Patent Publication Number: US-7906873-B1

Title: Modular wall box system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of application Ser. No. 12/652,429, entitled “Modular Wall Box System,” which has been formally allowed, the entire contents of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     Aspects of the present invention are directed to a modular wall box system. 
     A conventional wall box device that controls power delivered to a load and is fed with line voltage generally integrates load actuation and user interface functionality into a single device. Such devices include, for example, light dimmers for interior spaces. These light dimmers often feature replaceable front plates that are attached through a simple snap mechanism to the dimmer device. In some cases, multiple dimmers can be ganged together and finished by application of a cover plate made for the multi-gang box. Ganging of devices makes it possible to install triac-based dimmers, FET-based dimmers, relays and timers side-by-side. 
     It has been shown, however, that ganging devices of multiple vendors, or even the ganging of different product series by the same vendor, can often create slight esthetic problems due to the different materials, dimensions and color variations each product line features. In order to provide for more stringent esthetics, manufactures often feature devices that differ from the typical device dimensions to avoid the problem of mismatching. 
     To cater to the different tastes and requirements of the public, suppliers of wall box devices also offer different user interfaces, such as dimmers combined with a toggle switch, dimmers combined with a paddle switch, dimmers combined with a push-button switch, dimmers combined with a touch screen and so on. These user interfaces need to be produced in various device types, such as a 2-way dimmer, a 3-way dimmer, a FL-light dimmer, a remote controllable dimmer and so on. Unfortunately, in current devices, should a customer desire to change the user interface, say from a toggle switch to a paddle switch, the entire device has to be dismounted. This is wasteful as a perfectly good working dimming actuator has to be removed and often discarded for the sole purpose of upgrading the user experience. Further, if this operation is performed in commercial applications, in many instances the changing of a light dimmer needs to be executed by a licensed electrician with costs associated that often exceed the cost of the dimmer itself. Another problem arises when user interfaces become significantly costlier in relation to the load actuating parts. For example, the cost of a user interface that is based on an LCD and a touch screen, or the cost of a user interface with customized artwork often exceeds the cost of the dimming actuator. Should this actuator part fail, due to an overload situation during installation, a load failure such as a burned-out light bulb or the impact of a near-by lighting strike, the entire device would have to be removed and replaced in an unnecessarily wasteful and costly procedure. 
     A user interface being an integral part of a load controlling device is a further burden on the manufacturer. Customers often demand that devices installed comply with local and national building codes, such as the National Electric Code (NEC) and a common request is that devices are certified by Underwriter&#39;s Laboratories (UL) and or the Electrical Testing Laboratory (ETL). When a supplier of load controlling devices introduces a new series of products, they have to go through the entire certification process, even if, in essence, the load bearing and safety related aspects stay the same and just a new housing or user interface concept is applied. This slows down the development process and increases the cost of the product development. 
     For the stated reasons, it is desirable to methodically decouple the load actuating device part from the user interface so that they can be treated as two separate devices from a design, systems integration, installation and maintenance view point. 
     SUMMARY 
     In accordance with an aspect of the invention, a device is provided and includes an actuator, mounted to a wall box, including a power supply, a semi-conductor switch, an electrical load controller and a terminal coupled to the power supply and the controller, an actuator interface disposed to receive first commands relating to basic electrical load control by the controller and a separate interface, including a header to communicate with the terminal whereby the separate interface receives power and communicates with the controller, the separate interface being supportable at the wall box and, when the header and terminal communicate, configured to identify a type of the semi-conductor switch of the actuator and to receive second commands of a type unique to the identified actuator type and relating to the basic and enhanced electrical load control by the controller. 
    
    
     
       BRIEF DESCRIPTIONS OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other aspects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a view of a modular wall box system assembly; 
         FIG. 2  is a block diagram of a load bearing actuator device; 
         FIG. 3  illustrates inductive power transfer between an actuator device and a separate user interface; 
         FIG. 4  is a view of a multi-gang modular wall box system assembly; 
         FIG. 5  is a block diagram of a separate user interface for a single gang box device; 
         FIG. 6  is a block diagram of a separate user interface for a multi-gang box device; 
         FIG. 7  is a block diagram of power supplies of actuator devices that support paralleling at the separate user interface device; 
         FIG. 8  illustrates an external switch as being part of a construction cover; and 
         FIG. 9  illustrates a switch external from a load bearing actuator. 
