This trigger circuit was found in an American documentation from the 1980s. The amplifiers used can be replaced by equivalents with characteristics according to the frequency.
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...