showing an intermediate wall plate for receiving the wall plate; 
         FIG. 47  is a side view of a portion of attachment elements of a power adapter and a corresponding control attachment that may be located behind a wall plate, where the attachment element of the power adapted is on a back wall of the power adapter; 
         FIG. 48  is another side view of a portion of attachment elements of a power adapter and a corresponding control attachment that may be located behind a wall plate, where the attachment element of the power adapted is on a side wall of the power adapter; 
         FIG. 49  is a side view of a portion of attachment elements of a power adapter and a corresponding control attachment that may be accessible through a recess in a wall plate; 
         FIG. 50  is a rear view of a control attachment; 
         FIG. 51  is a front view of a control attachment having a toggle element and a dimmer control element; 
         FIG. 52  is a front view of a control attachment having a toggle element, a microphone and a speaker; 
         FIG. 53  is another front view of a control attachment having a toggle element and a dimmer control element; 
         FIG. 54  is a front view of a control attachment having a toggle element and a motion detector; 
         FIG. 55  is a front view of a control attachment having a toggle element and a display; 
         FIG. 56  is a front plan view of a control attachment having dedicated on and off switches and a sensor element that may be removable; 
         FIG. 57  is a side view of the control attachment of  FIG. 56 ; 
         FIG. 58  is a front and side view of the control attachment of  FIG. 56 ; 
         FIG. 59  is a front and side view of the control attachment of  FIG. 56  without the removable sensor element to show contact the elements in a recess; 
         FIG. 60  is a rear view of the removable sensor element showing contact elements; 
         FIG. 61  is a front and side view of a control attachment having a removable screen; 
         FIG. 62  is a front and side view of a control attachment having a removable screen exposing a camera that is movable within a receiving element and shown directed to the left; 
         FIG. 63  is a front and side view of a control attachment having a removable screen of  FIG. 62  showing the camera directed to the right; 
         FIG. 64  is a front inside view of a control attachment having a movable screen to enable controlling a direction of a sensor, such as a camera, by moving the screen; 
         FIG. 65  is a diagram of a control attachment having contact elements for electrically connecting contacts of an electrical interface; 
         FIG. 66  is a diagram showing an inner surface of a rear housing of the control attachment of  FIG. 65 ; 
         FIG. 67  is a block diagram of a power adapter arrangement using a control attachment according to the implementation of  FIG. 65 ; 
         FIG. 68  is a diagram of another control attachment having a switch and an electrical interface; 
         FIG. 69  is a diagram showing an inner surface of a rear housing of the control attachment of  68 ; 
         FIG. 70  is a block diagram of a power adapter arrangement using a control attachment according to the implementation of  FIG. 68 ; 
         FIG. 71  is a diagram of another control attachment having an actuator element; 
         FIG. 72  is a diagram showing an inner surface of a rear housing of the control attachment of  71 ; 
         FIG. 73  is a block diagram of a power adapter arrangement using a control attachment according to the implementation of  FIG. 71 ; 
         FIG. 74  is a diagram of a control attachment having two actuator elements; 
         FIG. 75  is a diagram showing an inner surface of a rear housing of the control attachment of  74 ; 
         FIG. 76  is a block diagram of a power adapter arrangement using a control attachment according to the implementation of  FIG. 74 ; 
         FIG. 77  is a block diagram of a power adapter arrangement showing an example of an interface circuit; 
         FIG. 78  is a flow diagram showing a method of implementing a power adapter arrangement having a single toggle switch; 
         FIG. 79  is another block diagram of a power adapter arrangement showing an example of an interface circuit; 
         FIG. 80  is a flow diagram showing a method of implementing a power adapter arrangement having two toggle switches; 
         FIG. 81  is a diagram showing an example of a control attachment adapted to receive a control module; 
         FIG. 82  is a diagram showing an inner surface of a rear housing of the control attachment of  FIG. 81 ; 
         FIG. 83  is a block diagram of a circuit for testing the connections associated with a power adapter; 
         FIG. 84  is another block diagram of a circuit for testing the connections associated with a power adapter; 
         FIG. 85  is a block diagram of a system having a plurality of power adapters implementing different communication protocols; 
         FIG. 86  is directed to a method of controlling a power adapter to provide power a load; 
         FIG. 87  is directed to a method of controlling the application of power to a load using a control attachment; 
         FIG. 88  is a block diagram of a power adapter having a removable power switching module; 
         FIG. 89  is a block diagram showing the removable power switching module removed from the power adapter; 
         FIG. 90  is a block diagram a power adapter arrangement having a power adapter and a control attachment comprising one or more outlets; 
         FIG. 91  is a front and side view of the power adapter of  FIG. 89 ; 
         FIG. 92  is a side view of the power adapter of  FIG. 88 ; 
         FIG. 93  is a side view of the control attachment of  FIG. 88 ; 
         FIG. 94  is a front view of the control attachment of  FIG. 88 ; 
         FIG. 95  is a front view of the control attachment of  FIG. 88  according to another implementation; 
         FIG. 96  is a front view of the control attachment of  FIG. 88  according to another implementation; 
         FIG. 97  is a front view of the control attachment of  FIG. 88  according to another implementation; 
         FIG. 98  is a block diagram a power adapter arrangement having a power adapter and a control attachment comprising one or more outlets according to another implementation; 
         FIG. 99  is front view of the power adapter arrangement of  FIG. 96  according to one implementation; 
         FIG. 100  is a front and side view of the power adapter arrangement of  FIG. 97  showing a module removed from a recess of the control attachment; 
         FIG. 101  is a block diagram of a power adapter having outlets and a recess for receiving a control attachment adapted to provide switching for power applied to a load; 
         FIG. 102  is a block diagram of a power adapter arrangement having a power adapter arrangement of  FIG. 101  and a control attachment having a connector arrangement for routing power received from the power adapter back to the power adapter; 
         FIG. 103  is a block diagram of a power adapter arrangement having a power adapter arrangement of  FIG. 101  and a control attachment having a control circuit for routing power received from the power adapter back to the power adapter; 
         FIG. 104  is a perspective view of a power adapter arrangement comprising a power adapter having an outlet and a control attachment adapted to be received by the outlet; 
         FIG. 105  is a perspective view of another power adapter arrangement comprising a power adapter having an outlet and a control attachment adapted to be received by the power adapter; 
         FIG. 106  is a rear view of the power adapter arrangement of  FIG. 105  showing an electrical interface comprising a plug; 
         FIG. 107  is a block diagram of a power adapter having a switch controllable by a control attachment to control the routing of power received from the power adapter back to the power adapter; 
         FIG. 108  is a block diagram of a power adapter arrangement comprising a power adapter and a switch, where the power adapter has a switch controllable by a control attachment to control the routing of power received from the power adapter back to the power adapter; 
         FIG. 109  is a block diagram of a power adapter arrangement having a power adapter and a control attachment configured to control two outlets; 
         FIG. 110  is a block diagram of a power adapter arrangement having a control attachment including a signal interface circuit; 
         FIG. 111  is a block diagram of a power adapter having a switch for controlling the application of power to an outlet; 
         FIG. 112  is a block diagram of a power adapter arrangement comprising the power adapter of  FIG. 111  having a switch for controlling the application of power to an outlet; 
         FIG. 113  is a flow chart showing a method of implementing a power adapter arrangement; 
         FIG. 114  is a front view of a power adapter showing a recess between a pair of outlets adapted to receive a control attachment; 
         FIG. 115  is a front view of another power adapter showing a recess between a pair of outlets adapted to receive a control attachment; 
         FIG. 116  is a perspective view of a control attachment according to one implementation; 
         FIG. 117  is a front view of an electrical interface having insulating elements between openings for receiving contact elements of a control attachment and contact elements of the power adapter; 
         FIG. 118  is a front view of the electrical interface of  FIG. 117  showing an arrangement of insulating elements covering contact elements of the power adapter; 
         FIG. 119  is a front view of the electrical interface of  FIG. 117  showing an arrangement of insulating elements of  FIG. 118  having connector elements of the control attachment positioned between portions of the insulating elements; 
         FIG. 120  is a front view of a power adapter having a door arrangement in a closed arrangement; 
         FIG. 121  is a front view of the power adapter of  FIG. 120  having the door arrangement in an open position; 
         FIG. 122  is a cross-sectional view of the power adapter of  FIG. 120 ; 
         FIG. 123  is a cross-sectional view of the power adapter of  FIG. 120  as shown in  FIG. 122  having a control attachment in a first position; 
         FIG. 124  is a cross-sectional view of the power adapter of  FIG. 120  as shown in  FIG. 122  having a control attachment in a second position; 
         FIG. 125  is a cross-sectional view of the power adapter of  FIG. 120  as shown in  FIG. 122  having a control attachment in a third position; 
         FIG. 126  is a diagram showing a power adapter arrangement having an outlet that is controllable using 2 wireless communication protocol; 
         FIG. 127  is a block diagram of a power adapter having a control switch and a recess for receiving a control attachment; 
         FIG. 128  is a block diagram of a power adapter arrangement comprising the power adapter of  FIG. 27  and having a control attachment; 
         FIG. 129  is a block diagram of a power adapter having a control switch and enable switches adapted to be coupled to actuator elements of a control attachment; 
         FIG. 130  is a block diagram of a power adapter arrangement comprising the power adapter of  FIG. 129  and a control attachment; 
         FIG. 131  is a block diagram of a power adapter having a switch and user interface elements; 
         FIG. 132  is a block diagram of a power adapter arrangement having the power adapter of  FIG. 131  and a control attachment; 
         FIG. 133  is a block diagram of a power adapter arrangement having the power adapter of  FIG. 131  adapted to receive a removable user interface module and a control attachment; 
         FIG. 134  is a perspective view of power adapter assembly adapted to receive a removable user interface module and a control attachment; 
         FIG. 135  is a block diagram showing the configuration of 2 power adapter arrangements configured in a 3-way switching arrangement to control a load; 
         FIG. 136  is a front view of a power adapter arrangement having a toggle element and a dimmer control element associated with the power adapter; 
         FIG. 137  is a front view of a power adapter arrangement having a toggle element associated with the power adapter and a dimmer control element associated with a control attachment; 
         FIG. 138  is a front view of another power adapter arrangement having a toggle element associated with the power adapter and a dimmer control element associated with a control attachment; 
         FIG. 139  is a front view of another power adapter arrangement having a toggle element associated with the power adapter and a capacitive dimmer control element having a dimming level display associated with a control attachment; 
         FIG. 140  is a front view of another power adapter arrangement having a toggle element and a dimmer control element associated with the power adapter; 
         FIG. 141  is another front view of a power adapter arrangement having a toggle element associated with the power adapter and a dimmer control element associated with a control attachment; 
         FIG. 142  is a front view of a power adapter arrangement having a multi-element control switch associated with the power adapter; 
         FIG. 143  is a block diagram a power adapter arrangement having a power adapter configured to authenticate a control attachment; 
         FIG. 144  is a flow chart showing a method of implementing a power adapter arrangement having a control attachment; 
         FIG. 145  is a flow chart showing a method of implementing a power adapter configured to receive a control attachment; and 
         FIG. 146  is a flow chart showing a method of configuring a control attachment adapted to receive power from a power adapter. 
     
    
    
     DETAILED DESCRIPTION 
     The power adapter arrangements, power adapters, control attachments, circuits, systems and methods set forth below provide a simple and efficient way for a building owner, building manager, or homeowner, to easily change the functionality of an electrical switch without having to replace the entire switch and, more importantly, without having to run the risk of making contact to a high voltage power line or high voltage power contact of an electrical system of the building, for example by connecting wires of the electrical system (e.g. from a junction box) to the power adapter. By selectively distributing elements between a power adapter and a control attachment of a power adapter arrangement, builders and purchasers of buildings (including residential home purchasers for example) can easily and efficiently design and construct a building with a fully operating electrical system having switches installed, and easily and efficiently change features of power adapter arrangements by simply changing a control attachment for some or all of the power adapter arrangements installed in the building. A power adapter arrangement having a power adapter that is configured to receive a control attachment as set forth below not only allows for changes or modifications to the configurations of power adapter arrangements after a building is constructed, but it also allows for easy updates to power adapter arrangements as technology changes and improved or different control attachments are available. 
     According to some implementations, power adapters having a power switching function are provided that enable the use of different control attachments having a range of functionalities, including basic control attachments that have limited functionality and more advance control attachments having different levels of functionality and different features. As will be described in more detail below, a common interface between a power adapter and all control attachments could be used. For example, the common interface could be adapted to receive both basic control signals, such as on/off control signals or dimmer control signals that are generated in response to a manual operation of a user (e.g. pressing a toggle element of control attachment_, and electrical signals generated by a circuit of the control attachment which may be independent of input of the user (e.g. on and off commands associated with a timer feature having a schedule for turning on or off power applied to a load controlled by the control attachment or an on command from a motion detector). A basic control attachment may use only a portion of the common interface, and the more advanced control attachments may use another portion of the common interface, where the portions may or may not overlap. According to some implementations, a first interface (e.g. a mechanical switch or a simple contact arrangement of a power adapter that is shorted by a contact element of the control attachment) could be provided for basic controls signals generated in response to manual user input on a user interface of the control attachment, and may be separate from a second interface, which may be adapted to receive more advanced signals, such as timing schedule signals associated with a timing pattern (i.e. at least one on time or off time for applying power to a device controlled by the power adapter arrangement according to a schedule, which may be based upon predetermined days or may be periodic (e.g. daily, weekly, monthly or yearly) which may be received by way of a wireless connection to a wireless control circuit of the control attachment or a control signal generated by a motion detector of the control attachment. 
     According to other implementations, a power switching function may be implemented in a control attachment, which provides flexibility in functions of the power adapter arrangement. For example, a simpler on/off switching arrangement could be provided using a relay in the control attachment, or a more advanced switching arrangement could be provided by using a TRIAC or other circuit to enable dimming functionality in the control attachment. That is, by placing a power switch, which enables the routing of power to a load in the control attachment, it is possible to provide a power adapter arrangement with or without dimming capabilities by providing a control attachment having a TRIAC or just a relay for performing power switching. As will be described in more detail below, many different variations of safe and flexible power adapter arrangements can be implemented. While a variety of embodiments of each of the power adapter and the control attachment having different levels of functionality and features are shown, it should be understood that various features and functionality could be interchanged between the different embodiments. 
     A description of example embodiments is provided on the following pages. The text and figures are provided solely as examples to aid the reader in understanding the invention. They are not intended and are not to be construed as limiting the scope of this invention in any manner. Although certain embodiments and examples have been provided, it will be apparent to those skilled in the art based on the disclosures herein that changes in the embodiments and examples shown may be made without departing from the scope of this invention. It will be understood that when an element is referred to as being (operatively or communicatively) “coupled with/to,” another element, it can be connected directly with/to the other element directly or coupled to the other element via a third element. 
     According to various implementations, a power adapter may be configured to provide power to a load. The power adapter may comprise a first plurality of contact elements comprising a first contact element configured to receive power and a second contact element configured to provide power to a load; a receiving element configured to receive a control attachment; a first interface comprising a second plurality of contact elements configured to provide one or more reference voltages to the control attachment, wherein the first interface comprises an electrical interface; and a second interface comprising a switch configured to control power applied to a load in response to an actuation of the control attachment. 
     Control attachments may also be implemented. For example, a control attachment adapted to control the application of power to a load may comprise a toggle element on the control attachment, wherein the toggle element is movable in response to a manual actuation associated with the control attachment; a first interface comprising an actuator element configured to make contact with a power adapter, wherein the actuator element is adapted to engage with a switch of the power adapter in response to the manual actuation; and an attachment element adapted to attach the control attachment to the power adapter; wherein a manual actuation of the toggle element enables controlling the power applied to the load by the power adapter. It should be understood that the control attachments may be implemented with the power adapter as described below. 
       FIGS. 1-5  show implementations of a power adapter arrangement  100  having power switching capability (e.g. a relay or a circuit having a control terminal to enable dimming, such as a triode for alternating current (TRIAC) in the power adapter). According to some implementations, it may be desirable to provide reduced functionality of a power adapter, which is a device that receives a source of power, such as a reference voltage and selectively routes the power to a load based upon a control signal, such as a control signal associated with a timing pattern or in response to a sensor or some other external input. The power adapter implements selected switching function (e.g. basic on/off switching or on/off switching with dimmer control), and implements additional control functionality according to signals from a control attachment, which is removably attached to the power adapter. By reducing the complexity of a power adapter to include the power switching capability, and by providing additional control functionality or other functionality in the control attachment, the power adapters can be widely and cost-effectively implemented in new construction, such as in new home construction, with control attachments that may be initially installed having limited functionality. 
     Some or all of the control attachments having limited functionality can be easily replaced with more advance control attachments after an owner of the new construction has an opportunity to evaluate the power control needs of the new home, such as determining where a timer, motion detector or smart speaker may be beneficial. That is, a builder can efficiently (i.e. by installing a single type of power adapter at all locations where a switch is to be installed) and cost effectively (i.e. by installing a power adapter with a basic control attachment at all locations except certain locations where additional functionality may be believed to be needed) build a new home having a fully functional electrical system with little or no input (or even inaccurate input) from a purchaser of the new home. Such a use of power adapter arrangements as set forth in more detail below allows the owner of the new home (and future owners) to easily and cost effectively make changes to the electrical system of the home by simply changing the control attachments where necessary. 
     As will be described in more detail below, a control interface between a power adapter and a control attachment may be configured to accept a basic control attachment having limited functionality such as on/off functionality or on/off functionality with dimmer capability, and also accept a more advanced control attachment having more advanced functions such the ability to send control signals associated with a timing schedule received at the control attachment using a wireless control circuit or control signals from a sensor, such as a motion detector, to the power adapter. By way of example, a power adapter arrangement having a basic control attachment attached thereto may function in a similar manner to a conventional switch having on/off capability or on/off and dimmer capability. However, it the owner determines that additional functionality may be useful, the owner would only need to change the control attachment to have the desired additional functionality, such as timer functionality or motion detection functionality for example. While reference is made to power control needs, where an owner may evaluate the needs to control power applied to a load attached to the power attachment, it should be understood that control attachments may have functionality beyond controlling the load attached to a power adapter. For example, the control attachment may enable functions separate from controlling the load, such as a camera function, information or entertainment functions (a microphone and speaker for providing requests for information and receiving audible feedback, such as in a smart speaker), sensor functions (e.g. temperature or humidity sensors for home automation), wired or wireless networking functions (e.g. WiFi router, WiFi node of a WiFi mesh arrangement, or Bluetooth node of a Bluetooth mesh arrangement), or other any other functions of an attachment that may or may not require power from the power adapter. 
     Turning first to  FIG. 1 , a block diagram of a power adapter arrangement  100  having a power adapter  102  coupled to a control attachment  104  comprising a basic control attachment is shown.  FIG. 1  shows a control interface configured to receive a signal by way of an actuator in response to user input. According to the implementation of  FIG. 1 , a very basic control attachment and a power adapter having a relay is disclosed. As will be described in more detail below, power adapters having more functionality, such as dimming functionality, and control attachments having more functionality, such as wireless communication functionality can be implemented. 
     According to the implementation of  FIG. 1 , the power adapter arrangement  100  comprises a power adapter  102  and the control attachment  104 . The power adapter comprises a plurality of contact elements, often call terminals or inputs and outputs, that are adapted to make electrical connections to electrical wires in a junction box. More particularly, the power adapter  102  comprises a power control circuit  105  adapted to receive one or more reference voltages, such as a power voltage received at a power input  106  and a neutral voltage received at a neutral input  108 . By way of example, the power voltage could be an electrical signal approximately 120 volts or 220 volts, depending upon the electrical system that is being used in the region. The power adapter may be designed to operate with a specific reference voltage, such as 120 volts or 220 volts. A ground voltage coupled to a ground input  107  and a neutral voltage coupled to a neutral input  108  are also provided. The use of neutral and ground terminals will be described in more detail below. A 3-way connection terminal  109 , also known as a traveler connection, may also be provided. The 3-way terminal enables the user of the power adapter arrangement in a 3-way connection, where two different switches can be used as toggle switches for a single load, as is well known. The power control circuit  105  controls the application of a power signal outside of the power adapter arrangement to a load  110 , which may be any device receiving power such as a light or appliance, at a load terminal  112 , which may be a contact element adapted to be coupled to a wire in an electrical wiring arrangement that provides power to the load. It should be understood that the power signal generated at the load terminal  112  may be different that the power signal applied to the power adapter at the power input  106 , such as due to voltage regulation (i.e. generate a signal having a known voltage and which may be filtered to eliminate spurious elements.) or dimming control for example. 
     There are generally three wires currently used in electrical wiring, including a live wire (i.e. the wire for providing power to a load, also called the hot wire), a neutral wire (i.e. are return path for the live wire), and a ground wire. While some older construction may only have 2 wires (e.g. there is only a live wire and a ground wire, where the ground wire is used as the return path for the live wire), most electrical outlets and switches in new construction include both a neutral connection and a ground connection, where 120 volt power is carried to homes through these two wires, and the live wire is the wire carrying current while neutral wire is the wire that completes the return path under normal conditions. Without the neutral wire, current cannot flow, and the neutral wire is always assumed to be charged hi an active circuit. The neutral wire is coupled to ground (by grounding the neutral wire to a ground connection at the switching box for the building for example) to make the terminal of neutral wire at zero potential. 
     A ground wire (also called earth in some countries) is a wire that is ready to take all the current into the ground in case of a mishap, such as a high current generated in an appliance. Both neutral and ground wires are for the safety of the building, wiring system, appliances and human beings. The ground wire is assumed to be at zero potential while the potential of neutral depends upon an imbalance between the wires. Ground is therefore universal reference which is always taken to be zero potential. Neutral is provided by the power company to make the path of electricity closed. The ground wire on the other hand, prevents any electrocution to humans in the case of a mishap, where a ground wire is run throughout electric wiring and is buried the earth (e.g. 10-15 feet) adjacent to the house or below it. 
     A ground represents an electrical path, normally designed to carry fault current when an insulation breakdown occurs within electrical equipment. For example, breakdowns can be forced by connecting a metal tool or conductive material from a voltage potential to the steel structure within a facility. Connections to the electrical path (Ground) are made convenient for the installation of electrical equipment. Some stray current will always flow through the ground path. This current will come from a number of normal sources. Capacitive coupling and inductive coupling between power conductors and the ground path (conductive conduit, conductive structure members, etc.) are the greatest sources of ground path current. 
     While the power adapter arrangement may be wired in different ways in a circuit to apply power to a load, it should be understood that the various terminals for power, ground, neutral, and 3-way terminals are provided by way of example, and that the power adapter arrangement is configured to provide power to a load, such as by providing a path for current to flow through the load, in response to a control signal which may be directly (e.g. by a user actuation of a switch by interacting with a control attachment) or indirectly (e.g. a remote wireless operation or a stored timing program stored in one of the power adapter or the control attachment as will be described in more detail below) provided to the power adapter arrangement. For example, a power voltage may be coupled to a light that is controlled by the switch if the power adapter or the power voltage may be coupled to the switch, depending upon how the power adapter arrangement is installed. In either case, the switch provides a current path that may be controlled to allow the power to be applied to the light. In order to control the application of power provided to the load (e.g. the application of a voltage to a load terminal to allow the flow of current through the load), the power control circuit  105  of the power adapter  102  comprises a switch (which may be a relay or a TRIAC for example as described in more detail below) that enables the application of power from the electrical system to the load in response to a signal from the control attachment  104 . 
     A switch, such as a relay or TRIAC for example, as implemented in a power adapter arrangement may provide switching functionality, e.g. turning on/off power to a load (e.g. a light or appliance). The switch may control a connection of a system at a voltage derived from the power supply that powers the power adapter arrangement and apply a voltage to a load. Accordingly, a switch may be powered from and/or control an electrical circuit at any commonly used voltage for controlling loads, such as 110V/120V, 220V/230V/240V, 50 Hz, 60 Hz, 5 A, 6 A, 10 A, 13 A, 15 A, alternating current (AC) for example, which are generally considered high voltage systems for example. It should be understood that the power signal (i.e. based upon a certain voltage or current) applied to the load may be different than the power signal provided to a terminal of the power adapter from the junction box, such as due to a dimming control function. 
     The power adapter  102  comprises a signal interface circuit  114  coupled to a control interface circuit  115 . The control interface circuit  115  is adapted to generate a power control signal based upon one or more actuation signals generated by the control attachment, where the power control signal enables power to be applied to the load. For example, an actuation signal may be a signal based upon a manual actuation of an actuator element of the control attachment or a signal generated by a circuit of the control attachment and provided the power adapter by way of an electrical interface, where the power control signals may comprise a toggle signal (i.e. an on or off signal) or a dimmer control signal. It should be understood that the control circuit  115  enables independent operation of the actuator element and a signal generated by a circuit of the control attachment and provided the power adapter by way of an electrical interface, allowing for different types of control signals to be provided to the power adapter. 
     The control interface circuit  115  may comprise a detector  116  and a control circuit  118 . The signal interface circuit  114  is adapted to be coupled to a corresponding signal interface circuit  120  of the control attachment  104 , and comprises a plurality of signal coupling elements, which may be elements that enable the transfer of electrical signals and reference voltages, including low power reference voltages. More particularly, the signal interface circuit  114  comprises a signal coupling element  122  coupled to a corresponding signal coupling element  124  of the signal interface circuit  120 . Another signal coupling element  126  is shown as a part of the signal interface circuit  114 , but is not used in the implementation of the power adapter arrangement  100  of  FIG. 1 . That is, other control attachments  104  may be configured to provide a signal to the signal coupling element  126 , as will be described in more detail in reference to  FIG. 2 . While coupling elements of the power adapter are shown in  FIG. 1 , it should be understood that only some coupling elements of the power adapter are shown, and that the power adapter may comprise additional coupling elements to provide interfaces for more advanced control attachments as will be described in more detail below. 
     The control attachment  104  comprises an actuator  130  That is adapted to receive a user input by way of a user interface input  132 . As will be described in more detail below, the user interface input  132  may comprise any type of interface for providing an input to the actuator  130  which generates a control signal to the signal coupling element  124 . The user interface input  132  may comprise a toggle switch for example. While paddle-type toggle switches are described in some examples below, it should be understood that any type of toggle switch could be employed. Also, the actuator  130  may comprise any time of signal actuator for generating a control signal in response to user input at the user interface input  132 , and may comprise a mechanical actuator, an electrical actuator, or an electro-mechanical actuator for example, as described in more detail below. 
     For example, in a mechanical application of the signal interface circuits  114  and  120 , the actuator  130  may be configured to receive an actuation at the user interface input  132 , such as the movement of a toggle switch, which may cause a movable element of the signal coupling element  124  to engage a corresponding movable element of the signal coupling element  122 , as described in more detail by way of example in reference to  FIGS. 81-82 . The engagement of the movable element of the signal coupling element  124  and the corresponding movable element of the signal coupling element  122  may be detected by the detector. That is, the signal coupling elements  122  and  124  may facilitate the transfer of an actuation of a toggle switch detected at the user interface input  132  to the detector  116 , where the detector  116  may be an electro-mechanical switch (e.g. a device that comprises a mechanical element that receives an input, such as a button which, when depressed, generates an electrical signal). 
     In electromechanical application of the signal interface circuits  114  and  120 , the signal coupling element  122  may comprise an electromechanical switch and the signal coupling element  124  may comprise a movable element that moves in response to an actuation at the user interface input  132  to depress a button of the signal coupling element  122  (implemented as an electromechanical switch). In an electrical application of the signal interface circuits  114  and  120 , each of the signal coupling elements  122  and  124  comprise electrical elements, which may be contact elements the enable the transmission of an electrical signal such as described in reference to  FIGS. 10 and 11 . 
     The control interface circuit  115  may comprises a detector  116  coupled to receive a control signal by way of the signal coupling element  122  in response to an actuator signal at the user interface input  132 . The detector may comprise a mechanical, electromechanical, or electrical element for detecting a signal from the actuator  130 , where the implementation of the detector may depend upon the particular implementation of the actuator  130  and the signal coupling elements  122  and  124 . For example, if the signal coupling element  124  is a mechanical element, such as a movable element adapted to engage a button of the detector or an opening in the control attachment enabling an actuator element (e.g. a projection) to engage a switch of the power adapter through the opening, the detector may comprise a switch having a button that is moveable in response to the movement of the actuator element and generate an electrical signal coupled to at least one of the control circuit  118  and the power control circuit  105 . If an electrical signal is generated by the signal coupling element  122 , the detector may comprise an electrical circuit configured to detect the electrical signal and provide the electrical signal to at least one of the control circuit  118  and the power control circuit  105 . 
     The control interface circuit  115  further comprises a control circuit  118  having a decoder circuit  119 . The control circuit  118  is coupled to the signal coupling element  126  that is configured to provide control signals from a control attachment. While the control attachment according to the implementation of  FIG. 1  is a basic control attachment that comprises an on/off actuator, other control attachments can be implemented that provide control signals, such as control signals received from a remote device, such as a smart phone, or dimmer control signals, as will be described in more detail below. The decoder circuit may not only be used to decode signals, but also to determine whether the control attached is an authorized control attachment that can interface with the power adapter. Because the distribution of high voltage electrical power signals in a residential or commercial building is dangerous, it is necessary to ensure that the control attachment is authorized to communicate with and control the power adapter and/or that the power adapter is authorized to receive signals from the control attachment. 
     While the control interface of  FIG. 1  is shown by way of example as having a separate detector and control circuit, it should be understood that the detector could be implemented as a part of the control circuit  118 , which may be a processor as will be described in more detail below. That is, the function of the detector and the function of the decoder may be implemented by a processor in response to signals detected by the processor. Similarly, while the decoder is shown as a part of the control circuit, the decoder could be implemented separate from the control circuit. 
     As shown in  FIG. 1 , the control attachment  104  is a basic control attachment, and signals are only sent to the power adapter from the actuator  130 . Therefore, it is not necessary that the decoder determines whether the control attachment is an authorized control attachment, but rather the power adapter is configured to operate with a control attachment that controls in on/off feature of the power adapter arrangement by way of a given control signal interface, such as a control signal interface requiring a physical actuation associated with the user interface input (e.g. the pressing of a toggle element of the control attachment). As will be described in more detail below, the use of switches having buttons that may be actuated by a movable element of the control attachment enable a control attachment having no electronic circuits that may interface with a portion of a control signal interface (e.g. signal interface circuit  120 ) transmitting electrical signals. Such an arrangement is beneficial to enable a cost-efficient power adapter arrangement  100 . That is, the control attachment  104  can be made primarily or completely of plastic, and have housings that may be adapted to be used with different types of control attachments (i.e. control attachments having basic functionality or control attachments having more advanced functionality). Further, such an arrangement enables a power adapter to be functional for providing at least on/off functionality when the control attachment is not attached to the power adapter. Therefore, a builder would be able to install power adapters throughout a building, and be able to use the power adapters without it control attachment before an owner or occupier of the building decided what types of control attachments to use at different locations of the building. That is, a power adapter may comprise one or more buttons to enable toggling of power to a load, where the user would be able to toggle the power to the load without a control attachment (i.e. by just pressing one or more switches that are exposed on the power adapter when the control attachment is not attached to the power adapter), or with the control attachment attached to the power adapter, as will be described in more detail below. 
