How do rain-sensitive windscreen wipers work?

Answer 1

The latest method uses optical sensors to detect the moisture. The sensor is mounted in contact with the inside of the windshield, near the rear-view mirror.

The sensor projects infrared light into the windshield at a 45-degree angle. If the glass is dry, most of this light is reflected back into the sensor by the front of the windshield. If water droplets are on the glass, they reflect the light in different directions -- the wetter the glass, the less light makes it back into the sensor.

The electronics and software in the sensor turn on the wipers when the amount of light reflected onto the sensor decreases to a preset level. The software sets the speed of the wipers based on how fast the moisture builds up between wipes. It can operate the wipers at any speed. The system adjusts the speed as often as necessary to match with the rate of moisture accumulation.

Previous systems using equipment to detect the impact of raindrops hitting the glass seldom worked properly - continually being set off by insects for a start . . .

Answer 2

from what i've read they use led sensors in the windshield, when i the rain lands on it the light bounces off the the rain telling the pc to turn on the wipers

Answer 3

yes there is a small area on the screen which has a sensor, when droplets of rain move across the sensor the wipers come on.

Answer 4

There's a sensor at the top centre of the windscreen that senses stuff landing on the screen.

Answer 5

A simple rain sensor consists of interleaved metal "fingers" and the electronics attached measure the resistance between the fingers. When it rains the water has less resistance (than the air) when it wets the fingers and therefore kicks the wipers into action.

Answer 6

There is a sensor attached to the windscreen that sensed the vibrations of rain hitting the glass.

Answer 7

dude, its just like a touch alarm, as water touches it activates!!!!!!!!!!!!!