Steuervorrichtung für Fenster mit elektrischem Scheibenheber

摘要

A control apparatus suitable for use in a power window regulator is provided which has an electric motor for selectively moving a window glass in either one of two directions in which the window glass is fully closed and opened when an automode switch is first turned on. An energized state of the motor is held until the window glass reaches a position where it is fully closed or opened. The control apparatus comprises a capacitor, a holding circuit for holding the motor in an energized state during a period in which a detection voltage corresponding to a voltage applied across the capacitor is greater than a reference voltage, a cut-off circuit for discharging the electric charge stored in the capacitor in accordance with a predetermined time constant when a cut-off voltage exceeds an auxiliary reference voltage, and a clamping circuit for clamping the detection voltage to a constant voltage higher than the reference voltage when the discharge of the electric charge stored in the capacitor is initiated by the cut-off circuit. The cut-off circuit serves to clamp the detection voltage to the constant voltage higher than the reference voltage, and the time necessary to tighten the window glass corresponds to the period of time required to reduce the constant voltage thus clamped up to the reference voltage, thus achieving a constant period of time at all times.