     Signals from the signal interface circuit  114  may be processed by the control interface circuit  115  and provided to the power control circuit  105  to control the application of power to a load. For example, a signal from the detector (in response to an actuation by the actuator  130 ) may be provided by way of a signal line  134  to a switch  135 , shown here by way of example as a relay and often referred to as a power switch, to control the application of power to the load. The switch may comprise any device that enables current to flow in a path including the load to provide power to the load, where the switch may comprise a path of controllable conductivity that conducts current from the power input to the load in response to a signal from the detector. 
     While the control attachment  104  of the implementation of  FIG. 1  comprises a basic control attachment only having an actuator for enabling the on/off operation of the power control circuit, other control attachments may provide other control signals to the control circuit, where the control signals may be used to control the application of power to the load by way of a signal line  136  or may be used to identify the control attachment, as will be described in more detail below. The detector  116  may also be coupled to the control circuit  118  by way of a signal line  138 , where the control circuit may provide signals to the power control circuit  105  by way of the signal line  136 . That is, the detector  116  and the control circuit  118  may independently provide signals to the power control circuit  105 , or the control circuit  118  may provide signals to the power control circuit  105  based upon a detected actuation of actuator  130  or control signals from a control attachment  104  having other circuits for providing additional features (e.g. on and off signals or dimming signals), as will be described in more detail below. 
     The control attachment  104  is removably attached to the power adapter. The power adapter may comprise a receiving element for interfacing with control attachment. The receiving element may be a surface of the power adapter that is configured to abut a portion of the control attachment, shown generally in  FIG. 1  as the dashed line between the power adapter and the control attachment. As will be described in more detail below, the receiving element may comprise interface elements, including contact elements, electrical connectors and electro-mechanical interfaces (such as one or more switches for example), and attachment elements for enabling a control attachment to be attached to a power adapter. 
     According to some implementations, the receiving element may comprise a planar surface having contact elements that are configured to make electrical contacts with corresponding contact elements of the control attachment as will be described in more detail below. According to some implementations, the power adapter may comprise a recess for receiving the control attachment, where contacts elements of the power adapter may be on a wall of the recess for example. The recess may also help with align the power adapter and the control attachment. Attachment elements may be implemented on the receiving element of the power adapter, such as in the case where the receiving element comprises a recess. Attachment elements may also be provided on the receiving element or another element of the power adapter (e.g. flanges of the power adapter that are used to attach the power adapter to a junction box) when the receiving element comprises a planar surface. Examples of a receiving element are described in more detail in reference to  FIG. 44 , which describes both a recess and a planar surface acting as a receiving element of a power adapter. 
       FIGS. 2-5  show different implementations of both the power adapter  102  and the control attachment  104 . For example, according to some implementations of the power adapter  102 , dimming functionality may be provided. Different control attachments are also shown in  FIGS. 2-5 , where the control signals provided to the power adapter  102  may be provided by different types of signal interface circuits  114  and  120 . 
     Turning now to  FIG. 2 , another block diagram of a power adapter arrangement  200  having a control attachment with additional features is shown. According to the implementation of  FIG. 2 , an additional interface is provided for receiving control signals. In addition to the actuator  130 , the control attachment  104  comprises an interface circuit  202 , which may comprise a communication interface circuit, configured to transmit and/or receive communication signals by way of a communication interface  204 . The communication signals may be provided directly to the communication interface  204  or indirectly, such as by a wireless connection or a wired connection. The signal interface circuit  120  also comprises a signal coupling element  206  that is adapted communicate signals with signal coupling element  126 . According to some implementations, the signal coupling elements  126  and  206  could be contact elements, where one may be a contact pad and another may be a pogo pin for example, that are adapted to provide control signals to the control circuit  118 . The interface circuit  202  may also comprise a feedback circuit  208  that is adapted to provide feedback signals by way of a feedback interface  210 . 
     The feedback signal interface  210  could be any type of interface that provides a user of the power adapter arrangement with a feedback signal associated with the operation or status of the power adapter arrangement generated by the feedback circuit  208 . For example, the feedback interface could be any type of interface, including an audio interface and/or visual interface. As will be described in more detail below in reference to  FIGS. 50-64 , the interface element may comprise one or more of speakers, microphones, display elements, lighting elements such as light emitting diodes (LEDs), sensors providing audio or visual feedback (e.g. a camera having an LED indicating that the camera is on), or tactile feedback elements. 
     According to the implementation of  FIG. 2 , the decoder circuit  119  can be used to authenticate the control attachment to ensure that the control attachment is an authorized control attachment. For example, the interface circuit  202  of the control attachment and the control circuit  118  can exchange signals to ensure that the control attachment is an authorized control attachment. The signals may include a variety of information that would enable the power adapter to not only identify the control attachment, such as by a serial number or some other unique identifier, but also information that would indicate the type of control attachment (e.g. Information that could indicate the available features or functions of the control attachment). If the control attachment is not an authorized control attachment, the power adapter may only allow the operation of the control attachment based upon manual actuations of an actuator in response to manual user interface input, such as manual actuations of the actuator  130  (e.g. a pressing of a movable element such as a toggle element of the control attachment). That is, the power adapter arrangement  200  will work with an unauthorized control attachment, but only based upon manual input detected by the control attachment. 
     According to some implementations, authentication could be achieved by a shared secret key authentication, where both the power adapter and the control attachment have a shared key that is used to exchange information to authenticate the power adapter. In cryptography, a shared secret key is a piece of data such as a random number, known only to the parties involved, in a secure communication. The shared secret key would be pre-shared (i.e. stored in a memory of both the power adapter and the control attachment. The shared secret can be fed to a key derivation function to produce one or more keys to use for encryption of messages. To make unique communication link between the power adapter and the control attachment and unique message keys, the shared secret key may be combined with the unique ID. While shared secret key is provided as one example of an authentication technique for authorizing a control module to operate with a power adapter, it should be understood that any type of authentication could be used. 
     Such a feature would prevent a power adapter from being used improperly, such as being “hijacked” and controlled by an unauthorized user of the power adapter arrangement. Because improper control of power by a power adapter arrangement may lead to an unsafe environment associated with the power adapter arrangement, it is beneficial to ensure that the control attachment is authorized. Because the control attachment could determine how power is applied to the load by the power adapter, it is beneficial if the control attachment controls the power in a safe manner, consistent with the operation of the power adapter. That is, the power adapter and the controller attachment are designed to operate safely with one another. An unauthorized control attachment may control the application of power to the load in a way that is not safe. For example, a fast toggling of a switch of the power adapter providing power to a load may lead to in unsafe electrical situation, which may cause an overheating of the power adapter or the load that may lead to a fire. Further, a low quality control attachment that is not an authorized control attachment may fail, resulting in power being applied to a load at a time or for a duration when it may be unsafe to apply the power. For example, an unauthorized control attachment may be used to control the application of power to a slow cooker, where the failure to turn off power to the slow cooker may result in and overheating of the slow cooker and a fire. Further, as will be described in more detail below, a user of a control attachment according to various implementations may be alerted when a control attachment is not operating properly or is defective. Therefore, it is beneficial to ensure that any control attachment would operate safely, according to specifications of the power adapter arrangement or a particular use of the power adapter arrangement, and that the control attachment is an authorized control attachment that has been determined to operate safely with the power adapter. 
     Additional implementations may allow for dimming control of a load, such as the dimming of power level applied to a light for example. According to the implementation of  FIG. 3  showing another block diagram of a power adapter arrangement  300 , a power adapter is implemented having a dimmer control circuit, and a second actuator is provided in the control attachment that enables dimming control. More particularly, an actuator  302  that is responsive to a user input at a user interface input  304  enables a user to manually control an amount of power applied to a load, such as a dimming of a light representing the load. A signal coupling element  306  of the signal interface  114  and a corresponding signal coupling element  308  of the signal interface circuit  120  are adapted to communicate signals from the control attachment to the power adapter in response to an actuation of the actuator  302 . 
     The signal coupling elements  306  and  308  may comprise an electrical, mechanical, or electro-mechanical Interface. For example, the actuator may be a movable element that enables the generation of a voltage that is used for controlling the power applied to the load (i.e. a dimming functionality). And this will be described in more detail below, the voltage for a dimming functionality may be generated at the control attachment or at the power adapter. For example, a resistor divider network may be implemented in the control attachment, where the voltage generated by the resistor divider network may be provided to the power adapter by an electrical interface comprising signal coupling elements  306  and  308 . According to another implementation, the signal coupling elements  306  and  308  may comprise a mechanical interface, where a movable element on the control attachment will align with and enable the movement of a corresponding movable element on the power adapter, where a movement of the movable element on the power adapter will generate the variable voltage (e.g. a voltage generated by a resistor divider) that may be used for dimming control. Also shown any implementation of  FIG. 3 , a dimmer control circuit  310 , which may comprise a TRIAC circuit for example, is implemented in place of or in addition to the switch  135 . That is, the TRIAC may be implemented to control dimming and block current applied to the load (i.e. turn off the load), or a separate relay may be used in addition to the TRIAC to block current applied to the load and turn off the load). 
     According to the implementation of  FIG. 3 , it is not necessary that the control attachment be authenticated. Rather, the control attachment  104  of  FIG. 3  is similar to the control attachment  104  of  FIG. 2 , where it provides limited control of the power adapter (i.e. on/off control and dimmer control). As his apparent from the implementation of  FIG. 3 , both the on/off control and the dimmer control be provided by a low technology control attachment, where the control attachment may completely or substantially comprise plastic components and have little or no electrical components, enabling a low-cost control attachment. For example, when the dimmer control voltage is provided the control attachment, a simple resistor divider receiving a power signal (i.e. the low power signal provided from power adapter to the control attachment) and the ground signal (or neutral signal) can be used to provide a dimmer control voltage. Such an arrangement would enable a low cost control attachment (which may be based upon the control attachment providing basic on/off functionality and modified to include the resistor divider. As will be described in more detail in reference to  FIGS. 4 and 5 , dimmer functionality may be provided, but it may also be required that the control attachment is an authorized control attachment. 
     As shown in the block diagram of a power adapter arrangement  400  of  FIG. 4 , dimming functionality can be provided in a control attachment that may include additional control features and may require authentication, as generally described above and will be described in more detail below. According to the implementation of  FIG. 4 , a power adapter having a dimmer control circuit, and the control attachment comprises an interface that enables wireless control. Rather than an actuator that may generate a dimmer control signal in response to a user input (e.g. by way of a movable element on the control attachment), the interface circuit  202  is configured to provide dimmer control signals, where the dimmer control signals may be a part of or associated with communication signals provided by way of the communication interface  204 . Therefore, the control circuit  118  will provide dimmer control signals by way of the signal line  136  to the dimmer control circuit  310  in response to signals received from the interface circuit  202 . Further, because they control attachment communicates by way of the signal coupling element  126  and corresponding signal coupling element  206 , enabling the transfer of electrical signals, the power adapter may authenticate the control attachment. Therefore, in addition to generating a dimming voltage signal, the communication interface may generate signals enabling the authentication of the control attachment. 
     Turning now to  FIG. 5 , another block diagram of a power adapter arrangement having dimming functionality and a control attachment with both dimming capability and an interface for transmitting or receiving communication signals is shown. According to the implementation of  FIG. 5 , the control attachment that enables dimmer control and wireless control, where the dimmer control may be either a manual dimming control provided by way the user interface input  304  or by way of dimmer control signals (e.g. electrical control signals) generated by the interface circuit  202 . As will be described in more detail below, the control circuit  118  may control the dimming in response to either control inputs provided by way of a user actuation or by way of the interface circuit  202 . 
     According to power adapter arrangement as shown in  FIG. 5 , the dimmer control functionality based upon the user interface input  304  may be an electrical interface, such as a capacitive coupling interface that is responsive to the touch of a user. That is, rather than a mechanical or movable element enabling diming control, where the location of the movable element would correspond to a level of dimming, the actuator  312  may be an electrical interface, where the level of dimming may be shown by lighting elements (e.g. LED lights) that can be change by the communication interface in response to changes to dimming control detected by the communication interface. For example, a user may change the dimmer control level associated with the load using a user interface input  304  (such as a capacitive coupling element that would change the dimming level (which level would be indicated by an LED of a plurality of vertically arranged LEDs providing an indication level)) and using the interface circuit  202  that may receiving dimmer control information from an external device such as a smart phone. 
     By providing both electrical control (e.g. a capacitive coupling interface) and an electrical signal feedback (e.g. the use of LED lights) associated with dimming, it is possible to easily changes the electrical signal feedback in response to a change in the dimming level using either manual user input or the interface circuit  202 . While it is possible to change the position of a mechanical switch associated with a dimming level for the power adapter arrangement, providing an electrical signal to control the dimming level and a visual feedback using LEDs for example, it is easy to enable a changing of the dimming level in response to both a mechanical or electro-mechanical actuator and a communication circuit that may receiving dimmer control signals based upon communication signals, such as wireless communication signals for example. That is, unlike a mechanical dimmer control element (i.e. movable element), the use of an electrical control element (i.e. capacitive coupling to detect a desired level), a dimming level can be both selected and display on the control attachment. 
     Further, the power adapter and the control attachment may communicate to enable the proper operation of a load controlled by the power adapter. For example, a control circuit of the power adapter may detect the type of device controlled by the power adapter, such as the type of light bulb (e.g. incandescent, halogen, LED, or CFL), or the number of watts that the bulb or other device draws, and therefore enables a control circuit of the control attachment to provide different control signals to the switching module to control the amount of power applied to the light bulb (such as a dimmable light bulb). That is, in addition to an implementation where the power adapter acts as a passive device, and only receives control signals from a control circuit of the control attachment, the power adapter and the control attachment could implement a bidirectional communication link according to another implementation to enable the control attachment to understand information received by the power adapter and better control the device controlled by the power adapter. Alternatively, the control module can detect the type or qualities of the light bulb by way of the electrical interfaces of the power adapter and the control attachment. 
     The range of current, voltage, or duty cycle of the voltage applied to the bulb (depending upon the type of dimmer used) could depend upon the type of bulb used. According to some implementations, the control attachment could provide a dimming control signal based upon the detected bulb, and apply a current, voltage or duty cycle of a voltage to the bulb over a range that will provide the correct dimming for the bulb. While the power adapter may be configured to provide a wide range of output power (e.g. a range of power that would power a 1 watt LED bulb or a 150 Watt incandescent bulb), the control attachment may control the range of dimming based upon at least one of the current, the voltage, or the duty cycle of the voltage applied to the bulb receiving power 
     It should be understood that both the magnitude of the range and the location of the range for a given bulb in the overall range could be provided by the power adapter. For example, an incandescent bulb may be adapted to receive a voltage in a range of approximately 5 volts to 120 volts, while a LED light may be adapted to receive a voltage in a range from approximately 1 to 5 volts. As can be seen, not only do the ranges for the incandescent bulb and the range for the LED bulb have a different magnitude, but the ranges cover different portions of the overall voltage range provided by the power adapter (i.e. 1-120 volts). While the examples of ranges provided relate to voltage ranges, the ranges could be set for different bulbs according to other criteria, such as current or duty cycle of the voltage. 
     According to one implementation, the control of a dimming control circuit of the power adapter arrangement could be based upon the signal provided to the dimmer control circuit of the power adapter, where the dimmer control circuit of the power adapter would be adapted to provide a wide range of power to any type of bulb. In response to detecting a particular type of bulb, a dimming control signal would be generated in a range of dimming control signals associated with the detected type of bulb. 
     By way of example, the dimming circuit of a power adapter may be configured to receive a dimming code having a value between 1 and 120, where a dimming code of 1 received by the dimming control circuit would result in 1 volt output provided to the load and a code of 120 would result in a 120 volt output provided to the load. Therefore, if a particular LED bulb is detected that would receive between 1 and 5 volts (i.e. the dimming range of the LED bulb), then the selection of a dimmer controller on the power adapter would generate a code between 1 and 5 in response to the movement of the dimmer controller through the full range. For example, for a dimmer controller  1526  that is movable vertically over a predetermined range in the guide  1524 , the dimmer control circuit of the power adapter would apply a voltage to the load in a range of 1-5 volts if the detected bulb is an LED bulb, but would apply a voltage in a range from 5-120 volts of the detected bulb is an incandescent bulb. 
     Similarly, for a power adapter that receives a dimmer control value by way of an electrical interface (e.g. a dimmer control voltage V dim  generated based upon voltage divider circuit or a capacitive coupling circuit of the control attachment), the control attachment would provide a control signal to the control circuit of the power adapter that would apply a voltage to the load in a range of 1-5 volts if the detected bulb in an LED bulb and would apply a voltage in a range from 5-125 volts of the detected bulb is an incandescent bulb. 
     While the power adapter arrangements of  FIGS. 1-5  are provided by way of example, it should be understood that various other configurations may be implemented within the spirit and scope of the invention. The power adapter arrangements of  FIGS. 1-5  provide examples of different interfaces (e.g. multiple interfaces including different types of interfaces) that may provide different level of access (e.g. a mechanical switch that provides access to control on/off functionality of the power adapter for any control attachment or an electrical interface for controlling advanced features, such as providing dimmer control). Additional information and examples related to different types of interfaces that could be implemented in signal interface  114  and  120  are provided below. 
     Turning now to  FIG. 6 , a block diagram of a dimmer control circuit that may be implemented in a power adapter or in a control attachment is shown. The dimmer control circuit of  FIG. 6  receives power from a power source  602 , such as an AC current source, coupled between a load  604  and a reference voltage, shown here by way of example as a neutral voltage. The load  604  is coupled to the dimmer circuit  310  by way of a switch  606 . A path of current (I) through a dimmer control circuit, shown by way of example as a TRIAC  608 , and a resistor  610  is provided to the neutral node. A control terminal  609  of the TRIAC receives a control voltage based upon a resistor setting of a variable resistor  612 . That is, the variable resistor  612  can be adjusted by a user to control the current in the TRIAC, and therefore provide a dimming function for the load, such as a dimming function for a light for example. A firing capacitor  614  may be provided between the control terminal  609  at the variable resistor  612  and the neutral terminal. An interference capacitor  616  may also be provided in parallel with the current path through the TRIAC. While  FIG. 6  is provided as one example of providing dimming control and employs a TRIAC, it should be understood that other circuits could be used for providing a dimming function, and the circuit of  FIG. 6  is one example of a dimmer control circuit. Other circuit devices could be used for providing a dimming function, such as a silicon controlled rectifier (SCR) for example. 
       FIGS. 7-11  provide examples of different types of interfaces that may include multiple types of elements that provide signals between a control attachment and power adapter, such as in signal interface circuits  114  and  120 . By providing different types of elements that transmit signals, it is possible to provide different control attachments, including basic control attachments and advanced control attachments. Turning first to  FIG. 7 , a block diagram of an interface between a power adapter and a control attachment is shown. The implementation of  FIG. 7  shows two manual switches, such as an on/off switch and a dimmer switch, and a connector arrangement for transmitting electrical signals, such as by way of contact elements. According to the implementation of  FIG. 7 , the dimmer control circuit is provided in the power adapter, and controlled by a movable element on the control attachment. As shown in  FIG. 7 , the pair of signal coupling elements  122  and  124  are configured as a mechanical on/off switch comprising a switch element  702  having a movable portion  704  associated with the power adapter and a switch actuator element  706  associated with the control attachment. The switch such as the switch element  702  located at an interface between the power adapter and the control attachment and that is accessible by a user or the control attachment on a surface of the power adapter may be considered an interface switch. 
     The pair of signal coupling elements  306  and  308  comprise a dimmer control interface  708  coupled to a dimmer control element  710 . By way of example, the dimmer control interface  708  may comprise an element that enables the interfacing of a dimmer control element  710  of the control attachment, which is movable, with a moveable element  712  of the power adapter, which may comprise a variable resistor for or resistor divider circuit creating a dimmer control voltage. The dimmer control interface  708  may comprise an aperture or guide to enable the dimmer control element  710  of the control attachment to engage the movable element  712 , so that a movement of the movable element  708  will cause a movement of the movable element  712 . The movable element  712  could comprise a variable resistor or voltage divider circuit to generate a dimmer control (Dimmer) voltage. 
     In addition to the two mechanical interfaces associated with on/off functionality and dimmer functionality, pairs of contact elements, shown by way of example as signal coupling elements  126  and  206 , enable the transfer of electrical signals, which may be low power electrical signals (e.g. approximately 5 volts, but in a range of approximately 0-24 volts). Input and output signals are provided to and from contact elements of an electrical interface  713  enabling the transfer of electrical signals between the control attachment and the power adapter. The electrical interface comprises contact elements for both the power adapter and the control attachment that make electrical contact when the power adapter is attached to the control attachment. According to some implementations, the electrical interface may be a connector for example. 
     Contact elements  714  of the control attachment are adapted to make an electrical connections to corresponding contact elements  716  of the power adapter for each of the pairs of contact elements as shown. For example, the contact elements  714  could be pogo pins adapted to make an electrical connection to corresponding contact pads  716  of the power adapter, or vice versa. The contact elements could be any type of contact elements to enable the transfer of electrical signals. According to some implementations, the electrical interface  713  may comprises a pair of contact blocks having contact elements, where the contact blocks can be implements as needed and based upon the number of contact elements needed to transfer electrical signals, as will be described in more detail below. For example, a contact block may comprise a plastic module (to provide electrical isolation between the contacts) that may be snapped into to a retaining element for the contact block, where a contact block having different numbers of contact elements may be selected. The electrical interface  713  may comprise contact elements that make contact for an electrical connection as a result of the control attachment being attached to the power adapter, or may comprise contact elements that are secured to one another, such as by a friction fit as a part of a connector or using attachment elements associated with the two components of the connector. For example, corresponding contact elements may comprise a female receptacle adapted to receive a male contact prong, as a part of a connector or as stand-alone contact elements associated with the control attachment and the power adapter. 
     Examples of signals provided to or transferred between the power adapter and the control attachment are also shown in  FIG. 7 . For example, the top three pairs of contact elements  714  and  716  provide reference voltages from the power adapter to the control attachment. Three reference voltages are shown by way of example, including a power voltage (shown here by way of example as a low power (LP) reference voltage), a ground reference voltage, and a neutral reference voltage, where the ground and neutral voltage may have a voltage corresponding to the ground and neutral voltage provided to the power adapter as described above. While the reference voltages may not be used for a basic control actuator having only on/off functionality (because there is no need for a power reference voltage in the control attachment) or a dimmer control functionality (in the case where no electrical signal is generated by the control attachment such as in  FIG. 7  where a dimmer control signal is generated in the power adapter), they may still be made available to any control attachment, in may be used by a control attachment that requires power. Both basic control attachments and more advanced control of attachments may require power. For example, as will be described in more detail below in reference to  FIG. 8 , a basic attachment having a dimmer control function may require that a dimmer control voltage is generated by the control attachment. Therefore, at least power and ground (or neutral) would be necessary to generate a reference voltage using a variable resistor for example in the control attachment, where the reference voltage is then provided to the power adapter. 
     Turning now to  FIG. 8 , another block diagram of an interface between a power adapter having a dimmer control circuit and a control attachment is shown. The implementation of  FIG. 8  also shows two manual switches and a connector arrangement for transmitting signals, but the dimmer control circuit is provided in the control attachment, and the dimmer control signal is provided from the control attachment to the power adapter by way of the electrical interface  713 . As shown in  FIG. 8 , a dimmer control circuit  802  is provided on the control attachment to provide a dimmer control signal to the contact element  714  of the electrical interface  713 . According to the implementation of  FIG. 8 , the control attachment would require power and ground voltages from the power adapter. 
     Turning now to  FIG. 9 , another block diagram of an interface between a power adapter and a control attachment having a dimmer control circuit is shown, where all of the signals are transmitted by an electrical signal through one or more contacts of a connector  904 . That is, as with the dimmer control circuit  802 , an on/off switch actuator  902  is configured to generate a voltage (e.g. a logical “0” for off and a logical “1” for on) that is transmitted by a pair of contact elements of the connector  904 . 
     As further shown in  FIGS. 7-9 , control signals may be communicated between the power adapter and the control attachment by way of the electrical interface  713 . For example, 2 control signals are provided by way of 2 sets of corresponding contact elements  714  and  716  from the power adapter to the control attachment (shown by way of example below the contact elements for providing reference voltages from the power adapter to the control attachment).  2  additional pairs of corresponding contact elements are provided at the bottom of the electrical interface  713  as shown to provide control signals from the control attachment to the power adapter. The control signals can be used for any types of functions associated with control attachment and the power adapter, including for example an authentication of the control attachment, a pairing of the control attachment and the power adapter, any functions for providing signals from the control attachment to the power adapter, as well as any functions for providing feedback to a user of the control attachment for example. 
     While a single electrical interface  713  is shown by way of example, it should be understood that the electrical interface  713  could be split into different electrical interfaces, such as different connectors associated with different functions. For example, the portion of the electrical interface  713  providing reference voltages from the power adapter to the control attachment could be separate from a portion of the electrical interface  713  for providing control signals between the power adapter in the control attachment. Such an arrangement would enable a modular assembly of a control attachment or power adapter. That is, it may be possible to provide a low-cost control attachment having dimmer capability, but no other transfer of control signals, where the control attachment would require a smaller contact block having fewer contacts, where only contact elements for the elements for an on/off signal or reference voltages would be needed. However, the control attachment could be configured to receive a larger contact block (or an additional contact block) also having contact the elements for control signal, as will be described in more detail below. 
     While wireless control signals could be coupled to a control attachment by way of contact elements as will be described in more detail below, it should be understood that wireless power signals and communication signals could be provided between the power adapter and the control attachment. The transmissions of signals could be achieved by any type of wireless connection, such as a Bluetooth protocol or a Near Field Communication (NFC) protocol for example. For example, a first wireless communication transceiver  1002  implemented in a power adapter could communicate with a second wireless communication transceiver  1004  implemented in a control attachment by way of a wireless communication link  1006 . Power could be provided to the control attachment by way of an inductive coupling circuit or any other type of wireless charging circuit. According to the implementation of  FIG. 10 , a switch element  702  could be implemented to enable an on/off function of the power adapter arrangement. While  FIG. 10  shows an example of an on/off switch, it should be understood that other types of switches could be used, or the on/off signal could be transmitted by way of the wireless communication link  1006  instead to provide a fully wireless interface. 
     Turning now to  FIG. 11 , an example of a switch configuration enabling a connection by shorting contacts of a connector of a power adapter is shown. That is, the implementation of  FIG. 11  would provide a simple method of sending a signal from a control attachment to a power adapter by merely shorting two contact elements  716 . As shown in  FIG. 11 , a contact element  1102  is movable too short to the contact elements  716  of the connector  904 , for example, to provide a closed circuit. Therefore, an off signal can be generated by the open circuit on the left of  FIG. 11 , while an on signal can be generated by the closed circuit on the right of  FIG. 11 . While various interface elements and combinations different interface elements are shown, it should be understood the interface elements and combinations of interface elements are shown by way of example, and that different interface elements and different combinations of interface elements could be employed. 
     While uni-directional control signals are shown by way of example in  FIGS. 7-9 , it should be understood that the corresponding contact elements of the power adapter and control attachment could be implemented to enable the transfer of bidirectional control signals. Further, the pairs of contact the elements could enable serial communication associated with a particular function, or collectively could represent a parallel communication interface. Any number of control signal contact elements could be implemented to enable the transfer of information between the power adapter and the control attachment, and the control signal contact elements could be configured in a way to implement any type of communication protocol. 
     For example, any number of pairs of contact elements could be used to implement a serial communication interface, such as a serial peripheral interface (SPI) having one wire for each of the power adapter and the control attachment and one wire for clock pulses, an RS-232 interface that provides a full duplex communication link, Ethernet, Universal Serial Bus (USB), or any other synchronous or asynchronous serial communication link. Similarly, any number of pairs of contact elements could be used to implement a parallel communication interface, such as a General Purpose Instrument Bus (GPIB, also known as the IEEE-488 standard) for example. 
     Turning now to  FIG. 12 , a block diagram of a data block having a plurality of fields enabling the transfer of signals between a power adapter and a control attachment is shown. According to the exemplary block diagram of  FIG. 12 , different fields are provided that enable the communication of signals between the power adapter and the control attachment. The data block of  FIG. 12  comprises a synchronization (Sync) field  1202 , a type (Type) field  1204 , an identification (ID) field  1206 , a preamble (Preamble) field  1208 , a command (Command) field  1210 , and a terminate (Terminate) field  1212 . The synchronization field  1202  enables a transfer of data between the control attachment and the power adapter to allow the control attachment to control the application of power to a load. For example, the synchronization signal could be used by one of the power adapter or control attachment too indicate that data, such as commands or identification information, is being sent. A type field may also be included and can be used to indicate the type of power adapter or control attachment that is used. An ID field is also provided to include an identification, which may be a unique identification for example, of either the power adapter the control attachment. As will be described in more detail below, the identification may be used to authenticate the control attachment and enable the control attachment to provide signals to and receive signals from the power adapter. The identification field may be a unique identification field. 
     A preamble may then be provided to indicate the type of information that might follow, such as commands or other data that might be exchanged. A command field could include any type of command or other information (e.g. information provided in response to a command) to be provided from one of the power adapter to the control attachment. Finally, a terminate field could comprise data indicating that the transmission has ended. Once a control attachment is authenticated as being an authorized control attachment, data may be transmitted between the power adapter and control attachment until the exchange of data between them is terminated using data in the terminate field, as described in more detail in reference to  FIGS. 13 and 14 . 
     While the fields of  FIG. 12  are shown by example, it should be understood that different fields or additional fields could be implemented to perform any necessary functions, including enabling the exchange of information between the power adapter and the control attachment, the control of the power adapter by the control attachment, and feedback from the control attachment to a user of the control attachment. Also, each of the fields may comprise sub-fields. Further, similar data could be included in different fields, and could be transmitted and received according to a predefined protocol. 
     Turning now to  FIG. 13 , a flow chart showing a method of enabling the control of a power adapter using a control attachment is shown. That is, the circuits and methods set forth below not only ensure that an approved control attachment is used for including advanced features for controlling the power adapter, but enables manual operation of basic features, such as manual on/off or dimming control. After the method is started at a block  1302 , such as in response to the detection of an event by a power adapter (e.g. determining that a control attachment may have been attached to the power adapter), it is determined whether a control attachment is attached to the power adapter at a block  1304 . If so, identification information is downloaded from the control attachment to the power adapter at a bock  1306 . A check of the identification information is then performed at a block  1308 . It is then determined whether the control attachment is an authorized control attachment. That is, the control attachment is authenticated as an authorized control attachment. An authorized control attachment may be a control attachment that is confirmed to be used with the power adapter. For example, the power adapter may analyze a unique identification signal provided by the control attachment to determine whether the control attachment is authorized to work with the power adapter. 
     Because the control of high voltage electrical signals can be dangerous, where the improper use of high voltage signals can lead to a fire or personal injury, it is beneficial to ensure that only authorized control attachments are allowed to control the application of power to a load, as described in more detail above. Therefore, if it is determined that the control attachment is not an authorized control attachment at a block  1310 , only manual inputs (i.e. inputs provided by a user to an interface of the control attachment, such as by a user engaging a toggle element for example) from the control attachment user interface will be accepted at a block  1312 . While it is beneficial to not only prevent an unauthorized control attachment (i.e. a control attachment that has not been authorized) from controlling a power adapter, it is also beneficial to allow the control attachment to control the power adapter in response to manual user inputs. That is, a user will be able to use simple functions of the power adapter so that the user can turn on and off the light until the control attachment can be replaced with an authorizes control attachment. Unlike an unauthorized control attachment that may not function properly with the power adapter, and may unsafely apply power to a load, the manual use of the control attachment should not provide any risk to the user. However, if it is determined that the control attachment is an authorized control attachment, all inputs from the control attachment will be accepted at a block  1314 , and the processes ended at a block  1316 . It should be understood that the authorization process in the block  1310  may be performed whenever a control attachment is attached. That is, once a control attachment is authorized, it may continue to operate with the power adapter until it is removed. 
