Abstract: An electrical control circuit is disclosed for controlling the operation of a pilotless gas system including an igniter and a gas supply valve, wherein the gas supply valve is initially opened a predetermined time after the igniter is activated, and the igniter is subsequently deactivated a predetermined time after the gas supply valve is opened. Specifically, a control first signal is produced to activate the appliance, which control first signal is delivered to a first logic circuit for activating the igniter, and to a first delay circuit which produces a second signal delayed from the first signal by a first predetermined time period. The second signal is delivered to a gas supply valve control circuit to open the supply valve, whereupon a detector produces a third signal in response to opening of the valve.

Abstract: A flame detection and proof device utilizing NAND logic implemented by MNOS devices which provides safe control of gas systems and appliances. Improved control is achieved by using a flame probe for providing signals indicative of flame and no-flame conditions connected to circuit means which includes at least one delay circuit for producing a first output signal during a set time period for ignition and also during indication of a flame condition and a second output signal after the set time period and during an indication of no-flame condition. A relay is responsive to the output of the circuit means to be activated during the first output signal and to be deactivated during the second output signal.