The water level gauge is a device used to measure the level of water or any other conductive liquid in a container. Following a very simple circuit, this device can be implemented. Along with indicating the water level, it will also give you an alarm when the tank is full.
Working
This device works by simply closing the circuit with the conductivity of the liquid. As seen in the next given circuit when the container is empty, the circuit will be open, therefore, the resistance implemented will cause the switch to open and, therefore, the LED will turn off. Similarly, when the liquid reaches the first installed probe, it will close the circuit between the base probe and the first probe, so the LED will light up indicating the water level.
Prerequisite: to implement this project will require
• a 6 V supply
• 4 no. of LEDs
• 4 no. of resistors of 330 ohms
• 4 no. of resistors 180K
• 1 no resistance of 2.2K
• 4 no. of switches (IC CD4066)
• a piezoelectric buzzer
• an on / off switch SPST
• a BC148 transistor
Circuit diagram