Abstract:
A fail-safe spark ignition system for gas burners includes a spark energy monitoring circuit for controlling the gas valve and bimetal spark gap disabling means for eliminating radio interference. Two circuit arrangements are shown for protection against short circuit failure of rectifiers energizing the gasvalve solenoid or other load from an AC power source, using a second rectifier and a fuse or fusible resistor for circuit disconnection.
Abstract:
Each heating device, with several beneath a common glass-ceramic plate, includes a coiled resistance wire in a groove in an end face of a body of high-temperature insulation having a peripheral band at such end which projects above the groove area and sealingly engages the underside of the plate. The devices are in a rough-in box on elevated supports and a blower circulates ambient air over the same for cooling.
Abstract:
A control circuit for a self-cleaning oven consisting of a switching system for alternatively connecting the bake and broil elements across the 236-volt powerline to generate heat for normal cooking operations, and for connecting the elements in parallel across the 236-volt line during the self-cleaning cycle. A semiconductor rectifier in series with the parallel-connected elements is utilized to control the rate of heat rise during the cleaning cycle to a predetermined cleaning temperature level, and to further limit power application thereafter. The switching system also controls temperature-regulating components and a safety circuit responsive to abnormal operation of the semiconductor rectifier to interrupt the cleaning cycle.