     Turning now to  FIG. 14 , an example of a signal transfer protocol for transferring signals between a power adapter and a control attachment is shown. As shown for example in  FIG. 14 , an attachment signal may be provided by the control attachment to the power adapter. The attachment signal may be a voltage that is generated in response to a power reference voltage being provided to the control attachment. That is, the power adapter would detect that the control attachment is receiving the power reference voltage from the power adapter and drawing current. The power adapter, in response to detecting the attachment signal, may then provide an information request. For example, the power adapter may request identification information to enable authenticating the control attachment. The information may then be provided to the power adapter, which way then provide an acknowledgement signal. Various control signals and feedback signals  1402  can then be transferred between the power adapter and the control attachment. The control signals and feedback signals can relate to the operation of the power adapter, the operation in the control attachment, signals received from the control attachment and provided to the power adapter to control the application of power to a load, or feedback signals provided to the control attachment. While an exemplary sequence of signals being transferred is shown, it should be understood that other sequences and other signals could be transmitted, or that similar types of signals could be transmitted according to a predetermined signaling protocol to achieve authorization of the control attachment and control of the power adapter. 
     Various examples of power adapters, control attachments, and a power adapter as coupled to control attachments are now shown. While some examples of power adapters and control attachments are shown, it should be understood that features of the power adapters and control attachments could be implemented differently, and features could be interchanged between the various implementations. The examples are provided in the following figures to demonstrate how features could be implemented. However, it should be understood that the various features could be implemented differently. 
     Turning first to  FIG. 15 , a front and side view of a power adapter  102  is shown. As shown in the implementation of  FIGS. 15-21 , an on switch and an off switch are provided on a surface of the power adapter to enable manual control of the power adapter using a basic control attachment, and even when the control attachment is not attachment. More advance features of a more advance control attachment can be implanted using connector shown near the bottom of the power adapter. While contact elements are also provided on the surface of the power adapter and exposed to a user of the power adapter when the control attachment is not attached or is removed to be replaced with a different control attachment, the contact elements do not include high voltage signals, and therefore are not a risk to uses of the power adapter. That is, a user of the power adapter can operate the power adapter without a control attachment attached to the power adapter without any risk to the user. Such a configuration makes the power adapter arrangement (having a power adapter that can be used without a control attachment) particularly beneficial to a home builder that may wire a house and allow a user to install control attachments, or allow the home builder to wire a house and install the control attachments at a later time after consultation with the home owner. However, during the time from the wiring of the power adapters and the time when a home owner may select control attachments, lights or other devices controlled by the power adapter may be used without a control attachment attached. 
     A wall,  1501  having a top  1502  in a planar surface, extending around a perimeter of the power adapter defines a recess  1503  extending to a rear surface  1504  comprising a back wall of the recess. A first switch  1506  comprising a switch control element  1507  and a second switch  1508  comprising a switch control element  1510  are positioned on the rear surface  1504  of the recess. The first switch  1506  and the second switch  1508  may comprise physical actuators that generate a signal in response to a physical external input (i.e. a manual input such as a pressing of the switch element). For example, the first switch  1506  and the second switch  1508  may be electro-mechanical actuators enabling on off control of the power adapter. 
     As described above, the first switch  1506  and the second switch  1508  may be used with or without a control attachment, and even with the control attachment that is not authorized. That is, because only low power voltage signals may be provided to an electrical interface  1512  having contact elements  1514 , a home builder can install the power adapter (even without control attachment, but with a wall plate if desired) without concern that the user of the power adapter would be exposed to a high voltage electrical signal. The user could control the power adapter by merely depressing the switch control element  1507  to turn power to the load on or depressing the switch control element  1510  to turn power to the load off. While the electrical interface  1512  may be used to receives signals from an authorized control attachment  104 , an unauthorized control attachment connected to the power adapter would be allowed to be used to turn on and off power to the load, but may be prevented from controlling the power adapter by way of the contact elements of the electrical interface  1512 . Further, while the electrical interface  1512  is shown at the bottom of the power adapter, it could also be placed between the switch is  1506  in  1508  of the power adapter, as will be shown in other implementations below, or at another location or in another orientation. 
     The power adapter would also comprise contact elements that are coupled to reference voltages of a building, which may include a high power reference voltage (e.g. 120 or 220 volt reference voltage), and ground and neutral reference voltages, as described above. For example, a first contact element  1516  is shown here by way of example as having a screw  1518  that is adapted to secure a wire to the contact element  1516 , and a second contact element  1520  having a screw  1522  adapted to secure a wire to the contact element  1520  are shown. While two contact elements are shown on a side of the power adapter, additional contact elements could be provided on the opposing side for example, or on the top or bottom, where any number of contact the elements are provided to enable the appropriate control of loads in an electrical circuit. For example, the contact elements such as contact elements  1516  and  1520  could be provided to enable connections to power, neutral, ground, and 3-way, as shown and described for example in  FIGS. 1-5 . 
     The power adapter may also comprise a dimmer control feature, where a guide element  1524  enables the movement of a dimmer controller  1526  to provide dimming control. A corresponding dimmer control element may be implemented in the control attachment, where the dimmer control elements are coupled to enable dimming control from the control attachment, as will be described in more detail in reference to  FIGS. 65-75 . While the dimmer control functionality is provided for manual dimmer control, it should be understood that dimming control could also be provided by way of the electrical interface  1512 , where dimming control can be coordinated using the 2 interfaces as will be described in more detail below. It should be understood that the dimmer controller  1526  is optional, and dimming control could be controller by non-mechanical elements from the control attachment by way of the electrical interface. A pair of flanges  1528  are included on the top and bottom of a power adapter that is configured to be attached to a junction box, where each flange comprises an opening  1530  for receiving a screw enabling the power adapter to be coupled to a the junction box and threaded portion  1532  for receiving a screw that enables a wall plate to be attached to the power adapter, as will be described in more detail below. 
     Turning now to  FIG. 16 , a cross-sectional view of the power adapter of  FIG. 15  taken at lines  16 - 16  is shown. As shown in  FIG. 16 , the switch control elements  1507  and  1510  of the switches  1506  and  1508  are exposed in the recess  1503 , enabling the user to use the switches without actuator elements of the control attachment normally used to control the switches. As also shown in the cross sectional view of  FIG. 16 , the recess  1503  provides space for receiving elements of the control attachment, such as circuit elements and/or mechanical elements of a control attachment for enabling operation of the power adapter, as will be described in more detail below. 
     Various types of control attachments are also described. According to some implementations, the control attachment could be configured to be placed behind the recess or opening of a wall plate, where a toggle element extends though the opening in the wall plate after the wall plate is attached to the power adapter, but cannot be inserted through or removed through the opening in the wall plate when the wall plate is attached to the power adapter. That is, the control attachment can only be attached to or detached from the power adapter when the wall plate is not attached to the power adapter, as described in reference to  FIG. 17  and other figures below. By requiring that the wall plate be removed to attach the control attachment to the power adapter or remove the control attachment from the power adapter, it is more difficult to remove the control attachment, making it more difficult for a control attachment to be stolen or removed as a prank. 
     Alternatively, the control attachments may be adapted to be inserted through a recess of a wall plate coupled to the power adapter. That is, a control attachment can be attached or removed when the wall plate is attached to the power adapter as will be described in more detail in reference to  FIG. 18  and other implementations below. As will be described in more detail below in reference to  FIGS. 48 and 49 , the attachment elements associated with the power adapter could be configured to receive control attachments that can be attached or detached when the wall plate is attached to the power adapter ( FIG. 49 ), or only when the wall plate is detached from the power adapter ( FIG. 48 ). That is, according to some implementations, a common power adapter can be provided, where the control attachment can be implemented to accommodate either type of control element. 
     According to various implementations, maintained switches (i.e. switches that a state of power applied to a load is maintained until another toggle event occurs) are shown, where the toggle element may be spring loaded to return to a common fixed position by one or more spring elements after a toggle motion (to either apply power to the load or remove power from the load) as described in reference to  FIGS. 17-21  or may move between 2 fixed positions as described in reference to  FIGS. 24-25 . 
     Turning now to  FIG. 17 , a front and side view of a control attachment having a portion that extends through recess of a wall plate and a portion including attachment elements that are located behind the wall plate (i.e. preventing the control attachment from being attached or detached when the wall plate is attached to the power adapter) is shown. As shown in  FIG. 17 , the control attachment  104  comprises a planar surface  1702  of a body portion  1703 , where a wall  1704  extends from the planar surface  1705 , and would extend through the opening in the wall plate when the wall plate is attached to the power adapter. That is, the wall  1704  will be aligned with the perimeter of the opening of the wall plate and extend through the opening of the wall plate when the control element is attached to the power adapter and the wall plate is then attached to the power adapter, where the wall plate will cover at least a portion of the planar surface  1702 . According to some implementations, the perimeter of the opening of the wall plate may abut the planar surface  1702 . The planar surface  1702  may also be aligned with the planar surface on top of the wall  1502  so that the planar surface on the top of the wall  1502  and the planar surface  1702  are in the same plane. Such an arrangement may make it easier for the wall plate to correctly align with the power adapter and control attachment when they are coupled together. 
     The control attachment  104  of  FIG. 17  may also comprise a toggle element  1706 , shown here by way of example as a paddle-type toggle element, that is movable within a gap  1708  within the base portion  1703 . The toggle element comprises a top portion  1710  and a bottom portion  1712  on either side of a center portion  1714 . The toggle element  1706  Is movably coupled to the base portion  1703  by way of hinge elements  1715 . As will be described in more detail below in reference to  FIGS. 19-21 , The toggle element main move between and on position and an off position. 
     The control attachment also comprises attachment elements  1716  and  1718  that enable attaching the control attachment to the power adapter. According to some implementations, the attachment elements may comprise movable elements, such as leaf springs having a projection for engaging with a corresponding element of the power adapter, as will be described in more detail in reference to  FIGS. 47-49 . According to the implementation of  FIG. 17 , the attachment elements are positioned so that they are not accessible when a wall plate is place over the control attachment and coupled to the power adapter. That is, a user of the power adapter any not be able to engage or interact with the attachment elements, and the base portion  1703  would not fit through the opening of the wall plate (and therefore the control attachment would not be able to be inserted or removed with the wall plate on). As will be described in reference to  FIG. 18 , the attachment elements would be accessible to the user when the wall plate is attached, enabling the user to insert or remove the control attachment when the wall plate is attached. 
     While a combination of power adapter and the control attachment in  FIGS. 15-17 , it should be understood that a power adapter having no recess could be implemented, where the rear surface  1504  is in the same plane as the top of the wall  1502 . Alternatively, the back wall could be raised with respect to the top of the wall, where the control attachment may have a peripheral flange that could be placed over the back wall and abut a planar surface around the top of the wall  1502 . It should also be understood that many different types of attachment elements could be implemented, and the attachment of the control attachment to the power adapter could be based upon any principle, including a friction fit, where the attachment elements would comprise attachment elements that abut one another and are attached based upon friction, such as when edges of the control attachment abut the inside portion of the wall  1501 , or when a peripheral flange abuts side walls of the back wall that is raised with respect to the wall  1501 . Any other type of attachment elements could be used, including spring loaded attachment elements, or projections and corresponding flanges or recesses adapted to receive the projection for example. 
     Turning now to  FIG. 18 , a front and side view of a control attachment that extends through opening or recess of a wall plate, where the attachment elements of the control attachment are accessible when the wall plate is attached to the power adapter is shown. While the wall plate is generally attached to the power adapter, the power adapter arrangement could be configured so that wall plate is attached to the control attachment. According to the implementation of  FIG. 18 , a base portion  1801  comprises a top portion  1802  of a wall  1803 , where both the top portion  1802  and at least a portion of the wall  1803  may extend through the opening of a wall plate when the wall plate is attached to the power adapter arrangement. That is, at least a portion of the base portion  1801  extends through the opening of wall plate so that a user can access the attachment elements associated with the based portion and remove the control attachment. 
     More particularly, the control attachment of  FIG. 18  comprises a gap  1804  between a toggle element  1805  and the wall  1803 . The toggle element  1805  comprises the top portion  1806  and a bottom portion  1808  on either side of a center portion  1810 , which comprises a pivot portion. Attachment elements  1816  and  1818  are positioned at the top and bottom of the base portion  1801  to enable the control attachment to be attached to the power adapter. It should be understood that the attachment elements  1716  and  1718  of  FIG. 17  and attachment elements  1816  and  1818  of  FIG. 18  could be configured to attach to the same attachment elements of the power adapter  102  as described in reference to  FIGS. 48 and 49 . Such an arrangement would enable a user to decide which type of power attachment to use (i.e. a control attachment that can be attached and detached when the wall plate is attached to the power adapter or a control attachment that can be attached or detached only when the wall plate is not attached to the power adapter). Having a choice of the types of control attachments is beneficial to a user because there may be different situations where one type of control attachment may be better than another. For example, an owner of a residential home could use control attachments that can be attached and detached when the wall plate is attached to the power adapter. However, in a commercial building where there is a chance that a control attachment may be stolen or removed as a prank, it would be beneficial to install control attachments that can only be removed when the wall plate is removed. That is, requiring that the wall plate be removed for the control attachment to be detached would make it more difficult for the control attachment to be stolen or removed by an unauthorized party. According to some implementations, a control attachment that can only be detached when the wall plate is removed could also be configured to require a special tool to be removed even after the wall plate is removed. 
     Turning now to  FIG. 19 , a side view of the control attachment of  FIG. 17  having a toggle element is shown. According to the implementation of  FIG. 19 , actuator elements  1902  and  1904  are movable in response to a user actuation of the top portion  1710  and the bottom portion  1712  of the toggle element  1706 . Also shown in  FIG. 19  is a control circuit  1910  coupled to contact elements  1912 , which would be present if the control attachment is a smart control attachment and comprises a control circuit, such as control circuit  118  as described above. While the control circuit  1910  is shown by way of example near the bottom of the control attachment, it should be understood that the control circuit can be placed at other locations along the control attachment. The control attachment may also comprise spring elements  1906  and  1908 . The spring elements  1906  and  1908  enable the toggle element to return to a standing position (i.e. a return-to-center type toggle element that remains in a fixed, center position whenever a portion of the toggle element is not being pressed). 
     Turning now to  FIGS. 20 and 21 , the state of the toggle element before returning to the center position is shown.  FIG. 20  shows a side view of the control attachment of  FIG. 19  having a movable toggle element in a first position, which may be considered an on position (for a switch that is not in a 3-way switch connection).  FIG. 21  is a side view of the control attachment of  FIG. 19  having a movable toggle element in a second position, which may be considered an off position (for a switch that is not a 3-way switch connection). As will be described in more detail below in reference to  FIG. 80 , different actions can be taken depending upon a current state of power applied to a device when either the top portion or the bottom portion of the toggle element  1706  is pressed. While  FIGS. 19-21  are based upon the control attachment of  FIG. 17 , it should be understood that the same toggle element arrangement could implemented according to the implementation of  FIG. 18 , where the control attachment is removable when the wall plate is attached. 
     Turning now to  FIG. 22 , a front and side view of a power adapter having a single toggle actuator and an optional dimmer control is shown. According to the implementation of  FIGS. 22-25 , a single on/off switch is included on the power adapter. According to the implementation of  FIG. 22  and also shown in the cross-sectional side view of  FIG. 23 , the switch  1508  is not included, where a toggle function depends upon a change of state of the switch  1506  having a movable switch control element  1507 . By using a single on/off switch, the area of the power adapter of  FIG. 15  having the second switch can be used for other functions, as will be described in more detail below. The control attachment that could be used with the power adapter of  FIG. 22  may comprise a spring-loaded toggle element that may be retained in an on or off position as described in  FIGS. 21-24  below to enable the use of a single switch on the power adapter. That is, the switch control element  1507  will be held in a certain state after an indication of a desire to change a state of the power applied to the load (i.e. by pressing the top portion of the toggle element), and then released in response to another indication of a desire to change the state of the power applied to the load (i.e. by pressing the bottom portion of the toggle element). 
     As shown in the implementation of  FIG. 23 , the flange  1528  may be contoured as shown to enable an attachment element of the control attachment to be coupled to a corresponding attachment element of the flange, such as to a projection  2302  of the flange That is, an attachment element of the flange may be adapted to receive a corresponding attachment element of a control attachment to enable attaching the control attachment to the power adapter. Such an arrangement may be beneficial when the power adapter does not comprise a recess  1503 , but rather the control attachment is attached to a planar surface of the power adapter. 
     Turning now to  FIGS. 24 and 25 , an example of a control attachment that could be used with the power adapter of  FIG. 22  is shown. The control attachment of  FIG. 24  is a static control attachment (i.e. remains in a fixed position when either the top portion or the bottom portion of the toggle element is moved), and comprises a toggle element that is moved to either a first static position as shown in  FIG. 24  or a second static position as shown in  FIG. 25 . A side view of a control attachment that may be implemented with the power adapter of  FIG. 22  and having a toggle element in a first state as shown in  FIG. 24 . The control attachment of  FIG. 24  may comprise a spring-loaded element  2402  that retains the toggle elements in either the first position or the second position when moved to that position. 
     More particularly, the spring-loaded element  2402  comprises a spring  2403  that may be extended when moved from a first position to a second position, where the spring is coupled between a first coupling element  2404  and a second coupling element  2406 , and the spring-loaded element  2402  is coupled to the control attachment at a hinge element  2408 . In the first state as shown in  FIG. 24  after the top portion of the toggle element is pressed, the spring  2403  is in a first resting state, holding the toggle element in the first state as shown in  FIG. 24 . When in the first state, the toggle element will hold the switch control element  1507  in a “pressed” state. 
     However, when the bottom portion of the toggle element is pressed, the spring-loaded element  2402  extends through an arc defined by angles  1  and  2  as shown. As the spring-loaded element  2402  passes through the 1st angle, the spring is extended, and then begins to return to a non-extended state (i.e. a second resting state) as the spring-loaded element  2402  reaches the end of the second angle as shown in  FIG. 25 . When the spring-loaded element  2402  reaches the end of the second angle, these spring is again no longer extended, holding the spring loaded element in the second state. While paddle-type toggle elements are shown in reference to  FIGS. 17-25 , it should be understood that any type of toggle element could be implemented. 
     Turning now to  FIG. 26 , a front and side view of a control attachment having a hinged toggle element is shown. According to the implementation of  FIGS. 26-31 , a hinged toggle element enables access to control elements that may include user interface elements behind the toggle element and a recess for receiving a control module. More particularly, a hinged actuator element  2602  is coupled to the control attachment base portion  1703  by hinge elements  2604 . As shown in the side view of  FIG. 27  of the control attachment of  FIG. 26 , elements are included that enable the control of an actuator of the power adapter for controlling the power adapter. For example, a top portion  2701  can be depressed within a wall portion  2702 , where an opening  2703  is provided in the back wall of the control attachment that enables a switch actuator element  2704 , shown here by way of example as a projection, to extend through a back wall of the control attachment and make contact with an actuator of the power adapter. It should be understood that the switch actuator element  2704  could engage an intermediate actuator element, as will be described in more detail below in reference to  FIGS. 81 and 82 . A spring element  2706  may be included to enable the toggle element to return to a fixed state, as shown in  FIG. 27 . The control attachment may also comprise a control circuit  2710  and contact element  2712  near a bottom portion  2714  of the hinged toggle element. 
     Turning now to  FIG. 28 , a front and side view of the control attachment of  FIG. 26  with the hinged toggle element in an open position and exposing a control module and optional user interfaces is shown, where the inner surface  2808  of the hinged toggle element comprises the switch actuator element  2704  and the spring element  2706 . More particularly, a rear surface  2802  of an inner portion of the control attachment (i.e. visible when the movable toggle element is open) may comprise various user interfaces or be adapted to receive a control module. For example, a recess  2804  may be included to receive a controller  2806 , which may comprise a control module or insert for example. The inner surface may also comprise a user interface  2814 , which may comprise actuator elements or electrical connectors for programming the control attachment or power adapter or otherwise controlling the power adapter. The user interface  2814  may be coupled to the controller  2806  by way of a signal line  2816 . 
     Turning now to  FIG. 29 , a front and side view of the control attachment of  FIG. 26  with the controller  2806  of  FIG. 28  removed is shown. The recess  2804  may comprise attachment elements  2902 , which may be implemented on either side of the recess for example. The recess may also comprise an electrical interface  2904 , which may be a connector or contact block, having contact elements  2906 . According to the implementation of  FIG. 30 , rather than having an electrical interface, the recess may comprise an opening  3002  that enables the contact elements of the controller  2806  to be exposed on the back of the control attachment, enabling electrical connections to corresponding contact elements of the power adapter. 
     According to the implementation of  FIG. 31 , the controller  2806  comprises a rear surface  3102  that is adapted to abut a rear surface of the recess  2804 . The rear surface  3102  comprises an electrical interface  3104 , such as a connector or contact block having contact elements  3106 . The context elements  3106  may make an electrical contact with the contact elements  2906  of the control attachment when the controller  2806  is inserted into the recess  2804 . Alternatively, the contact elements  3106  may make contact with corresponding contact elements of the power adapter according to the implementation of  FIG. 30 . Attachment elements  3108  are adapted to couple with corresponding attachment elements  2902  to secure the controller  2802  in the recess and ensure an adequate electrical connection between the corresponding contact elements. 
     According to the implementation of  FIG. 32 , a control module  3206  may be accessible when a hinged toggle element is in a closed position as shown. More particularly, a front and side view of a control attachment having a control module  3206  that is accessible through a recess in a toggle element, such as a hinged toggle element as shown. According to the implementation of  FIG. 32 , a hinged toggle element may comprise a recess for receiving a control module, where the control attachment comprises in control actuator  3202  having a top portion  3203  that enables a toggle selection and a recess  3204  adapted to receive a control module  3206 . The control module  3206  may comprise a lens  3208  (e.g. a translucent region that may be adapted to accommodate a sensor such as a camera or a motion detector), which is also shown in  FIG. 33 , where the control module  3206  may comprise contact elements  3302  that may be coupled to contact elements of the control attachment or the power adapter as described in reference to  FIGS. 29 and 30 . As shown in  FIG. 33 , the control module  3206  may be attached to or detached from the control attachment while the control actuator  3202  is in a closed position. The control actuator  3202  also comprises hinge elements  3210  to enable both an actuator motion (i.e. a movement of the control actuator to enable an actuation of a switch of the power adapter) and an opening of the control actuator  3202  to expose user interface elements on an inside surface of the control attachment as shown in  FIG. 34 . An inside surface  3402  of the control actuator  3202  may comprise the switch actuator element  2704  and the spring element  2706  as described above. 
     Turning now to  FIG. 35 , a front and side view of the toggle element  3203  of  FIG. 32  that may be removed is shown. More particularly, the actuator element  3202  comprises a first and second leg portions  3502  and  3504  associated with the hinge elements  3210 . As shown in  FIG. 36 , the base portion  1703  of the control attachment may comprise a hinge element  3602  adapted to receive the hinge element  3210 . For example, a protrusion  3604  associated with a base portion  3606  comprises first and second projections  3608  and  3610  to form a recess  3612 . The recess  3612  is sized to receive the hinge element  3210  such that the control actuator  3202  may be attached to and detached from the control attachment. 
     Turning now to  FIG. 37 , a block diagram of a power adapter and a control attachment that may be connected using a variety of connection elements is shown. The exemplary elements of the power adapter  102  and the control attachment  104  of  FIG. 37  may be implemented to perform the operations of the power adapter and the control attachment as described in reference to  FIGS. 1-5  for example or other figures, and the wireless and physical interface elements between the power adapter and the control attachment of  FIG. 37  may be implemented as described in reference to  FIGS. 7-10  for example or other figures. However, it should be understood that  FIG. 37  provides an example of a configuration of elements that could be used to enable the operation of a power adapter arrangement having a power adapter and a control attachment. Different elements could be implemented in the power adapter arrangement, or the elements as shown could be configured or distributed differently in the power adapter arrangement within the spirit and scope of the invention. Certain functions implemented by way of example in multiple blocks of the functional block diagram of  FIG. 37  may be implemented in a single block. For example, a test circuit of the power adapter may be implemented as a part of a control circuit of the power adapter. Examples of test circuits that could be implemented are shown in  FIGS. 83 and 84 . Further, different functions of the power adapter arrangement may be distributed differently between the power adapter  102  and the control attachment  104 , as described in the different examples set forth herein. 
     The block diagram of  FIG. 37  shows elements of a power adapter arrangement, such as the power adapter arrangement of  FIGS. 1-5  for example. As shown in  FIG. 37 , a control circuit  3702  is coupled to various elements of the power adapter  102  to provide power to and enable communication with the control attachment  104  and control the operation of the power adapter. The control circuit  3702  may control at least one of the other components of the power adapter  102 , including controlling power applied to a load, and/or perform an operation or data processing relating to communication with the control attachment  104 . 
     The control circuit  3702 , as well as the control circuit  3732  described in more detail below, may comprise a processor suitable for the execution of a computer program, and may include, by way of example, both general and special purpose microprocessors, a central processing unit (CPU), an application processor (AP), or a communication processor (CP), or any type of processor that could be used to communicate with the control attachment or an external device or control the switching operation of the power adapter. The control circuit  3702  could be an ARM processor, an X86 processor, a MIPS processor, a general purpose unit GPU, or any other processor configured to execute instructions stored in a memory. The control circuit  3703  could be implemented in one or more processing devices, including a processor and other dedicated logic circuits. 
     Generally, a processor will receive instructions and data from memory, such as a read only memory or a random access memory or both, where the processor is configured to perform actions in accordance with instructions. One or more memory devices may be included as a part of the processor or separate from the processor for storing instructions and data. Devices suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; or any other type of memory device. The processor and the memory can be supplemented by, or incorporated with, special purpose logic circuitry. According to other implementations, the control circuits  3702  and  3732  may be implemented by logic circuits, such as an application specific integrated circuit (ASIC). 
     A transformer  3704  is coupled to an input port  3705  for receiving a neutral voltage and an input port  3706  to receive an input voltage that enables providing power to a load by way of an output of the power adapter. That is, the transformer receives a high power signal, and the power adapter controls the application of the high power signal to a load. The input ports comprise contact elements that could be for example wires or connector screws that are wired into a junction box or could be contact elements associated with an electrical outlet in a wall of a residential or commercial building. The control circuit also receives a ground potential at a ground terminal  3708 , which may be another contact element such as a ground wire or ground contact, or a ground prong of an outlet of the power adapter for example. 
     The transformer  3704  also provides power, which will be a low power signal, to the control circuit  3702  by way of a power line  3707 . That is, the transformer  3704  will generate a low power signal (e.g. approximately 0-24 Volts) that is used to power electronic circuits of the power adapter and/or electronic circuits of the control attachment. The control circuit  3702  may also receive power by way of a backup battery  3709  to retain any information such as operational information or timing patterns in the event of a power loss. While a battery is shown by way of example, a different source of backup power could be implemented, such as a capacitor that will provide power to the power adapter and/or the control attachment in the event of a power loss. 
     An input portion  3710  may be implemented to enable the input of information or the selection of features of the power adapter, such as timing patterns that may be implemented by the power adapter. The input portion may include one or more buttons that can be selected to enable a resetting of the power adapter or a pairing of the power adapter and the control attachment as will be described in more detail below. Examples of user interface elements that may be implemented by the input portion  3710  are described in more detail below in reference to  FIG. 44 . 
     A memory  3712  is coupled to the control circuit and may store operational information, timing patterns, software programs, data for implementing software programs, and any other data used in operating the power adapter or control attachment. It should be noted that the input portion  3710  of the power adapter may also include the connector for receiving the portable memory device such as a USB thumb drive or an SD memory to download any type of data, such as operational information, programming data, or firmware as will be described in more detail below. An oscillator  3713  may be coupled to the control circuit to enable the control circuit to maintain a current time. 
     A switch  3720  is coupled to receive power from the transformer by way of a power line  3722  and provide power to an output  3723  (which may be another contact element that is coupled to a load such as by a wire in an electrical system or a contact element of an outlet adapted to receive a plug) in response to control signals generated by the control circuit  3702  on a line  3724  from the control circuit. The control signals may be any type of signals for regulating power applied to a load, such as on and off signals and dimming signals for example. The switch  3720  may be a relay or TRIAC for example for coupling high power signals to a load as described above. The control signals may be generated in response to signals received by the power adapter, including signals received from the control attachment. The control signals may be associated with a timing pattern that is stored in a memory of the power adapter arrangement, including a memory of one or both of the power adapter and the control attachment. The power adapter arrangement may control the application of power to the load based upon a timing pattern that is stored in a memory (e.g. memory  3712  or memory  3742 ), or in response to signals provided to the control attachment (such as by way of the wireless communication circuit  3748 ) in real time (i.e. the control attachment controls the application of power to the load as it receives a command by way of the wireless communication circuit  3748 ). The control signals by also be generated in response to other information received by the control attachment, such as by a sensor of a control attachment or information received from the control attachment received from an external device, such as a smart phone or other computer device or element of a wireless network. 
     The output  3723  may be wires or screws that can be coupled to wires in the case of an in-wall power adaptor that are coupled to a device (i.e. load) that is powered by the power adapter (or contact elements of an outlet that receives a plug for the device controlled by the power adapter). 
     A wireless communication circuit  3726  could be used to receive various information, such as operational information, programming data, or firmware updates from the control attachment  104  or from some other source, as will be described in more detail below. The wireless communication circuit  3726  could be adapted to implement any type of wireless communication protocol as described herein, by way of a wire communication connection with the control attachment  104  or with an external device other than the control attachment. 
     The power adapter  102  and the control attachment  104  may communicate by way of an interface  3727 , which may be an electrical interface, such as a connector or a plurality of contact elements, as described herein. The interface  3727  enables a communication link  3728  with an interface  3729 , which may also be an electrical interface, such as a connector or a plurality of contact elements. The communication link may comprise contact elements of the interfaces  3727  and  3729  to enable the transfer of communication signals between the interfaces. The communication link may also provide reference voltages including power and ground (or neutral) reference voltages to power elements of the control attachment. 
     The control attachment  104  comprises a control circuit  3732 , which may be any type of processing circuit for (i) receiving inputs, such as by way of an input portion  3734  or by way of a wireless connection, and (ii) controlling the operation of the control attachment  104 , including communicating with the power adapter to control the application of power to the load. The input portion could be implemented to receive inputs (e.g. mechanical inputs, sensor inputs, etc.) as shown and described in reference to the various control attachments described herein. A battery  3736  or some other source of energy such as a capacitor may be used to power the control attachment  104  or function as a backup power source during a power loss (if the control attachment  104  normally receives power by way of the interface  3729 ). A display  3746  may also be provided. 
