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 project that we present below is very interesting, serving to identify remote calls such as in...
This experimental AM radio circuit was found in a 1979 English magazine. It can be fitted with a...
The purpose of this circuit is to amplify the signal of a phone pickup and to be able to reproduce the...