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

Sound Continuity Test LM3909 (CB11536E)
The output of this circuit can be a crystal phone or a piezoelectric capsule. The circuit tests the...
Conductance Mixer (CB14019E)
This circuit was obtained in an English publication of 1977. The operational is of the type with...
LED Indicator 4093 (CB14963E)
This circuit was found in a Poptronics of the 90's. It can be powered by voltages between 6 and 15...