FAIL-SAFE GAS VALVE SYSTEM WITH SOLID-STATE DRIVE CIRCUIT

摘要

A solid-state fail safe gas valve system in which first and second gas valves ar e arranged in series in a gas passageway, the valves being actuatable by first and second solenoid operators respectively, the second operator requiring a voltage greater than the operating voltage supplied to the valve system to achieve actuation. The operato rs are separately energized through microprocessor controlled switches so that a capaci tor connected across the second operator and its switch is pumped to a voltage above the supplied voltage by voltage induced by interrupted energization of the first ope rator.