Abstract:
A power outlet device for regulating the operation of an appliance, such as a window mounted air conditioner is provided. The device includes a power inlet and a power outlet coupled to a switch. A controller having a communications device controls the state of the switch. The controller is connected to a temperature sensor that measures the ambient temperature of the room. A user interface allows the user to define a maximum temperature for the room. In response to the receipt of a signal via the communications device, the controller regulates the flow of electrical power to the appliance based on the defined maximum temperature. A timer is also provided that minimizes short time period cycling of the appliance.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The subject matter disclosed herein relates to power outlet and in particular to a power outlet having a controller for regulating the operation of an appliance. 
         [0002]    Air conditioning units, such as those mounted in windows, are a popular appliance that is broadly utilized during warm weather periods. These appliances are popular since they may be added to an existing space by a homeowner or apartment resident without need for contractors. This is especially advantageous where the space is rented and the lease prohibits modification of the structure. The appliances are also movable, allowing them to be installed when desired and removed when the tenant moves or during cooler weather conditions. 
         [0003]    While air conditioning appliances are convenient for homeowners and tenants, these appliances consume a large amounts of electrical power. This may be especially problematic in large metropolitan areas having a high population density. While central or whole-building air conditioning system can be cycled (turning the compressor off while keeping the fan on to comfort) easily by building managers or utilities during peak demand periods, window or room air conditioners do not provide an easy way for utilities to control and offer an acceptable level of comfort to the users at the same time. 
         [0004]    Accordingly, while existing appliance control systems are suitable for their intended purpose, there remains a need for improvements in coordinating control of a plurality of individual appliances during peak demand time periods and offer the adequate level of comfort to the users. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0005]    According to one aspect of the invention, a power outlet device is provided. The power outlet device includes a power inlet and a switch electrically coupled to the power inlet. The switch has a first open position and a second closed position. A power outlet is electrically coupled to the switch. A controller is operably coupled to the switch to selectively move the switch between the first position and the second position. A temperature sensor is operably coupled to the controller. A communications circuit is operably coupled to the controller. 
         [0006]    According to another aspect of the invention, a power outlet device is provided. A switch is movable between a first state and a second state. A controller is operably coupled to the switch. A temperature sensor is operably coupled to the controller. A communications device is operably coupled to the controller. Wherein the controller includes a processor that is responsive to executable computer instructions when executed on the processor for moving the switch between the first state and the second state in response to a signal from the communications device when the temperature sensor measures a temperature less than a predetermined set point. 
         [0007]    According to yet another aspect of the invention, a method of operating an air conditioning unit is provided. The method includes electrically coupling the air conditioning unit to a power outlet device having a switch arranged to electrically couple and decouple the window mounted air conditioning unit from an electrical circuit. A set point temperature is selected with a user interface on the power outlet device. An ambient temperature is measured with a temperature sensor on the power outlet device. A wireless command signal is received at the power outlet device. The air conditioning unit is decoupled from the electrical circuit with the switch in response to the wireless command signal when the measured temperature is less than the set point temperature. 
         [0008]    These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0009]    The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
           [0010]      FIG. 1  is a block diagram illustrating power outlet device in accordance with an exemplary embodiment of the invention; 
           [0011]      FIG. 2  is a block diagram of the power outlet device of  FIG. 1  coupled for communication to a home area network; 
           [0012]      FIG. 3  is a block diagram of the power outlet device of  FIG. 1  coupled for communication with an electrical utility meter; and, 
           [0013]      FIG. 4  is a flow diagram illustrating a method for operating an air conditioning appliance. 
       
    
    
       [0014]    The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    Embodiments of the invention described herein provide advantages in controlling the operation of a plurality of air conditioning appliances using a power outlet device. Embodiments of the invention, when integrated with a Home Area Network (HAN), provide advantages in allowing an electrical utility or a building operator to implement demand response programs in residences using individually controlled window mounted air conditioning appliances. Embodiments of the disclosed power outlet device provide advantages in allowing a user to set a maximum temperature the conditioned space may achieve without the appliance operating. The disclosed power outlet device may provide further advantages in allowing the set point to be locally programmed or via a computer network. The disclosed power outlet device may provide yet further advantages in allowing a user to over-ride a demand response command. 
