ELECTRONIC TACHOMETER CIRCUIT

摘要

An electronic tachometer circuit uses a cyclically discontinuous position error signal PES to derive a velocity signal. The signal PES is differentiated by a narrow bandwidth high pass filter in a position channel 27. Motor current signals are used to derive a current reference signal by a low pass filter in a current channel 29. Discontinuous portions of the signal PES are detected by a level detector 42 which then activates a track and fill circuit 32 to provide a fill-in signal from the current reference signal to the position channel 27.