Water Level Detector With Alarm

This is a simple alarm circuit which produces a musical tone when water or some conducting liquid comes in contact with the two sensor wires provided. The circuit is based on four transistors and one melody generator IC (M 3482). When water comes in contact with the sensors wires A & B, the base of Q1 gets connected with the negative and it conducts.This makes Q2 and Q3 ON. When Q3 is ON the power is available for the music generator circuit and it starts producing 12 different melodies one after another. The music continues as long as there is water between the sensor wires. The POT R12 can be used as a volume controller.

Circuit diagram with Parts list:

Notes:

• Assemble the circuit on a good quality PCB or common board.
• Two insulated aluminum wires can be used as the sensor.
• The IC1 must be mounted on an IC holder.
• The speaker can be a 8 Ohm, ½ W tweeter.

Filed Under: Detector, Water level