Found in a 1980s manufacturer documentation, this circuit can be used as an optical shield. The integrated circuit is from the era and modern equivalents can be tried out.
We found this circuit in the April 1975 Radio Electronics magazine. The circuit has a latch and...
We found this sophisticated home alarm in a 1994 documentation. The circuit supports sensors of...
This circuit was found in the 1991 Electronics Experimenter's Handbook. It activates a relay when...