     A wireless communication circuit  3748 , which may be a wireless receiver or both a wireless transmitter and receiver (i.e. a wireless transceiver), comprises an antenna  3750 . Data received by the wireless communication circuit  3748  may be provided to the control circuit  3732 , or data generated by the control circuit  3732  may be transmitted by the wireless communication circuit  3748 . Data, such as a timing pattern or operational information (e.g. time, date and location information) entered by the input portion or received by way of the wireless communication circuit  3748 , may be stored in a memory  3742 . 
     The wireless communication circuit  3748  may be any type of receiver for receiving wireless communication signals, such as GPS receiver, a cellular receiver, a radio frequency (RF) receiver, a WiFi receiver, a Bluetooth receiver, and NFC receiver, or any other type of receiver adapted to receive data according to any wireless communication protocol, where the information may include operational information, programming data, software updates, or any other type of information enabling operation of the power adapter arrangement. According to some implementations where the control attachment comprises a smart speaker (i.e. a device having a microphone and often a speaker that is configured to response to commands, including controlling other device such as in-wall or plug-in timers, or respond to questions by providing answers to questions) as described in more detail below, data and information may be received by the wireless communication circuit  3748  of the control attachment from an external device associated with a system employing a smart speaker, such as an Alexa brand system from Amazon.com, Inc., a Google Home brand system from Alphabet Inc., or Apple Home from Apple, Inc. for example. 
     The operational information, control information, sensor information, or any other data or information received by the control attachment, such as by way of the input portion  3734  or by way of a wireless connection, may be provided to the control circuit to enable the operation of the control circuit and the implementation of the timing patterns to control the load. A GPS receiver is commonly available from SiRF Technology, Inc, for example, while a cellular receiver could be implemented in an integrated circuit chip or module, such as a chip or module available from u-blox Holding AG of Thalwil, Switzerland. Operational information including time, date and location that may be necessary to implement a timing pattern for example may also be received from a network, such as a Wifi network, from a smart phone (which may receive the operational information from a cellular network for example) communicating with the control attachment by way of a WiFi network, or a short range connection, such as Bluetooth or NFC. Therefore, actuators for entering time, date and location information could be eliminated from one or both of the power adapter and the control attachment with the use of a wireless communication circuit  3748 . 
     While the wireless communication circuit  3748  for receiving communication signals from a remote network, such as a GPS network, a cellular network, a local area network such as WiFi, or short range connection such as Bluetooth or NFC, is shown as a part of the control attachment  104 , some information received by the wireless communication circuit  3748  could instead be received by the wireless communication circuit  3726  of the power adapter  102 . That is, the wireless communication circuit  3726  could be adapted to receiving operational information or any other data wirelessly from a remote device using any wireless communication protocol or wirelessly from the control attachment by way of the corresponding wireless communication circuit  3752 . 
     An oscillator  3744  or some other device for keeping a time for the control attachment may be coupled to the control circuit, where a current time or other data may be displayed on the display  3746 . While separate oscillators are shown in the power adapter  102  and the control attachment  104 , it should be understood that a single oscillator could be implemented, and an oscillating signal or other signal based upon the oscillating signal (e.g. a clock signal) could be shared between the power adapter  102  and the control attachment  104 . 
     The wireless communication circuit  3752  has an antenna  3754  enabling the communication of signals with a corresponding wireless communication circuit  3726  (having an antenna  3759 ) of the power adapter by way of a wireless communication link  3756 . While both a physical connection for transferring signals and/or power is provided by way of the communication link  3728  and a wireless communication link  3756  is provided by way of the corresponding wireless communication circuits  3726  and  3752 , it should be understood that one of the communication links could be implemented. A test circuit  3760  coupled to the interface  3727  and the control circuit  3702 . The test circuit  3760  could be used to determine whether the power adapter is wired in an electrical system correctly, as will be described in more detail below. Alternatively, the test circuit  3760  could be implemented in the control attachment  104 , as described in more detail in reference to  FIG. 84 . Such an arrangement would reduce the complexity of the power adapter and apply the cost to the control attachment. While some control attachments may not the capability to perform a test, a dedicated test control attachment could be used to ensure that the power adapter is wired properly. While a dedicated test circuit is shown, which may comprise a voltage detector for example, it should be understood that some or all of the testing operation could be performed in the control circuit  3702  and/or  3732  for example. 
     In addition to the communication link  3728 , other interfaces can be provided to enable the communication of signals between the control attachment and the power adapter. For example, a connector  3761  of the control attachment and a connector  3762  of the power adapter enable a communication interface  3764 . According to one implementation, the communication interface  3764  may comprise an electrical interface enabling the transfer of electrical signals between the control attachment and the power adapter. For example, separate interfaces may be implemented to transfer control signals and power signals. Further, an actuator element  3770  of the power adapter, such as a switch, may be configured to receive an actuator input from a corresponding actuator element  3772 . According to one implementation, the actuator elements  3770  and  3772  may be adapted to receive a manual input, such as a pressing of an actuator elements of a control attachment as described herein. 
     A wireless protocol implemented by one of the wireless communication circuits may be, but is not limited to, a standard for transmitting signals and/or data through electromagnetic radiation in different frequency spectrums. Examples of current wireless standards include, but are not limited to IEEE 802 standards, UMTS, GSM 850, GSM 900, GSM 1800, GSM 1900, GPRS, ITU-R 5.138, ITU-R 5.150, ITU-R 5.280, IMT-1000, Bluetooth (BT), Bluetooth-low-energy, also known as BLE, Wi-Fi, Ultra-Wideband, WiMAX, and Infrared, Some standards may be a conglomeration of sub-standards such as IEEE 802.11 which may refer to, but is not limited to, IEEE 802.1a, IEEE 802.11b, IEEE 802.11g, or IEEE 802.11n as well as others under the IEEE 802.11 umbrella. Wireless links may also include any cellular network standards used to communicate among mobile devices, including, but not limited to, standards that qualify as 1G, 2G, 3G, or 4G, including specifications or standards maintained by International Telecommunication Union. The 3G standards, for example, may correspond to the International Mobile Telecommunications-2000 (IMT-2000) specification, and the 4G standards may correspond to the International Mobile Telecommunications Advanced (IMT-Advanced) specification. Examples of cellular network standards include AMPS, GSM, GPRS, LTE, LTE Advanced, UMTS, Mobile WiMAX, and WiMAX-Advanced. Cellular network standards may use various channel access methods e.g. FDMA, TDMA, or CDMA. 
     Turning now to  FIG. 38 , a diagram showing a control attachment adapted to control both a light and a fan is shown. According to the example of  FIG. 38 , a control attachment  3802  that may be coupled to a power adapter comprises interfaces for controlling a light, including dimming functionality, and controlling the speed of a fan. More particularly, the control attachment  3802  is adapted to communicate with a fan  3804  by way of a wireless communication signal  3806 . The control attachment may comprise a switch  3808  having a status indicator  3810 , which may comprise an LED for example that made provide an indication of these status of the power applied to the fan. The control actuator  3802  may also comprise movable elements for controlling the dimming of the light as well as the speed of the fan. More particularly, a first control element  3812  may be movable within a channel  3814  to control the dimming of the light. Similarly, a second control element  3816  may be movable within a channel  3818  to control the speed of the fan  3820 , which may comprise a control circuit  3822  having a wireless communication circuit adapted to communicate with a corresponding wireless communication circuit of the control attachment  3802 . While the control elements are shown by way of example, it should be understood that other control elements can be implemented. 
     Turning now to  FIG. 39 , an arrangement of a power adapter and a control attachment having a power switch is shown. According to the implementation of  FIGS. 38-42 , the power switching functionality is provided in the control attachment. That is, unlike the embodiments of  FIGS. 1-37  that implement low power signals between the power adapter and control element, high power signals are provided through the interface between the power adapter and the control attachment. According to the implementation of  FIG. 39 , a power adapter  3902  is coupled to a control attachment  3904 , where the power adapter may comprise a 3-way control input  3908 , a ground input  3910 , a neutral input  3912 , and a power input  3914 . A signal interface  3915  enables the transfer of signals to and from the power adapter and between the power adapter and the control attachment. A load terminal  3916  is also provided to be coupled to a load. Because the control attachment is configured to receive a high power voltage, the control attachment may also include an outlet for receiving a plug. 
     The power adapter arrangement of  FIG. 39  comprises a plurality of interface elements  3920  and  3921 , which may include contact elements for example. More particularly, a connector element  3922  is coupled to a corresponding connector element  3924  for providing a power signal there is routed to the load. That is, rather than having a switching element, such as a relay or a TRIAC operating as a dimmer control circuit, in the power adapter, it may be provided in the control attachment according to the implementation of  FIG. 39 , where power routed to the power adapter is routed through the control attachment and back to the load. The connector also comprises a connector element  3926  coupled to a corresponding connector element  3928  to provide a ground signal from the power adapter to the control attachment. A connector element  3930  is coupled to a corresponding connector element  3932  to provide a neutral signal from the power adapter to the control attachment. A power signal, which may be based upon the power signal provided to the power adapter, is provided by way of a connector element  3933  to a corresponding connector element  3934 . The interface element  3920  may comprise a single connector, a plurality of connectors, is shown by way of example in  FIG. 40 . 
     The control attachment comprises elements for receiving the power from the power adapter, and selectively applying power to a load by way of the signal interface  3915 . More particularly, the control attachment  3904  comprises a control circuit  3936  adapted to receive signals from various interfaces and control a dimmer control circuit  3937  for providing the power to a load by way of the connector elements  3922  and  3924 . The control attachment comprises various actuators in a user interface for receiving input signals that may be used by the control circuit  3936  to control the dimmer controller, and generate output signals. An actuator  3938  comprises a user interface input  3940  for receiving user interface input. By way of example, the actuator  3930  may comprise an on off button. An actuator  3942  comprises a user interface input  3944  for receiving additional user interface input, such as dimmer control input. An additional interface  3946  may be coupled to a feedback circuit  3948 , and may receive signals by way of a communication interface  3950  and generate feedback signals by way of a feedback output  3952 . The communication signals provide to the control attachment may be wireless communication signals for example. The feedback signals may be any type of audio or visual feedback signals for any type of user interface as described herein. Accordingly, the power adapter  3902  is configured to receive high voltage power from an interface of the power adapter, where the power is routed through the control attachment and back to the power adapter to be provided to the load. By configuring the switching control of power of the power adapter arrangement of  FIG. 39  in the control attachment, it is possible to provide a simplified power adapter, where the functionality of the switching is provided in the control attachment. 
       FIGS. 40 through 42  show an example of connections for routing the signals between the control attachment and the power adapter. As shown  FIG. 40 , a front and side view of the power adapter  3902  of  FIG. 39  includes a contact block  4002 , shown here by way of example as having a plurality of discrete contact elements  4004 , which may comprise female receptacle contact elements for example. As shown in  FIG. 41 , receptacle  4102  coupled to a signal line  4104  is adapted to receive a contact pin  4202  of the control attachment of  FIG. 42 . Because the contact block  4002  comprises a contact element having high voltage, it should be understood that the contact block would be configured to prevent any inadvertent contact with the high voltage power, such as including protection elements currently found in outlets to prevent injury to a user. 
     Turning now to  FIG. 43 , a flow chart shows a method of enabling a wiring fault detection. Whatever implementing a device that is coupled to high voltage electric power, it is important that the device is properly installed to prevent any injury to the installer or a user. If a device is improperly installed, it may not be obvious to a user, and any injury may occur without notice to the user. Accordingly, it is beneficial to indicate whether a device has been improperly, or a condition has changed such that the device he has a fault for example. One common fault that may occur is a ground fault, where the ground is not properly attached, or the ground and neutral are inverted. Accordingly, it may be beneficial to evaluate the ground and neutral voltages with respect to one another to determine whether there is a ground fault. For example, After the method is started at a block  4302 , such as after a control attachment is attached to a power adapter, a timeout period may be set at a block  4304 . It is then determined whether the timeout period has expired in a block  4306 . If the timeout period has expired, voltages for the ground connection in the neutral connection are received at a block  4308 . The voltages for the ground connection and the neutral connection are then compared in a block  4310 . It is then determined whether the voltages are the same at a block  4312 . If not, the timeout period is again set at the block  4304 . However, if the voltages are not the same, an indication of an improper wiring connection is provided in a block  4314 , and the processes ended in a block  4316 . 
     Turning now to  FIG. 44 , a block diagram of an expanded view of elements of an in-wall power adapter and control attachment that is adapted to be installed in a junction box and to receive a wall plate is shown. A junction box describes the housing into which a power adapter arrangement is inserted. A junction box may be formed from metal, plastic or PVC for example, and may be defined as being 1-gang for having a single power adapter arrangement or 2-gang for having 2 power adapter arrangements, as is well known. A “wall plate” (also referred to as face plate or switch cover) refers to, but is not limited to, a typically plastic or metal cover designed to fit around and/or over at least a portion of the power adapter arrangement while in the junction box, and generally overlaps the surrounding wall or ceiling for example to provide an aesthetically and/or functional cover. 
     A power voltage, also referred to as an electrical supply, is a reference voltage to provide electrical power for the load controlled by the power adapter arrangement as described above. According to the implementation of  FIG. 44 , a junction box  4402  is coupled to conduit  4404  having wires  4406  that may be used to provide power by way of the reference voltages to the power adapter arrangement by way of a terminal portion  4408  of the wires that extend into a recess  4410  adapted to receive the power adapter arrangement. Flanges  4412  and  4414  receive a screw or other attachment element by way of a threaded portion  4416  to enable attaching corresponding flanges of the power adapter to the flanges  4412  and  4414 . 
     The power adapter  102  comprises a front surface  4424  that defines a recessed portion  4426  extending from the front surface to a back wall  4427 . The switching portion may also comprise an attachment element  4430  adapted to be coupled to a corresponding attachment element of the control attachment. The power adapter may also comprise flanges  4432  having a threaded portion  4434  for receiving a screw to secure a wall plate to the modular power adapter and a hole  4436  which comprises an opening for receiving a screw that can be inserted into the threaded portion  4416  and can be used to secure the power adapter  102  to the junction box  4402 . 
     User interface elements and other elements enable a user to implement the power adapter with a control attachment within the recess  4426 , such as on a back wall of the recess for example (or on another surface accessible by a user in an implementation not having a recess). For example, a communication port  4438 , which may comprise a connector or a plurality of contact elements for example, may be implemented. The contact elements may be contact pads adapted to be in electrical contact with contact elements of the control module, where the contact elements may be spring loaded contacts such as pogo-pins, or other flexible or spring loaded contacts that extend from a back surface of the control attachment and align with and make electrical contact with the contact pads of the power adapter. Alternatively, contact pads can be implemented on the control attachment and the corresponding contacts can be implemented on the back of the recess of the power adapter. While the contact elements are indicated as being on the back surface of the power adapter and the control attachment, it should be understood that the contacts can be placed on other surfaces, such as a side of the power adapter and a side of the control module. 
     The power adapter may also comprise a control button  4440 , which may function as a reset button or a pairing button for enabling the pairing of the control module with the power adapter. The control button may be used to reset the power adapter, enabling the power adapter to receive new data associated with a control attachment, and therefore to enable the power adapter and the control attachment to communicate and control a device receiving power from the power adapter arrangement. The control button  4440  could also enable a pairing function to pair an authorized control attachment to communicate with the power adapter. That is, a pairing function can be implemented, wherein a control button on each of the power adapter and the control attachment can be selected to enable the transfer of information between the control attachment and the power adapter. It may be necessary to charge the control attachment by coupling the control attachment to the power adapter to enable the control attachment to perform a reset operation and to enable a pairing of the control attachment with the power adapter. Alternatively, separate buttons may be implemented for a reset button and a pairing button. 
     The pairing operation is beneficial to ensure that only an authorized control attachment is implemented to prevent for example unauthorized control of a power adapter which may have a wireless control feature. For example, the control of the device receiving power from the power adapter may be compromised, and unauthorized use of a device under the control of the power adapter may occur. Further, the power adapter and the control attachment may communicate to enable the proper operation of a load controlled by the power adapter. For example, a control circuit of the power adapter may detect the type of device controlled by the power adapter, such as the type of light bulb (e.g. halogen, LED, or CFL), or the number of watts that the bulb or other device draws, and therefore enables the control circuit of the control attachment to provide different control signals to the power adapter to control the amount of power applied to the light bulb (such as a dimmable light bulb or a low power light bulb for example). 
     In addition to an implementation where the power adapter acts as a passive device, and only receives control signals from a control circuit of the control attachment, the power adapter and the control attachment could implement a bidirectional communication link according to another implementation to enable the control attachment to understand information received by the power adapter and better control the device controlled by the power adapter. Alternatively, the control attachment can detect the type or qualities of the light bulb by way of the communication ports of the power adapter and the control attachment. 
     A wireless communication circuit  4442  (shown in dashed to indicate that it may be behind the back wall  4427  of the recess) may also be implemented in the power adapter. The wireless communication circuit  4442  could be for example the wireless communication circuit  3726  of  FIG. 37  for example. A communication port  4440 , which may be a USB port or a port for receiving another type of memory card, such as an SD card, may be implemented on the power adapter, and may receive any type of information, such as operational information, timing patterns for turning the device controlled by the power adaptor on or off, or other data that is beneficial in implementing the operation of the control attachment. A timing pattern may include for example on and off times for a timing feature of the modular power adapter. While the USB port is shown on the power adapter, it should be understood that a USB port could instead be implemented on the control attachment, or implemented on the control attachment in addition to a USB port on the power adapter. An electrical interface, which may correspond to one of the electrical interfaces (e.g. electrical interface  713  of  FIG. 7 ) described above may also be implemented. An electrical interface  4444  comprises contact elements  4446  for receiving reference voltages, such as ground and power signals providing current to a load, are also provided on the power adapter, as described above. While contact elements comprising screws are shown, contact elements comprising wires adapted to be coupled to wires in a junction box could also be implemented. 
     The control attachment  104  may comprise a rear portion  4450  that is inserted into the recess  4426 . The various interfaces of the control attachment align with the corresponding interfaces of the power adapter to enable the communication of at least one of control signals and power between the power adapter and the control attachment. The wall plate  4459  can be attached to the power adapter using holes  4464 , where the holes receive screws that can be inserted into threaded portions  4434  of the flanges  4432 . 
     The dimensions of the various elements of modular power adapter are selected to enable the modular power adapter to be attached to a junction box, such as a conventional residential junction box. Therefore, the width w s  of the power adapter may be selected to be less than the width of a conventional residential junction box, and the height h s  may be selected to be less than the height of a conventional residential junction box. A depth ds of the recess  4426  is also selected to ensure that, when the control attachment is attached to the power adapter, the contact elements of the communication ports provide an adequate electrical connection to enable the transfer of data signals and/or power signals (e.g. provide adequate pressure between contacts and contact pads will enable an electrical connection). Also, the dimensions of back portion  4450  of the control attachment has a width w c  and a height h c  that are just slightly less that the width w s  and the height h s  to ensure that the control attachment fits into and aligns with the power adapter (or the width and height of the recess  4426  if the power adapter comprises a recess). 
     The dimensions of a front portion  4454  are also selected to extend through opening  4462  in a wall plate, and ensure that the edges of the opening of the wall plate cover the flange  4455  of the control attachment. The connector element  4458  is adapted to be secured to a corresponding connector element  4430  of the power adapter  102 . The edges  4460  define opening  4462 . Because the height h p  and the width w p  of the opening  4462  are slightly greater that the height h c ′ and the width w c ′ of the front portion  4454 ′, the front portion  4454  can extend through the opening  4462 , where the edges  4460  of the opening  4462  will generally cover the flange  4452 . Outer edges  4459  and  4460  of the wall plate extend beyond the perimeter of the junction box to cover the junction box. 
     Alternatively, the control attachment  104  may be implemented without the flange  4455  to enable the control attachment to be inserted and removed while the wall plate is in place. According to one implementation, the control attachment may be implemented in a ski-boot arrangement. For example, a flange  4456  (shown by the dashed line) may be implemented as attachment element for the bottom of the recess (i.e. in place of the attachment element  4430  as shown at the bottom), and may be adapted to receive a corresponding flange  4455 . That is, for an implementation of a control attachment  104  that is adapted to be inserted or removed through an opening of a wall plate, the flange  4455  can be inserted through the opening and behind the flange  4456 , and then the attachment element  4458  at the top of the control attachment can be coupled to the attachment element  4430 . The attachment elements at the top of the control attachment and power adapter could be implemented as described in reference to  FIG. 49 . It should be understood that the power adapter  102  and control attachment  104  of  FIG. 4  could be implemented as any of the power adapters or control attachments as described herein. 
     Turning now to  FIG. 45 , a front view of the power adapter arrangement and wall plate of  FIG. 44  when combined is shown. According to the implementation of FIG. of  45 , a power adapter arrangement based upon the control attachment of  FIG. 18  (where the control attachment can be removed when the wall plate is attached to the power adapter) is shown when a wall plate is attached to the power adapter. As can be seen, the wall plates  4502  comprises holes  4504  for receiving screws to attach the wall plate to the power adapter. As is apparent in  FIG. 45 , the attachment elements  1816  and  1818  are exposed through the hole in the wall plate, and the control attachment can be removed. 
     According to the implementation of  FIG. 46 , the control attachment is based upon the control attachment of  FIG. 17 , where the attachment elements are not exposed through the opening of the wall plates  4602 , and therefore the wall plate must be removed to insert or remove the control attachment. As also shown, there are no holes for receiving screws to attach the wall plate to the power adapter. Rather, an intermediate wall plate  4604  that may be attached to the power adapter by way of openings  4606  is implemented, where attachment elements  4608  are configured to be attached to corresponding attachment elements of the wall plate  4602 , eliminating the requirement for screws, which can be unsightly. 
     Turning now to  FIG. 47 , a side view of a portion of attachment elements of a power adapter and a corresponding control attachment that may be located behind a wall plate (shown in dashed lines), where the attachment element of the power adapted is on a back wall of the power adapter, is shown. More particularly, a flange  4702  extending from a projection  4704  enables an attachment element of the control attachment to be coupled to the flange. For example, a body portion  4706  of an attachment element of the control attachment comprises an attachment element actuator  4708  that moves about a hinge  4709  so that an attachment element  4710  having a projection  4712  with beveled edges can engage with the flange  4702  (i.e. be positioned behind the flange  4702  to secure the control attachment to the power adapter). For example, a user of the control attachment can move the projection  4712  using the attachment element actuator  4708  to cause the attachment element  4710  to rotate and the projection  4712  to disengage from the flange  4702 . The wall plate can then be attached, covering the attachment element of the control attachment. 
     Turning now to  FIG. 48 , another side view of a portion of an attachment element of a power adapter and a corresponding control attachment that may be located behind a wall plate (shown in dashed lines), where the attachment element of the power adapted is on a side wall of the power adapter, is shown. According to the implementation of  FIG. 48 , a body portion  4802  comprises an attachment element actuator  4804  that is movable by way of a leaf spring portion  4806 . When the attachment element actuator  4804  is moved away from the top of the wall  1502  of the control attachment, a projection  4808  having beveled edges is removed from a recess  4810  in an end portion  4812  of the power adapter, enabling the control attachment  104  to be removed from the power adapter  102 . As is apparent from  FIGS. 47 and 48 , the wall plate, as shown in dashed lines, would have to be removed to be able to access the attachment elements and therefore remove or detach the control attachment from the power adapter. 
     However, according to the implementation of  FIG. 49 , which shows a side view of a portion of attachment elements of a power adapter and a corresponding control attachment that may be accessible through a recess in a wall plate, the control attachment can be removed without removing the wall plate (shown in dashed lines). More particularly, an attachment element  4901  is movable within the control attachment, and can be moved so that the control attachment clears an end wall  4902  of the control attachment, allowing the control attachment to be removed with the wall plate in place. The control attachment comprises a projection  4903  that extends through an opening  4904  in the end wall  4902 , and extends to a terminal end  4905  that is adapted to being received by the attachment element of the power adapter (shown here by way of example as a recess  4810  in the side wall of recess  1503 ) of the power adapter. The actuator element  4901  is movable within a recess  4908 . A rod  4910  is configured to receive a spring  4912 , where the rod extends into a shaft  4914  of the attachment element  4901 . 
     As can be seen in  FIG. 49 , the spring loaded arrangement comprising the attachment element  4901 , the rod  4910  and spring  4912  enable both securing the control attachment to the power adapter and allowing the control attachment to be removed with the wall plate in place. That is, when the attachment element  4901  is moved towards the wall  4916  of the control attachment, compressing the spring, the terminal end  4905  would extend into the opening  4904 , allowing the control attachment to be removed by clearing the wall plate. 
     It should be noted that the embodiments o  FIGS. 48 and 49  use the same attachment element for the power adapter. That is, according to the implementations of  FIGS. 48 and 49  using the same power adapter, a user of the power adapter could install a control attachment that can be removed when the wall plate is in place, or could install a control attachment that can only be removed when the wall plate is removed. Such a feature provides flexibility for not only a user of the power adapter, but also for builders who may be installing the power adapters. That is, the builder can install a single power adapter in all locations for any type of structure, and install the desired control attachment that meets the needs of the user, including control attachments that can be removed with a wall plate in place, or only when the wall plate is removed. While examples of a control attachment having a leaf spring and having a helical spring are shown, it should be understood that any type of control attachment could be used. For example, control attachment arrangements could be implemented where a movable element on either the power adapter or the control attachment could be moved to couple an attachment element of the other of the power adapter or the control attachment. Alternatively, the control attachment may be coupled to the power adapter using only friction, particularly where a portion of control attachment is located behind the wall plate. 
     Various control attachments are shown in  FIGS. 50-64 . While the control attachments are shown by way of example, it should be understood that other control attachments could be implemented, or various features in the different control attachments could be combined or changed as desired. While specific examples of power adapter arrangements, including interfaces on both a power adapter and a control attachment as will be described in more detail below, are shown, it should be understood that both input elements and output elements may include a variety of features. Input devices may include any type of interface for providing information to or controlling, directly or indirectly, either the power adapter or the control attachment, where an input from the user can be received in any form, including acoustic, speech, or tactile input. Feedback elements may also be used to provide for interaction with a user as well. For example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback). 
     Turning first to  FIG. 50 , a rear view of a control attachment is shown, where a control circuit  5002 , which made comprise a wireless control circuit for example is included. A button  5004 , which may be a reset button or a button for pairing the control attachment with the power adapter, is included. While a single button is shown by way of example, it should be understood that multiple buttons could be included for performing different functions, such as a reset function or pairing function. An electrical interface  5006  may also be included to enable the communication of signals between the control attachment and a power adapter, as described above. 
     Examples of interface elements on the front of the control attachment are now shown. A front view of a power adapter of  FIG. 51  has a toggle element  5102 , such as a paddle toggle element for example. and a dimmer control element  5104  that is movable within a guide  5106 . An interface element  5108  could also be included, and may include an input elements such as a connector or an output element such as a status indicator, such as an LED. 
     Turning now to  FIG. 52 , a front view of a power adapter having a toggle element, a microphone and a speaker is shown. More particularly, a toggle button  5202  (also known as an on/off switch), which may have a status indicator  5204 , such as an LED light, are also included. The control attachment may also include a microphone  5206  and a speaker  5208 , enabling the control attachment to function as a smart speaker, such a smart speaker that may be adapted to operate according to a smart speaker protocol from Amazon, Inc. (using the Alexa brand protocol), Alphabet Inc. (using the Google Home brand protocol) or Apple, Inc. (using the Apple Home brand protocol) for example. 
     Turning now to  FIG. 53 , another front view of a power adapter having a toggle element and a dimmer control element is shown. According to the implementation of  FIG. 53 , a control attachment having dimmer functionality comprises a toggle element  5302  that may comprise a status LED  5304 . A movable dimmer controller  5306  that is movable within a guide  5308  is also included. 
     Turning now to  FIG. 54 , a front view of a power adapter having a toggle element and a sensor is shown. According to the implementation of  FIG. 54 , in addition to a toggle button  5202 , a sensor  5402  could be included on a front surface. A sensor as used herein may refer to, but is not limited to, a transducer providing an electrical output generated in dependence upon a magnitude of a measure and selected from the group comprising, but is not limited to, environmental sensors, biological sensors, chemical sensors, ambient environment sensors, position sensors, motion sensors, thermal sensors, infrared sensors, RFID sensors, a light sensor, a microphone, a camera, a thermometer, a humidity sensor, a smoke detector, and an air quality sensor, such as for carbon monoxide. 
     By way of example, the sensor  5402  could comprise a sensor for detection motion, such as a camera or a motion detector. Power could be applied to the load in response to the detection of motion, and the application of power could be overwritten by the toggle button  5202 . Alternatively, when a sensor comprising a camera is activated in response to motion, and the camera could record activities within range of the camera after motion is detected. 
     According to some implementations, for a control attachment configured to detect motion in a room, the sensor device can include one or more of passive sensors (e.g., passive infrared (PIR) sensor), active sensors (e.g., microwave (MW) sensor, ultrasonic sensors etc.) and hybrid sensors that include both passive and active sensor (e.g., Dual Technology Motion sensors). The passive sensors do not emit any energy and detect changes in energy of the surrounding. For example, a PIR sensor can detect infrared energy emitted by the human body (due to the temperature associated with the human body). In contrast, active sensors may emit electromagnetic or sonic pulses and detect the reflection thereof. For example, MW sensor emits a microwave pulse and detects its reflection. Hybrid sensors can include both active and passive sensors and therefore motion can be sensed both actively and passively (hybrid sensing). Hybrid sensing can have several advantages. For example, the probability of false positive detection of motion can be smaller in hybrid sensors compared to active/passive sensors. Data associated with a motion sensor can be used to indicate that motion has been detected in an area proximal to a load comprising a light, for example. The detected motion can be used to turn on a light controlled by the power adapter. According to some implementations, the power adapter may use the detected motion for providing a security feature, and may provide power to the load for a predetermined period of time, such as to deter an intruder or provide light outside a home in the event that an individual is detected outside the home. 
     Turning now to  FIG. 55 , a front view of a power adapter having a toggle element and a display is shown. More particularly, the control attachment of  FIG. 55  comprises a display  5502 . In addition to the microphone  5206  in the speaker  5208 , the display  5502  can provide additional information to a user. 
     Any of the exemplary control attachments of  FIGS. 50-55  may comprise a wireless circuit for receiving control signals or for acting as a WIFI extender or implemented as a WiFi mesh node in a WiFi mesh arrangement or a Bluetooth mesh node in a Bluetooth mesh arrangement. A control attachment may also be configured as a network extender or network repeater, as will be described in more detail below in reference to  FIG. 85 . 
     Turning now to  FIG. 56 , a front plan view of a control attachment having dedicated on and off switches and a sensor element that may be removable is shown. According to the implementation of  FIG. 56 , a power adapter having 2 toggle elements  5602  and  5604  (e.g. an on toggle switch on top and an off toggle switch on bottom) are movable within a gap  5606  and can be implemented with a sensor module  5608  (also known as an insert) that not only controls operation of a load controlled by a power adapter arrangement, but also may comprise a sensor element, such as one or more of a camera, motion detector or any sensor as described above beneficial to a home automation system. The outputs of the sensor may be used not only to control the application of power to the load or control some other operation of the load, but also can provide information to other elements of a system implementing a power adapter arrangement having a control attachment as shown in  FIG. 56 . 
