Patent attributes
A hybrid switch circuit includes a hybrid switch that couples an input conductor connected to an AC power supply to an output conductor connected to a load. The hybrid switch includes a power semiconductor in parallel with an electromagnetic relay. A control circuit turns on the hybrid switch by turning on the power semiconductor at a zero-voltage crossing of the AC voltage to provide a conductive path and then closing the relay to provide a conductive bypass path that bypasses the power semiconductor. The control circuit turns off the hybrid switch by opening the relay and subsequently turning off the power semiconductor at a zero crossing of the load current. The control circuit operates in response to a hybrid switch control signal that indicates whether an operating fault condition exists.
