Water Level Indicator Circuit Schematic Using IC CD4066

This circuit of water level indicator not only shows the amount of water inside the overhead tank, but also gives sign when the tank is already full.

This circuit uses IC CD4066 and CMOS IC switch to indicate the water level through LED. When the water is empty, the circuit inside the tank would open, resistor 180k ohm would pull the switch to low position, and LED OFF. When the water is start filling, wire inside the tank is connected to S1, closing S1 switch, and turn LED1 ON. When the water continue to fill the tank, LED2, 3, and 4, would turn ON one by one. Here is the schematic :

Water Level Indicator Circuit Diagram Using IC CD4066

Estimated price : $1.5

Parts list :

  • Resistor R1-R4 : 180k ohm
  • Resistor R5 : 2.2k ohm
  • Resistor R6-R10 : 330 ohm
  • LED1-LED4 : LED 5mm
  • Piezoelectric buzzer
  • S1-S4 : IC CD4066
  • 6V power supply