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

Rain Alarm (CB15108E)
This alarm, from a 1996 magazine, can be fitted with two BC548s in the original configuration...
Simple touch switch (CB9563E)
Using only one general purpose transistor this circuit is powered by batteries. The lamp of the...
Programmable attenuator (CB9031E)
Can be used as a shield, this old American documentation circuit offers digitally selected...