     
    
    
     DETAILED DESCRIPTION 
     In accordance with aspects of the invention, a load bearing wall box device is provided with a relatively simple user interface for ON/OFF control that can be installed and operated independently from a final user interface. The final user interface may be compatible with other load bearing devices that receive power for their operation from the load bearing wall box device and may control the latter with enhanced capabilities, such as dimming or timing. A modular actuator and user interface method are provided that allow for the combination of various user interface types with various actuator types. 
     Other aspects of the invention provide for the ganging of load bearing devices in wall boxes for both new and retrofit installations and a user interface. The user interface offers shared resources such as microprocessor resources and communication transponders for multiple load bearing actuator devices and is capable of identifying the type of the connected wall box load actuating device. The user interface may also operate the actuator based on a programmed rule set that includes the possibility to reject operation if the load or actuator does not conform to a preset rule. 
     The load actuating wall box device can be certified by UL and ETL without a final user interface having been installed, with the final user interface being a class-2, low voltage, device that does not require UL or ETL approval. The load actuating wall box device can be installed without the final user interface in place and then operated in a construction mode until the final user interface arrives at the project site just before arrival of the tenants. 
     Accordingly, a modular wall box system includes a series of load bearing control devices with their own simple user interface. These load bearing devices can be triac-based dimmers, FET-based dimmers or relay controllers. These load bearing devices provide power to a user interface and provide the necessary means to be controlled by the user interface. The power connection and communication components between the load bearing device and the user interface are standardized so that every load bearing device can be operated from any compatible user interface device. The load bearing actuator devices provide for identification by the user interface so that the user interface can adapt its functionality to the corresponding capabilities and loads. In accordance with the aspects of the present invention, the resources of the user interface, such as the microprocessor, the touch screen, the backlighting infrastructure and the communication unit can be shared across multiple load bearing actuator devices for improved economy. 
     Referring now to  FIGS. 1 and 2 , a modular wall box system in accordance with aspects of the invention includes a load bearing actuator  10 , a yoke  11  and a separate user interface  20 . The load bearing actuator  10  is supportably mounted proximate to a user accessible portion  31  of a wall box  30  and includes a power supply  54  and an electrical load controller  57  to control an electrical load  51 . An actuator interface  14 , such as a slider switch, is disposed on the load bearing actuator  10 . The actuator interface  14  is receptive of first commands relating to basic electrical load control by the controller  57  that are to be transmitted to the controller  57 . A communication system, including a terminal  12  that is disposed on the load bearing actuator  10 , is coupled to the power supply  54  and the controller  57 . 
     The separate user interface  20  includes a cable  22  and a header  21  to communicate with the terminal  12  whereby the separate user interface  20  receives power and communicates with the controller  57 . The separate user interface  20  is removably supportable at the user accessible portion  31  of the wall box  30  and, when the header  21  and the terminal  12  communicate with one another, is configured to identify a type of the load bearing actuator  10  and to receive second commands of a type unique to the identified type of the load bearing actuator  10 . These second commands relate to both the basic electrical load control by the controller  57  and to enhanced electrical load control by the controller  57  and are to be transmitted to the controller  57 . 
     The basic electrical load control may refer to various relatively simple controls, such as on/off switching or possibly light dimming. The enhanced electrical load control may include those basic controls and additional functionality. For example, the enhanced electrical load control may include dimming, user interface backlighting, LCD control, touch-sensitive control, user proximity sensing, communication transponder operation, scene control participation, demand-based control and occupancy-based control. 
     The user accessible portion  31  of the wall box  30  will generally be proximate to a face of the wall box  30  that faces an interior of a space to be occupied by a user, such as a hotel room or an office. The load bearing actuator  10  may be fastened to yoke  11  by any known method, such as a four screw mounting or some other similar method, and may then be positioned within a cavity of the wall box  30  such that the actuator interface  14  faces the space. The load bearing actuator  10  may further include an indicator LED  13  to indicate the present status of the load and the terminal  12 . The terminal  12  may be a connector by which power and communications may be provided to the separate user interface  20 . 
     The load bearing actuator  10 , being attached to yoke  11 , may be fastened by, for example, a two screw mounting into the wall box  30  with line voltage connection wires from a power supply and/or the load  51  being connected to the load bearing actuator  10  via actuator wires  15 . Yoke  11  may serve as a heat sink for the load bearing actuator  10  and may be made of metal or some other similar material that provides for efficient heat transfer characteristics. 
