A conditioning circuit for resistive sensors combining frequency and duty-cycle modulation of the same output signal
Vittorio Domenico Ferrari, C. Ghidini, D. Marioli, A. Taroni · Measurement Science and Technology · 1997
A signal conditioning circuit based on a relaxation oscillator is presented for use with resistive transducers. Both the frequency and the duty-cycle of the output signal carry independent information coming from a pair of different sensors. Namely, the frequency of the output signal changes linearly with the resistance deviations detected by a Wheatstone bridge, while the duty-cycle is dependent on the resistance of a second sensor.