Water Level Detector using BC547 transistor

Water is one of the precious resources. This simple circuit helps to save water from overflowing while filling it. Here is a simple Water Level Detector Circuit using BC547 based on five npn transistors and a buzzer pair to detect the water level in any container. This circuit produces different visible alarm using LED  when the water reaches at different level and audible signal using buzzer when water reaches at highest level. This is a useful device and play an important role in various industries, office, college, home etc. to save water.

Components Required for this project:

For this project the required components are

BC547 5Pcs
Buzzer 1Pcs
9V Battery 1Pcs
Resistor(1K) 5Pcs
LED(Green, Yellow, Red) 5Pcs
Breadboard 1Pcs
Connecting Wire ——  

Circuit Diagram

Water is one of the precious resources. This simple circuit helps to save water from overflowing while filling it

Connection of Making Water Level Detector using BC547 Transistor:

We make a water level detector circuit using 5 transistor, buzzer, five 1K resistor and five LED.

    To connect the all components according to above circuit diagram.

  • Positive terminal of 9V power supply is connected with five 1K resistance, 1K resistance and positive terminal of buzzer.
  • Each emitter of transistor is grounded and each collector is connected in series with neagative terminal of LED .
  • The last collector of transistor is also connected with buzzer.
  • Positive terminals of five LEDs are connected with five 1K resistance separately.
  • Each base of transistor is connected with wire and other terminal place inside the container at different height.

Working of Level Detector using BC547 Transistor:

The main purpose of this water level detector circuit is to turn on the LED and produce audible alarm when when the water reaches at different level and audible signal using buzzer when water reaches at highest level. When the tank is empty no current flowing through base of any transistor. So, then all the LEDs and buzzer are in off condition. When water reaches at any base then this transistor turn on. This construction works on the principle of “Transistor Switch” when we giving voltage at the base terminal the transistor starts the conduction. When we remove the supply from the base of the transistor goes to cutoff condition.

When water level touches the lowest or bottom wire then green LED will turn on. In this way when water touches next wires three yellow LEDs will turn on. When water reaches at the highest level the current can pass through the base of the transistor. So, then all the LEDs and buzzer turn on. 

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