     While an example of the control attachments of  FIGS. 56-64  describe a camera or motion detector by way of example, it should be understood that any sensors as described above could be used to transmit or receive information that may be beneficial in any aspect of a home automation system for example. According to some implementations, the sensor module  5608  may include a microphone and a speaker for detecting commands, questions, or other inputs and providing audio feedback, such as is commonly performed by smart speakers as mentioned above. The implementations of  FIGS. 56-64  provide another example of power adapter arrangement having a power adapter and a control attachment, where the control attachment is implemented as a modular element of the power adapter arrangement. 
     As shown in the side view of  FIG. 57 , actuator elements  5702  and  5704  are included to enable on and off functionality using the toggle elements  5602  and  5604 . A front and side view of the control attachment of  FIG. 56  is shown in  FIG. 58 . 
     Turning now to  FIG. 59 , a front and side view of the control attachment of  FIG. 56  without the removable sensor element shows contact the elements in a recess  5902 . As shown in  FIG. 59 , an electrical interface element  5904 , such as a connector or contact block having a plurality of contact elements  5906 , comprises contact elements provided on a rear surface of a recess adapted to receive the sensor module  5608 , which may be a sensor module for example. The contact elements may transfer data and other signals between the control attachment and the power adapter. That is, the contact elements may provide signals to circuits of the control attachment  104 , or may provide signals directly to the power adapter by way of contacts of the power adapter. 
     Turning now to  FIG. 60 , a rear view of the removable sensor module  5608  shows contact elements, and particularly a rear surface  6002  having an electrical interface element  6004  comprising contact elements  6006 . Signals can be transmitted between the sensor module  5608  and the power adapter. According to another implementation, an opening could be provided in the rear surface of the control attachment to enable the contact elements of the sensor module make a direct connection to corresponding contact elements of the power adapter as described above in reference to  FIG. 30 . 
     Turning now to  FIG. 61 , a front and side view of a sensor module  5608  having a removable screen  6102  is shown. In addition to a sensor  6106 , which may comprise a camera or motion detector for example, the removable sensor module may also comprise control elements adapted to control settings of the sensor module, as shown by way of example as a movable element  6108  that is movable in a guide  6110 . For example, the control element may control a sensitivity setting of a motion detector or camera or any other sensing element. The removable screen may be tinted or otherwise opaque to obscure the sensor and the control elements (if possible, without affecting the operation of the sensor). Attachment elements  6112  on the sides of the sensor module  5608  may be coupled to corresponding attachment elements  6114 . 
     Turning now to  FIG. 62 , a front and side view of a control attachment having a removable screen exposing a camera that is movable within a receiving element and shown directed to the left is shown. According to the implementations of  FIGS. 62 and 63 , the sensor element  6202  may be movable within an opening  6204  to improve the operation of the control attachment. For example, the power adapter arrangement may be placed in a location of a room where it may be beneficial when the sensor element, such as a camera or motion detector, is directed towards a certain location, such as towards a door or window for example. Even in the event that a sensor is used for detecting a wide area of a room, it may be beneficial to be able to adjust the direction or orientation of the sensor when the power adapter arrangement is on a wall switch location that may be on a side of a room rather than near the center of the room. A front and side view of a control attachment having a removable screen of  FIG. 62  shows the camera directed to the right in  FIG. 63 . 
     Turning now to  FIG. 64 , a front inside view of a control attachment having a movable screen to enable controlling a direction of a sensor, such as a camera, by moving the screen is shown. The implementation of  FIG. 64  enables the simple adjustment of the orientation or direction of a camera or sensor by adjusting the screen itself. That is, the sensor may be attached to the screen, where the screen can be rotated to provide a desired orientation. The screen may be tinted or opaque to obscure the presence of the sensor, as shown in  FIG. 64  where the sensor  6402  is lightly shaded to indicate the opaque nature of the screen. Because it may be difficult to see the direction or orientation of the sensor, a marker  6204  may be provided to enable the orientation of the sensor to easily be determined. While the screen as shown in  FIG. 64  enables a horizontal adjustment of the sensor, it should be understood that the screen could be adjusted in any orientation, where the screen may be a ball that swivels to provide both horizontal and vertical adjustments. 
     While various control attachments are shown, it should be understood that functionality of the control attachment may be distributed between the main portion of the control attachment and the removable sensor module, or completely located in the removable sensor module. 
     Groups of figures are now provided that show arrangements of interfaces, including for example electrical interfaces, mechanical interfaces, and electromechanical interfaces.  FIGS. 65-67  show a single interface for providing signals to the power adapter from the control attachment, where the single interface comprises an electrical interface for a basic control attachment having no dimming control, where on and off signals are generated in response to a user actuation.  FIGS. 68-70  also shows a single interface comprising an electrical interface, where a dimmer control signal may be generated in response to a user actuation on the control actuator or from a control circuit or control module.  FIGS. 71-73  show multiple interfaces, including at least a mechanical or electro-mechanical interface and an electrical interface, where an on or off signal may be generated in response to a user actuation of a toggle element of the control attachment, and other signals may be sent by way of an electrical interface.  FIGS. 74-76  also show multiple interfaces, but includes 2 mechanical or electro-mechanical interfaces and an electrical interface, where an on or off signal may be generated in response to a user actuation of a toggle element using the 2 mechanical or electro-mechanical interfaces, and other signals may be sent by way of an electrical interface. 
     Turning first to  FIGS. 65-67 ,  FIG. 65  shows a diagram of a control attachment having contact elements for electrically connecting contacts of an electrical interface. According to the implementation of  FIGS. 65-67 , a single toggle element is used, where a detection of a toggle actuation may be detected by the shorting of two contacts on a rear surface of the control attachment. In the event that the control attachment is used with a power adapter having dimmer functionality, but the control attachment does not have a dimmer control, the dimmer contact of the control attachment can be pulled high so that the power adapter controls the load at a maximum output. 
     An expanded view of the control attachment of  FIG. 65  comprises a rear housing  6502  and a front housing  6504  that are coupled together, and shows the outer surface of the rear housing  6502  and the inner surface of the front housing  6504 . For example, the front housing and the rear housing may be snapped together using attachment elements, glued together, thermally bonded, or attached using any type of attachment elements or attachment process. The rear housing  6506  comprises a dimmer control channel  6506  that provides an opening for allowing a dimmer control element to move within the dimmer control channel and control a corresponding dimmer control element of the power adapted, such as the dimmer control element  1526  of  FIG. 15 . 
     The rear housing also comprises an electrical interconnect element  6508 , which may be a connector or a contact block for example, having a plurality of contact elements adapted to make an electrical connection with corresponding contact elements of a power adapter. An exemplary arrangement of contact elements of the electrical interconnect element  6508  is shown in the dashed oval. More particularly, seven contact elements are shown, including a neutral contact element  6510  for providing a neutral voltage signal from the power adapter to the control attachment, a ground contact element  6512  for providing a ground voltage signal from the power adapter to the control attachment, an on/off (1/0) contact element  6514  for providing an on signal or an off signal from the control attachment to the power adapter, a power contact element  6516  for providing a low power voltage signal (e.g. approximately 3-5 volts) to the control attachment for providing power for electric circuits that may be implemented in the control attachment. 
     The on/off contact element  6514  and the power contact element  6516  may be positioned next to each other as a contact element pair  6518  so that they can be easily shorted, such as by a contact element on a toggle element of the control attachment. 
     The electrical interface element  6508  may also comprise a dimming contact element  6520  for receiving a dimmer control signal from a dimmer control circuit of the control attachment. According to the implementation of  FIG. 65 , which is a basic control attachment having no dimming capability, the dimming contact element  6520  is coupled to the power contact element  6516 , such as by a metal trace  5626  or jumper, to provide a high voltage signal to the corresponding dimming contact element of the power adapter. That is, if the power adapter has dimming capability, but the control attachment does not provide dimming control, it would be beneficial to pull the dimmer control signal high so that the full amount of power would be provided to the load. 
     Control contact elements  6522  and  6524  could also be included to transmit signals, such as control signals, between the control attachment and the power adapter. While specific contact elements are shown in the example electrical interconnect element  6508  of  FIG. 65 , it should be understood that fewer contact elements, additional contact elements, or different contact elements could be implemented. For example, any number of contact elements could be used for transmitting control signals or other data, as will be described in more detail below. 
     The front housing  6504 , the inside portion of which is shown in  FIG. 65 , could include various elements enabling the operation of the control attachment. More particularly, a toggle element  6532  is positioned within a gap  6534  and coupled to the front housing  6504  by hinge elements  6536 . A spring element  6538  enables the toggle element to be held in a first position or a second position, as describe above. That is, the spring element  6538  may be configured to hold the toggle element  6532  in either first position where the ground contact  6512  and contact element  6514  are not shorted, and a second position where the ground contact  6512  and contact element  6514  are shorted, as described above in reference to  FIGS. 24 and 25 . 
     More particularly, a contact element  6540  comprises a receiving element  6542  for receiving a contact portion  6544 , which comprises a conductive element. The contact portion  6544  may be used too short two of the contacts of the electrical interface  6508 , such as the ground contact  6512  and on/off contact element  6514  to enable providing an off signal to the power adapter (where an on signal is generated when the ground contact  6512  and on/off contact element  6514  are not shorted). Attachment elements  6546 , shown here by way of example on four corners of the front housing  6504 , may be used to attach the front house in  6504  to the rear housing  6502 . A dimmer control channel  6548  may also be included and is adapted to receive a movable dimmer control element  6550  for engaging with a corresponding dimmer control element of the power adapter, as described above in reference to  FIG. 15 . 
     Turning now to  FIG. 66 , a diagram shows an inner surface of a rear housing and an outer surface of the front housing of the control attachment of  FIG. 65 . More particularly, an inner surface  6602  comprises an area  6604  that is adapted to receive a circuit board or control module, as will be described in more detail below. In expanded view of a portion of the electrical interface  6508  is shown in the dashed oval, where a contact element  6606  and a contact element  6608  are provided to enable shorting of the context elements by the contact portion  6544 . Also shown in  FIG. 66  is the jumper  6526  that couples the dimming contact element  6520  to the power contact element  6516 , as described above. 
     It should be noted that the control attachment  104  of  FIGS. 65 and 66  are adaptable such that the same front housing and rear housing can be used in basic control attachments having no circuit board or circuit module as shown in  FIG. 66 , but can be adapted to retain a circuit board or circuit module, and therefore be implemented as a smart control attachment. For example, a circuit board or circuit module can be attached to the inner surface  6602  of the rear housing  6502 , where the front housing  6504  is then attached to the rear housing  6502 . Such an arrangement would achieve economies of scale for production of the control attachment and enabling different types of control attachments to be easily assembled and used in a power adapter arrangement. 
     Turning now to  FIG. 67 , a block diagram of a power adapter arrangement  6700  using a control attachment according to the implementation of  FIGS. 65 and 66  is shown, where the block diagram of  FIG. 67  shows an example of an electrical interface  6702  having connectors or contact blocks each having contact elements that enable the communication of signals between the control attachment in the power adapter. According to the implementation of  FIG. 67 , a single electrical interfaces provided, namely a first electrical interface  6702  associated with the control attachment and a second electrical interface  6704  associated with the power adapter. 
     A neutral contact element  6706  is adapted to be electrically coupled to neutral contact element  6510 . A ground contact element  6708  is adapted to be electrically coupled to ground contact element  6512 . A toggle contact element  6710  (e.g. on/off (1/0) contact element) is adapted to be electrically coupled to contact element  6514  (e.g. on/off (1/0) contact element). A power contact element  6712  (e.g. low voltage—approximately 5 volts) is adapted to be electrically coupled to a corresponding power contact  6516  to receive a low voltage reference power signal. A dimmer contact element  6714  is adapted to be electrically coupled to dimmer contact  6520 . A signal contact element  6716  (e.g. first control signal) is adapted to be electrically coupled to control contact element  6522  (e.g. for a first control signal). Signal contact element  6718  (e.g. second control signal) is adapted to be electrically coupled to control contact element  6524  (e.g. second control signal). While there are no electrical connections to some of the contact elements, such as the neutral and ground contact the elements or the signal contact elements (because the control attachment does not comprise a control circuit for example), other embodiments of the control attachment will include electrical connections to the contact elements of the control attachment to enable in operation of the control attachment, as will be described in more detail below. 
     An on or off signal is provided in response to a manual actuation, as shown by contact portion  6544  which could be used to short the contact element  6514  with the power contact element  6516 . Also shown in the arrangement of  FIG. 67  is the shorting of the dimmer contact  6520  to the power contact element  6516 . Each of the electrical interfaces  6702  and  6704  may comprise connectors having contact elements that are electrically coupled together when the control attachment is attached to the power adapter for example, or may just comprise contact elements that will make an electrical contact when the control attachment is attached to the power adapter. That is, it is not necessary that the electrical interfaces of the control attachment and power adapter are necessarily connectors that are adapted to mate with one another, but rather may just be contact elements that make electrical contacts when the control attachment is attached to the power adapter (e.g. the contact elements may comprise pogo pins in corresponding contact pads, or just contact pads that will make contact). 
     According to the implementation of  FIG. 67 , because the control attachment does not include dimmer functionality, but the power adapter does include dimmer functionality, the dimmer contact element  6520  is pulled high (i.e. coupled to the power contact element  6516 ) to receive the power signal as an input to the control circuit  118 . Therefore, the power adapter will apply full power to the load, and the only control signal for controlling power applied to the load would be the signal generated at the toggle contact  6710 . 
     Turning now to  FIG. 68 , a diagram of another control attachment having a switch and an electrical interface is shown. According to the implementation of  FIGS. 68-70 , dimmer functionality can also be provided on the control attachment. As shown in  FIG. 67 , a dimmer control channel  6802  is adapted to receive a dimmer control element  6804 . The dimmer control element  6804  is movable to select a dimmer setting and is adapted to be coupled to and to control a corresponding dimmer control element of a power adapter. 
     As shown in  FIG. 69 , which is a diagram showing an inner surface of a rear housing of the control attachment of  68 , the dimmer contact element  6520  is coupled to receive a dimmer control signal V dim  by way of a signal line  6902 . The V dim  signal may be generated by a circuit within control attachment. For example, a resistor divider circuit adapted to receive the power and neutral signals from the power adapter may be configured to generate the dimmer control signal V dim , which is provided back to the power adapter to control the power to the load, as will be described in reference to  FIG. 70 . Rather than controlling the motion of a corresponding dimmer control element of the power adapter, the V dim  value may be generated by movement of the dimmer control element  6804  which would control a resistance of a variable resistor and therefore the V dim  value. 
     Turning now to  FIG. 70 , a block diagram of a power adapter arrangement using a control attachment according to the implementation of  FIG. 68  is shown. According to the implementation of  FIG. 70 , a control circuit  7002  is coupled the power contact element  6516  and the ground contact  6512 , and is configured to provide the dimmer control voltage V dim  to the control circuit  118  by way of the contact element  6520 . The dimmer control voltage could be generated by the control circuit  7002  in response to one or both of a user actuation or a signal received from an external device, such as a smart phone or other computer device. For example, the control circuit  7002  could comprise a resistor divider circuit (i.e. a variable resistor) that generates the dimmer control voltage. Alternatively, or in addition to the resistor divider circuit, the control circuit  7002  may comprise a wireless transceiver that receives dimming signals from an external device. 
     Turning now to  FIGS. 71 and 72 , diagrams of another control attachment having an actuator element are shown. According to the implementation of  FIGS. 71-73 , an actuator element is adapted to control a switch in response to a manual actuator input, such as the pressing of a toggle element of the front housing of the control attachment. For example, the switch may be associated with the power adapter, and an actuator element  7102 , which may be a projection extending from the toggle element, can extend to or through a rear housing of the control attachment, such as through an aperture  7104 , to enable the actuation of a switch on the power adapter. While the implementation of  FIGS. 71-73  shows an arrangement where the actuator element would extend through a recess in the rear housing, it should be understood that the rear housing could be implemented as described in  FIGS. 81 and 82 , where a flexible projection may be used to make contact with a switch of the power adapter. That is, there may be one or more intervening elements between the actuator element  7102  and the switch on the power adapter, where the one or more intervening elements enable the actuator element  7102  to indirectly control the switch, such as to generate an on or off signal. 
     Turning now to  FIG. 73 , a block diagram of a power adapter arrangement using a control attachment according to the implementation of  FIG. 71  is shown. As shown in  FIG. 73 , 2 control interfaces are provided, including the electrical interfaces  6702  and  6704  as described above, and the interface between the control attachment and power adapter comprising the actuator element  7102  and the aperture  7104 , where the actuator element  7102  comprises a prong or projection for engaging, directly or indirectly, a switch  7302 . The switch may comprise an electro-mechanical switch (i.e. comprises a movable element to generate an electrical signal) used to generate an on or off signal detected by the detector  116  to control the power applied to the load. The control attachment may also comprise a control circuit  7304 , which may comprise a circuit board or circuit module that is attached to a housing of the control attachment. The control module may comprise a wireless transceiver for example, and may receive control signals (e.g. on or off signals and dimming signals) for controlling the operation of the power adapter. As will be described in more detail below in reference to  FIGS. 80 and 81 , the control circuit  7304  may be attached to the rear housing  6502 , enabling the front and rear housings of the control attachment to be used in basic control attachments, or advanced control attachments, such as a control attachment having a control module. 
     Turning now to  FIGS. 74 and 75 , a diagram of a control attachment having two actuator elements is shown. That is, rather than having a single actuator element for enabling generating on and off control signals, the control attachment of  FIGS. 74 and 75  include 2 actuator elements, where one may be used for generating an on signal and the other may be used for generating an off signal. For example, the actuator element  7102  may be used for generating an on signal in response to a pressing of a top portion of the toggle element, while an actuator element  7402  may be used for generating an off signal in response to a pressing of the bottom portion of the toggle element, where the actuator element  7402  may directly or indirectly engage with a second switch of the power adapter, such as through an aperture  7104  or by way of intermediate elements between the actuator element  7402  and the second switch  7602  as described in reference to  FIG. 76 . 
     Turning now to  FIG. 76 , a block diagram of a power adapter arrangement using a control attachment according to the implementation of  FIG. 74  is shown. As shown in  FIG. 76 , in addition to a switch  7302  that is adapted to receive a manual on signal in response to movement of the actuator element  7102 , a second switch  7602  may be implemented on the power adapter, where the second switch  7602  may be an electro-mechanical switch configured to receive a manual off signal in response to the movement of the actuator element  7402 . 
     Turning now to  FIG. 77 , a block diagram of a power adapter arrangement shows an example of a portion of the signal interface circuit  114 . More particularly, the signal interface circuit  114  of  FIG. 77  comprises circuit elements that enable the detection of both an on or off signal generated by a manual input or an on or off signal received by or generated by a control circuit. That is, the circuit of  FIG. 77  is intended to show a circuit that enables different types of controls signals being provided to the control attachment. The control attachment may comprise a switch  7702  having a switching element  7704  adapted to receive a manual input, where an output signal generated (e.g. a high output generated by the switch  7702  when the switch element  7704  is closed) In response to the manual input, a change-of-state (COS) circuit  7706  will detect when a manual input (e.g. a pressing of the toggle element) is received on the control attachment. An output of the COS circuit  7706  is provided to a first input of a selection circuit  7708 , shown here by way of as a multiplexer. A receiver circuit  7710 , having an antenna  7711 , is adapted to receive control signals, such as on and off signals or dimming signals, where the receiver circuit provides a control signal to a toggle logic circuit  7712 . That is, the toggle logic circuits  7712  is adapted to receive both the output of the COS circuit  7706  and an electronic input by way of the receiver  7710  (e.g. a signal indicating a change in the on or off state from the wireless receiver or a control circuit of the control attachment that may be applying a timing pattern for example). 
     A decoder circuit  7714  is configured to receive control signals, such as first and second control signals as shown, and generate an enable signal that is coupled to a control terminal  7716  of the multiplexer. That is, the decoder  7714  may determine the type of control attachment, and select the output of the COS circuit  7706  if the control attachment does not have having a control circuit or wireless receiver that may provide a toggle signal, or select the output of the toggle logic  7712  if the control attachment comprises a control circuit or wireless receiver that may provide a toggle signal. The toggle logic circuit will receive both the output of the COS circuit and the electronic input to generate the power control signal. An output of the selection circuit  7718  may comprise a power control signal that is provide to a register  7718 , shown here by way of example as a flip-flop, an output of which is provided to the power control circuit  105 . Because there is a single manual actuator, which may be implemented as described in reference to  FIGS. 22-25  and  FIGS. 65-73 , the state of the switch controlling power to the load may be changed whenever a toggle signal is detected, as will be described in more detail in reference to  FIG. 78 . 
     Turning now to  FIG. 78 , a flow diagram shows a method of implementing a power adapter arrangement having a single toggle switch. After the method is started at a block  7802 , it is determined whether the control attachment is authenticated at a block  7804 . If not, a low enable signal would be generated by the decoder  7714  at a block  7806 , thereby selecting the output of the COS circuit  7706  at a block  7808 . That is, if the control attachment is not authenticated (or is a basic control attachment that does not have a control circuit), the power adapter will still be able to receive control signals from the control attachment based upon manual inputs (such as a manual toggle detected by a switch of the power adapter). It is then determined whether a change of state has occurred in a block  7810 . If so, is change of state of the power control signal is performed, such as by the signal interface circuit  114 , at a block  7812 . Therefore, the control attachment will continue to operate as a “dumb” control attachment, where the power adapter responds to manual toggle signals (or manual dimmer control signals if both the power adapter and the control attachment are configured to receive manual dimmer control signals). 
     If the control attachment is authenticated at the block  7804 , a high enable signal is generated at a block  7814 , where both the manual inputs and the electronic inputs can be monitored at a block  7816 , such as by the toggle logic circuit  7712 . It is then determined whether a toggle signal is received at a block  7818 . If so, the power control signal may be changed to indicate a change of state of the power to the load at a block  7820 . It should be understood that detecting whether a toggle signal is received at the block  7818  may be based upon either the manual input detected by the COS circuit  7706 , or in response to a signal received by the receiver circuit  7710  (or based upon a toggle signal that is provided as an electronic input to the toggle logic  7712  based upon a timing pattern stored in the control attachment or stored in the power adapter). 
     For example, when using a control attachment having a toggle element that stays in a fixed position after the top or bottom of the tangle element is pressed, the toggle logic will determine that the user intends to change the state when the toggle element is pressed. That is, because a user will know that, even if the bottom of the title element is flush with the control attachment, the top of the toggle element must be pressed to change the state, as is commonly the case with the use of a 3 way switch for example. In contrast, when implementing a toggle element that returns to a steady state position (i.e. will always return to a center position whether the top of the toggle element or the bottom of the toggle element is pressed), the interface circuit may consider the pressing of the top of the toggle element to be an indication that the user intends to apply power to the load or the pressing of the bottom of the toggle element to be an indication that the user intends to turn off power to the load, as will be described in more detail below in reference to  FIGS. 79 and 80 . 
     Turning now to  FIG. 79 , another block diagram of a power adapter arrangement showing an example of an interface circuit is shown. According to the implementation of  FIG. 79, 2  separate switches are provided. More particularly, a switch  7902  has a switch element  7904  is that is adapted to receive an on manual input signal, such as the pressing of the top of a toggle element, and a switch  7906  has a switch element  7908  is that is adapted to receive an off manual input signal, such as the pressing of the bottom of the toggle element. Comparator logic  7912  may be implemented to detect a change of state that may be desired by a user. That is, the comparator logic may be used to detect whether power is currently being applied to a load, and whether the selection of the top of a toggle element is intended to change that state, or to detect whether power is not currently being applied to a load, and whether the selection of the bottom of a toggle element is intended to change that state, as will be described in more detail in reference to  FIG. 80 . That is, because the state of power applied to the load may be controlled by additional inputs other than the toggle element (e.g. an input associated with a wireless signal or a signal associated with a timing pattern generated by a control circuit of the control attachment or the power adapter), it may be necessary to determine whether a user actually intends to change the state of power applied to the load 
     Turning now to  FIG. 80 , a flow diagram shows a method of implementing a power adapter arrangement having two toggle switches of  FIG. 79 . After the process is started at a block  8002 , such as when the control attachment is attached to the power adapter, it is determined whether an on button is detected (e.g. pressing the top portion of the toggle element) at a block  8004 . If so, it is determined whether power is already applied to the device controlled by the switch (i.e. the load) at a block  8006 . If not, power is applied to the device controlled by the switch of the power adapter at a block  8008 . However, if power is already applied to the device controlled by the switch, the power adapter will continue to apply power to the switch at these step  8010 . Similarly, if the off button (e.g. pressing the bottom portion of the toggle element) is detected any block  8014 , it is determined whether power is already applied to the device controlled by the switch at a block  8016 . If so, power is removed from the device controlled by the switch of the power adapter at a block  8018 . Otherwise, the current state of no power being applied to the load by the switch is maintained at a blocked  8020 . 
     Turning now to  FIGS. 81 and 82 , expanded diagrams show an example of a control attachment, and more particularly, a flexible arrangement that allows common components (i.e. the same components over multiple devices) to be used in a range of different control attachments. The implementations of  FIGS. 81 and 82  show another aspect of a modular control attachment, where a circuit board or control module is implemented inside the control attachment. As will be described in more detail below, the control attachment of  FIGS. 81 and 82  may be implemented as a modular control attachment, where the control attachment may receive a circuit board or circuit module or a module comprising a connector or contact block. The circuit board or control module may also include or be coupled to a speaker and microphone to enable any aspect of a home automation system. 
     One beneficial aspect of the implementation of a control attachment of  FIGS. 81 and 82  is that a basic control attachment (i.e. a control attachment having no control circuit) can be implemented at a low cost, but also converted to an advanced control attachment having a variety of features. For example, in some cases, both the front and rear housing of the control attachment may be used for both basic and advanced control attachments. In other cases, the front housing may be different, such as in the case where a speaker and microphone is implemented in the control attachment, where an opening for the speaker and microphone are provided on the front housing. 
     A rear housing  8102  is adapted to be coupled to a front housing  8104 . The rear housing comprises attachment elements  8106 , shown here by way of example as an aperture that is adapted to receive a corresponding attachment element of the front housing  8104 . However, it should be understood that other types of attachment elements could be implemented, such as a flange that is adapted to receive a corresponding attachment element on the front housing  8104 . An opening  8108 , is included in the rear housing, and may comprise an intermediate actuator element. That is, because it may be beneficial to provide an intermediate actuator element so that the actuator element of the front housing does not need to extend so far to reach a switch of the power adapter, the intermediate actuator element may enable the actuator element of front housing two more easily control the switch of the power adapter. According to the implementation of  FIG. 81 , a flexible projection  8110  extends to an actuator element  8112 , which may be a prong for example. The flexible projection acts like a leaf spring, and will move in response to a movement of an actuator element of the front housing, such as in the actuator element on a toggle element. That is, when the actuator element of the front housing is moved towards the power adapter, the intermediate actuator element  8112  will also move toward the power adapter, and engage the switch of the power adapter. According to the implementation of  FIG. 81 , a second intermediate actuator element may also be in included, shown here by way of example as an actuator element positioned below the electrical interface  6508 . 
     The front housing  8104  comprises a plurality of attachment elements  8116 . According to the example of  FIG. 81 , the attachment elements  8116  comprise flanges that are adapted to be inserted into the corresponding attachment elements  8106 , which are shown as recesses before receiving the flanges. According to some implementations, the recess is could enable a user to depress the flanges of the attachment elements  8117  and remove the front housing. Such an arrangement would allow a user to replace the front housing to change the color of the control attachment (e.g. white or beige). According to other implementations, the attachment elements of the rear housing may receive the flanges of the front housing, but may not be accessible to the user on the outside of the control attachment. An inner surface  8118  of a toggle element that is movable within a gap  8120  using hinge elements  8122  comprises being plurality of spring elements  8124 , such as leaf springs as shown. The spring elements enable the toggle element to return to a steady state position, as described above in reference to  FIGS. 18-21  for example. While leaf springs are shown by way of example, it should be understood that any type of spring could be used. Actuator elements  8126  are provided to control the application of power applied by a power adapter to a load, and may directly engage a switch of the power adapter or may engage an intermediate actuator as described above. 
     The diagram of  FIG. 82  shows an inner surface of a rear housing of the control attachment, and particularly an arrangement that allows flexibility in implementing different features in a control attachment, such as implementing a rear housing that is adapted to receive a control circuit on a circuit board, or a control module comprising a module having a circuit board, as will be described in more detail below. An inner surface  8204  comprises wall portions  8206  defining the inner surface in a recess of the rear housing. Attachment elements  8210 , such as an aperture or a flange adapted to receive a corresponding attachment elements, are shown. The rear housing may also comprise a receiving element  8212 , as shown here by way of example as having walls  8214  for defining a recess adapted to receive a circuit board or circuit module configured to implement advanced features of the power adapter arrangement. Attachment elements  8216  of the walls  8214  enable receiving corresponding attachment elements of a circuit board, a control module having a circuit board, or a cover adapted to enclose a circuit board or control module. According to the implementation of  FIG. 82 , attachment elements  8218  are shown here by way of example are threaded portions for receiving corresponding screws to attach a circuit board  8220  to the rear housing using holes  8222 . According to some implementations, the circuit board may comprise a contact  8224  adapted to receive a corresponding contact on a cover for the circuit board that may have a printed antenna element. More particularly, a cover  8230  may be adapted to attach to the receiving element  8212 , such as by using corresponding attachment elements  8232  that are attached to the attachment elements  8216 . The contact element  8224  may be coupled by a contact  8234  to an antenna element  8236 , which may be a wire for example, or may be a printed antenna on the cover  8230 . Rather than having a circuit board and cover, a control module may be snapped into the receiving element  8212 . 
     Turning now to  FIG. 83 , a block diagram of a circuit for testing the connections associated with a power adapter when the contacts of the power adapter are electrically connected to wires providing power to the power adapter is shown. The test circuit  8301  comprises circuits for comparing voltages at the contacts of the power adapter (e.g. contact elements  1516  and  1520  of  FIG. 5 ). According to the implementation of  FIG. 83 , one or more comparator circuits are used to compare voltages at the contacts that receive reference voltages as shown to determine whether the power adapter is improperly wired or not functioning properly. 
     According to one implementation, a first comparator circuit  8302  is coupled to the load contact (to receive the voltage on the load contact) and coupled to the neutral contact (to receive the voltage on the neutral contact). A second comparator circuit  8304  is coupled to the load contact (to receive the voltage on the load contact) and coupled to the ground contact (to receive the voltage on the ground contact). A third comparator circuit  8306  is coupled to the neutral contact (to receive the voltage on the neutral contact) and coupled to the ground contact (to receive the voltage on the ground contact). A fourth comparator circuit  8308  is coupled to the ground contact (to receive the voltage on the ground contact) and the power contact (to receive a voltage associated with the earth ground). A comparator circuit  8310  may also be implemented to compare the neutral contact to power. The switch  8311  may be controlled by control signals from the control circuit  8312  by way of a control line  8314 , while signal lines  8315  maybe be provided from the control circuit  8312  to the control circuit  8316 . It should be noted that the power contact of the power adapter receiving power signal from the building system could also be monitored and compared to other signals. An improper wiring of the power contact of the power adapter receiving power signal from the building system may be less important in terms of safety, and any issue related to a wiring error associated with the power contact may have more to do with an operating error. In contrast, a wiring error where power is coupled to a ground or neutral contact or a ground or neutral contact is not properly wired may lead to a serious safety condition. Further, monitoring of the load contact would not only provide voltage information, but would also provide information related to the operation of the power adapter arrangement. However, it should also be understood that both the power contact (i.e. line voltage) and the load contact could be monitored. It should be noted that the voltage values detected at the contact elements of the power adapter from the wires of a junction box may be high voltage values, and can be converted to lower value voltages (representing a level of the detected voltage, but in a lower voltage range) for comparison, particularly when any comparison is performed in the control attachment. 