         [0016]    An exemplary embodiment of the power outlet device  20  is illustrated in  FIG. 1 . The power outlet device  20  includes a power inlet  22  that is configured to connect with a standard electrical wall outlet plug  28 . In the exemplary embodiment, the power inlet is configured to connect with a National Electric Manufacturers Association (NEMA) type 5-15 wall outlet. The power inlet  22  is connected with a power outlet  24  by a relay or switch  26 . The power outlet  24  is configured to receive the electrical power plug, such as a NEMA 5-15 plug for example, from an appliance  30  such as a window mounted air conditioning appliance for example. 
         [0017]    The switch  26  may be any suitable device, such as a switch, a relay or a solid state device for example, capable of moving between a first state and a second state to electrically decouple and couple the appliance  30  from a source of electrical power. In the exemplary embodiment, the first state or open state is one where the appliance  30  is electrically decoupled from the wall outlet plug  28 . The second state or closed state is one where the appliance  30  is electrically coupled to the wall outlet plug  28 . It should be appreciated that when the switch  26  is in the first state, the appliance  30  will shut off and will not operate. In the exemplary embodiment, the switch  26  is configured to switch 120-240 Volts of electrical power. 
         [0018]    The power outlet device  20  further includes a control device  32 . The control device is a suitable electronic device capable of accepting data and instructions, executing the instructions to process data and storing the results. The control device may accept instructions and data through a user interface  34 , or other means such as but not limited to electronic data card, voice activation means, manually operable selection and control means, radiated wavelength and electronic or electrical transfer. Therefore, the processor  38  can be a microprocessor, microcomputer, a minicomputer, an optical computer, a board computer, a complex instruction set computer, an ASIC (application specific integrated circuit), a reduced instruction set computer, an analog computer, a digital computer, a molecular computer, a quantum computer, a cellular computer, a superconducting computer, a supercomputer, a solid-state computer, a single-board computer, a buffered computer, a computer network, a desktop computer, a laptop computer, or a hybrid of any of the foregoing. 
         [0019]    It should be appreciated that while the control device  32  is described herein as a digital processor, this is for exemplary purposes and embodiments of the control device  32  may also be embodied as an analog circuit. 
         [0020]    In the exemplary embodiment, the control device  32  includes a controller  36  having a processor  38  and memory  40 . The controller  36  is coupled to transmit a signal to the switch  26  and cause the switch  26  to move between the first state and the second state. The memory  40  may include one or more types of memory, including random access memory (RAM), non-voltile memory (NVM) or read-only memory (ROM). 
         [0021]    The controller  36  includes operation control methods embodied in application code, such as that illustrated in  FIG. 4  for example. These methods are embodied in computer instructions written to be executed by the processor  38 , typically in the form of software. The software can be encoded in any language, including, but not limited to, assembly language, VHDL (Verilog Hardware Description Language), VHSIC HDL (Very High Speed IC Hardware Description Language), Fortran (formula translation), C, C++, Visual C++, Java, ALGOL (algorithmic language), BASIC (beginners all-purpose symbolic instruction code), visual BASIC, ActiveX, HTML (HyperText Markup Language), and any combination or derivative of at least one of the foregoing. Additionally, an operator can use an existing software application such as a spreadsheet or database and correlate various cells with the variables enumerated in the algorithms. In one embodiment, the controller  36  includes an imbedded web server that allows service personnel to communicate with the controller  36  from remote locations. Furthermore, the software can be independent of other software or dependent upon other software, such as in the form of integrated software. 
         [0022]    As will be discussed in more detail below, the user may interact with the controller  36  via the user interface  34 . In the exemplary embodiment, the user interface  34  includes a digital display  42  that displays the current set point defined by the user. The user interface  34  may also include buttons or actuators, such as first actuator  44  and a second actuator  46  for example. The user depresses the actuators  44 ,  46  to raise and low the desired set point. The user interface  34  may further have an override button or selector that allows the user to bypass the control functionality of the controller  36  and moves the switch  26  to the closed state. 
