Current sensing load demand apparatus and methods

Abstract

An apparatus supplies AC power to a load. The apparatus includes a set output terminals, a primary circuit, and a load sensing circuit. The primary circuit is electrically coupled to a source of AC power and to the output terminals for selectively providing power at a low voltage at the output terminals or electronically coupling the source of AC power directly to the output terminals. The load sensing circuit coupled to the primary circuit and the source of AC power for determining a resistance associated with the load at initial application of the load and controlling the primary circuit to electronically couple the source of AC power directly to the output terminals if a proper load is detected.

What is claimed is: 
     
         1 . An apparatus for supplying power to a load, comprising:
 a pair of output terminals;   a primary circuit electrically coupled to a source of power and to the output terminals for selectively providing power to the output terminals, the primary circuit for providing power at the low voltage at the application of the load, the primary circuit including a sensor for detecting application of the load; and,   a load sensing circuit coupled to the primary circuit and the source of power for determining a resistance associated with the load at initial application of the load and controlling the primary circuit to electronically couple the source of power directly to the output terminals if a proper load is detected, the load sensing circuit for sensing application of a proper load or an improper load at application of the load.   
     
     
         2 . An apparatus, as set forth in  claim 1 , the primary circuit electrically for selectively electronically coupling the source of power directly to the output terminals. 
     
     
         3 . An apparatus, as set forth in  claim 1 , wherein the load sensing circuit continues to supply power at the low voltage at least during initial load characteristics associated with the application of the load. 
     
     
         4 . An apparatus, as set forth in  claim 1 , the primary circuit including a switch coupled between the source of power and the output terminals and having a first position where power at the low voltage is provided at the output terminals and a second position where the source of power is electrically coupled directly to load, the load sensing circuit including a microcontroller coupled to the primary circuit, the microcontroller for monitoring a value of the low voltage during initial application of the load and controlling the switch in response thereto. 
     
     
         5 . An apparatus, as set forth in  claim 1 , including a second pair of output terminals and a second primary circuit, the second primary circuit being electrically coupled to the source of power and to the second pair of output terminals for selectively providing power at a low voltage to the second pair of output terminals, the second primary circuit for normally providing power at the low voltage at the second pair of output terminals when no load is connected to the second pair of output terminals, wherein the load sensing circuit is coupled to the second primary circuit power supply for determining a resistance associated with a second load at the second pair of output terminals at initial application of the second load and controlling the second primary circuit to electronically couple the source of power directly to the second pair of output terminals if a proper load is detected at the second pair of output terminals. 
     
     
         6 . An apparatus, as set forth in  claim 5 , the second primary circuit electrically for selectively electronically coupling the source of power directly to second pair of the output terminals. 
     
     
         7 . An apparatus, as set forth in  claim 1 , wherein the apparatus is embodied in an electrical receptacle, the output terminals being electrically coupled to respective female openings for receiving a respective prong of a plug of the load. 
     
     
         8 . An apparatus, as set forth in  claim 7 , wherein the sensor is coupled to the load sensing circuit for detecting the presence or insertion of a prong into one of the female openings. 
     
     
         9 . An apparatus, as set forth in  claim 1 , further including an audio and/or visual indicator coupled to the load sensing circuit for providing an indication of a proper or improper load. 
     
     
         10 . An apparatus for supplying power to a load, comprising:
 a pair of output terminals;   a primary circuit electrically coupled to a source of power and to the output terminals for selectively providing power to the output terminals, the primary circuit for providing power at the low voltage at the application of the load, the primary circuit including a sensor for detecting application of the load; and,   a load sensing circuit coupled to the primary circuit and the source of power for determining a resistance associated with the load at initial application of the load and controlling the primary circuit to electronically couple the source of power directly to the output terminals if a proper load is detected, the load sensing circuit having a capacitor which supplies an inrush current to the load during application of the load, a characteristic of the inrush current being indicative of one of a proper load and an improper load.   
     
     
         11 . An apparatus, as set forth in  claim 10 , the primary circuit electrically for selectively electronically coupling the source of power directly to the output terminals. 
     
     
         12 . An apparatus, as set forth in  claim 10 , wherein the load sensing circuit continues to supply power at the low voltage at least during initial load characteristics associated with the application of the load. 
     
     
         13 . An apparatus, as set forth in  claim 10 , the primary circuit including a switch coupled between the source of power and the output terminals and having a first position where power at the low voltage is provided at the output terminals and a second position where the source of power is electrically coupled directly to load, the load sensing circuit including a microcontroller coupled to the primary circuit, the microcontroller for monitoring a value of the low voltage during initial application of the load and controlling the switch in response thereto. 
     
     
         14 . An apparatus, as set forth in  claim 10 , including a second pair of output terminals and a second primary circuit, the second primary circuit being electrically coupled to the source of power and to the second pair of output terminals for selectively providing power at a low voltage to the second pair of output terminals, the second primary circuit for normally providing power at the low voltage at the second pair of output terminals when no load is connected to the second pair of output terminals, wherein the load sensing circuit is coupled to the second primary circuit power supply for determining a resistance associated with a second load at the second pair of output terminals at initial application of the second load and controlling the second primary circuit to electronically couple the source of power directly to the second pair of output terminals if a proper load is detected at the second pair of output terminals. 
     
     
         15 . An apparatus, as set forth in  claim 14 , the second primary circuit electrically for selectively electronically coupling the source of power directly to second pair of the output terminals. 
     
     
         16 . An apparatus, as set forth in  claim 10 , wherein the apparatus is embodied in an electrical receptacle, the output terminals being electrically coupled to respective female openings for receiving a respective prong of a plug of the load. 
     
     
         17 . An apparatus, as set forth in  claim 16 , wherein the sensor is coupled to the load sensing circuit for detecting the presence or insertion of a prong into one of the female openings. 
     
     
         18 . An apparatus, as set forth in  claim 10 , further including an audio and/or visual indicator coupled to the load sensing circuit for providing an indication of a proper or improper load.