Intermittent windscreen wiper motor operation - using automatic interval adjustment related to engine performance or vehicle movement with RC element controlling transistor

摘要

The wiper motor is fitted with a limit switch and an RC-element is connected before the switch. The element determines the duration of the interval. The RC element is operated by a timing switch. The RC element controls a switching transistor with its collector circuit connected to a relay for the wiper motor. Parallel to the RC elements resistor a further resistor is fitted which is connected in series with a further switching transistor connected via a further RC element. The output end of the latter's resistor is connected to a wheel speed sensor emitting pulses to the capacitor of the latter RC element. The latter is designed in such a way that the switching transistor becomes conductive when the revolutions of the wheel correspond to a vehicle speed of 10km/h.