Hartley Oscillator for Code (CB26327E)

This oscillator uses a small transistor amplifier or radio output transformer. We found it in a Popular Electronics from the 90s.

Modulated Siren 555 (CB6421E)
In the original publication of the 90s a 556 consisting of a double 555 is suggested. The circuit...
Filter with sample and hold (CB8877E)
This circuit was found in a 1966 EEE. The circuit uses transistors from the time but can be made...
Photosensitive power circuit (CB25193E)
This circuit can be used in alarms by activating a relay or a current load that depends on the...