Water Level Sensor

Objective:

This is a simple water level indicator circuit or water sensor circuit. The circuit is very easy to build and contains only three transistors and some other components.

Components:

Resistors 470 Ω

LEDs (3)

Battery 9V

PNP transistors (A1015)

Circuit Diagram:

Description and working:

This is a very useful circuit to detect the level of water in a tank. The circuit consists of LEDs of three colors. It will indicate low, medium and full level of water in the tank.

The three probes for low, medium and full water levels are shown in the circuit to attach on desired levels in the tank. The ground probe should be attach at the bottom of the tank.

The water is basically completing the circuit. When water level reaches to probe 1, the Red LED will be switched ON and will indicate that water level is filled up to 1^st level. When water level reaches to the probe 2, it will complete the circuit of the Yellow LED and will switch it ON. And similarly it will switch ON Green LED when water level reaches to probe 3.