     The separate user interface  20  is electrically coupled to the load bearing actuator  10  through a cable  22 , such as a flat ribbon cable or some other similar type of cable, which is terminated with the header  21 . The header  21  is insertable into terminal  12  or otherwise able to communicate with the terminal  12 . In an exemplary embodiment, the header  21  and the terminal  12  are standardized such that the separate user interface  20  can be mated and, therefore, electrically coupled with any type of load bearing actuator  10  in which case the separate user interface  20  will receive different sets of unique second commands. 
     In a further exemplary embodiment, the separate user interface  20  may be magnetically mounted onto or otherwise mechanically fastened to either the yoke  11  or the wall box  30  in such a way as to cover the user accessible portion  31  of the wall box  30  and the load bearing actuator  10 . As such, the outward appearance of the modular wall box system will be established by the appearance of the separate user interface  20 , which can be designed with any number of visual and/or functional options. In addition, the actuator interface  14  may be covered and, therefore, inaccessible to a user with the basic electrical load control being provided by the separate user interface  20 . 
     With reference now to  FIG. 2 , the load bearing actuator  10  is illustrated as a device that provides for electronic dimming control although it is understood that this is merely exemplary and that other configurations are possible. As shown in  FIG. 2 , the load bearing actuator  10  may include semiconductor switch  50 , which is typically either a triac, which is normally used for resistive and inductive load types, or a field effect transistor (FET), which is normally used for resistive and capacitive loads. Semiconductor switch  50  modulates the line power towards the load  51  provided from source N by, e.g., modulation schemes such as leading edge or trailing edge dimming. Semiconductor switch  50  may be coupled to a heat sink  560 , which dissipates the heat generated by the semiconductor switch  50  to the environment. For additional heat dissipation, the heat sink  560  can be coupled to the yoke  11 . 
     Power to the semiconductor switch  50  can be interrupted by the air gap switch  53 . Air gap switch  53  contains a contact that can carry the entire load current and may include a plastic lever that is manually operated. With this configuration, a gate drive circuit may be set active by default if no separate user interface  20  is connected to the load bearing actuator  10  and the load  51  is relatively simply operated by operation of the air gap switch  53 . 
     Alternatively, air gap switch  53  functionality can be performed by a relay contact. In this embodiment, the size of the relay can be maintained if the switching of the load  51  is delegated to the semiconductor switch  50  and the relay changes its position only when the semiconductor switch  50  is in the off state. Here, contacts of the relay may have to be rated solely for the load current but not for the load switching aspects. This requires that the air gap switch  53  be properly timed in relation to semiconductor switch  50  such that, when the air gap switch  53  contact is closed, the semiconductor switch  50  is not operated until the contact bouncing of the relay contact has passed. Conversely, before opening the relay contacts, the current through the semiconductor switch  50  has to be fully dissipated, which, in the case of a triac-based dimmer, could mean a delay for up to a half cycle of line power. 
     Controller  57  arbitrates the signals to the semiconductor switch  50  and the air gap switch  53  and receives signals from the separate user interface  20  as to operating the air gap switch  53  (i.e., in a service mode) and the semiconductor switch  50  (i.e., a dimming control signal). The controller  57  further receives a signal from the actuator interface  14 , which may be a slider switch, and which, if closed, signals that the load  51  has to be turned off. If the actuator interface  14  is opened but the separate user interface  20  is connected to the load bearing actuator  10 , controller  57  will take the signals from separate user interface  20  into account and operate the semiconductor switch  50  and air gap switch  53  according to the signals of the separate user interface  20 . If the separate user interface  20  is not connected, the signals are defaulted to control the load  51  based on the inputs to the actuator interface  14 . Controller  57  can optionally operate LED  13  to indicate the on/off state of the load  51 . 
     Controller  57  can be implemented with a low cost microprocessor or microcontroller and may include a processing unit and a memory unit. Executable instructions may be stored on the memory unit, which when executed, cause the processing unit to operate according to a predefined set of routines. Alternatively, controller  57  can be implemented with a small number of discrete components to provide the described lock-out mechanism. 
