Proximity detection circuit having short protection

Abstract

A proximity detection circuit is contemplated to detect connection of a cordset to a vehicle charging system or connection of another device to some other electrical circuit where it may be desirable to facilitate detection. A short protection circuit may be included as part of the proximity detection circuit to facilitate disconnection in the event of a shorter other condition where undesirable currents and/or voltages may be propagated to other systems of portions of the vehicle charging system.

1 - 17 . (canceled) 
     
     
         18 . A proximity detection circuit for use within a vehicle having a vehicle charging system configured to facilitate charging a vehicle upon connection of a charging cordset, the proximity detection circuit comprising;
 a connection portion configured to output a first voltage when the charging cordset is disconnected from the vehicle charging system and a second voltage when the charging cordset is connected to the vehicle charging system, the connection portion having an input configured to receive current from a low-voltage power supply; and   a protection portion configured to disconnect the input from the low-voltage power supply upon occurrence of a reverse current flow through the connection portion.   
     
     
         19 . The proximity detection circuit of  claim 18  wherein the connection portion includes a switch at the input, the switch being connected directly to the low-voltage power supply such that a voltage output from the low-voltage power supply approximately equals an input voltage at the input, and wherein the protection portion is configured to open the switch upon occurrence of reverse current. 
     
     
         20 . The proximity detection circuit of  claim 18  wherein the connection portion and the protection portion in total consume less than 150 μA of current from the low-voltage power supply when the charging cordset is disconnected.