In the water level sensor schematic, the common probes connecting the underground tank and the overhead tank to +9V supply are marked ‘C’. The other probe in underground tank, which is slightly above ...

Posted in green hacks Tagged alarm, led, level, meter, transistor, water ← Autonomous RC Car Navigates By Waypoints Hackaday Links: Sunday, June 16th, 2013 → ...

It will switch off only after the water drops below level A. Figure 2 illustrates the complete circuit. Using a rail-to-rail op amp for U2 allows for the application of a single 5-V power supply.

And, the SCR's trigger is connected to sensor A for detecting the water's upper level. The anode, C, which is connected to the +12-V supply, is kept at the lowest water level, below B.

This simple water level indicator will activate an active buzzer (e.g. BeStar BPT-23CX ) in order to make a noise when a certain level of water is being reached. Because the water sensor and the ...