     With reference to  FIGS. 8 and 9 , the actuator interface  14  may be disposed at a location which is remote from or otherwise external to the load bearing actuator  10 . In this case, the actuator interface  14  acts similarly to the separate user interface  20  but still does not contain customization or extended functionality to allow for, e.g., performance of functions across multiple load bearing actuators  10 . That is, a main function of an external actuator interface  14  is to provide for user control of its associated load bearing actuator  10  in a basic fashion at a location which is not strictly limited to the load bearing actuator  10 . The actuator interface  14  is also removable from the load bearing actuator  10  and replaceable by the separate user interface  20 . As shown in  FIG. 8 , the actuator interface  14  may be embodied as switch  314  mounted on, for example, a thin plastic sheet  315 . The plastic sheet  315  contains adhesive tape  316  that allows a user to stick the plastic to the yoke  11 . The plastic sheet  315 , which may be referred to as a “paint guard cover,” is slightly larger than the wall box  30  so that construction dust and paint does not impair the cleanliness of the final installation. Further, keeping the taps of the yoke  11  clean will provide a further improvement in that the separate user interface  20  will be better affixed to the yoke  11  once the construction cover gets replaced with the final separate user interface  20 . 
     The zero crossing detector  55  provides line voltage phase information to the separate user interface  20  by way of a zero crossing signal. Device identification unit  56  indicates a device type of the load bearing actuator  10  to the separate user interface  20  and may include a resistive element, with a resistance value thereof that can be measured by the separate user interface  20 . For example, a resistance value of 10 kOhm could indicate a triac-based dimmer for light control applications, a 12 kOhm resistor could be a FET-base dimmer for light control applications, a 15 kOhm resistor could identify a relay controller and a 20 kOhm resistor could identify a variable speed motor controller. 
     The ability of the separate user interface  20  to identify a type of the load bearing actuator  10  allows the separate user interface  20  to be customizable on-site such that, for example, the separate user interface  20  could be installed onto different load bearing actuators  10  and have the ability modify its own functionality for each. As an example, the separate user interface  20  could be first installed on a light dimming load bearing actuator  10  and then onto an environment controlling load bearing actuator  10 . In the first case, the separate user interface  20  is programmed to identify the light dimming function of the load bearing actuator  10  and to thus provide light dimming control options to a user along with other light scene control options. These exemplary “lighting control options” would be a first type of second commands. In the latter case, the separate user interface  20  identifies the environment control function of the load bearing actuator  10  and thus provides environmental controls along with additional associated controls. These exemplary “environmental control options” would be a second type of second commands. 
     Controller  57  may be implemented as a microcontroller that manages signal protocols between the load bearing actuator  10  and the separate user interface  20 . In an exemplary embodiment, the zero crossing signal of the zero crossing detector  55  would be fed directly to controller  57  and the separate user interface  20  would send control commands, such as device control signal commands for setting the dim level to a specific value or to operate the air gap switch  53 , to the controller  57 . Further, a protocol-based link between the load bearing actuator  10  and the separate user interface  20  also allows for the storing of the device identification unit  56  inside the microcontroller memory. 
     The load bearing actuator  10  contains the power supply  54 . The power supply  54  provides power to all or most of the components inside the load bearing actuator  10  and to the separate user interface  20  by way of the terminal  12 , which provides for both the powering of the separate user interface  20  and the transmission of data signals between the load bearing actuator  10  and the separate user interface  20 . The data signals may include the zero crossing signal and data reflective of the product identification information of the load bearing actuator  10 . The separate user interface  20  transmits the timing signals to operate the semiconductor switch  50  and a signal that is used to operate the air gap switch  53 . If the load bearing actuator  10  uses a microprocessor as controller  57 , the protocol between the load bearing actuator  10  and the separate user interface  20  may be based on, for example, an IIC or an SPI protocol. 
     In an embodiment, power to the separate user interface  20  may be transmitted through inductive coupling with communication between the load bearing actuator  10  and the separate user interface  20  occurring through short-haul wireless means, such as IrDA transceivers. As an example, as shown in  FIG. 3 , the load bearing actuator  10  creates an AC voltage (AC power in) that is fed to the primary winding  100  of a split-core transformer. In the separate user interface  20 , the secondary coil  101  of this split core transformer receives the transmitted power and the voltage is fed into a rectifier  102  and a filter capacitor  103 . This magnetically coupled power can then be further processed and used in the separate user interface  20 . The communication between the load bearing actuator  10  and the separate user interface  20  can be performed by commercially available IrDA transponders. 
