only few parts like Buzzer, Transistor, 300K variable resistor and a 9V battery or power supply. The circuit is using BC547B NPN transistor but you can use any other general purpose transistor in the place of this transistor like 2N2222 or 2N3904.
Working of the Circuit
Working of this water level sensor is simple; the transistor used in the circuit is working as a switch. When the two probes detect water the transistor becomes switched on and as a result the voltage start passing through the transistor, which will activate the buzzer.
Copyright 2012 © CircuitDiagram.Org. All rights reserved.