Rain detector

This rain detector electronic circuit project is an very simple alarm circuit , that will start an audio warning , if the liquid is present on the sense pad . This rain detector electronic circuit diagram is based on two transistors . When the sense pads conducts , Tr1 and Tr2 from an audio oscillatory circuit that will generate a pitch sound .

This circuit needs a 12 volts power supply circuit and the speaker needs to have a 32 ohms . The sense pad can be constructed on a small piece of printed circuit board .