A proximity detection circuit suitable for use with an on-board vehicle charger, such as but not limited to the type of chargers used within hybrid and electric vehicles, to facilitate current conservation during period of time when it is unnecessary or otherwise undesirable. The on-board charger can test for connection of a cordset or other electrical connection used to connect the on-board charger to a charging station or other current source. The on-board charger can be used to detect two different cordsets or vehicles using different charging circuitries.