         [0023]    Control device  32  further includes a temperature sensor  48  that measures the ambient temperature of the environment in which the power outlet device is located. The temperature sensor  48  transmits a signal to the controller  36  that indicates the ambient temperature. In one embodiment, the temperature sensor  48  may be a thermocouple or a thermistor for example. In another embodiment, the temperature sensor  48  may be bimetal strip coupled to a mercury switch. 
         [0024]    The control device  32  further includes a communications device  50  that is coupled to send and receive signals from the controller  36 . In the exemplary embodiment, the communications device  50  provides a means for the controller  36  to communicate signals embodying information on communications carriers as will be described in more detail herein. The communications device  50  may incorporate any type of communications protocol capable of allowing the controller  36  to receive, transmit and exchange information with one or more external devices. Communications device  50  may use wireless communication systems, methodologies and protocols such as, but is not limited to, IEEE 802.11, IrDA, infrared, radio frequency, electromagnetic radiation, microwave, Bluetooth, and laser. Further, communications device  50  may include one or more wired communications systems, methodologies and protocols such as but not limited to: TCP/IP, RS-232, RS-485, Modbus, power-line, telephone, local area networks, wide area networks, Ethernet, cellular, and fiber-optics. 
         [0025]    In the exemplary embodiment, the communications device  50  may include one or more communications circuits or devices, such as IEEE 802.11 device commonly referred to as Wifi, a satellite device, a CDMA compliant cellular device, a GSM compliant cellular device, a radio frequency device, a IEEE 802.15.4 device commonly referred to as Zigbee, and a Bluetooth compliant device. In the exemplary embodiment, the communications device  50  is an IEEE 802.15.4 device that communicates with a home area network. In another embodiment, the satellite device transmits data on a frequency range of 3 to 40 gigahertz. In another embodiment, the radio frequency device transmits on a frequency range of 30 kilohertz to 3000 megahertz. The controller  36  may further include an optional antenna to assist in the transmission to the communication medium or carrier. 
         [0026]    In one embodiment, the control device  32  may also include a timer  52 . As will be discussed in more detail below, the timer  52  is activated when the switch  26  is move between the first state and the second state. The timer  52  measures a predetermined amount of time, such as ten (10) minutes for example, and is used to prevent the power outlet device  20  from repeatedly cycling the electrical power to the air conditioning appliance  30  at a shorter than desired interval. It is believed that repeated cycling of the air conditioning appliance  30  may result in unnecessary wear on the air conditioner compressor and other internal components. It should be appreciated that while the timer  52  is illustrated as separate from the controller  36 , the timer  52  may be embodied in software executed on the processor  38 , on a separate processor (not shown), or as an analog circuit. 
         [0027]    In operation, the power outlet device  20  is plugged into a wall outlet  28  as illustrated in  FIG. 2 . The power outlet device  20  communicates with communication device  50  with a home area network  53  using a communications protocol such as IEEE 802.15.4 for example. This provides two-way communications that allow the power outlet device  20  to transmit signals, such as the temperature set point or switch  26  state for example, and to receive signals. In one embodiment, the utility or electric power provider may have a program sometimes referred to as a “demand response program” for lowering energy consumption during peak periods to reduce the stresses on the electrical network. In this embodiment an external party, such as utility  54  for example, transmits a signal via the Internet  56 . The signal is addressed to the power outlet device  20  and is received via a computer or router  58 . The router  58  transmits the signal via the home area network  53  to the power outlet device  20 . As will be discussed in more detail below, when the power outlet device  20  receives the signal, the power outlet device  20  will selectively couple and decouple electrical power to the air conditioning appliance  30 . It should be appreciated that while embodiments herein describe the external party transmitting the signal as a utility, the claimed invention should not be so limited and the transmitting entity may be a public utility, an energy provider, a power aggregator, a building owner, or a building manager for example. In one embodiment, the signal may be transmitted or originate from a building management system. 