     With reference to  FIG. 4 , an embodiment of a multi-gang application is shown. Here, two load bearing actuators  10 A and  10 B are mounted on a single yoke  11  of double-gang size. Each load bearing actuator  10 A and  10 B is electrically a self-contained product with its own power supply, terminals  12 A and  12 B and actuator interfaces  14 A and  14 B, respectively, to control the respective loads for each when no separate user interface  20  is present. In this configuration, the separate user interface  20  features two cables  22 A and  22 B, each of which is terminated a header  21 A and  21 B. When the electrical connections between the load bearing actuators  10 A and  10 B and the headers  21 A and  21 B are made by way of the terminals  12 A and  12 B, the separate user interface  20  identifies the respective types of both of the load bearing actuators  10 A and  10 B and operates each of them. 
       FIG. 5 . shows a schematic illustration of the separate user interface  20  according to embodiments of the invention. Separate user interface  20  is connected via cable  22  and header  21  to the load bearing actuator  10 . Through cable  22 , the power supply  202  of the separate user interface  20  is received along with load bearing actuator  10  identification information and zero-crossing signals. By way of software or suitable executable instructions stored in a memory of the controller  201 , controller  201  scans for user inputs inputted through a keypad embodied by, e.g., switches  203  or other similar devices such as capacitive touch interfaces, resistive touch screens and sliders. Controller  201  also operates visual indicators  204 , which can be LEDs or strings of LEDs, an LCD or an OLED. Controller  201  may further operate a wireless transponder  205  or, in some cases, a networking unit, to communicate with remote system parts  250  of a larger building control application. The load bearing actuator  10  can also be remotely controlled through transponder  205 . Additionally, user interactions at the separate user interface  20  can be reported to remote locations. Such events could, for example, include a light scene command that is broadcasted to other members of a larger system. 
       FIG. 6  shows a schematic illustration of a separate user interface  20  for a multi-gang application in accordance with embodiments of the invention. Here, the power of load bearing actuators  10 A and  10 B can be provided in parallel to the separate user interface  20 . Controller  201  maintains a separate communication link to each load bearing actuator  10 A and  10 B and thereby identifies the device type of each load bearing actuator  10 . For this communication link, a multiplexed bus system can be considered as long as the separate user interface  20  can differentiate between the exact gang position of the load bearing actuators  10 A and  10 B so that they can be operated in a meaningful way. 
     As shown in  FIG. 6 , the shared separate user interface  20  operates in a similar fashion as described above. That is, through cables  22 A and  22 B, the power supply  202  of the separate user interface  20  is received along with load bearing actuator  10 A and  10 B identification information and zero-crossing signals. By way of software or suitable executable instructions stored in a memory of the controller  201 , controller  201  scans for user inputs inputted through a keypad embodied by, e.g., switches  203  or other similar devices such as capacitive touch interfaces, resistive touch screens and sliders. Controller  201  also operates visual indicators  204 , which can be LEDs or strings of LEDs, an LCD or an OLED. Controller  201  may further operate a wireless transponder  205  or, in some cases, a networking unit, to communicate with remote system parts  250  of a larger building control application. The load bearing actuator  10  can also be remotely controlled through transponder  205 . Additionally, user interactions at the separate user interface  20  can be reported to remote locations. Such events could, for example, include a light scene command that is broadcasted to other members of a larger system. 
       FIG. 7  shows a schematic power supply diagram for the power supplies of load bearing actuators  10 A and  10 B. As examples, load bearing actuator  10 A contains a power supply  71 , such as a switched-mode power supply with a 12VDC/100 mA capability and load bearing actuator  10 B contains a power supply  72 , such as a switched-mode power supply with a 12VDC/200 mA capability. Each power supply  71  and  72  may contain a resistive element R A    73  and R A    74 , respectively, such as a shunt resistor, which are each configured such that the respective output voltages V A  and V B  reach a specific voltage below, e.g., a nominal 12VDC output. For example, the output voltage at full nominal current could be defined as 1 VDC below the nominal non-loaded power supply voltage. This is achieved by making resistive element R A    73  a 10 Ohm resistor and resistive element R A    74  a 5 Ohm resistor. The power supplies of load bearing actuator  10 A and  10 B can now be safely paralleled and the total current consumed by the power supply  75  in the separate user interface  20  properly balances the current from each power supply of the load bearing actuators  10 A and  10 B. 
     While the disclosure has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the disclosure not be limited to the particular exemplary embodiment disclosed as the best mode contemplated for carrying out this disclosure, but that the disclosure will include all embodiments falling within the scope of the appended claims.