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.
The integrated circuit of this 1976 configuration is the 7400 and the type crystal in televisions of the...
We found this divider in a circuit manual from the 90s. The circuit is intended for operation with...
Recommended for automotive applications, this circuit was found in an April 1982 Radio Electronics...