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

CMOS 4001 Alarm with Latch (CB24374E)
We found this circuit in the April 1975 Radio Electronics magazine. The circuit has a latch and...
Alarm System (CB16793E)
We found this sophisticated home alarm in a 1994 documentation. The circuit supports sensors of...
Light Activated Alarm (CB26164E)
This circuit was found in the 1991 Electronics Experimenter's Handbook. It activates a relay when...