     The comparator circuits  8302 - 8310  may comprise voltage comparators for example. According to other implementations, the comparator circuits may be adapted to detect currents within the power adapter when the power adapter is operating to detect abnormal operating conditions of the power adapter or a device powered by the power adapter, or detect power usage by a device powered by the power adapter. While comparators  8302 - 8310  are shown by way of example, it should be understood that additional comparators could be implemented to compare any voltage detected at various input nodes (e.g. power, neutral, ground, 3-way, etc.) in the power adapter and generate information that may be beneficial in determining whether a power adapter is installed correctly (e.g. is correctly wired) or is operating correctly (e.g. is not a defective product). While multiple comparator circuits are shown, it should be understood that a single comparator could be implemented, where the nodes (e.g. load, neutral, ground and power) could be selectively coupled to a comparator. For example, a switch  8311  coupled to receive voltages at various nodes could enable the selection of inputs to a single comparator circuit. 
     A control circuit  8312  may be coupled to the comparators  8302 - 8310  to receive output signals generated by the comparators indicating the results of the various comparisons. By way of example, the comparator circuits could generate a difference in the voltages on the lines coupled to the comparator, or could provide a result representative of the difference in voltages (such as for high voltage signals). While the control circuit  8312  may be configured to process information and communicate test results to reduce the number of signal lines to a control circuit  8316  of the control attachment  104 , the outputs of the comparator circuit could be provided directly to the control attachment  1004 . For example, the control circuit  8312  could receive detected voltages values, where the control circuit  8316  could determine an improper wiring condition based upon the detected voltage values and provide a message on the display  8328 . 
     It should be noted that a testing function can include circuits that are distributed between the power adapter and the module. That is, while voltages associated with the power adapter could be detected by a circuit in the power adapter, such as by one or more voltage detectors, other processing to detect improper wiring or a defective power adapter or module may be performed in the power adapter (such as by using control circuit  8312  of the power adapter), by the module (using control circuit  8316  of the module), or distributed between the power adapter and the module. 
     The control circuit  8312  may not only receive signals from the comparators, but may also provide control signals that enable the testing of the power adapter to the  8316 . According to one implementation, a test of the connections of the power adapter may be performed whenever a module is attached to a power adapter. For example, the control circuit of one the power adapter and the control attachment may detect the connection of the control attachment to the power adapter, and initiate a testing of the connections of the power adapter. For example, in the implementation of  FIG. 83 , the control circuit  8316  may detect one or more outputs of the control circuit  8312  to determine whether the power adapter is improperly wired or is defective. Alternatively or in addition to an automatic testing initiated by one of the control circuit  8312  or the control circuit  8316  (such as when a control attachment is attached or a periodic test), a user interface element  8318 , shown here as a button by way of example, may be used to initiate a testing of the connections by a test circuit of the power adapter or the control attachment. That is, a user may desire that a check be performed to make sure that the power adapter is properly wired and operating correctly or the power adapter and control attachment are operating correctly. The test results can then be provided to the user. By way of example, the test results can be displayed on a display  8328 . 
     Turning now to  FIG. 84 , another block diagram of a circuit for testing the connections associated with a power adapter when the contacts are electrically connected to wires providing power to the power adapter is shown. According to the implementation of  FIG. 84 , a switching circuit  8402  coupled to the various nodes (e.g. contact elements  1516  and  1520  of  FIG. 5 ) enables the connection of the nodes to single voltage detector  8404  that can provide a measured voltage value to the control circuit  8312  (or directly to the control circuit  8316  as described above). The voltage detector can sequentially detect voltages at different nodes to determine whether the power adapter is improperly wired or not operating properly. While a single voltage detector is shown, it should be understood that multiple voltage detectors could be implemented. Also, while voltages are shown as being detected, it should be understood that currents be detected instead of voltages or in addition to voltages. 
     There are different conditions that can be detected to determine whether a power adapter is wired properly and working properly. When a power adapter is wired correctly, the line (i.e. power wire) is connected to a power contact of the power adapter (which may be detected at the power or load contact), the neutral line is connected to the neutral contact, and ground line is connected to the ground contact. However, the ground contact may be improperly connected to the neutral contact to form an improper ground connection, commonly called a bootleg ground. A particularly dangerous condition can exist when there is not only an improper connection of the ground contact to the neutral wire, but the line (power) and neutral connections are reversed, commonly known as a reverse polarity bootleg ground. What makes this improper wiring condition particularly dangerous is that the ground connection, which is improperly connected to a power line, may make portions of the power adapter have a high voltage electrical charge and may lead to an electrical shock or an electrocution of the user of the power adapter. 
     In order to detect the improper wiring of a power adapter, it is necessary to use a voltmeter, where the voltage between ground and neutral (as detected by a voltage detector and comparator) will be very close to zero. However, to detect a reverse polarity bootleg ground connection, it is necessary to connect a prong of a voltmeter to earth ground, and test each of the power, neutral and ground contacts with respect to earth ground. Because a recess adapted to receive a control attachment provides access to measurements associated not only with the power, neutral and ground terminals of an outlet, but also an earth ground (by determining a voltage associated with the power adapter, such as by determining the voltage of the flange electrically connected to the junction box, which should be at earth ground), it is possible to detect improper wiring conditions. That is, a test circuit could not only be coupled to the power (or load), neutral and ground contacts to detect voltages at those contacts, but could also detect a voltage of earth ground to use as a reference voltage. Because a junction box receiving the power adapter is at earth ground, the voltage at earth ground can be detected by determining the voltage of the junction box, such as by determining the voltage of a flange of the power adapter connected to the junction box. A test circuit internal to the power adapter could detect the voltage at earth ground by providing a conductor coupled to a flange of the power adapter (e.g. flange  1520  of  FIG. 15  that is electrically coupled to the junction box and therefore at earth ground). It should be understood that test circuits could be implemented in power adapters receiving any type of power adapter modules as described above. 
     Turning now to  FIG. 85 , a block diagram of a system having a plurality of power adapters implementing different communication protocols is shown. The system of  FIG. 85  shows power control devices that can be used to control a variety of elements in the system. According to the implementation of  FIG. 85 , a single central controller  8502  can provide multimodal control of different control devices or different sets of control devices. The control devices could be power adapter arrangements as set forth above or other suitable control devices that could be coupled to control a device or integrated in the device to control the device. The single controller  8502  could be for example a smart phone, a tablet computer or any other computer or device enabling a wireless connection to multiple control modules by way of different wireless protocols as described above. For example, the controller  8502  could communicate with a first set  8504  of control devices, a second set  8506  of control devices, and a third set of control devices  8508 . The first set of control devices may include an outdoor light  8510 , an indoor light  8512 , and a water heater  8514  that are controlled by way of a first wireless connection  8516 . As shown in  FIG. 85 , the central controller  8502  is directly in communication with devices of the first set of devices using a short range communication protocol. That is, there is no intervening control element, such as a base station or wireless hub, that receives control signals from the central controller and provides control signals to the control devices. By way of example, a first set of devices could communicate with central controller by way of a Bluetooth connection, where the devices could be implemented in a Bluetooth mesh network, or a near field communication (NFC) link. The short range communication protocol may be accessible at a distance of approximately 100 feet for example. The devices of a first set could be implemented in different locations, and could include for example an indoor device, an outdoor device, a device controlling a specific device, such as a water heater or an under-cabinet lighting fixture. The first set of control devices could be associated devices that a user does not wish to access remotely, or a device about which the user may have security concerns and may not want to have controlled by a lower security protocol, such as an IEEE 802.11 communication protocol, also known as WiFi. The first communication protocol may therefore be a local communication protocol, and more particularly a direct local communication protocol. 
     The second set  8506  of control devices may be controlled by way of a second connection, which may be for example a network. The second set of devices  8606  could include devices that are controlled by the controller using a local area network, including a base station or wireless hub that communicates with a plurality of devices. By way of example, the local area network (LAN) could be a WiFi network including a WiFi base  8518  enabling communication links  8520  and  8521 . The local area network could also be accessible by a wide area network such as a cellular network to enable remote access to devices. The WiFi network could be any network implementing any IEEE 802.11 standard for example. The second set of appliances controlled by the devices could include the types of devices that a user may desire to access from a remote location, such as an indoor light  8522 , a curling iron  8524 , a coffee machine  8526 , a particular lamp, or a wireless-controlled door lock  8528 . That is, these devices may be devices that a user may wish to check to make sure that they have been turned off, or the types of devices that a user may wish to turn on while they are away. 
     The third set of devices  8508  could be controlled by another wireless base  8530  enabling communication links  8532  and  8534  to control other specialty devices such as pool controls or specialty lighting. According to the example of  FIG. 85 , an outdoor light  8536 , and indoor light  8538 , and a pool heater  8340  could be controlled by the wireless base  8530 . The wireless base  8330  could be a Z-Wave or a ZigBee controller for example. Therefore, a short range communication link or a WiFi connection of system  8500  could be integrated with an existing system employed by the user, such as a Z-Wave or ZigBee system for example. 
     One beneficial aspect of the system is that a single controller can control a plurality of devices using a plurality of different connections implementing different wireless communication protocols and having different capabilities. The controller can also access a server  8342  by way of one of the elements of the system, such as the WiFi base  8318 . The server may receive information from or provide information to the server  8342 . For example, the server may receive information from the central controller related to the state or operation of various devices on the system  5600 , or may provide information or data enabling the operation of the devices on the system  8300 . For example, the information can be related to analysis of the devices implemented on the system, or could be information of interest to a user, such as news or weather, which could be displayed on a device of the system. By implementing a variety of different communication protocols, it is possible to implement the different devices with the most suitable communication protocol from a single controller. For example, while a WiFi enables remote access, it may also be more susceptible to hacking or other security issues. However, a Bluetooth or NFC connection, because of its short-range nature, may have fewer hacking or security issues, but is generally not remotely accessible. While different types of devices are described, the system of  FIG. 85  could be implemented a gas meter, a sprinkler, a fire alarm, a thermostat, a street light, fitness equipment, a hot water tank, a heater, or a boiler with any type of device for home security, home automation, or internet-of-things (IoT) device). The system could also include devices that are incorporated in or improve networks, such as wireless communication networks. For example, the devices could include a network extender (e.g. provide greater range for the network) or be a node for a mesh network, such as a WiFi network or Bluetooth network. 
     According to some implementations, authentication could be achieved by a shared secret key authentication, where both the power adapter and the control attachment have a shared key that is used to exchange information to authenticate the power adapter. In cryptography, a shared secret key is a piece of data such as a random number, known only to the parties involved, in a secure communication. The shared secret key would be pre-shared (i.e. stored in a memory of both the power adapter and the control attachment. The shared secret can be fed to a key derivation function to produce one or more keys to use for encryption of messages. To make unique communication link between the power adapter and the control attachment and unique message keys, the shared secret key may be combined with the unique ID. While shared secret key is provided as one example of an authentication technique for authorizing a control module to operate with a power adapter, it should be understood that any type of authentication could be used. 
     Control attachments may be multifunctional, and where one function may be used for the benefit of another function. For example, a control attachment having wireless capability may have be used to provide information to a user associated with another function of the control attachment. For example, a control attachment having a WiFi wireless control circuit may send a level of an expendable material used in the module, such as a fragrance in a refillable module or a replaceable module (an empty module having a fragrance can be removed from the control attachment and replaced with a new module having the fragrance) that may be used to provide a scent to a room to a user of the control module. 
     Turning now to  FIG. 86 , a method of controlling a power adapter to provide power a load is described. The method of  FIG. 86  as well as the method of  FIG. 87  described below may be implemented using any of the systems or circuits as described above. It should be understood that additional elements could be implemented in the method based upon the systems and methods as described above. 
     More particularly, a first contact element of a first plurality of contact elements is configured to receive electrical power at a block  8602 . A second contact element of a first plurality of contact elements is configured to provide power to a load at a block  8604 . A first interface comprising a second plurality of contact elements is configured to provide one or more reference voltages to a control attachment, wherein the first interface comprises an electrical interface at a block  8606 . A second interface comprising a switch is configured to control power applied to a load in response to a manual actuation of the control attachment at a block  8608 . 
     Turning now to  FIG. 87 , a method of controlling the application of power to a load using a control attachment is described. More particularly, a toggle element is provided on the control attachment, wherein the toggle element is movable in response to a manual actuation at a block  8702 . A first interface comprising an actuator element adapted to make contact with a power adapter is provided, wherein the actuator element is adapted to engage with a switch of the power adapter in response to the manual actuation at a block  8704 . An attachment element is provided to attach the control attachment to the power adapter at a block  8706 . The control of power applied to the load by the power adapter is enabled in response to a manual actuation of the toggle element at a block  8708 . While the elements of  FIG. 86 , which is directed to a method of controlling a power adapter, and  FIG. 87 , which is directed to controlling the application of power to a load, are shown separately, it should be understood the elements of the figures could be implemented together to implement a power adapter arrangement as described above. 
     Power is distributed in an electrical system of a building through different branches of the electrical system. More particularly, a load center receives power for a building and enables the distribution of power to groups of loads. Typically, each load of the groups of loads may comprise multiple outlets and switches. For example, one group of loads may comprise all of the outlets and switches associated with a kitchen, and a second group of loads may comprise all of the outlets and switches associated with a family room. Outlets and switches are wired in the electrical system at a location that is associated with a group of loads. For power adapters comprising outlets (e.g. typically having 2 outlets adapted to receive corresponding plugs), the loads comprise the devices that are plugged into the outlet. Power adapters comprising switches may control one or more devices receiving power by way of the power adapter. For example, a load controlled by a power adapter comprising a switch may comprise a light in the kitchen. In some instances, the power adapter comprising a switch may control multiple devices, such as multiple lights in kitchen. Power adapters comprising switches may also control outlets, such as two switched outlets in a living room for example. 
     One primary function of a load center is to distribute power to different groups of loads, and provide over-current protection (which may indicate a short circuit or some other electrical anomaly) for the different groups of loads. One conventional way of providing over-current protection is the use of a fuse for each group of loads. By way of example, a load center may distribute power to 20 groups of loads, where 20 fuses may be used to provide over-current protection to the corresponding 20 groups of loads. Over-current protection is beneficial to prevent personal injury to an individual using an outlet or switch (e.g. shock or electrocution) or a fire in the event of too much current flowing to the load. While fuses need to be replaced in the event that too much current causes the fuse to blow, circuit breakers are more commonly used because they do not need to be replaced, and can be reset in the event that the circuit breaker is tripped. 
     However, there is cost associated with either fuses or circuit breakers to provide over-current protection, and providing a fuse or circuit breaker for each power adapter (e.g. a power adapter comprising an outlet or a power adapter comprising switch). Providing over-voltage protection for each power adapter in a building would be cost prohibitive. Load centers provide a benefit of grouping loads for reducing the number of over-current protection devices in a building, such as  20  circuit breakers rather than providing over-current protection for each of a larger number of switches or outlets in an average residence, which may be more than 100 outlets and switches for example. Load centers also provide convenience to switch off power to a section of a residence having power adapters associated with multiple loads. For example, if a homeowner is replacing a switch in the kitchen, it is possible to turn off power to all of the power adapters in the kitchen to safely replace one of the power adapters (i.e. without having to turn off power to the entire residence, such as by way of main switch which may be provided in the load center for controlling the application of power to each of the circuit breakers and therefore all of the power adapters receiving power in the residence). 
     While load centers provide a benefit of reducing cost for over-current protection and disabling power to a group of power adapters for convenience, where circuit breakers are located in the load center and are not used for controlling to power to a single load, power adapters are distributed beyond the load center to provide switching capability to one or more loads. As power adapters continue to advance, it is beneficial to provide flexibility in power adapters without increasing the cost in a way that would make it cost prohibitive to install the more advanced power adapters. Different power switching devices, such as relays or TRIACs may have different advantages and disadvantages related to cost, size and switching characteristics. Power adapters may also provide flexibility in the application of power applied to a load and may be used to provide power to other elements that are dependent upon the location of the power adapter, such as sensor capability for use in a security system or a smart home for example. Providing flexibility in power adapters for implementing different power switching devices is beneficial, as will be described in more detail below. 
       FIGS. 88 and 89  show an implementation of a power adapter having a removable power switching module to enable a user of the power adapter to select a power switching functionality of the switching module. As described above, there are different types of power switching, including conventional on/off power switching and power switching with dimming control. However, there are different costs associated with the different functionality. For example, as described above, conventional on/off power switching may be achieved by a relay, which may be less expensive than a power adapter having dimming functionality, which may require a more expensive device such as a TRIAC. Because a builder or homeowner may not be certain where it may be necessary to have dimming functionality, it may be costly to install power adapters that have dimming capability and that are adapted to receive control attachments everywhere in a new construction. However, it is also costly and time consuming for a homeowner to later change a power adapter that does not have dimming capability to a power adapter that has dimming capability. That is, not only would the homeowner have to incur the cost of a complete power adapter, but the homeowner may also have to incur the cost of hiring an electrician or expend the time to replace the power adapter. According to the implementation of  FIGS. 88 and 89 , the homeowner may be required to only replace the power switching module, thereby reducing both hardware cost and installation time and/or expense. 
     While a user should turn off the power to the power switching module as described in reference to  FIGS. 88 and 89  when replacing the power switching module, additional protective measures can be provided to increase the safety of implementing a power adapter having the power switching module. The contact elements of the power adapter can be implemented as tamper resistant contact elements to prevent a user from inadvertently making contact with a high voltage contact of the power adapter if the user failed to turn off the power to the power switching module. For example, a shutter mechanism may be implemented with the contact elements to block access to the contact elements unless a power switching module is inserted. Further, the removable power switching module can be implemented as a child proof module, such as by requiring that the module be screwed in to the power adapter. Such a power switching module being screwed in would not only prevent a child from making contact with a high voltage contact, but also prevent an adult from inadvertently making contact with a high voltage contact. That is, the power switching module that is screwed into the power adapter could only be removed by taking an active step of removing the screws, but not by an inadvertent bumping or other contact with the power switching module. 
     Turning first to  FIG. 88 , a block diagram of a power adapter having a removable power switching module is shown. The implementation of  FIG. 88  may be based upon the power adapter of  FIG. 15  for example. The power adapter of  FIG. 88  is configured to receive a control attachment as described above (e.g. a control attachment as described in  FIG. 17-21 or 24-34 ) and provide a power switching function. A removable power switching module  8802  is attached to the power adapter  102  by attachment elements  8804 , shown here by way of example as a flange adapted to receive a screw. However, it should be understood that any type of attachment element could be employed, including attachment elements that enable the power switching module to be easily attached or detached (as described above in reference to attaching a control attachment to a power adapter) of different types of attachment elements that provide safety to a user (i.e. prevent an inadvertent removal of the power switching module) 
     As shown in  FIG. 89 , the removable power switching module  8802  may be removed from the power adapter, where a recess  8902  having contact elements  8904  is exposed. Contact elements  8906  of the removable power switching module (shown in dashed lines as extending from the rear of the removable power switching module) are configured to be inserted into and make electrical connections with the contact elements  8904  in the recess of the power adapter. The power switching module  8802  is configured to provide a current path for power to be applied to a load, and may be controlled in response to a signal provided to the power switching module, such as from a control attachment by way of a contact element  1514  of the electrical interface  1512 . 
     Any number of contact elements  8906  could be implemented, and may depend upon the functionality of the power switching module. However, the number of contact elements  8904  should be at least as large as the number of corresponding contact elements of any power switching module  8802  that may be used. That is, it is possible that different power switching modules  8802  may have different numbers of contact elements based upon the functionality, but the number of contact elements  8906  should be as least as great as the number of contact elements  8906  of any power switching module. The contact elements  8906  should include as many contact elements as necessary to implement the features of power switching module. For example, more contact elements may be required for a power switching module having dimming functionality than a power switching module that only provides on/off capability. According to one implementation, the power switching module could be a simple power switch, such as a relay, where one of the contact elements  8906  is coupled to receive power and another contact element of the contact elements  8906  is coupled to the load. That is, two contact elements could be used for implementing the current path for enabling power to be applied to the load, where the power may be applied to the load based upon the state of the relay. The state of the relay (e.g. opened or closed) could be controlled by a third contact. For example, the relay may be switched in response to a signal provided to a third contact element of the contact elements  8906  comprising a control terminal (i.e. a signal applied to the control terminal can be used to close the relay to apply power to the load or open the relay to cut off the power applied to the load). 
     According to another implementation, the power switching module could comprise a TRIAC or some other device enabling a dimming operation, where one or more contact elements power switching module can be used for switching on or off power and controlling dimming. For example, the dimmer control circuit  310  as shown in a  FIG. 6  could be implemented in a power switching module  8802 . According to the dimmer control circuit  310 , four contact elements may be necessary. In addition to the two contact elements used to provide a current path enabling power to be applied to a load, two additional contact elements may be used for both controlling the switching of power (i.e. on and off functionality) and for providing dimming control. That is, a third contact element can be used for controlling the switch  606  of  FIG. 6  to control on and off functionality and a fourth contact can be used for controlling the resistance value of the resistor  612  to provide dimming control. 
     As can be seen, the power adapter of  FIGS. 88 and 89  enables a single power adapter to be installed and easily converted from a lower-cost power adapter (e.g. having a relay) to a higher-cost power adapter (e.g. having a TRIAC). Such a conversion can be achieved without the need for an electrician and with reduced time and expense. That is, a user can simply turn off the power and safely replace the power switching module, without having to buy a complete power adapter and without having to attach the power adapter to wires of an electrical system. The user can also replace the control attachment to include dimming features. That is, while the user would not be able to use dimming features with a power adapter only having a relay for example, the user would be able to use a larger variety of control attachments (e.g. control attachments having dimming capability) by replacing a power switching module with a power switching module having dimming capability. While contact elements of the power adapter are on a surface of a recess for receiving a control attachment, it should be understood that the power adapter may be implemented with a surface that is not in a recess and flush with the control attachment when the control attachment is attached to the power adapter. 
     Turning now to  FIG. 90 , a block diagram of a power adapter arrangement having a power adapter and a control attachment comprising one or more outlets is shown. More particularly, the power adapter arrangement  9000  comprises a power adapter  9002  and a control attachment  9004 . The power adapter  9002  comprises a signal interface  9008  adapted to receive a ground signal at an input  9010 , a neutral signal at an input  9012  and a power input at an input  9014 . The ground, neutral and power inputs are configured to provide current paths as described above to provide power to a load attached to an outlet of the control attachment. Outputs of the signal interface (which may filter signals for example) are provided to an electrical interface  9020 . 
     The electrical interface  9020  is adapted to be coupled to a corresponding electrical interface  9022 . More particularly, a contact element  9026  is coupled to a corresponding contact element  9028 , a contact element  9030  is coupled to a corresponding contact element  9032 , and a contact element  9034  is coupled to a corresponding contact element  9036 . While specific contact elements are shown, it should be understood that other contact elements could be provided, including contact elements for transmitting low power signals between the power adapter and the control attachment. 
     The control attachment  9004  comprises an interface circuit  9038  having a control circuit  9040  that is configured to control a power control circuit  9042 . The interface circuit  9038  comprises elements for enabling a user to interact with the control attachment, directly or indirectly. For example, an actuator  9044  may be coupled to receive a user interface input at an input  9046 . The actuator  9044  could be any type of user interface actuator, such as a button or some other movable element for example. The control attachment may also comprise an interface circuit  9052  configured to receive communication signals by way of an input  9050 . The communication signals may be wireless communication signals received, directly or indirectly, from a remote device. According to some implementations, the remote device could be a dedicated remote device, such as a radio frequency (RF) device that is provided to communicate with the control attachment. According to other implementations, the remote device could be a computer device. For example, the computer device could be a portable device, such as a smart phone, tablet or some other portable computer. The remote device could also be a fixed computer, such as a control terminal attached to a wall and may be associated with a security system for example. The interface circuit  9052  may be configured to transmit and receive communication signals according to any communication protocol as described above, including any wireless communication protocol. The interface circuit  9052  may also comprise a feedback circuit  9053  configured to send a feedback signal by way of an output  9054 . The feedback signal may be any type of audio, visual, or tactile feedback signal that may provide information to a user related to the state or operation of the power adapter arrangement, including for example an on/off state of power applied to a load or any state or operation of the control attachment. 
     As can be seen in  FIG. 90 , the power control circuit  9042  receives the power signal, which is a high voltage power signal as described above, and selectively provides the power signal to the load  9062  in response to a control signal from the control circuit  9040 . The power control circuit may be implemented as a power control circuit as described above in reference to  FIGS. 1-5 , and may include a relay that enables on and off functionality (i.e. applying power to or cutting off power to the load) or a dimming control circuit that not only enables on and off functionality, but also enables dimming functionality. The control signal (generated by the control circuit  9040  and provided to the power control circuit  9042 ) may be based upon an input provided to the actuator  9044  or the interface  9052 . For example, power may be applied to the outlet  9060  in response to a user input to the actuator  9044  or communication signals provided to the interface circuit  9052  to control the application of power to a load. As can be seen in  FIG. 90 , power, neutral and ground signal are provided to the outlet  9066 , and therefore outlet  9066  is always on (i.e. always receiving power). In contrast, outlet  9060  is configured as a switched outlet (i.e. an outlet that may be controlled to selectively apply power to the outlet). While the application of power to one of the outlets (i.e. outlet  9060 ) is controlled, it should be understood the control attachment could be configured so that both outlets (i.e. outlet  9060  and outlet  9066 ) are controlled outlets, where they may be controlled together (i.e. both are responsive to a single signal) or controlled separately. 
     Turning now to  FIG. 91 , a front and side view of the power adapter that may be implemented according to the power adapter arrangement of  FIG. 90  is shown. The power adapter  9100  comprises a plurality of contact elements (e.g. contact elements  1516  and  1520 ) configured to receive power signals (e.g. high voltage power signals and ground or neutral signals) as described above, and transmit the power signals between the power adapter and the control attachment. That is, rather than implementing power switching functions in the power adapter, the power signal received by the power adapter is provided to the control attachment by contact elements on the power adapter, where the switching of power that is applied to a load by way of an outlet of the control attachment is controlled by elements of the control attachment, such as described above in reference to  FIG. 90 . The three contact elements  9026 ,  9030  and  9034  of  FIG. 90  are shown as female receptacles adapted to receive corresponding male contact elements of the control attachments, such as prongs as described in  FIG. 93 . While an example using a male and female contacts is described by way of example, it should be understood that any type of contact element arrangements could be employed. 
     Turning now to  FIG. 92 , a side view of the power adapter  9100  is shown. As shown in  FIG. 92 , the contact element  9030  comprises a receptacle  9202  for receiving the corresponding contact element  9032 , as shown for example as a prong in  FIG. 93 . When the control attachment of  FIG. 93  is attached to the power adapter of  FIG. 91 , the contact element  9032  extends into the receptacle  9202  of the contact element  9030  and makes an electrical contact to the corresponding contact  9030  of the power adapter to enable the transfer of an electrical signal between the power adapter and the control attachment. A signal line  9204  enables the transfer of signals to between the power adapter and the control attachment. As shown in  FIG. 93 , attachment elements  9302  are provided to enable attaching the control attachment to the power adapter. The attachment elements could be any type of attachment element as described above. Further, the control attachment could be implemented so that it can be inserted into or removed from the power adapter through the opening of the wall plate while the wall plate is attached to the power adapter. For example, the attachment elements could be exposed through the opening of a wall plate to enable the attachment element to be inserted into or removed from the power adapter through the opening of the wall plate, such as described above in reference to  FIG. 17  for example. Alternatively, the attachment elements could be behind the wall plate so that the wall plate must be removed for the control attachment to be inserted into or removed from the power adapter, as described above in reference to  FIG. 18  for example. 
     Further, user interface elements  9304  may also be provided, and may include any element for implementing interface circuit  9038 . The interface elements may include elements enabling direct interaction (e.g. a button, a switch, a connector) or indirect interaction (e.g. a speaker microphone). For example, connectors  9402  and  9404 , shown here by way of example as USB and USB Type C contact elements, enable a user to receive power or transmit communication signals to a device attached to the connector. While connectors are shown by way of example in  FIG. 94 , it should be understood that any type of user interface elements could be implemented as described above, such as described in reference to  FIGS. 51-64 , either for receiving a user input at the control attachment or providing information to a user. For example, as shown in the implementation of  FIG. 95 , the interface circuit  9038  is shown in dashed lines in  FIG. 93  as being internal to the control attachment, but may have interface elements that are exposed. For example, as shown in  FIG. 95 , a sensor  9502  may be implemented. The sensor could be any type of sensor as described above, such as a camera or a motion detector. According to the implementation of  FIG. 96 , the interface circuit may comprise a smart speaker having a microphone  9602  and a speaker  9604 . 
     It should be noted that some implementations of the interface circuit  9038  may require more space than is available between 2 outlets  9060  and  9066 . Therefore, as shown in the implementation of  FIG. 97 , a single outlet is implemented, where the remaining space that is exposed though an opening of a wall plate can be used for other interface elements. That is, more space may be needed for a single function, or for providing multiple functions, including any combination of user interface elements as described above. In addition to elements of a smart speaker having a microphone  9602  and a speaker  9604 , the interface circuit  9038  may include another user interface element  9704 , which may be any type of user interface element, such as a sensor or connector as described above. 
     While the control attachment arrangements of  FIGS. 93-97  have user interface elements that are integrated into the control attachment, the control attachment may be configured to receive a removable user interface element, which may be a removable module for example. As shown in  FIG. 98 , a removable module  9802  is coupled to the control circuit  9040 , and enables the implementation of user interface elements as described above. The module  9802  may comprise a connector  9804  having contact elements  9806 . The control attachment may also comprise a corresponding connector  9808  having contact elements  9810 . While a physical connector is shown by way of example, it should be understood that any type of interface for communication signals between the module  9802  and control circuit  9040  could be implemented as described above. 
     The module  9802  may comprise various user interface inputs, which may be physical user interface inputs or wireless user interface inputs. For example, a user interface input  9812  may be implemented to receive an actuation signal from an actuator accessible by a user. A communication input  9814  may be implemented to transmit and receive communication signals, such as any of the communication signals as described above, while an output  9816  may be implemented to provide feedback to a user, such as audio, visual or tactile feedback. As described below in reference to  FIGS. 99 and 100 , the control attachment may be implemented with a recess to receive the module  9802 . The module  9802  may transmit and receive communication signals using any wireless communication protocol, and control an outlet or provide any user interface function (e.g. a camera, a motion detector, a smart speaker), as described above. 
     As shown in  FIGS. 99 and 100 , module  9802  may be detachably inserted into a recess  10002 , and attached to the control attachment by attachment elements  9904  to corresponding attachment elements  10004  as shown. The attachment elements  9904  and  10004  may implemented according to any of the power adapter arrangements as described above. An electrical interface  10008  may comprise contact elements  9810  for example. While the module  9802  is configured to be inserted into a recess, the module  9802  may be attached to an external surface of the control attachment. 
