Found in a 1970 documentation, this circuit makes use of 741 operational amplifiers that are common today. Note that the power supply must be symmetrical.
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...