Rotation signal detection device of DC motor with brushes

摘要

Disclosed is a rotation signal detection device for use with a circuit for driving a DC motor with brushes, the device comprises a differential amplifier for detecting a pulse signal component of a waveform of the current supplied to the motor, a circuit for shaping an output of the differential amplifier, thereby actuating a logic circuit for controlling rotation of the motor by a DC level signal obtained from said shaped waveform.