Switching cct. for vehicle windscreen wipers - provides timed drive to wiper motor which is short circuited in the park position

摘要

After leaving the parked position a supply voltage is applied until the new stop position is reached when the short circuit is again applied. The short circuit of the motor is connected to the normal position of the change over switch of a switching relay. The working contact of the motor is independent of the parking position switch. The switching relay is connected via an interval generating switch with regulated period of switching impulse. The input is less than the cyclic period of the motor, but the length of period is greater than the wiper cycle. The switching relay has also a contact switch for controlling the wiper angle. The interval generating switch is a rotating type with several switch positions.