Rain Alarm

This is an interesting electronics project to detect if there is raining or not. Same circuit can also be used as water level indicator or as a tank overflow indicator. Working: Water is a conductor of electricity. When water is in contact with the probe then there is a flow of current toward the base of  NPN transistor (BC548), which conducts. With the conduction of NPN transistor, electron reaches to Q2, which is a PNP transistor . PNP transistor (BC558) also [...]