Simple Water Level Detector This simple water detector circuit uses alternative voltage in order to prevent the corrosion of the electrodes. It is easy to build and uses N1 as a trigger Schmitt gate which generate the AC. If between the electrodes is a electricity conductor, for example an aqueous solution, then because of the rectification action of D1 and D2, the C4 capacitor is charging.
Simple water detector circuit diagram:
When the capacitor voltage reaches switching threshold of the N2 trigger Schmitt, the relay will trigger and connect, for example a drain pump. The pump will be disconnected as soon as the electrodes won’t touch the liquid.
Components List:
R1 = 470K
R2 = 10M … 22M
C1 … C4 = 2.2nF
N1, N2 = 1/2 4093
D1 … D3 = 1N4148
T1 = pnp transistor (BC557)
