Patent ID: 7378761
Filing Date: 2008-05-27
Classification: H02H

Abstract:
1. A control circuit including: at least two input terminals for electrically connecting with at least two conductors of a power source; at least two output terminals for electrically connecting with a load; a sensor having a sensor relay that is energized in response to a reference signal being within a predetermined range, the reference signal being derived from a voltage differential between one or more of the conductors and a floating reference point that is electrically isolated from the conductors when in use, wherein the sensor provides a sensor signal in response to the sensor relay being energized; and a switching device having a switching relay that is responsive to the sensor signal for progressing between a first mode and a second mode wherein: in the first mode the input and output terminals are respectively electrically connected for allowing the load to receive power from the source via the switching relay; and in the second mode, the input and output terminals are electrically disconnected for preventing the source from supplying power to the load via the switching relay.