Windshield Wiper Controls

Basic Description

Windshield wipers keep the windshield of a vehicle clear from rain water, snow, dust and road spray. The first windshield wipers were operated manually by moving a lever inside the car. Most wipers today use an electric motor coupled with a linkage mechanism actuated by a knob beside the steering wheel. The wiper blade speed can be adjusted by the driver.

Windshield wipers may also be run intermittently on most vehicles today. The intermittent wiper option cycles the wipers on and off every few seconds rather than running constantly. Intermittent control first appeared in automobiles in the 1970's. The original intermittent wipers were controlled by a constant power source that was routed through a series of switches. Now, virtually all automotive wipers are controlled by a microprocessor.

Modern wiper systems use a rain sensor to detect the speed at which the raindrops are falling on the windshield. A microprocessor evaluates the signals from the sensor to calculate the speed at which the wipers should move.

Sensors

Wiper switch, rain sensor

Actuators

Wiper Motor

Data Communications

Rain sensing wiper controls generally use CAN or LIN data communication between sensors and control unit.

Manufacturers

Bosch, Continental, Denso, Preh, Rain Tracker, TRW, Valeo

For More Information

[1] Windshield Wiper Control, How Stuff Works.

[2] History of automatic windshield wipers, Ohio History Central

[3] Windshield Wipers, www.autotropolis.com

[4] Rain sensor, Wikipedia

[5] Hella Raintronic Working on Volvo 850, YouTube video, 2008

[6] LEXUS RX 2010 - QuickGuideDVD: Rain sensing windshield wipers and rear window wiper, YouTube video, 2009.