Automatic control for windscreen wipers - uses capacitance monitors and impulse control to differentiate between fine and large raindrops

摘要

The incidence of moisture on the windscreen is monitored by capacitative monitors and the output signal is used to drive the windscreen wiper control for automatic wiping. The control is fitted with an impulse amplifier to differentiate between large and small raindrops, so that for large drop the wipers are switched on sooner, and at a faster rate. Conventional controls do not differentiate between fine rain and heavy rain but are controlled by the number of drops falling per unit area. The wipers are then operated too soom in fine rain and too late in heavy downpours. The apparatus provides a more realistic response and results in a safer vehicle.