APPARATUS AND METHOD FOR CONTROL OF SWITCHING CIRCUITRY

摘要

A protection circuit includes one or more electro-mechanical force-guided safety relays and one or more solid state relays. The solid state relays are coupled electrically in series to the electro- mechanical force-guided safety relays. The electro-mechanical force-guided safety relays and the solid state relays are disposed between a power source and one or more controlled devices, and regulate current flow between the power source and the one or more controlled devices. The electro-mechanical force-guided safety relays and solid state relays are selectively instructed to open upon a determination of an unsafe operating condition in a system. The electro-mechanical force-guided safety relays open when the solid state relays malfunction and fail to open.