Water Level Indicator Alarm

Last Updated on March 16, 2024

Water is very precious thing and we need to conserve adequately and should ensure proper water resource management. To avoid the loss of overflow water we (Electronic Engineers) can take a step by the way of simple water level indicator alarm circuit. Lot of water level indicator and alarm devices are available in the market but they comes with high price tags.




Here water level indicator alarm circuit designed by using few easily available components, this tank water level alarm can be used in any type of house hold water tank and by proper implementation of this circuit we can avoid loss of overflow water.

Circuit Diagram

Components Required

1. Transistor BC547 = 4
2. Buzzer
3. LED = 3
4. Resistor 330Ω = 4
5. Resistor 220Ω = 3
6. Battery 9V
7. Wire.

BC547 pin details

Construction & Working

This water level indicator circuit with alarm works properly when the sensing wires L1 – L4 and common supply wires are placed correctly in the water tank, use insulation less wire (remove the insulation plastic and use conducting core) in the tank and first place the common supply wire to the possible bottom of water tank and it should be below the L1 wire, next thing you can place the level wires L1, L2, L3 and L4 with different height level in the water tank. Each level wires are connected to the separate transistor base and transistors Q1 – Q4 are connected with LED indicators and one buzzer device, this circuit powered by the 9V battery.

When the supply applied to this circuit all transistors are works as a switch and if it don’t have base supply then it reacts as open switch, if the tank water fills and connects common supply wire to level wires (L1 – L4) corresponding transistor will get base supply and reacts as closed switch, then LED starts glow, Buzzer produce alert sound when the water reaches L4 wire.