WATER LEVEL INDICATOR CIRCUIT with circuit diagram

WATER LEVEL INDICATOR CIRCUIT

Its a circuit that indicate the level of water in the tank when its low by means of red light. When the water Is at medium it will indicate by means of a yellow light and when the water is at its maximum it then indicate by means of green light.

CIRCUIT DIAGRAM

COMPONENTS    USED

1.      470 Ohms (6)
2.      BC558 Transistor (3)
3.      LED (Red)
4.      LED (Yellow)
5.      LED (Green)
6.      DC Power Supply

 Working Principle

This circuit is built around three PNP Transistors (Bc558). For a PNP Transistor to turn ON it needs a negative current at its base terminal. The Base terminals of the three Transistors are connected through a 478 ohms resistors to conductors of different lengths which are suspended into the water tank as shown above in the circuit diagram OR dogged inside ground if the ground water level is to be detected.
            When the water tank is filled to the brim with water, the base terminal of Transistor Q1, Q2 and Q3 will be earthed, and that takes a negative current to the base terminals of the three Transistors. This negative current turn ON the three Transistors, and LED D1 (Red), LED D2 (Yellow) and LED D3 (Green) turn ON indicating a full tank.
            When the tank is half filled, only the base terminals of Transistors Q1 and Q2 are earthed. This implies that only Q1 and Q2 will turn ON, that is, only LED D1 (Red) and LED D2 (Yellow) will be ON indicating a half filled tank.
            When the tank water is low and almost empty only the base of Transistor Q1 is earthed. This implies only Transistor Q1 will be ON (only LED D1-Red will be ON) indicating that water level is low and should be refilled as soon as possible.

AREAS OF APPLICATION  

           
This simple circuit can be apply  in homes, companies, factories and any other places where water tanks, reservior,well and drums are used to help detect the level of water at any time. This will enable one to know when to turn ON the water pumping machine to refill water.

I hope you find this article useful.