This circuit was found in an 80's General Electric documentation. The circuit uses uncommon components today like the PUT. Unijunction admits equivalent.
This simple metal detector was found in a 1960 Sylvania transistor manual. The phone must be high...
This is one of the many versions of this type of indicator that the reader can find on our...
Found in an English publication from the 1980s, this circuit can be built with equivalent...