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

Residential Alarm (CB16909E)
This 1995 circuit uses interruption sensors or NC connected in series in any quantity. With the...
Telephone Spy (CB18047E)
This circuit transmits the audio signals from a telephone line to an FM receiver placed nearby. The...
Reference Voltage Amplifier (CB4906E)
This circuit is from an old manual of operational amplifiers. The setting can be adapted to work...