         [0028]    Another embodiment where the power outlet device  20  receives a signal from an external party, such as utility  54  for example, is illustrated in  FIG. 3 . In this embodiment, the utility  54  includes an infrastructure that allows for two-way communication with electrical meters  60 . In one embodiment, the electrical meter is an Advanced Metering Infrastructure (“AMI”). The AMI meter  60  has a processing and communication circuits that allow the meter  60  to communicate information and receive instructions from the utility  54 . The meter  60  further has communications circuitry to communicate with the home area network  53 . This may allow the customer to control or monitor their electrical consumption in real-time or near-real time such as with a person computer  64  or a mobile device (e.g. cell phone) for example. The communications between the meter  60  and the home area network  53  may be wireless, using a protocol such as IEEE 802.15.4 (e.g. Zigbee) for example, or using a wired connection such as Ethernet or powerline carrier systems for example. 
         [0029]    When the utility desires to reduce demand on the electrical grid, a first signal is transmitted from the utility  52  through the communications infrastructure  62  to the meter  60 . The meter  60  receives the first signal from the utility and transmits a second signal to the power outlet device  20  via the home area network  53 . In one embodiment, the second signal may pass through an intermediary device  66  connected to the home area network  53 . The intermediary device  66  may be a home energy monitor  66  or base unit that allows the user to monitor and/or control appliances to reduce energy consumption. When the power outlet device  20  receives the signal, the power outlet device  20  will selectively couple and decouple electrical power to the air conditioning appliance  30  to reduce electrical consumption as will be discussed in more detail below. 
         [0030]    Referring now to  FIG. 4 , a method  68  of operating the power outlet device  20  will be described. The method  68  starts in block  70  and proceeds to query block  72  where it is determined if there is a demand response signal from the utility or energy provider. As discussed above, the demand response signal may come from any source that the user provides access, such as the electrical utility, a power aggregator or even the user themselves. In one embodiment, the signal may be transmitted by the user remotely via their cellular phone or other wireless device for example. If the query block  72  returns a negative, the method  68  proceeds to block  74  where the switch  26  is set to the closed or connected state and the method  68  loops back to start block  70 . 
         [0031]    If query block  72  returns a positive, meaning that a signal has been received, the method  68  proceeds to query block  76  where it is determined if the temperature at the power outlet measured by sensor  48  is greater than the temperature T set  defined by the user via user interface  34 . It should be appreciated that if the user defines T set  to be a higher temperature than the normal operating temperature of the air conditioning appliance, then there will be a reduction in electrical usage by the air conditioning appliance. If the query block  72  returns a negative, meaning the measured temperature is less than T set , then the method  68  proceeds to block  78  where a where the switch  26  is moved to the open state and the power to the air conditioning appliance is halted. If the query block  72  returns a positive, meaning the measured temperature is greater than T set , then the method  68  proceeds to block  80  where the switch  26  is closed allowing electrical power to flow to the air conditioning appliance. It should be appreciated that if the switch  26  is already in the desired position or state when the method  68  reaches block  74 , block  78  or block  80 , then the switch  26  simply remains in the desired position. 
         [0032]    After completing block  78  or block  80 , the method proceeds to block  82  where the timer  52  is initiated. It has been found that repeated cycling of the power to an air conditioning appliance may result in unnecessary wear on the appliances components, such as the compressor for example. Therefore, the timer  52  is initiated to allow a predetermined amount of time to elapse before the state of switch  26  may be changed. In the exemplary embodiment, the timer  52  is set for ten (10) minutes. 
         [0033]    Once the timer  52  is initiated, the method  68  proceeds to query block  84  where it is determined if the timer  52  has expired. If the query block  84  returns a positive, meaning the timer  52  expired, then the method  68  loops back to query block  72  to determine if the demand response or demand curtailment is still desired. If the query block  84  returns a negative, then method  68  proceeds to query block  86  where it is determined if the customer has overridden the set temperature. In one embodiment, the power outlet device  20  has an override selector that allows the user to prevent the device  20  from turning the air conditioner appliance off. If the query block  86  returns a positive, the method  68  loops back to block  74  where the state of the switch  26  is set to the closed state or position. If the query block  86  returns a negative, the method  68  loops back to query block  84  until the timer  52  expires. 
         [0034]    While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.