This stereo circuit is from Japanese 1960 documentation. The circuit was originally designed to work with a tube amplifier, removing power from it. The transistors are germanium.
This simple alarm circuit was found in a 1998 documentation. When the sensors are activated, the...
This circuit was found in an old American documentation. The integrated circuit used is uncommon...
Found in a 90s Electronic Design, this suggestion to have a higher voltage in a fixed regulator...