Intercom (CB21660E)

This good gain circuit was found in a Popular Electronics from April 1967. The transistors are germanium of the time.

Wein Bridge Oscillator (CB10775E)
This circuit was obtained from Popular Electronics in 1993. It consists of a low frequency...
LM380 2.5 W amplifier (CB10900E)
The traditional circuit was taken from a French magazine Radio Plans that no longer exists but can...
400 mA Buck Regulator CIR16840S CB12942E (CB12942E)
The circuit shown in the figure consists of a fixed buck regulator using the MIC23021 integrated circuit...