CONTROL CIRCUIT FOR A DC MOTOR

摘要

A DC power supply for a DC motor is controlled by a drive transistor. An "ON" state of the drive transistor is maintained by a comparator or means which compares a terminal voltage at a point between the DC motor and the drive transistor with a reference voltage supplied from the power supply. A clock pulse is applied to the drive transistor to make it periodically turn off in order to detect an induced voltage depending upon rotation rate of the DC motor. The drive transistor returns to turn off upon stopping the rotating DC motor by force. A regulator is provided between the power supply and the reference voltage. A restraint torque and a rotation rate control means are also provided. Alternatively, a pulsating power supply is provided instead of the DC power supply and the clock.