Audio Oscillator 7400 (CB22415E)

The frequency of this circuit is determined by the 1 uF capacitors. These components can be changed. The circuit must be supplied with 5V voltage.

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...