Rectangular Oscillator 555 (CB22449E)

This oscillator with different outputs has frequencies selected by the S2 switch in 3 bands. We found it in a Popular Electronics from 1992.

50 mW Amplifier (CB24449E)
This low-power transistorized amplifier was found in documentation from the 90s. The circuit uses...
Metal Detector (CB12077E)
This circuit is from Popular Electronics from March 1991. It can still be assembled with the...
Symmetric Power Supply (CB15712E)
The voltage of this symmetrical power supply depends on the regulating integrated circuits, which...