Rail to Rail Oscillator 555 (CB9099E)

Found in an Electronic Design from the 80s, this circuit generates a 500 Hz signal and can be used as a shield

Telephone in use indicator (CB9467E)
We found this circuit in a Hands-On Electroncs from the 90s. The circuit uses an LED indicator. Diodes...
Passage Alarm (CB10708E)
This circuit was obtained in a 1973 national publication, translated from an English publication of the...
Solar Radio (CB10406E)
We found this circuit in a 1983 English magazine, but it can be easily assembled with the BC548...