WIRELESS TELEMETRY CIRCUIT STRUCTURE FOR MEASURING TEMPERATURE IN HIGH TEMPERATURE ENVIRONMENTS

摘要

A circuit affixed to a moving part of an engine for sensing and processing the temperature of the part. The circuit generates a signal representative of the temperature sensed by a thermocouple (110) and amplified by an amplifier (112). A square wave oscillator (113) with a temperature sensitive capacitor (C8) varies its frequency in response to changes of a local temperature of the circuit. A chopper (114, J27) converts the output of the amplifier into an alternating current signal. The chopper is gated by the square wave oscillator and a second input is coupled to an output of the amplifier. Thus, the chopper has an output signal having a frequency representative of the local temperature and an amplitude representative of the thermocouple temperature, whereby the combined signals represent the true temperature of the part