Patent ID: 8614866

Claim:
A hybrid switch circuit for coupling an AC power supply to a load, comprising: a hybrid switch coupling an input conductor configured to be connected to the AC power supply to an output conductor configured to be connected to the load, the hybrid switch comprising: a power semiconductor switchable between on and off states in accordance with a power semiconductor control current, wherein, in the on state, the power semiconductor provides a conductive path for an AC current between input and output terminals thereof and, in the off state, the conductive path provided by the power semiconductor is opened; and a relay having contacts in a conductive bypass path connected in parallel with the power semiconductor, the contacts being controllable between open and closed states in accordance with a relay control current taken from an output terminal of the power semiconductor, wherein, in the closed state, the relay provides a conductive bypass path between the input and output conductors that bypasses the power semiconductor; and a control circuit configured to switch the hybrid switch from a non-conductive state to a conductive state, the control circuit comprising: a pair of control conductors terminating in a common connection to carry the power semiconductor control current electrically in parallel with the relay control current; and at least one current switch coupled to at least one of the control conductors and switchable between conducting and non-conducting states in accordance with a state of at least one switch control signal, wherein, in the conducting state, the at least one current switch provides at least one conductive path for the power semiconductor control current and the relay control current and, in the non-conducting state, the at least one conductive path is opened.