AUTOMATIC CAR WIPER

Here is the working of rain sensitive wipers with circuit schematic. The main component of this circuit is a 555 timer IC that works in monostable mode. Two metal sheets fixed at a small distance apart are used as rain detector sensors. From the working of a monostable 555 timer, a negative voltage on the trigger pin will cause a high output. So when it rains, trigger pin gets a negative voltage. Output of one shot 555 (monostable) is connected to a relay through a transistor. The transistor acts as a switch for the relay to turn ON the wiper motor during rain.

 

1. IC 555
2. Transistor BC 548
3. Resistor (1K,10K,1M,)
4. Capacitor(0.1uF)
5. Relay (12V,10A)
6. Rain sensor (Two metal sheets as figure)