Two pole ground fault circuit interrupter with improved rectified supply and transient suppression for a trip circuit

Claim 1

A two pole ground fault circuit interrupter comprising: a differential transformer core, a plurality of primary windings on said core, said plurality of primary windings including at least two line conductors and a neutral conductor of an AC electrical distribution system; a secondary sensing winding on said core for sensing current unbalance between said primary windings; means responsive to a predetermined sensed signal to open said line conductors and comprising a trip circuit having two terminals connected across said sensing winding, said means also comprising circuit breaker contacts and associated solenoids for each of said line conductors, each solenoid having a respective trip coil having one end connected to one of said line conductors, each of said coils having another end connected respectively to first and second like poled zener diodes, said first and second zener diodes having a common connection remote from said trip coils, said common connection being conductively connected to a third terminal of said trip circuit; a conductive circuit branch connecting a fourth terminal of said trip circuit to said neutral conductor, and a third zener diode connected between said conductive circuit branch and said common connection.