A circuit for processing the signal generated by a variable-reluctance electromagnetic rotation sensor.

摘要

The circuit comprises a first threshold comparator (A) with hysteresis arranged to provide a reference signal (V1) indicative of the zero-crossing of the sensor signal (Vp ). Also connected to the sensor (1,W,P) is an integrator circuit (B) whose output is connected to the input of a second threshold comparator (C). The latter provides an enabling output (V 2) signal only when the integrated signal (V i) remains above a reference signal (S2). A logic circuit (D) is connected to the two threshold comparators (A,C) and transmits the output reference signal (V1) provided by the first comparator (A) only when the second comparator (C) outputs the enabling signal (V 2). Immediately after the first comparator (A) has transmitted this reference signal (V1 ) to the logic circuit (D), the logic circuit (D) is disabled. This can conveniently be achieved by the stopping of the operation of the integrator (B). The time window during which the logic circuit (D) is enabled is thus reduced and the danger that the logic circuit (D) may transmit spurious output signals generated as a result of interference picked up is consequently reduced.