Found in American documentation from the 90s, this circuit uses a high voltage relay and has no grid isolation. The high values of R1 and R2 prevent the shock when it touches the sensors.
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...