Abstract: A temperature sensor system for a household appliance, such as a microwave oven, that provides for a non-contact self-calibrating measurement of the temperature of an object disposed in a chamber of the appliance. The system comprises an infrared transmitter and an infrared receiver, as well as a distribution apparatus for coupling the transmitter and receiver to the appliance chamber. A scan pattern of infrared radiation is provided for the chamber and the detected infrared radiation from the chamber is used by a processor to generate an accurate measure of the temperature of the object in the chamber.

Abstract: An emergency lighting system includes a switching transistor inverter circuit for starting and operating a fluorescent lamp from a battery upon failure of line voltage. A lockout arrangement serves to shut down inverter operation should the lamp be removed from its fixture. Included is an interlock in the lamp fixture and circuitry responsive to an open condition at the interlock to ground the input to a system controller inhibit function thereby to effect removal of battery power from the inverter circuit.

Abstract: An emergency lighting system includes a two-level switching transistor inverter circuit for starting and operating a fluorescent lamp from a battery upon failure of line voltage. One of the switching transistors of the two transistor inverter is arranged for connection first to a tap, then to one of the feed-in terminals of an output transformer coupled with the lamp. A timing controller effects this switching thereby automatically to provide, first, a high power level for starting the lamp, and then, a second lower power level for operating the lamp after starting.