This simple humidity sensor can be used in rain or leak detectors. The circuit is for 12 V supply, but can be used with higher voltages, up to 24 V with current up to 3 A. The SCR in the case of higher currents, must be equipped with a heat sink.

This simple humidity sensor can be used in rain or leak detectors. The circuit is for 12 V supply, but can be used with higher voltages, up to 24 V with current up to 3 A. The SCR in the case of higher currents, must be equipped with a heat sink.