Honeywell International Inc.

Mark F Merry

Jeff D Miller

Frank J Madison

An electronic circuit for generating a trapezoidal excitation waveform includes a controllable frequency source and a trapezoidal waveform generator. The controllable frequency source generates a source waveform that, upon energization thereof, has an initial frequency value, and decreases in frequency to a substantially constant frequency value a time period after energization. The trapezoidal waveform generator receives the source waveform and, in response, generates a trapezoidal waveform at least when the source waveform frequency attains the substantially constant frequency value.

Flame detector trapezoidal excitation generator output control circuit and method

A circuit and method for determining the wiper resistance of a potentiometer that includes the step of electrically coupling a sense resistor having a substantially constant sense resistance to the potentiometer third terminal. The potentiometer is electrically energized, and a potentiometer voltage, which is a voltage potential between the potentiometer first and second terminals, is determined. The wiper position is determined based at least in part on the determined potentiometer voltage. The sense resistor is electrically coupled to a potential that causes a wiper current to flow through the wiper and sense resistor. A magnitude of the wiper current is determined, and the wiper resistance is determined based at least in part on the potentiometer resistance, the determined potentiometer position, the determined wiper current magnitude, and the sense resistance.

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Tucson, AZ, United States of America

Mark F Merry