Noise reduction circuit for path sensor differentiator in vehicle speed measuring system - consists of hysteresis circuit comprising buffer amplifier and positive feedback path of capacitor and parallel connected second operational amplifier and antiparallel clamping diodes, with ratio of resistors determining hysteresis voltage

摘要

A circuit (H) for the prodn. of hysteresis is provided, across which the signals (U1(t)) to be differentiated are supplied to the differentiator (D). A low pass filter (R2,C2) is arranged at the output of the differentiator (D). The circuit (H) for producing the hysteresis has at least two operation amplifiers (OP1,OP2) and at least two diodes (D1,D2), connected in antiparallel. The two diodes are connected across the input and output of the operation amplifier (OP2). USE/ADVANTAGE - Facilitates reliable suppression of vehicle vibration noise or signal interruption in drive control system and simultaneously no phase shift of speed signal.