Circuit to reduce the speed at reversing point of a windscreen wiper having a motor controlled by pulse width modulation

摘要

A control circuit for windscreen wipers uses a pulse-width-modulated wiper motor which is reversible. A Hall sensor on the motor drive system, or on the wiper linkage, provides accurate data on the position of the wipers to reduce the motor speed to a minimum through the reversing point for the wiper blades. The reduction in motor speed is progressive. The speed of wiping is adjustable between two fixed wiping speeds, with the wiping speed independent of the load on the wipers.