Water Level Monitor

This single chip based CMOS circuit can detect water levels in a water tank,pool,channel etc,. and display on an easy to interpret is level display. In case the level exceeds a certain level ,the circuit can sound ana alarm (optional).Built around a single CMOS hex inverter ,this circuit lends portability as well.

CD4049 forms the heart of the circuit.When water crosses a certain level, it bridges sensor Sc (common) and S1 through S6 This water resistance, being less than that due to R1 through R6, the outputs go high and the corresponding LED is activated.The piezo buzzer is optional.Normally a small 20 mm piezo won't warm up to the IC but if a bigger one is used, a 100 ohm series resistor should be inserted.

The Schematic Water Level Monitor

The sensor is made as shown in figure a.The sensor has a plastic or PVC rod of the height of the tank etc and has metallic rings fixed at equal spaces,The connection are made using ribbon cables.

Figure a

The Finished devise can given a panel shown in figure b.This panel may either be photo copied on to film or used directly.The sensors can be fixed on one side of the water whose level is to be measured.

figure b