3-way control (CB7047E)

This is a simple circuit to control a set of lamps from 3 different points. We found it in an old Popular Electronics.

Metal locator (CB7506E)
This simple metal detector was found in a 1960 Sylvania transistor manual. The phone must be high...
Balance indicator for stereo (CB7309E)
This is one of the many versions of this type of indicator that the reader can find on our...
Drum synthesizer (CB22204E)
Found in an English publication from the 1980s, this circuit can be built with equivalent...