This circuit, from a 303 Circuits from the 90s, uses a telephone pickup coil as a sensor to capture power grid noise, thus making it possible to locate electrical wiring.
The critical point in this 2005 project is the adjustment of the optical system, mainly to avoid...
This simple SCR trigger was found in a 1965 General Electric SCR manual. The circuit makes use of a...
We found this circuit in a 1976 technical documentation, but it can be assembled with modern...