Automatic Water Level Controller Using Transistors or 555 Timer IC


Introduction: Automatic Water Level Controller Using Transistors or 555 Timer IC


Hii Everyone here we are going to learn about Saving the water efficiently. so go through the steps and the Sentences carefully. Water tank overflow is a common problem which leads to the wastage of water. Though there are many solutions to it like ball valves which automatically stop the water flow once the tank gets full. The water level controller circuit is a simple mechanism to detect and control the level of water in the overhead tank and also in the other containers. Nowadays, all the householders/owners are storing the water in overhead tanks by using the pumps. When the water is stored in the tank, no one can identify the level of water and also, no one can know when the water tank will fill. Hence there is an overflow of water in the tank, thus there is a wastage of energy and water.

To Resolve this type of problems by using the water level Controller circuit using BC547 transistor it helps and control the overflow level of water. The cost of the water level controller manufacturing cost is low and its use full for the overhead water tanks, swimming pool boilers, etc.. The water level controller circuits are used in the factories, chemical plants, and electrical substations and also in other liquid storage systems.

This simple transistor based water level controller circuit is very useful to indicate the water levels in a tank. Whenever tank gets filled, the motor Switches off. Here we have created 3 levels (Main, Low, High), we can create alarms and LED for more levels as we need. When tanks gets filled completely the motor will Turn Off. We guys are Ankit Gupta R, Bala Murugan N G and Mohammed Jaffer M made this Project.

Step 1: Components Required:

1. BC 547 Transistors = 3 Nos

2. 220k Resistor= 1 Nos

3. 5.6k Resistor= 1 Nos

4. 12v Dc Relay= 1 Nos

5. 2 Pin PCB Connector= 3 Nos

6. 3 Pin PCB Connector= 1 Nos

7. 1N4007 Diode=1 Nos

The Circuit Components cost nearly 40Rs. In dollar it should be less than 1$. If you are using IC555, the circuit components are mentioned in the circuit diagram.

Step 2: Circuit Diagram

Follow the Circuit Diagram as it is. Carefully read step by step procedure so that we should get the output. Using Ic555 to get the Output easily.

Step 3: Transistors and Other Components

Use this type for sensor wiring connections. In SPDT relay we are having 5 terminals Com(Movable Contact), Coil terminals, NO and NC

NO= Normally Opened

If your Motor Positive end is connected to NO. When the relay is switched, the motor will turn ON. Otherwise it is in OFF state.

NC=Normally Closed

If your Motor Positive end is connected to NC. When the relay is switched, the motor will turn OFF. Otherwise it is in ON state.

In the COM port we must add the external power supply to drive the motor. The coil terminals is only for Switching the relay from NC to NO. The relays are of different types here am using 12v DC SPDT Relay.

BC 547 transistor are very negligible so handle the transistor carefully and don't change the polarity of the battery terminal to the circuit.

Step 4: Overall Setup of My Automatic Water Controller

Here I used 12v Submergible motor for my purpose so I Designed 12v DC power supply connect to both circuit and Com Port of the Relay. We can also give 5v for the circuit if you are using 5v Relay.If you need your circuit for 230v motor control operation, you just connect the 230v positive terminal to Com port of Relay and the negative terminal connect to motor another end(-)Gnd. No need to change any components.

Step 5: Conclusion

Finally we Designed the circuit and make sure that your circuit should be tested in Breadboard after that you can go for the Soldering in PCB or Dot Board. We can also use IC555 timer for the automatic water level controller to get the output in a Effective manner because transistors may burst any time . See you next time to my Next Project. If you have any queries kindly ask in the comments, we will clarify you at any time.


Bala Murugan N.G

Ankit Gupta R

Mohammed Jaffer M



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    Please be positive and constructive.





    You build the 3 transistor version as the pictures show. If it works, could you please correct the schematic for it, as it is flawed in several ways and will never be able to work as is.

    The terminal named "-VC" should be 0V, not 12V and please check which nodes go to which terminal of the water tank and correct the transistor connections as well.

    The 555 circuit seems OK.

    Have a nice day :)


    3 replies

    It works well omnivent. There is no error in the circuit diagram. I practically saw the output so just follow the ckt.
    1. The 12 -ve indicates the ground of the power supply or battery you used
    2. The main terminal connects to transistor 1 base . The low level terminal connects to 3rd transistor collector terminal. And the high level directly connects to the 12v +ve


    Your ground reference should be named 0V or ground, it can't be 12V, as this is your reference for all other voltage measurements.

    I spent some time tidying up your schematic so that others are able to follow it and have attached it here.

    Have a nice day :)


    The people who are well in circuits should know 12v -ve refers to ground. Anyway thanks for the correction

    Thankyou Aj my dr friend

    Thanks,, tomatoskins