HEXA

ELECTRICAL 108 RAIN LIGHT SENSOR SYSTEM RAIN LIGHT SENSOR DESCRIPTION: RAIN SENSOR: It is an optical system, which operates in the infra-red wavelength range. The sensor houses 6 infra-red LED’s forming a segment of a circle around a receiver diode. Any rain drops landing on the windscreen in the sensitive area of the sensor cause spontaneous imbalance in the reflection, which results in production of a voltage with the clocking frequency of the LED’s. These brief deviations are detected by an electronic analyzer and output as digital pulses. The pulse duration is a measure of droplet size whereas the number of pulses is a measure of the number of droplets. LIGHT SENSOR: The Light / Tunnel Sensor is a optical system. It operates with different optical receiving diodes. The two receiving diodes A, B have different characteristics. Diode A is used to measure the global ambient light. Diode B has a beam in forward direction of the car. BLOCK DIAGRAM: