This 1967 Raytheon circuit uses a Raystor, an optical coupler with a lamp and an LDR. The circuit can be adapted to use another type of coupler.
This radio's transistor is powered with the signal's own energy, producing its amplification....
Found in a 90s Electronic Design, this circuit can be used as a shield in current projects. The...
The integrated circuit used in this regulator is not very common today. The circuit is from old...