Wiring device with heat removal system

Abstract

A wiring device includes a housing that encloses a line voltage port and/or a low voltage port for providing power to at least one removable load. The housing has an intake opening and an exhaust opening for drawing cooling air into the housing and for exhausting heated air. A fan is disposed within the housing and operates to move the air through the housing. A thermal load such as a heat sink or a transformer is positioned within the housing and receives cooling air to reduce the temperature of the load. The fan is energized when a sensed temperature in the housing exceeds a first predetermined threshold. Power to the line and/or low voltage port is reduced or shut off if the sensed temperature in the housing exceeds a predetermined value that is greater than the first predetermined threshold.

What is claimed is: 
     
         1 . An in-wall electrical outlet comprising:
 a housing sized and configured as a single gang wall box mounted device, the housing including a low voltage port configured to provide power to a removable load, the housing having at least one opening configured to allow intake air to be drawn therethrough and exhaust air to be expelled therethrough;   a fan at least partially disposed within the housing, the fan operable to draw the intake air and to expel the exhaust air through the at least one opening;   a thermal load disposed at least partially within the housing;   a temperature sensor configured to sense a temperature of an internal portion of the housing;   a microcontroller logic circuit configured to determine a temperature hysteresis based on a plurality of sensed temperatures, the microcontroller logic circuit further configured to selectively energize the fan; and   wherein the microcontroller logic circuit selectively energizes the fan in accordance with the temperature hysteresis when the sensed temperature exceeds a first predetermined threshold.   
     
     
         2 . The electrical outlet of  claim 1  wherein the thermal load is positioned at least partially within an airflow path between the intake air and the exhaust air. 
     
     
         3 . The electrical outlet of  claim 1 , wherein energizing the fan comprises adjusting a speed of the fan. 
     
     
         4 . The electrical outlet of  claim 1 , wherein the at least one opening further comprises an intake opening and an exhaust opening, and wherein the fan is operable to draw the intake air through the intake opening and to expel the exhaust air through the exhaust opening. 
     
     
         5 . The electrical outlet of  claim 1 , wherein the microcontroller logic circuit is configured to de-energize the fan in accordance with the temperature hysteresis when the sensed temperature is determined to be below a second predetermined threshold, the second predetermined threshold being lower than the first predetermined threshold. 
     
     
         6 . The electrical outlet of  claim 5 , wherein the microcontroller logic circuit is configured to adjust a speed of the fan dependent upon the temperature hysteresis and the sensed temperature. 
     
     
         7 . The electrical outlet of  claim 1 , wherein a current to the low voltage port is reduced to a non-zero magnitude so that the outlet operates in a reduced power mode when the sensed temperature is determined to be above the first predetermined threshold. 
     
     
         8 . The electrical outlet of  claim 7 , wherein the microcontroller logic circuit is configured to vary a speed of the fan dependent upon the temperature hysteresis and the sensed temperature. 
     
     
         9 . The electrical outlet of  claim 7 , wherein the microcontroller logic circuit uses the temperature hysteresis and compares the sensed temperature to the first predetermined threshold and a second predetermined threshold and in accordance with the temperature hysteresis selectively energizes the fan based on the comparison. 
     
     
         10 . The electrical outlet of  claim 1 , wherein the thermal load is at least one of a transformer and a heat sink. 
     
     
         11 . The electrical outlet of  claim 1 , wherein the low voltage port is configured to provide one of: a predetermined amount of power to the removable load, an amount of power required by the removable load, and a level of power based on the removable load. 
     
     
         12 . The electrical outlet of  claim 1  further comprising a cover plate, wherein the in-wall electrical outlet is flush mounted within an electrical box and the cover plate is configured to conceal at least a portion of the strap and at least a portion of the housing. 
     
     
         13 . The electrical outlet of  claim 1  further comprising a fan control circuit coupled to the fan and the microcontroller logic circuit, the fan control circuit is a switching circuit configured to selectively energize the fan. 
     
     
         14 . An in-wall electrical outlet comprising:
 a housing sized and configured as a single gang wall box mounted device, the housing at least partially enclosing a low-voltage electrical port, the low voltage electrical port being configured to provide power to a removable load, the housing including at least one opening configured to allow intake air to be drawn therethrough and exhaust air to be expelled therethrough;   a strap to fasten the housing to an electrical box located in a wall or ceiling;   a fan at least partially disposed within the housing, the fan operable to draw intake air and exhaust air through the at least one opening;   a temperature sensor configured to determine a sensed temperature of an internal portion of the housing;   a microcontroller logic circuit;   a thermal load at least partially disposed within the housing; and   wherein the microcontroller logic circuit is configured to:
 determine a temperature hysteresis based on a plurality of sensed temperatures; 
 energize the fan in accordance with the temperature hysteresis when the sensed temperature is determined to exceed a first predetermined threshold; 
 de-energize the fan when the sensed temperature is determined to be below a second predetermined threshold, the second predetermined threshold being lower than the first predetermined threshold. 
   
     
     
         15 . The electrical outlet of  claim 14  wherein the fan is positioned adjacent to the thermal load such that, when the fan is energized, the thermal load is at least partially within an airflow path between the intake air and the exhaust air. 
     
     
         16 . The electrical outlet of  claim 14 , wherein the at least one opening further comprises an intake opening and an exhaust opening wherein the fan is operable to draw the intake air through the intake opening and to expel the exhaust air through the exhaust opening. 
     
     
         17 . A method for removing heat from an in-wall electrical outlet having a strap to fasten the outlet to an electrical box located in a wall or ceiling, the method comprising:
 receiving a current from a power supply;   providing the received current to a low voltage port of the outlet;   providing a first removable load with the current via the low voltage port of the outlet;   determining a plurality of sensed temperatures within a housing of the outlet;   determining a temperature hysteresis based on the plurality of sensed temperatures;   energizing a fan disposed within a housing of the outlet in accordance with the temperature hysteresis when the sensed temperature inside of the housing is determined to exceed a first predetermined threshold;   de-energizing the fan when the sensed temperatures inside of the housing is determined to be below a second predetermined threshold, the second predetermined threshold being lower than the first predetermined threshold.   
     
     
         18 . The method of  claim 17 , further comprising, when the fan is energized, drawing cooling air into the housing and exhausting heated air out of the housing through at least one opening in the housing. 
     
     
         19 . The method of  claim 18 , further comprising, when the fan is energized, drawing cooling air into the housing through an intake opening and exhausting heated air out of the housing through an exhaust opening. 
     
     
         20 . The method of  claim 17 , further comprising passing air from the fan over a thermal load located at least partially within the housing when the fan is energized.