Itt Industries, Inc.

Uwe Knobloch

Hans Prohaska

Horst Rachner

Horst Goertler

Wolfgang Spieth

Heribert Klement

Friedrich Hetzel

Hans Muller

Hermann Carle

A safety control circuit for electric motors of power windows of automotive vehicles and which differentiates between a tight fitting of the window pane and an obstacle blockage. The motor current is selectively detected to provide a signal representative of the instantaneous rather than static current values. The detected signal is compared to a reference signal. When the detected signal exceeds the reference signal by a given value or longer than a predetermined interval, which indicates that an obstacle blockage has occurred, the motor current is switched off or reversed.

Circuit arrangement for power windows

This invention refers to a circuit arrangement for a motor for the purpose of driving a window in motor vehicles comprising a motor current supervising stage for switching the motor in case of blocking, wherein the motor current supervising stage responds to a change in time of the motor current. The dynamic supervising of the motor current offers a greater reliability than the known static supervising of the motor current. The circuit senses a rapid change in motor current to indicate that the window has met an undesired (e.g a human) obstacle.

Window lifter installation

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Heilbronn-Sontheim, Germany

Uwe Knobloch