Control device for an electromagnetic consumer in a motor vehicle, in particular a magnetic valve or an adjusting magnet

摘要

A control device is proposed for an electromagnetic engine valve or an electromagnetic final control element. The control device operates with closed-loop current control, and the maximum current is ascertained via a measuring resistor located in series with a switching transistor, while the free-running circuit is controlled in accordance with time. This control in accordance with time is effected via a comparator having dynamic positive feedback and acting as a comparison stage. The free-running control circuit includes a diode for protective purposes switched parallel to a transistor.