This circuit was found in a 1985 documentation. It provides an audiovisual indication of the presence of moisture or water in the sensor. The circuit can be powered by voltages from 6 to 9 V.
In this circuit the gain decreases as the input signal intensity increases. The circuit is from a...
This circuit was found in an American 1980s documentation. Dual FETs can be replaced by single...
September 2016 - Mouser Electgronics already has in stock the new moisture digital sensor HDC1010...