Water Level Sensor and Alarm Circuit with CD4066

water level sensor circuit

For circuit not only indicates the amount of water in the tank head, but also gives an alarm when the tank is full.
This circuit uses the widely available to show IC number CD4066 bilateral switch CMOS IC to the water level through LEDs.
If the water is empty the wires in the tank are open circuit and the 180K resistors pulls the switch to open the little switches and LEDs are off. When the water begins to fill the first wire connected to the reservoir in the S1 and the + supply are shorted by water. This closes the S1 and turns the LED1 ON. As the water further into the tank, LEDS2, 3 to 4 pm light gradually filled.
No. Levels of the display to 8 if 2 can CD4066 ICs are used to increase similarly.

If the water is full, the base of the transistor BC148 is pulled up with water and saturate the transistor, turning the buzzer ON. The SPST switch has to be opened to turn off the ringer.
Remember, the switch ON while pumping water otherwise the buzzer does not sound!