     According to additional implementations set forth below, a power adapter arrangement can be implemented where outlets or switches are provided as a part of the power adapter, and a control attachment coupled to the power adapter may be used to control the switching of power to a load (either electrically connected to a contact element of the power adapter such as by a wire associated with a device wired in an electrical system of a building (e.g. ceiling light) or a device plugged into the power adapter (e.g. lamp or appliance)), as will be described in more detail below. By placing switching functionality for power applied to the load in the control attachment of a power adapter arrangement, power adapters (implemented to include either an outlet or a switch) can be universally installed at a low cost, allowing a resident or occupant of the building to cheaply and easily install a control attachment that provides switching. That is, because of the cost associated with switching, such as the cost of a relay or a TRIAC for example, it is beneficial to provide basic switching capability (e.g. a manual switch) for a switch or “always on” outlets of a power adapter comprising outlets, where the control attachment providing additional functionality can be cheaply and easily added later. 
     When a “dummy” control attachment is used in a power adapter providing switching functionality, the power adapter will function as a conventional switch having manual on and off capability. However, when a control attachment having switching capability is attached to the power adapter, the power adapter arrangement may provide additional functionality (e.g. wireless control of power applied to the load or sensor capability for use in a security system or smart home). Similarly, when a dummy control attachment is used in a power adapter having outlets, the outlets will provide power as normally provided in a conventional outlet (i.e. “always on” outlets). However, when a control attachment having switching capability is used in the power adapter having outlets, one or more of the outlets can be implemented as a switched outlet, where the switching capability (e.g. a relay or a TRIAC) for the switched outlet is provided by the control attachment. By configuring the power adapter to receive either a dummy control attachment or a control attachment having switching capability, a low cost switch or low cost outlet can be provided, where the low cost switches or outlets can be universally installed, and easily upgraded without having to replace the entire power adapter. That is, in addition to reducing cost, time and effort of replacing an entire outlet or switch installed in a junction box, additional cost reductions can be achieved by only having to provide additional hardware of a control attachment. The switch and the outlet on the power adapter installed in the junction box will remain, and will not need to be replaced. As will be described in more detail below, the power adapters for switching and power adapters having an outlet can be configured to receive the same control attachments. As will further be described in more detail below, control attachments can be provided with other functionality, which may be in addition to switching functionality, and may include any user interface elements for implementing a smart home or security system. 
     Turning first to  FIG. 101 , a block diagram of a power adapter having outlets and a recess for receiving an insert adapted to provide switching for power applied to a load is shown. The power adapter of  FIG. 101  is configured to receive a control attachment, wherein the control attachment routes power received from the power adapter back into the power adapter. That is, the power adapter is configured to receive power from an electrical system (such as by being electrically connected to wires in a wall of a building or plugged into an outlet) and provide power that is routed through a control attachment inserted into a recess of the power adapter back to an outlet of the power adapter. By routing the power that is provided to an outlet through the control attachment, it is possible to provide switching of power (provided to a switched outlet for example) in the control attachment if desired. Unlike conventional outlet devices having no switching capability (where the entire power adapter would need to be replaced to achieve a switched outlet), only the control attachment would need to be added to achieve switching capability by placing the switching capability in the control attachment. 
     As shown in  FIG. 101 , a power adapter  10102  comprises a body portion  10103  having a recess  10106  configured to receive a control attachment that may have power switching functionality. The power adapter comprises an electrical interface  10108  (functioning as an interface for routing signals) that is coupled to a plurality of inputs, shown here as a contact element  10110  adapted to be coupled to a ground node of an electrical system, a contact element  10112  adapted to be coupled to a neutral voltage, and a contact element  10114  configured to receive a power signal (which may provide a voltage or a current for driving a load as described above). The signal interface  10108  may be included to provide voltage regulation and signal conditioning to remove noise for example. That is, a ground voltage is generated on a signal line  10120  at an output of the signal interface, a neutral voltage is generated on a signal line  10122  at an output of the signal interface, and a power voltage is generated on a signal line  10124 , where current may flow on the signal lines  10122  and  10124  depending upon the control of power applied to a load, and current may flow on the ground signal line  10120  depending on any condition that may require power to flow to ground (such as a for safety in the event of too much current flowing in the circuit). 
     The ground signal line  10120 , the neutral signal line  10122 , and the power signal line  10124  are coupled to corresponding signal lines  10130 ,  10132 , and  10134  that provide current paths to an outlet  10136 , which is adapted to receive contact elements  10137  (e.g. electrical prongs of a plug adapted to be inserted into the outlet) associated with a load  10138 . Similarly, the ground signal line  10120  and the neutral signal line  10122  are coupled to corresponding signal lines  10142  and  10144  that provide current paths to an outlet  10146  that is adapted to receive contact elements  10147  (e.g. electrical prongs of a plug) associated with a load  10148 . 
     The ground signal line  10120 , the neutral signal line  10122 , and the power signal line  10124  are also coupled to corresponding contact elements  10150 ,  10152  and  10154  to provide voltages and enable current paths for allowing power to be applied to a load and for providing current paths for safe operation. Unlike the configuration of signal lines provided to the output  10136  that provides power to the load  10138  (where all of the signal lines  10120 ,  10122 , and  10124  are connected to corresponding signal lines  10130 ,  10132  and  10134 , and the outlet  10136  comprises a non-switched outlet, also known as an “always on” outlet), only the neutral signal line  10142  and the ground signal line  10144  are electrically connected to the corresponding neutral signal line  10122  and ground signal line  10120 . A power signal on the power signal line  10124  is routed through a control attachment by way of the contact element  10154  and a contact element  10156 , as will be described in more detail below, such as by the control attachments as shown in  FIGS. 102 and 103 . That is, rather than implementing the outlet  10146  as an unswitched outlet, power provided to the outlet  10146  is routed through a control attachment by way of the contact elements  10154  and  10156 . As can be seen in  FIG. 101 , the switching of power is not performed in the power adapter, but rather in a control attachment inserted into the power adapter. By placing any circuits for switching power in the control attachment, a low-cost power adapter having outlets (which may be implemented as a conventional outlet having “always on” outlets for example) may be implemented. As will be described in more detail below, a simple, low-cost control attachment may be implemented to configure and operate the outlet  10146  as a non-switched outlet, while other control attachments can be implemented to configure and operate the outlet  10146  as a switched outlet. 
     As shown in the implementation of  FIG. 102 , a control attachment may comprise a connector arrangement for routing power received from the power adapter back to the power adapter as shown. The control attachment  10202 , which may be considered a dummy control attachment, comprises contact elements  10204 ,  10206 ,  10208 ,  10210  that are adapted to be coupled to the corresponding contact elements  10150 ,  10152 ,  10154  and  10156 . As shown, a signal line  10212  can be provided between the contact element  10208  and  10210  to enable routing a power signal from the contact element  10154  to the contact element  10156 , and therefore to the signal line  10140  to provide power to the outlet  10146 . According to the configuration of  FIG. 102 , the outlet  10146  will receive power and operate as an unswitched outlet, where the signal line  10212  operates as a jumper. It should be understood that the contact elements  10204  and  10206  may not be necessary, but may be implemented to provide additional safety or provide mechanical alignment when the control attachment is inserted into the recess of the power adapter. 
     Implementing a control attachment having a power control circuit that may be used to control the switching of power received by the power adapter and applied to the load enables the outlet  10146  to be implemented as a switched outlet. According to the implementation of  FIG. 103 , the power adapter  10102  as shown comprises a control attachment having a control circuit for controlling the routing of power received from the power adapter back to the power adapter. More particularly, the power adapter  10302  comprises a power control circuit  10304  that controls the switching of power received from the power adapter, and therefore enables the outlet  10146  to be operated as a switched outlet. The control circuit  10306  is coupled to the power control circuit  10304  by way of a signal line  10307  to control the operation of the power control circuit. The control circuit  10306  could be implemented in a processor as described above, and is configured to process signals received from an interface circuit  10308 , such as signals from a wireless communication circuit or a sensor of the interface circuit  10308 . According to some implementations, the power control circuit  10304  may comprise a relay having a path of controllable conductivity coupled to the contact elements  10208  and  10210 , where a control terminal of the relay (i.e. the terminal controlling the flow of current through the relay) may be controlled by a control signal on the control signal line  10307  to allow power to flow from the power adapter and back to the power adapter through the control adapter  10302 . 
     According to other implementations, a TRIAC circuit such as described in reference to  FIG. 6  could be used in the power control circuit. While dimming may be less likely to be used in a power adapter having outlets (as compared to a power adapter having a switch as described below), the TRIAC circuit could be operated to turn on or off power to the outlet, and not necessarily for dimming. That is, the TRIAC circuit may have advantages compared to a relay, such as cost or size advantages. Further, because a TRIAC may be commonly used when a control attachment is used in a switch, it may be beneficial to implement a TRIAC in a control attachment to enable the control attachment to be implemented in both a power adapter having an outlet and a power adapter having a switch, as will be described in more detail below. 
     The control circuit  10306  may be coupled to one or both of neutral and ground contacts  10150  and  10152  to provide a reference voltage and to provide a discharge path to prevent a shock or other injury to a user as a result of contact with the control attachment. The control circuit  10306  may also be coupled to an interface circuit  10308  by way of a signal line  10309  to enable the communication of signals between the control circuit  10306  and the interface circuit  10308 . The interface circuit  10308  may be any type of interface for generating signals that may be used to control the operation of the power adapter arrangement and the application of power to a load. For example, the interface circuit  10308  may receive user interface inputs at an input  10310 . That is, a user interface may be provided on the control attachment and exposed through an opening of a wall plate attached to the power adapter arrangement. The control attachment may comprise any types of user interface elements, such as any type of actuator for receiving a manual input from a user, such as an on/off actuator, a dimmer control circuit, or any other actuator, including the user interface elements as described in  FIGS. 136-142 . The user interface elements may also be a passive user interface element, such as a microphone, a speaker, or a sensor. 
     The interface circuit  10308  may also comprise an input/output element  10312  for receiving and transmitting communication signals, such as wireless communication signals sent to or from a wireless communication circuit  10316  of the interface circuit that may implement a wireless communication protocol as described above, such as described above in reference to  FIG. 37  for example. For example, the interface circuit may receive a schedule or timing pattern for applying power to a load by way of the wireless communication circuit from a remote device, such as a smart phone, as described above. The control circuit may then implement the schedule for applying power to a load based upon the signals received from by the wireless communication circuit and stored in a memory, as described for example in reference to the power adapter and control attachment of  FIG. 37 . According to some implementations, the timing pattern may be stored in a memory of the control attachment, where various interface elements of the control attachment of  FIG. 103  may use elements as described in reference to  FIG. 37  for example. The interface circuit  10308  may be coupled to one or more user interface elements, such as actuators or buttons accessible by a user or passive elements such as a microphone. The interface circuit  10308  may also comprise one or more feedback elements  10314  that may provide feedback to a user. The interface circuit may also comprise one or more sensors  10318 , including any of the sensors as described above. The sensors may be used for detecting conditions external to the power adapter arrangement, and providing signals to the control circuit  10306  based upon the conditions detected by the sensor. Signals generated by a wireless control circuit or a sensor may be used by the control circuit to generate control signals provided to the power control circuit  10304  to control the application of power to a load. The feedback element could comprise any type of visual (e.g. LEDs or a display), audio (e.g. speaker) or tactile feedback element as described above. It should be understood that the wireless communication circuit  10316  and one or more sensors  10318 , including any of the sensors as described above, may be implemented in an interface circuit  10308  of any of the implementations having the interface circuit. 
     While the signal interfaces to the control circuit are described as signal lines  10307  and  10309 , it should be understood that the signal lines  10307  and  10309  may comprises a multi-line bus or any other type of signaling interface. It should be noted that the control attachment could comprise any user interface elements or circuits that could receive or provide information beneficial to the operation of the power adapter arrangement or any device external to the power adapter arrangement, such as a device associated with a home automation system or a home security system. 
     Turning now to  FIG. 104 , a perspective view of a power adapter arrangement comprising a power adapter having an outlet and a control attachment adapted to be received by the outlet is shown. More particularly, a power adapter arrangement having a power adapter, a control attachment, and a wall plate is shown in an expanded view. A front surface  10402 , which has a wall  10404  to provide a raised front surface that extends through an opening in a wall plate, comprises the recess  10106  extending to a rear surface  10406 . An electrical interface  10408 , shown here by way of example on the rear surface  10406 , comprises a plurality of contact elements  10409 , which may have tamper resistant elements (i.e. child protection elements) to prevent inadvertent contact with a high voltage power contact. While electrical interface  10408  is shown by way of example on a rear surface of the recess  10106 , it should be understood that the electrical interface  10408 , or individual contacts of the electrical interface  10408 , could be located on another wall of the recess  10106 . 
     An electrical interface  10410  comprises contact elements  10110 - 10114  on an outer surface of the power adapter to enable the power adapter to be coupled to wires of a junction box. While the contact elements  10110 - 10114  are shown on the same outer surface of the power adapter  10102 , It should be understood that the contact elements could be distributed among different outer surfaces of the power adapter. Distributing the contact elements provides convenience for installing the power adapter in a junction box (i.e. causing the wires of the junction box to be dispersed in the junction box, making it easier for the power adapter to fit in the junction box). While the contact elements  10110 - 10114  are shown as screw-type contact elements adapted to receive a wire from the junction box, it should be understood that any type of contact elements could be employed, including wires extending from the power adapter. Further, the contact elements, such as the screw type contact elements as shown, could be recessed on the outer surface as is commonly done, where the contact elements are generally exposed or accessible on an outer surface to secure a wire of the contact element. 
     As will be described in more detail below, one or more additional electrical interfaces, such as a low power electrical interface, may be provided in the recess  10106 , where the additional electrical interface may be provided on the rear surface or any other surface of the recess, or contact elements of the additional electrical interface may be distributed on different surfaces of the recess. 
     The power adapter  10102  also comprises attachment elements  10412 , which may be adapted to engage with corresponding attachment elements  10260  of the control attachment. The attachment elements  10412  and  10260  may be implemented according to any of the attachment elements as described above, including for example as described in reference to  FIGS. 47-49 , or other suitable attachment elements. The control attachment  10302  as shown in  FIG. 104  is adapted to be inserted into the recess  10106 , where contact elements  10414  (e.g. male contact elements) are configured to be inserted into corresponding contact elements  10409  (e.g. female contact elements). According to some implementations, the contact elements  10414  comprise prongs that are inserted to corresponding contact elements of the power adapted configured to receive the prongs. That is, as with an outlet configured to receive prongs of a plug, an arrangement of prongs and contact elements receiving the prongs enable the contact elements of the power adapter (which may be high voltage contacts) to be recessed within the power adapter (such as within the recess  10106  for example) and be further protected by insulating elements associated with a tamper resistant element. While the contact elements  10409  may include high voltage contacts, it should be understood that the contact elements  10414  and corresponding contact elements  10409  may be used to route low voltage signals, such as low voltage control signal as will be described in more detail below. 
     The power adapter  10102  of  FIG. 104  also comprises flanges  10420  to enable the power adapter to be attached to a junction box, such as using screws that extend through a recess  10422 . The flanges may also comprise threaded portions  10424  for receiving screws to secure a wall plate  10430  to the power adapter. That is, an edge  10434  defines an opening  10436  that is adapted to receive the front surface  10402  and wall portion  10404 , where screws can be extended through holes  10438  to the threaded portion  10424  to secure the wall plate to the power adapter. It should be understood that the control attachment and power adapter could be configured so that the control attachment can be inserted and removed when the wall plate is attached to the power adapter, as described above in reference to  FIG. 18  for example, or so that the control attachment can only be inserted and removed when the wall plate is not attached to the power adapter, as described above in reference to  FIG. 17  for example. According to some implementations, the power adapter can be configured to receive different types of control attachments, include control attachments that can be inserted/removed when the wall plate is attached, or inserted/removed only when the wall plate is not attached, as described above in reference to  FIGS. 48 and 49 . 
     Turning now to  FIGS. 105 and 106 , a perspective view of another power adapter arrangement comprising a power adapter having an outlet and a control attachment adapted to be received by the power adapter is shown. A rear view of the power adapter arrangement of  FIG. 105  is shown in  FIG. 106 , where an electrical interface comprising a plug extends from the rear surface. That is, contact elements  10110 - 10114  comprise prongs of a plug adapted to be inserted into an outlet to receive power that is applied to a load by way of one of the outlets  10136  and  10146 . While a plug extends from the rear surface  10602  of the implementation of  FIG. 106 , it should be understood that a cord having a plug could extend from the rear surface, as is commonly used in an extension cord or a power strip. 
     Turning now to  FIG. 107 , a block diagram of a power adapter having a switch controllable by a control attachment to control the routing of power received from the power adapter back to the power adapter is shown. While the implementation of  FIG. 102  having a control attachment comprising a simple contact arrangement for routing the power signal from the power adapter back to the power adapter through the control attachment, it may be beneficial to have a control attachment that does not require any electrical connectors (i.e. the control attachments may simply comprise a plastic housing, and the power adapter may operate without any control attachment). According to one implementation, the power adapter may comprise a switch  10702  that detects a control attachment adapted to control the application of power to a load. That is, the switch  10702  may be implemented to provide power to the outlet  10146  (i.e. enabling the outlet  10146  to operate as an always on outlet), unless a control attachment is configured to control power to the load. Therefore, when a dummy control attachment is inserted (or no control attachment is inserted), it will not change the state of the switch, where the power signal line is coupled to the outlet which operates as an always on outlet. For example, an actuator  10704  of the switch  10702 , which is accessible through a recess  10706  in a wall of the recess  10106 , would remain in the same state when a dummy control attachment is attached to the power adapter (or when no control attachment is inserted). 
     However, when a control attachment is adapted to control power applied to the outlet  10146  (making the outlet  10146  a switched outlet), the control attachment may engage the actuator  10704 , changing the state of the switch to decoupled power applied to the outlet  10146  by way of the switch. As shown in  FIG. 108 , the switch  10702  is controllable by a control attachment  10802  to control the routing of power received from the power adapter back to the power adapter through the control attachment. More particularly, the control attachment  10802 , which may comprise control and interface elements as described above in reference to  FIG. 103  for example, also comprises an actuator element  10804  that is provided on the control attachment and configured to engage the actuator element  10704  when the control attachment is inserted into the recess  10106  as shown. That is, when the control attachment  10802  is inserted into the recess  10106 , the actuator element  10804  engages the actuator  10704  (such as by pressing the actuator  10704  configured as a button for example), causing the switch  10702  to open (i.e. prevent the transmission of power from the power signal line  10124  to the signal line  10140 ) and therefore making the outlet  10146  a switched outlet controllable by the power control circuit  10304  and the control circuit  10306 . While a switch  10702  is configured by way of example to have a button as shown, it should be understood that other types of switches could be used. As can be seen in the implementation of  FIGS. 107 and 108 , the power adapter arrangement can be implemented with a dummy control attachment having no elements that are necessary for the operation of the power adapter operating with  2  always on outlets, or with a control attachment controlling the application of power to a load coupled to the outlet  10146 . 
     The control of outlets and the arrangement of elements of a power adapter could be implemented in different ways, as will be described in reference to  FIGS. 109-112 . Turning first to  FIG. 109 , a block diagram of a power adapter arrangement having a power adapter and a control attachment configured to control two outlets is shown. Unlike the arrangement of the power adapter of  FIGS. 107-108 , the power adapter of  FIG. 109  may be implemented so that the power control circuit  10304  controls both outlets  10136  and  10146 . In addition to the contact elements  10154  and  10156  used for coupling signals to the power control circuit  10304 , a contact element  10903  and a corresponding contact element  10904  enable the power control circuit  10304  to control the application of power to the outlet  10136 . That is, rather that having the outlet  10136  coupled to the power signal line  10124 , the signal line  10134  is coupled to the contact elements  10903  and  10904  to receive power from the power control circuit, enabling the outlet  10136  to be operated as a switched outlet. The outlets  10136  and  10146  could be controlled independently or together. 
     According to the implementation of  FIG. 110 , a control attachment may be implemented to have a signal interface circuit as shown. That is, some or all of the signal interface functions, which may include noise filtering and voltage regulation as described above, may be implemented in the control attachment (i.e. in addition to or in place of the signal interface  10108 ). For example, the control attachment  11002  of  FIG. 110  may include a signal interface circuit  11004  coupled to the contact elements  10154  and  10208  as shown to the receive the power signal, where noise filtering and/or voltage regulation can be performed in the signal interface  11004  of the control attachment. It should be understood that the partitioning of elements, such as signal interface elements between the power adapter and the control attachment may be determined by factors such as cost factors associated with the power adapter (i.e. minimizing the complexity and cost of the power adapter to promote a more widespread installation of the power adapters), size factors associated with control attachments (i.e. space requirements for circuits implemented in the control attachment), and other considerations that may impact consumer adoption of certain power adapter arrangements (e.g. including all of the signal interface elements are in the power adapter so that no circuit element is required in the control attachment). 
     According to the implementations of  FIGS. 111 and 112 , control circuits provided in both the power adapter and the control attachment to enable authenticating the control attachment, where the power adapter having a switch for controlling the application of power to an outlet is shown. As can be seen in  FIG. 111 , a contact element  11102  is provided for routing signals from the control attachment to a control circuit  11104 , an output of which is provided to a switch  11106  that is configured to receive a power signal from the power control circuit  10304  and route the power to the signal line  10140 . The power control circuit  10304  and the switch  11106  enable the power adapter arrangement to operate the outlet  10146  as a switched outlet using the control attachment  11202 , as shown in  FIG. 112 . The control circuit  10306  is coupled to the contact element  11204  to enable the transfer of signals between the control circuit  10306  of the control attachment  11202  and the control circuit  11104  of the power adapter  10102 . According to some implementations, the control circuit  11104  of the power adapter may communicate with the control attachment to authenticate the control attachment as set forth above. If the control attachment is not authenticated, the control circuit  11104  may open the switch  11106  to prevent power from being applied to the signal line  10140 . However, if the control attachment is authenticated, the switch may be closed, enabling the power control circuit  10304  to operate the outlet  10146  as a switched outlet. 
     While different features are shown in the different implementations of  FIGS. 101-112 , it should be understood that the various features may be interchanged between the different implementations. According to some implementations, some of the operations of the control circuits  10306  and  11104  in conjunction with other elements of the power adapter or the control attachment are described in reference to  FIG. 113 . 
     Turning now to  FIG. 113 , a flow chart shows a method of implementing a power adapter arrangement having an outlet. More particularly, it is determined whether a control attachment is received by a power adapter at a block  11302 . If not, the power adapter operates in a default condition of a power adapter having no control attachment at a block  11304 . For example, the default condition could be that a switched outlet of the power adapter is in an always on state, as described above in reference to  FIGS. 107 and 108 . Alternatively, the default condition is that the switched outlet is disabled when a control attachment is not attached to the power adapter. 
     If a control attachment is received by the power adapter, it may then be determined whether the control attachment is a “dumb” control attachment (i.e. a control attachment having no circuits for controlling the application of power to a switched outlet, also known as a blank attachment) at a block  11306 . If so, one or more of the outlets operated as switched outlets may be operated as always on outlets at a block  11308  until the control attachment is removed. If the control attachment is removed at the block  11309 , the power adapter operates according to the default condition at the block  11304 . 
     If the control attachment is not a dumb control attachment (i.e. the control attachment comprises circuits for controlling the switching of a switched outlet or any other circuits that may receive power from the power adapter, such as a sensor or any other element of a user interface as described above), it may optionally be determined whether the control attachment is authenticated to operate with the power adapter as described above at a block  11310 . It the control attachment is not authenticated, the power adapter is operated according to the default condition at the block  11304 . If the control attachment is authenticated, the control attachment is enabled to control the power adapter at a block  11312 , such as the application of power to a load, or communicate signals between the control attachment and the power adapter. For example, the power adapter and control attachment could be operated as described above in reference to  FIGS. 111 and 112 . 
     If the control attachment is not a dumb attachment and authenticated (if necessary), it may then be determined whether a signal is received from an interface of the control attachment at a block  11314 . If not, the power adapter arrangement maintains the state of power to the load at a block  11316 . If a signal is received, the state of the power to the load may be changed based upon the received signal, or any other type of operation or communication of signals may be performed based upon the received signal at a block  11318 . The control of the application of power to a load may be performed by a control circuit of the control attachment and or the control circuit of the power adapter using a power control circuit having a relay or a TRIAC for example. The control of the application of power may be based upon any inputs received at a user interface circuit of the control attachment as described above. Until the control attachment is removed, the control attachment continues to monitor for received signals at the block  11314 . If it is determined that the control attachment is removed at a block  11320 , the power adapter is operated in the default condition at the block  11304 . The flow chart of  FIG. 113  may be implemented in one or more of the power control circuit  10304  and the control circuit  10306  of the control attachment or the control circuit  11104  of the power adapter (i.e. if authentication is required). 
     Turning now to  FIGS. 114-125 , examples of contact elements for implementing a power adapter arrangement having a control attachment configured to receive a power signal and route the power signal back to the power adapter. Because a contact element carrying a high voltage power signal is provided on the power adapter (to enable providing the power signal to the power adapter), it is beneficial to increase the safety of implementing a power adapter by implementing the contact elements as tamper resistant contact elements to prevent a user from inadvertently making contact with a high voltage contact (e.g. 120 volts or some other voltage that may be dangerous) of the power adapter. In addition to being less accessible than the contact elements of an outlet for receiving a plug, the contact elements of the power adapter configured to receive corresponding contact elements of a control attachment may be implemented as tamper resistant contact elements, such as those that are currently implemented on the contact elements of an outlet. 
     As shown in  FIG. 114 , a front view of a power adapter shows the recess  10106  between the pair of outlets  10136  and  10146  adapted to receive a control attachment. More particularly, an electrical interface  11402  on a rear surface  11404  of the recess comprises a plurality of contact elements  11406 , shown here by way of example as tamper resistant contact elements. The electrical interface  11402  may comprise the contact elements the contact elements  10150 ,  10152 ,  10154 ,  10156 , and a contact  11406 . That is, the electrical interface  11402  may comprises an additional contact element  11406  in the power adapter having outlets to accommodate a control attachment that may have more contact elements than needed in a power adapter having an outlet, such as a control attachment used in a power adapter having a switch which may also require a 3-way switch terminal. The electrical interface  11402  could be in the recess of the power adapter of any of the embodiments of  FIGS. 101-112 . While the electrical interface is shown by way of example on the rear surface, it should be understood that the electrical interface could be implemented on any other surface of the recess, or distributed on different surfaces. 
     As shown in the implementation of  FIG. 115 , an additional electrical interface  11502  having contact elements  11504  may be provided. According to some implementations, the electrical interface  11502  may comprise a low power electrical interface (e.g. approximately 5 volts or less), which may be implemented as described above for example in  FIGS. 1-44 . For example, low voltage control signals may be used to communicate between a control circuit of the power adapter and a control circuit of the control attachment. 
     According to some implementations, low power control signals may be communicated between the power adapter and the control attachment using the contact elements of the electrical interface  11404 . That is, although tamper resistant contact elements may not be necessary for low voltage electrical interfaces, it may be beneficial to include a single electrical interface for both high voltage and low voltage signals. According to other implementations, low power communication signals could be provided on the high voltage lines. For example, a high frequency signal having a low voltage could be transmitted by way of the power contact elements of the power adapter and the control attachment. That is, the power contact elements, in addition to transmitting a high voltage power signal, could also function as a serial communication interface as described above to transmit communication signals between the power adapter and the control attachment using a high frequency signal. According to other implementations, multiple contact elements of the electrical interface  11402  of the power adapter could be used for transmitting communication signals according to parallel communication protocols as described above. While the electrical interface  11402  is shown having physical contact elements, it should be understood that the electrical interface  11402  could comprise any type of interface, such as wireless or optical interfaces. 
     Turning now to  FIG. 116 , a perspective view of a control attachment according to one implementation is shown. The control attachment  10302  comprises contact elements of one or more electrical interfaces extending from a rear surface of a body portion extending from a rear surface to a front surface as shown, where user interface elements may be positioned on the front surface of the control attachment. The body portion is implemented to fit within the recess of a power adapter. More particularly, an electrical interface  11602  comprises a plurality of contact elements  11604 - 11612  comprising prongs adapted to be inserted to the corresponding contact elements  10150 - 10156  and  11406  of the power adapter as shown in  FIG. 115 . The contact elements  11604 - 11612  preferably have a shape and dimension to enable the insertion into the corresponding contact elements of the power adapter and to be able to carry sufficient current to apply to a load. For example, the contact elements  11604 - 11612  could be similar to prongs of a plug that are adapted to be inserted into an outlet. The contact elements  11604 - 11612  are preferably configured to have a shape and sufficient strength to separate insulating components of a tamper resistance contact, as will be described in more detail below in reference to  FIGS. 117 and 118 . A second electrical interface  11614  having contact elements  11616 , which is configured to connect to the electrical interface  11502  for example, may be implemented. Various edges of the rear wall, including the side edges  11620  and  11622  and front and back edges  11624  and  11616 , may be used to enable the control attachment to open a locked barrier, as will be described in more detail in reference to  FIGS. 120-125 . While the contact elements are shown on the rear surface as shown by way of example, it should be understood that the contact elements for routing power can be positioned on any other surface of the body portion of the control attachment other than the front surface that is exposed to a user and may comprise user interface elements. However, it should be understood that contact elements may positioned on the front surface, such as for a connector accessible by a user (e.g. a USB connector for charging an external device such as a phone or a laptop or a connector for transmitting and receiving data). 
     Turning now to  FIG. 117 , a front view of an electrical interface having insulating elements between openings for receiving contact elements of a control attachment and contact elements of the power adapter is shown. A safety contact block  11701 , which may be implemented as a portion of the electrical interface  11402 , comprises a plurality of insulating elements adapted to cover corresponding contact elements. According to some implementations, pairs of insulating elements  11702 - 11710 , which are movable within the contact block  11701 , may be located behind an outer surface  11712  having openings  11714 , shown here by way of example as circular openings to enable a contact element (e.g. a prong) to extend through the opening and separate the insulating element of the pair of insulating elements, as shown and described in reference to  FIGS. 118 and 119 . 
     More particularly,  FIGS. 118 and 119 , which have the outer surface  11712  removed to show the pairs of insulating elements, show the pairs of insulating elements in a closed state (i.e.  FIG. 118  when prongs of a control attachment are not inserted) and an open state (i.e.  FIG. 119  when prongs of a control attachment are inserted). As shown in  FIG. 118 , each of the pairs of insulating elements  11702 - 11710  are movable (e.g. slidable) within rails  11802  and  11804  and between ends  11806  and  11808 . Spring elements  11810  may be provided between the pairs of insulating elements and between the first pair of insulating elements  11702  and the end  11806  and the last pair of insulating elements  11710  and the end  11808 . As shown in  FIG. 119 , where contact elements  11604 - 11612  are inserted into the corresponding pairs of insulators  11702 - 11710  to make contact to contact elements of the power adapter, the springs are compressed, but return the uncompressed state of  FIG. 118  to cover the contact elements of the power adapter when the control attachment is detached from the power adapter. 
       FIGS. 120-125  show a barrier arrangement providing a tamper resistant feature to prevent inadvertent contact with a contact element of the power adapter. As shown in the implementation of  FIGS. 120 and 121 , a pair of movable doors  12002  and  12004 , which abut one another at an interface  12006 , may be opened as shown in  FIG. 121 . As will be described in more detail in the sequence of  FIGS. 122-125 , the doors  12002  and  12004  may be in a locked position when closed, and may be unlocked as the control attachment  10302  is inserted into the power adapter. 
