We find this circuit in an old documentation, but it can be made using modern transistors. The circuit trips, producing a continuous sound when the sensor is wet. The 1 mOhm resistor is actually 1 Mohm.
This circuit is from the 70s. The integrated circuit used is not common today and the supply is...
This project was found in a documentation from 1980. It is a central of sound effects, a simple...
This range is normally used in marine communications as indicated in the 1989 documentation. The...