Receptacle with arc protection circuitry

Abstract

An electrical receptacle includes at least one motion sensor for detecting movement of a blade of an electrical plug in the receptacle, an extraction detector operatively connected to the motion sensor for generating a signal in response to movement of the blade at a predetermined rate, a position detector operatively connected to the motion sensor for determining the position of the blade in the receptacle, a switch operatively connected to the extraction detector and the position detector for de-energizing the receptacle when the extraction detector detects extraction of the blade from the receptacle at a rate equal to or greater than the predetermined rate and wherein the extraction detector and switch are operative to de-energize the receptacle in less than six milliseconds when the extraction detector detects extraction of the blade from the receptacle at a rate equal to or greater than the predetermined rate.

What is claimed is: 
     
         1 . An electrical receptacle with arc prevention circuitry, including:
 a receptacle body including a plurality of contacts mounted therein for receiving and contacting the blades of an electrical plug inserted in the receptacle;   at least one motion sensor mounted on the receptacle, the motion sensor detecting movement of a blade of an electrical plug in the receptacle relative to the contacts and outputting a signal in response thereto;   an extraction detector operatively connected to the motion sensor, the extraction detector generating a signal in response to movement of the blade;   a position detector operatively connected to the motion sensor for determining the position of the blade in the receptacle;   a switch operatively connected to the extraction detector and the position detector, the switch operative to energize the receptacle when the position detector detects the blade at a predetermined position corresponding to complete insertion of the plug into the receptacle; and   wherein the extraction detector and switch are operative to de-energize the receptacle when the extraction detector detects extraction of the blade from the receptacle at a rate equal to or greater than a predetermined rate.   
     
     
         2 . The arc protector of  claim 1  wherein the electrical plug has three prongs, comprised of a neutral blade, a hot blade and a ground blade, wherein the hot and neutral blades are associated with the hot and neutral terminals of an AC supply and the ground is adaptable to be connected to earth ground, and wherein the at least one blade of which movement is detected by the motion sensor comprises the neutral blade. 
     
     
         3 . The arc protector of  claim 2 , wherein the switch is operable to selectively connect the hot blade to the AC supply. 
     
     
         4 . The arc protector of  claim 2  wherein the neutral blade is polarized relative to the hot blade and the receptacle is configured to require the neutral blade to be inserted in a selected one of a plurality of slots formed in the receptacle. 
     
     
         5 . The electrical receptacle of  claim 1  wherein the extraction detector comprises a combination of a pulse generator and a pulse stretcher. 
     
     
         6 . The electrical receptacle of  claim 1  wherein the position detector is operative to de-energize the receptacle before separation of the plug blades from the receptacle contacts. 
     
     
         7 . The electrical receptacle of  claim 1  further comprising a shunt operatively connected to the switch, the shunt dissipating load energy when the switch de-energizes the receptacle. 
     
     
         8 . The electrical receptacle of  claim 1 , wherein the extraction detector comprises a pulse generator circuit connected to a potentiometer and to a monostable vibrator circuit. 
     
     
         9 . The electrical receptacle of  claim 1 , wherein the switch comprises one of MOSFET and IGBT transistors. 
     
     
         10 . An arc protector for use with an electrical receptacle having a receptacle body, the arc protector comprising:
 a motion detector mounted in the receptacle body, the motion sensor comprising a linear potentiometer generating a variable voltage change correlated to sensing movement of a blade of the plug in the receptacle;   an extraction detector operatively connected to the motion sensor, the extraction detector generating a signal in response to movement of the at least one blade in a direction of extraction;   a position detector operatively connected to the sensor for determining the position of at least one of the blades in the receptacle; and   a switch operatively connected to the extraction detector and the position detector, the switch operative to energize the receptacle when the position detector detects the blade at a predetermined position upon insertion of the plug into the receptacle and wherein the extraction detector and switch are operative to de-energize the receptacle when the extraction detector detects extraction of the at least one blade from the receptacle.   
     
     
         11 . The arc protector of  claim 10  wherein the electrical plug has three prongs, comprised of a neutral blade, a hot blade and a ground blade, wherein the hot and neutral blades are associated with the hot and neutral terminals of an AC supply and the ground is adaptable to be connected to earth ground, and wherein the at least one blade of which movement is detected by the motion sensor comprises the neutral blade. 
     
     
         12 . The arc protector of  claim 11 , wherein the switch is operable to selectively connect the hot blade to the AC supply. 
     
     
         13 . The arc protector of  claim 10 , wherein the switch comprises one of MOSFET and IGBT transistors. 
     
     
         14 . The arc protector of  claim 10 , further comprising a shunt, the shunt dissipating load energy when the switch de-energizes the receptacle and wherein the shunt comprises a metal oxide varistor connected across the transistors. 
     
     
         15 . The arc protector of  claim 10 , wherein the motion detector comprises a linear potentiometer with a wiper output that is physically interfaced with the at least one of the blades when inserted in the respective receptacle such that movement of the wiper causes a change in a voltage output. 
     
     
         16 . The arc protector of  claim 10  further comprising a zero voltage crossing detector, the zero voltage crossing detector preventing current surges upon insertion of the blades in the receptacle. 
     
     
         17 . An arc protector for an electrical receptacle comprising:
 a sensor, the sensor determining movement of a plug having blades received in the receptacle;   a first detector operatively connected to the sensor, the first detector generating a signal in response to movement of at least one of the blades at a predetermined rate;   a second detector operatively connected to the sensor for determining the position of a plug blade in the receptacle;   a switch operatively connected to the first and second detector, the switch operative to energize the receptacle when the second detector detects the blade at a predetermined position corresponding to insertion of the plug into the receptacle to a predetermined position, the switch de-energizing the receptacle when 1) the first detector detects extraction of the blade from the receptacle at a rate equal to or greater than the predetermined rate or 2) when the second detector detects movement of the blade past a predetermined position in the receptacle.   
     
     
         18 . The electrical receptacle of  claim 17 , wherein the first detector and the second detector are operatively connected to the switch with an AND gate. 
     
     
         19 . The arc protector of  claim 17  further comprising a zero voltage crossing detector, the zero voltage crossing detector preventing current surges upon insertion of the blades in the receptacle. 
     
     
         20 . The arc protector of  claim 17 , wherein the first detector comprises a linear potentiometer with a wiper output that is physically interfaced with the at least one of the blades when inserted in the respective receptacle such that movement of the wiper causes a change in a voltage output.