     As shown in  FIG. 122 , a latch element  12202  comprises a spring element, shown here by way of example as a leaf spring  12204  that extends to a flange  12206  which is movable within a recess  12208 . Each of the movable doors  12002  and  12004  comprise spring elements  12210  having a first terminal portion  12212  and a second terminal portion  12214 . As will be described in reference to  FIGS. 123-125 , the movable doors  12002  and  12004  may be forced open in response to the control attachment  10302  being inserted into the recess, and return to the closed position as shown in  FIG. 122  by the spring elements  12210  when the control attachment is removed from the recess. 
     By the time that the control attachment  10302  reaches the doors as it is being inserted into the recess, the side edges  11620  and  11622  of the control attachment cause the flange  12206  to be driven into the recess  11208 , enabling the doors  12002  and  12004  to begin to open. That is, the flange  12206 , which is provided to enable a tamper resistant feature, will no longer block the doors from opening as a control attachment is being inserted into the recess as shown in  FIG. 123 . As the control attachment  10302  continues to advance into the recess, the front and back edges  11624  and  11626  drive the doors  12002  and  12004  open as shown in  FIG. 124 . The control attachment is shown completely inserted into the recess in  FIG. 125 . 
     It should be noted that the tamper resistant feature of  FIGS. 122-125  could be used alone or in addition to the tamper resistant feature or  FIGS. 120-121 . It should be noted that the tamper resistant features could be used in a power adapter comprising outlets or implemented as a switch, as will be described in more detail below in reference to  FIGS. 127-143 . 
     Turning now to  FIG. 126 , a diagram shows a power adapter arrangement having an outlet that is controllable using 2 wireless communication protocols. The arrangement of elements of a room in  FIG. 101  comprises an outlet  12602 , such as an outlet having a control attachment as described in  FIGS. 90-100  for example or some other suitable outlet, on a wall  12604 . The outlet  12602  is adapted to communicate with a first wireless communication device  12606  (which may be a remote computer device such as a smart phone or a tablet for example) by way of a first wireless communication protocol and with a second wireless communication device  12610  (shown here by way of example as a wireless wall switch on a wall  12612 ) by way of a second wireless communication protocol  12614 . 
     The outlet  12602  may be implemented having a control attachment having 2 wireless communication devices such as described in reference to  FIG. 37 , where the wireless communication circuit  3748  may be implemented to enable communication with and control one or more outlets (or other user interface elements) of the control attachment. For example, the wireless communication circuit  3748  of the control attachment may be implemented to communicate directly with a remote device, such as by using an RF or a Bluetooth connection, or by indirectly (e.g. through a base station) such as by using a WiFi or Z-wave connection. The second wireless communication device, such as wireless communication device  3752 , may implement a second communication protocol to enable a wireless communication link with a corresponding wireless communication device  12610 . For example, the wireless communication protocol  12614  may provide a direct wireless communication link, such as an RF communication link or a Bluetooth communication link, or an indirect wireless communication link, such as a WiFi or Z-Wave communication link. 
     Such an arrangement not only provides convenience to a home owner by enabling multiple devices to control an outlet, but may also reduce the cost to a home builder by reducing the wiring requirements. For example, when an outlet is implemented as a switched outlet (i.e. one of the outlets of the switched outlet can be controlled by a switch that controls the application of power to a load plugged in to the outlet), it is necessary to provide wires from the switch (such as at the location of the wireless communication device  12610 ) to the outlet  12602 . However, by providing a wireless communication device  12610 , it is not necessary to provide the conduit and junction box required to wire a switch at the location of the wireless communication device to the outlet  12602 . While wireless control of an outlet from a portable remote device (such as a smart phone or tablet) is beneficial, homeowners may also appreciate the convenience of having a wall switch to easily control a switched outlet. Therefore, with the implementation of the outlet  12602  having a wireless communication link between the wireless communication device  12610  and the outlet  12602 , the cost of implementing the outlet  12602  can be reduced while still having the convenience of a remote switch. 
     As with power adapters having outlets that are adapted to receive control attachments configured to control the application of power to a switched outlet as described above in reference to  FIGS. 90-126 , power adapters having a switch for controlling the application of power applied to a load may also be configured to receive a control attachment to control the application of power to the load, as will be described below in reference to  FIGS. 127-143 . 
     Turning first to  FIG. 127 , a block diagram of a power adapter having a control switch (such as a toggle switch for toggling power applied to a load) and a recess for receiving a control attachment is shown. A power adapter  12702  comprises a body portion  12703  having a recess  12704  for receiving a control attachment for receiving power from the load and routing the power back to the power adapter to provide power to the load. The power adapter  12702  comprises a signal interface  12708  adapted to be coupled to one or more contact elements of a power adapter, such as contact elements on an external surface of the power adapter as will be described in more detail below, where the signal interface may be implemented to provide signal processing, such as voltage regulation and noise filtering as described above. 
     The power adapter  12702  also comprises a switch  12710  that is accessible by a user of the power adapter on an outer surface of the power adapter when the power adapter is installed in a junction box. The switch  12710  may comprise a toggle switch for switching power applied to the load. The switch  12710  comprises a switch actuator  12712  coupled to a switch element  12714 , where the switch element is adapted to route power from the power adapter to the control attachment by way of contacts of the power adapter and the control attachment. More particularly, a first terminal  12716  of the switch  12710  is coupled to a power signal line of the power adapter and a second terminal  12718  of the switch  12710  is coupled to a contact element of the power adapter (such as a contact element in the recess  12704 ) that is configured to route a power signal to the control attachment. 
     The power adapter  12702  comprises a plurality of inputs external to the power adapter, which may be contact elements that are not exposed when the power adapter is attached to a junction box for example, and adapted to be coupled to power signals. For example, the power adapter  12702  may comprise a power input  12730 , a ground input  12732 , and a neutral input  12734 . Signals may be routed on signal lines including a power signal line  12740 , a ground signal line  12742 , a neutral signal line  12744 , and a load signal line  12746 . The power signal line  12740  may be coupled to a contact element  12750 , the ground signal line  12742  may be coupled to a contact element  12752 , the neutral signal line  12744  may be coupled to a contact element  12754 , and a load signal line  12746  may be coupled to a contact element  12756 . A contact element  12758  is coupled to the terminal  12718  to receive the power signal by way of the power signal line  12740  and the switch  12710 . The switch  12710  and the arrangement of contact elements enables the power signal to be routed to the load line  12746  using a control attachment, as will be described in reference to  FIGS. 128-130 . 
     As shown in  FIG. 128 , a dummy control attachment  12802  may be used to couple the contact element  12756  to the contact element  12758 . Therefore, the power adapter arrangement  12800  of  FIG. 128  operates as a simple toggle switch, where the switching element  12714  and actuator element  12712  could implement a conventional paddle-type toggle switch for example. That is, when the switch element  12714  is closed, power from the power line  12740  is provided by way of the switch element  12714  to the load line  12746  through the contact element  12804  (e.g. a jumper). When the switch element  12714  is open, power is not provided to the load. As can be seen, a low cost power adapter comprising a switch can be implemented with a simple control attachment having only a contact element  12804 . As will be described in more detail below in reference to  FIGS. 129 and 130 , switches could be provided in the power adapter to enable the power adapter to be implemented with a control attachment (or even without a control attachment), similar to the implementations as described above in reference to  FIGS. 107 and 108  for a power adapter having an outlet. 
     Turning now to  FIGS. 129 and 130 , a block diagram of a power adapter having a control switch (such as a toggle switch) and enable switches adapted to be coupled to actuator elements of a control attachment is shown. Rather than relying on an element of the control attachment, such as a jumper of the control attachment as described above in reference to  FIG. 128 , the power adapter  12901 , including a body portion having a recess  12902  for receiving a control attachment, comprises one or more switches (which may be considered enable switches) for enabling the use of the power adapter by controlling the routing of a power signal received by the control switch in response to an actuation signal from the control attachment, such as by insertion of the control attachment into the recess of the power adapter. More particularly, a first switch  12903  comprises a switch element  12904  controlling a signal path as shown coupled between the terminal  12936  of the control switch and the load line  12756 . The switch  12903  comprises an actuator  12906  that is accessible on a surface of the recess  12902 . The power adapter also comprises a second switch  12910  having a switch element  12912  controlling a signal path as shown coupled to the terminal  12938  of the control switch  12930 . The switch  12910  also comprises an actuator  12914  that is accessible on a surface of the recess  12902 . In addition to the contact element  12758 , a contact element  12916  may be coupled to a terminal of the switch  12930 . As will be described in reference to  FIG. 130 , the actuators  12906  and  12914  of a control attachment may be engaged by a corresponding one or more actuator elements of the control attachment to change the state of the switches. The operation of the switches  12903  and  12910  functioning as enable switches and the switch  12930  functioning as a control switch (i.e. toggle switch) will be described in more detail below. 
     In addition to the inputs  12730 - 12736 , the signal lines  12740 - 12746  and the contact elements  12750 - 12756 , the power adapter may comprise an input  12922  for receiving a 3-way signal, which may be a contact element on the power adapter for example. A 3-way signal received at the input  12922  is coupled by way of a signal line  12924  to a contact element  12926 . 
     In operation, the control switch  12930 , which may function as a toggle switch as described above in reference to  FIG. 127 , comprises a 3-terminal switch that routes power to one of two outputs. That is, unlike the toggle switch  12710 , which provides an open circuit or provides a closed circuit to route a power signal from an input to an output of the toggle switch, the control switch  12930  is adapted to route power to one of two outputs, and may be implemented as a part of a 3-way circuit. The control switch  12930  comprises a switch element  12934  having a first terminal  12936  coupled to the switch  12903  and the contact element  12758  as shown. The switch  12930  also comprises a terminal  12938  coupled to the switch  12910  and the contact element  12916  as shown. The switch  12930  also comprises a power terminal  12940  coupled to the power line  12740 , where the switch  12930  is configured to switch the application of power between the terminal  12936  and  12938  to provide the power to contact elements of the power adapter. 
     The switches  12903  and  12910  enable the power signal to be provided to the load directly or by way of the control attachment. According to one implementation, the switches  12903  and  12910  may be implemented in a closed state (commonly referred to as normally closed or NC), where that application of power to the load is based upon a change of state of the switch  12930 . As can be seen in  FIG. 129 , if the switches  12903  and  12910  are closed, the power signal on the power line  12740  will be coupled to either the load line  12745  (and therefore the load terminal  12736 ) or the 3-way switch line (and therefore the 3-way switch terminal  12922 ). If the power adapter is not implemented in a 3-way connection, the switch  12930  will connect the power signal to or disconnect the power signal from the load signal line  12746  in response to a toggling of the actuator element  12932  of the switch  12930 . The operation of the power adapter  12901  implemented in a 3-way connection will be described in more detail in reference to  FIG. 135 . 
     The switches can be retained in a closed state even when a dummy control attachment is inserted. That is, the dummy control attachment will not engage the actuator elements  12906  and  12914  (e.g. a recess could be provided in the dummy control attachment so that the actuator elements  12906  and  12914  are not depressed when the control attachment is inserted into the recess  12902 ). However, the switches  12903  and  12910  can be changed to an open state if a control attachment adapted to control the application of power to the load is inserted into the recess  12902 . For example, as shown in  FIG. 130  having the control attachment  13001  inserted in the recess  12902 , an actuator element  13002 , such as a prong or other projection, of the control attachment will engage the actuator element  12906 , causing the switch element  12904  to change state to an open state. Similarly, an actuator element  13004  of the control attachment will engage the actuator element  12914 , causing the switch element  12912  to change state to an open state. 
     If the switches  12903  and  12910  are open (i.e. preventing a routing of the power signal from the switch  12930  to one of the signal lines  12746  or  12924 ), the power signal routed by the switch  12934  can be routed to either the contact element  12916  or the contact element  12758 , which can be detected as a toggling of the switch  12930  by the control circuit  10306 . A signal indicating the toggling of the switch  12930  can be provided from the control circuit  10306  to the power control circuit  10304  by way of the signal line  10307 . 
     The power control circuit  10304  is also coupled to the 3-way signal line  12924 , and can detect a change in the signal on the 3-way terminal, and therefore to determine whether to change the application of power to the load terminal  12736  or the 3-way terminal  12922  based upon a toggling of the switch  12930 . For example, if a toggle of the switch  12930  is detected, the power control circuit  10304  will change the routing of the power signal from the power signal line  12740  to the load signal line  12646  (if the power is currently routed to the 3-way signal line) or change the routing of the power signal to the 3-way line (if the power is currently routed to the load signal line) as described in reference to  FIG. 135  and the flow chart of  FIG. 143 . 
     If the power adapter is not implemented in a 3-way circuit connection, the power control will toggle the power on the power signal line  12740  to the load signal line  12746 , subject to any toggle signal generated by the interface circuit  10308 . That is, the control circuit  10306  may monitor both the switch  12930  and the interface circuit  10308 . The interface circuit  10308  is adapted to communicate with the control circuit  10306  by way of a signal line  10309  as described above in reference to  FIG. 103 , enabling the control circuit  10306  to control the power control circuit  10304  to change the state of the power applied to the load in response to any toggling signal. 
     Turning now to  FIG. 131 , a block diagram of a power adapter arrangement  13100  having a switch and user interface elements is shown. As shown in  FIG. 131 , additional user interface elements  13102  and  13104 , which may be actuator elements for example, may be implemented to enable a user to provide input to or control the control attachment. As will be described in more detail below, the user interface elements  13102  and  13104  may comprise dimming control actuators for example. The actuator elements  13102  and  13104  may be coupled to an electrical interface  13106  having corresponding contact elements  13108  and  13110 . 
     As shown in  FIG. 132 , the power adapter arrangement  13200  having the power adapter of  FIG. 131  and a control attachment  13201  is configured to align the electrical interface  13106  with a corresponding electrical interface  13202  having contact elements  13204  and  13206  (adapted to make an electrical connection with contact elements  13108  and  13110  respectively). The control circuit  10306  is adapted to receive signals generated by the user interface elements  13102  and  13104 , and may control the application of power to a load based upon signals generated by the user interface elements  13102  and  13104 . 
     Turning now to  FIG. 133 , a block diagram of a power adapter arrangement having the power adapter of  FIG. 131  adapted to receive a removable user interface module and a control attachment is shown. A user interface module  13302 , which comprises a user interface similar to the user interface as shown in  FIGS. 131 and 132 , may also comprise an electrical interface enabling signals associated with the switch  12730  to be routed to the power adapter when the user interface module  13302  inserted into another recess of the power adapter (as will be described in more detail in reference to  FIG. 134 ). More particularly, as shown in  FIG. 134 , an electrical interface  13304  associated with the body portion  12905  of the power adapter comprises a plurality of contact elements configured to make an electrical contact with corresponding contact elements of the user interface module  13302 . A contact element  13306  (coupled to the power signal line  12740 ) is coupled to a contact element  13307  for providing the power signal to the switch  12730 . A contact element  13308  (coupled to the switch  12710 ) is coupled to a contact element  13309  (for receiving a signal from the switch  12930 ). A contact element  13310  (coupled to the switch  12903 ) is coupled to a contact element  13311  (also for receiving a signal from the switch  12730 ). 
     According to some implementations, the user interface module  13302  may be configured to be attached and detached to the power adapter body by a user of the power adapter, enabling a user to select a user interface module based upon functionality and/or appearance. According to other implementations, the user interface module  13302  may be configured to be attached to the power adapter body by a manufacturer of the power adapter, providing flexibility in the manufacturing of the power adapter. That is, a manufacturer may insert one type of user interface module for one customer and a second type of user interface module for a second customer, where the user interface module may have the same functionality, but different appearance to differential power adapter products for different customers. According to other implementations, the manufacturer may be able to manufacture different power adapters having different functionality. While the user interface module may be selected by a user for a particular customer, it may be attached to the power adapter in a way that is not removable by the user. 
     It should be noted that the same control attachments may be used for both the power adapters having outlets as described in reference to  FIGS. 101-125  and the power adapters having switches as described in reference to  FIGS. 127-131 . According to some implementations, power adapters having outlets as described above in reference to  FIGS. 101-112  for example and power adapters having switches as described in reference to  FIGS. 127-132  could be implemented having the same electrical interfaces (and particularly electrical interfaces having female contact elements adapted to receive male contact elements). 
     While some of the contact elements of a control attachment may be used for a power adapter having a switch (e.g. a contact element for a 3-way switch input), a power adapter having an outlet may be implemented with a contact element for a 3-way switch input (even if it is not used) to enable a control attachment having a 3-way switch contact element to be used in both types of power adapters. That is, the power adapter having an outlet may be configured with a female contact element (which may not be used) to receive a male contact element of a control attachment adapted to be used with a power adapter having a switch. While the male contact element may be used with the power adapter having a switch, the female contact element of the power adapter having an outlet may not be connected to any circuit of the power adapter and therefore may ignore the signal on the male contact element. However, by providing the female contact element (unused but present to receive the male contact element), the same control attachment may be used for both power adapters having outlets and power adapters having switches. 
     Specific examples of configurations of a power adapter and a control circuit are shown in  FIGS. 134-142 . Turning now to  FIG. 134 , a perspective view of power adapter arrangement  13400  adapted to receive a user interface module (which may be removable or may be fixed during a manufacturing process) and a control attachment is shown. The power adapter arrangement  13400  comprises a plurality of contact elements (such as contact elements  12730 - 12736  and  12922 ) on a surface of the power adapter  13402 , and flanges  13406  enabling the power adapter to be attached to a junction box and receive a wall plate as described above. The contact elements  12730 - 12736  and  12922  of the electrical interface  13404  are on an external surface of the power adapter, but may be configured so that they are not exposed when the power adapter is positioned within a junction box. In addition to the recess and electrical interface arrangement for receiving a control attachment  13001  as described above, the power adapter may comprise a second recess  13410  for receiving the user interface module  13302 . The user interface module  13302  may comprise an electrical interface  13412  (shown here by way of example as comprising male contact elements) and an electrical interface  13414 , both of which are shown in dashed lines as being on a rear surface to make electrical contact with corresponding electrical interfaces of the power adapter. The recess  13410  may comprise an electrical interface  13416  (shown here by way of example as electrical interface similar to electrical interface  11402  for routing high voltage signal as described above) and an electrical interface  13418  (shown here by way of example as an electrical interface for low power signals, such as electrical interface  11502  as described above). While the user interface module  13302  is shown by way of example as being a removable control attachment, it should be understood that the user interface module  13302  could be a fixed control attachment or manufactured as a part of the power adapter (i.e. it is not removable or implemented in a modular arrangement in the manufacturing process). The electrical interfaces of the power adapter that are in the recess are not exposed when a user interface module and a control attachment are inserted into the recess. 
     Turning now to  FIG. 135 , a block diagram having 2 power adapter arrangements configured in a 3-way switching arrangement to control a load is shown. The arrangement of 3-way switches  13502  and  13504  is wired to control load  13606 . Any of the power adapters adapted to provide 3-way switching as set forth above (e.g.  FIGS. 129-133 ) could be implemented as the 3-way switches  13502  and  13504 . As shown in  FIG. 135 , the power provided to the line input is coupled to be routed by way of the load outputs of both switches  13502  and  13504  and the line terminal of the switch  13504  to the load  13606 . If either of the 3-way switches is toggled (e.g. the line terminal is coupled to the 3-way terminal), the power signal will no longer be routed to the load. However, if either of the 3-way terminals is then toggled again, power will again be provided to the load. For example, if the switch  13502  is again toggled, the 3-way switching arrangement will return to the previous state as shown in  FIG. 135 . However, if the switch  13504  is toggled (after the switch  13502  had been toggled), power will be provided to the load by way of the 3-way terminals of the switches  13502  and  13504  (i.e. both switches  13502  and  13504  will be in the opposite state compared to the state of the switches as shown in  FIG. 135 ). 
     Various arrangements of a power adapter arrangement comprising a power switch for controlling the application of power to a load and a control attachment are shown. In addition to other user interface elements, the implementations of a power adapter arrangement shown in  FIGS. 136-142  provide examples of enabling dimming control and other user interface control for the switch. Turning first to  FIG. 136 , a front view of a power adapter arrangement having a toggle element and a dimmer control element associated with the power adapter is shown. As shown in  FIG. 136 , a power adapter arrangement  13602  comprises flanges  13604  as described above for attaching a power adapter to a junction box and a control attachment. The power adapter has a toggle element  13606 , shown here by way of example as a paddle-type toggle switch. While a single toggle element is shown, a toggle element having separate on and off toggle elements could be implemented as shown in  FIGS. 56-58  for example. 
     The power adapter arrangement also comprises a control attachment  13608 . While the control attachment is shown by way of example below the toggle element, it should be understood that the toggle element and the control attachment could be arranged differently. The control attachment  13608  may include one or more user interface elements  13607 , which may be any user interface element as described above in reference to a control attachment, such as a control button (e.g. controlling an on and off toggling of the power to the load), a control actuator, a connector (e.g. a USB connector), a sensor (including any type of sensor as described above), a speaker, a microphone, a status element (e.g. an LED), a display, or any combination of user interface elements as described above. 
     According to the implementation of  FIG. 136 , a dimmer control element could be implemented on a front surface of the body portion of the power adapter, and may comprises a guide  13610  adapted to receive a movable dimmer control element  13612 . According to other implementations, the dimmer control element implemented in any of the power adapter arrangements of  FIGS. 136-142  may comprise separate up and down buttons or a capacitive coupling interface, where the level of dimming may be provided on a level indicator  13614 , which may comprise a series of LEDs indicating a dimming level for example. 
     Turning now to  FIG. 137 , a front view of a power adapter arrangement having a toggle element associated with the power adapter  13702  and a dimmer control element associated with a control attachment is shown. According to the implementation of  FIG. 137 , the control attachment  13704  comprises a dimmer control element, shown here by way of example as a guide  13706  and a movable dimmer control element  13708 . As shown in the implementation of  FIG. 138 , the guide  13706  and dimmer control element  13708  is positioned horizontally to provide a greater range of movement of the dimmer control element. 
     Turning now to  FIG. 139 , a front view of another power adapter arrangement having a toggle element associated with the power adapter and a capacitive dimmer control element  13902  having a dimming level display  13904  having lighting elements  13906 , such as LEDs associated with a control attachment, is shown. The capacitive dimmer control element  13902  will detect the movement of a finger along the dimmer control element to change the dimming level. 
     Turning now to  FIG. 140 , a front view of another power adapter arrangement having a toggle element and a dimmer control element associated with the power adapter is shown. According to the implementation of  FIG. 140 , the power adapter  14002  comprises a push-type toggle element  14004 . The toggle element  14004  may have a status indicator  14006  to provide a status of power to the load or a status associated with a function of the control attachment  14012 , such as a status of a wireless connection to the control attachment. The power adapter also comprises control elements  14008  and  14010 , shown here by way of example as up and down control elements. According to some implementations, the control elements  14008  and  14010  may be providing dimming control. 
     According to the implementation of the power adapter arrangement of  FIG. 141 , a power adapter  14102  includes the toggle switch  14004  and a control attachment  14104  having control elements  14106  and  14108  (which may be implemented as described above in reference to  FIG. 140  for providing dimming control). By implementing the control elements  14106  and  14108  on the control attachment, it is possible to reduce the cost and complexity of the power adapter, and provide flexibility in the types and function of user interface elements used for the power adapter arrangement. While the control elements  14106  and  14108  may be used for dimming control, they may also be used for other control, such as audio control for a speaker of a control attachment operating as a smart speaker or control of sensor sensitivity for a control attachment having a sensor. 
     Turning now to  142 , a front view of a power adapter arrangement having a multi-element control switch associated with the power adapter is shown. According to the implementation of  FIG. 142 , a power adapter  14202  is adapted to receive a control attachment  14204 . The power adapter comprises a multi-element control switch  14206  having a toggle element  14208  (which may comprise a status indicator  14210 , such as an LED). The toggle element may comprise a plurality of selection control elements, including an up key  14212 , a right key  14214 , a down key  14216 , and a left key  14218 . The control attachment  14204  may comprise a display  14220 , where the multi-element interface may enable navigating through a menu for example, or performing other control functions associated with the control attachment.  FIGS. 136-142  could be implemented as shown in  FIGS. 128-134  above. While the examples of  FIGS. 136-142  show a control attachment that is removable, it should be understood that the examples of  FIGS. 136-142  could be implemented with a user interface module that is removable, such as the user interface module  13302  as described above in reference to  FIGS. 133 and 134  for example. 
     Turning now to  FIG. 143 , a block diagram of a power adapter arrangement having a power adapter configured to authenticate a control attachment is shown. That is, the control attachment can be authenticated by the power adapter in a similar manner as described above in reference to a power adapter having an outlet. More particularly, a control circuit  14302  in the power adapter is configured to control the application of power to a load based upon whether a control attachment is authenticated. The control attachment comprises a signal line  14304  configured to route control signals necessary for the power adapter to authenticate the control attachment, where the control signals may be routed through contact elements  14306  and  14308  as shown. The control circuit  14302  is configured to control a switch  14310  that is adapted to control the power to the load from the power control circuit and a switch  14312  that is adapted to control power to the 3-way terminal as shown. That is, the application of power to the load may be controlled by the switch  12930 , but the control circuit may block the application of power through the control attachment using the switches  14310  or  14312 . The switches  14310  and  14312  may be a relay for example, which may be open if the control attachment is not authenticated or closed if the control attachment is authenticated. The switches  14310  and  14312  may be placed is other locations to control the application of power to a load, or additional switches may be employed to control the application of power to a load by way of the load terminal or 3-way terminal. 
     Turning now to  FIG. 144 , a flow chart shows a method of implementing a power adapter arrangement having a switch and a control attachment. More particularly, it is determined whether a control attachment is received by a power adapter at a block  14402 . If not, the power adapter operates in a default condition of a power adapter having no control attachment at a block  14404 . For example, the default condition could be that a switch of the power adapter may be used to control the application of power to a load, such as using the power adapters as described above in reference to  FIGS. 127-142 . Alternatively, the default condition is that the switch of the power adapter does not function when a control attachment is not attached to the power adapter. 
     If a control attachment is received by the power adapter, it may then be determined whether the control attachment is a “dumb” control attachment (i.e. a control attachment having no circuits for controlling the application of power to a load, also known as a blank attachment) at a block  14406 . If so, the power adapter arrangement is operated as a conventional switch, such as a conventional toggle switch, at a block  14408  until the control attachment is removed. If the control attachment is removed at the block  14409 , the power adapter operates according to the default condition at the block  14404 . 
     If the control attachment is not a dumb control attachment (i.e. the control attachment comprises circuits for controlling the switching of power applied to a load or any other circuits that may receive power from the power adapter, such as a sensor or any other element of a user interface as described above), it may optionally be determined whether the control attachment is authenticated to operate with the power adapter as described above at a block  14410 . If the control attachment is not authenticated, the power adapter may be operated according to the default condition at the block  14404 . If the control attachment is authenticated, the control attachment is enabled to control the power adapter at a block  14412 , such as the application of power to a load, or communicate signals between the control attachment and the power adapter. For example, the power adapter and control attachment could be operated as described above in reference to  FIGS. 127-133 . 
     If the control attachment is not a dumb control attachment and authenticated (if necessary), it may then be determined whether a signal is received from an interface of the control attachment at a block  14414 . If not, the power adapter arrangement maintains the state of power to the load at a block  14416 . If a signal is received, the state of the power to the load may be changed based upon the received signal, or any other type of operation or communication of signals may be performed based upon the received signal at a block  14418 . The control of the application of power to a load may be performed by a control circuit of the control attachment and or the control circuit of the power adapter using a power control circuit having a relay or a TRIAC for example. The control of the application of power may be based upon any inputs received at a user interface circuit of the control attachment (e.g. a user interface circuit associated with the interface circuit  10308 , such as where a signal from the user interface circuit is provided to the control circuit using any element of the user interface circuit  10308  as described above. Until the control attachment is removed, the control attachment continues to monitor for received signals at the block  14414 . If it is determined that the control attachment is removed at a block  14420 , the power adapter is operated in the default condition at the block  14404 . The flow chart of  FIG. 144  may also be implemented in one or more of the power control circuit  10304  and the control circuit  10306  of the control attachment or the control circuit  11104  of the power adapter (i.e. if authentication is required). 
     Turning now to  FIG. 145 , a flow chart shows a method of implementing a power adapter configured to receive a control attachment. A method of configuring a power adapter to provide power to a load is described. The method may comprise configuring a first contact element of a first plurality of contact elements to receive power and a second contact element adapted to be coupled to a load at a block  14502 . A surface adapted to receive a control attachment may be provided at a block  14504 , wherein the surface comprises a second plurality of contact elements. A third contact element of the second plurality of contact elements may be configured to receive power from the first contact element of the first plurality of contact elements at a block  14506 . A fourth contact element of the second plurality of contact elements may be configured to receive power from the control attachment at a block  14508 . 
     According to other implementations, power may be applied to the load by way of the second contact element of the first plurality of contact elements. For example, a surface may comprise providing a second plurality of contact elements comprises providing female contact elements adapted to receive corresponding male contact elements of the control attachment. The method may further comprise receiving a control attachment having a third plurality of contact elements, wherein the third plurality of contact elements is coupled to the second plurality of contact elements on the surface of the power adapter. The control attachment comprises an outlet adapted to receive power by way of the third plurality of contact elements, or may comprise a switch that is accessible on an outer surface of the control attachment for controlling the application of power to a load. 
     Turning now to  FIG. 146 , a flow chart shows a method of configuring a control attachment adapted to receive power from a power adapter. A method of controlling a power adapter to provide power to a load is described. A first plurality of contact elements may be configured on an outer surface of the power adapter, the first plurality of contact elements may comprise a first contact element configured to receive power at a block  14602 . A recess comprising a second plurality of contact elements and adapted to receive a control attachment may be provided at a block  14604 . A second contact element of the second plurality of contact elements may be configured to receive power by way of the first contact element of the first plurality of contact elements at a block  14606 . A third contact element of the second plurality of contact elements configured to receive power by way of the control attachment may be provided at a block  14608 . 
     Configuring a second plurality of contact elements of the power adapter may comprise configuring female contact elements adapted to receive corresponding male contact elements of the control attachment. A switch on the power adapter may also be provided for controlling the application of power to a load. A switched outlet may also be provided for controlling the application of power to a load. A control attachment having a third plurality of contact elements coupled to the second plurality of contact elements of the power adapter may also be received by the power adapter. The application of power to a load may be controlled in response to signals received by a control attachment. 
     While the specification includes claims defining the features of one or more implementations of the invention that are regarded as novel, it is believed that the circuits and methods will be better understood from a consideration of the description in conjunction with the drawings. While various circuits and methods are disclosed, it is to be understood that the circuits and methods are merely exemplary of the inventive arrangements, which can be embodied in various forms. Therefore, specific structural and functional details disclosed within this specification are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the inventive arrangements in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting, but rather to provide an understandable description of the circuits and methods. 
     It can therefore be appreciated that new circuits for, systems for and methods of implementing power adapters have been described. It will be appreciated by those skilled in the art that numerous alternatives and equivalents will be seen to exist that incorporate the disclosed invention. As a result, the invention is not to be limited by the foregoing embodiments, but only by the following claims.