Abstract: A vehicle-mounted motor drive apparatus which stops the rotation of a motor immediately after an object obstructs a movable part driven by the motor. The drive apparatus includes a motor drive device for selectively driving and stopping a motor, an electric current measuring device for measuring a value of electric current flowing through the motor, a change-in-current-value detecting device for detecting an incremental change in the motor current, and a motor control device for supplying a first control signal or a second control signal to the motor drive device. The motor drive device continuously drives the motor according to the polarity of the detected increment of the current value in response to the first control signal, and immediately stops driving the motor in response to the second control signal.

Abstract: An on-car motor driving apparatus is equipped with a motor for moving a moving unit such as a window of a motor car, a motor driving controller which controls the revolution, stop, and rotational direction of the motor, and a current measuring and comparing device which measures the variation in current per unit time of the motor and compares the measured variation in current with a preset value. The on-car motor driving apparatus stops the revolution of the motor and/or reverses the rotational direction of the motor through the motor driving controller. The apparatus is further equipped with a voltage measuring device for measuring motor driving voltage and a voltage-based time setting device which changes the length of the unit time in accordance with the driving voltage value measured by the voltage measuring device. Line voltage is supplied to a differential amplifier only when the line voltage is supplied to the motor.