Water Level Indicator Circuit Using Transistor bc547

We generally worry about the wastage of water, when we switch ON the motor and forget to turn it off. The Water Level Indicator employs a simple mechanism to detect and indicate the water level in an overhead tank or any other water container. We have posted already a Water Level Indicator and Controller using IC ULN2003. In this article, we are presenting a very useful, cheap, and simple circuit using transistors (bc547) for beginners. This circuit indicates the level of water in the water tank using LEDs with transistors. you can use this project as a college project.

Circuit Diagram

The connections arrangements are shown in the circuit diagram shown above. The +9V power supply or battery is used. In this circuit, we have used all the transistors as a switch. The water touches the wires contact with the base of each transistor, a small current flows through the base and turns on the transistor as transistor turns on, LED connected to it glows. LEDs will be turned on depending upon the level of water. We have used a buzzer with the last transistor as water touches the base of the last transistor collector the collector and emitter connected and buzzer rings. The relay can be connected instead of the buzzer to auto control the water level in the tank.


Some pieces of wire

5 – 9v battery + battery clip/power supply

4 – BC547 transistors

3 – 220-ohm resistors

1 – Buzzer

3 – LEDs

Water Level Indicator with an auto ON-OFF Circuit :

In this circuit we have used a relay instead of the buzzer as the tank will become full relay will be changing its state and will cut off the power. We are going to control the water pump with this relay, So you must use a powerful relay because a low power relay will be damaged as more impairs will cross through it.

Applications & Uses Of Water Level Indicator

Stream lev

  • Water tank level control
  • Automatically turn ON/OFF water pumps
  • It is used in factories, commercial complexes, apartments, home,
  • Fuel tank level indicator
  • Oil tank level control and indicator
  • High & low level alarms
  • Pool water level control
  • Leach-ate level control
  • Cooling tower water level control
  • Sewage pump level control
  • Remote monitoring liquid
  • Pump controller Auto
  • Stream level monitoring auto

The water level indicator is defined as a gadget which gets the records about the water level in reservoirs or in tanks that is used in houses. Through the use of the water level indicator we can overcome the overflow of water from the tankers.

We will be happy to hear your thoughts

Leave a reply

Enable registration in settings - general