water level indicator with


Posted on Feb 7, 2014

When the water is empty the wires in the tank are open circuited and the 180K resistors pulls the switch low hence opening the switch and LEDs are OFF. As the water starts filling up, first the wire in the tank connected to S1 and the + supply are shorted by water. This closes the switch S1 and turns the LED1 ON.


water level indicator with
Click here to download the full size of the above Circuit.

As the water continues to fill the tank, the LEDs2, 3 and 4 light up gradually. When the water is full, the base of the transistor BC148 is pulled high by the water and this saturates the transistor, turning the buzzer ON. The SPST switch has to be opened to turn the buzzer OFF.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Arc Welder Simulator
AC Motor Speed Control circuit
Low-Distortion Amplifier/Compressor
Battery Charger
Ac Wiring Locator Circuit
Getting more amperage from a 555 output
and filter 1 3 5w power rf amplifier
Battery charger using LM350
Radio Jammer
Lithium-Polymer Peak Charger
Glowing Hybrid Amp
A Push-Pull Hartley VFO transmitter
Ensemble RX Builders
Pulsed Magnetic Field Therapy (PMFT) Circuit



Top