Custom Search

Water Sensor Alarm Circuit using IC M3482

Water Sensor Alarm Circuit using IC M3482This is a simple musical alarm circuit that produces a musical tone when water or some conducting liquid comes in contact with the 2 sensor wires provided. The circuit relies on four transistors and one melody generator IC M 3482.

When water comes in contact with the sensors wires A & B, the bottom of Q1 gets connected with the negative and it conducts. This makes Q2 and Q3 ON. When Q3 is ON the power is offered for the music generator circuit and it starts producing 12 completely different melodies one after another. The music continues as long as there's water between the sensor wires. The POT R12 will be used as a volume controller.


  • 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.