Found in a 1960s RCA documentation, this circuit applies to most common triacs. The trigger device is a neon lamp and the sensor is an LDR. R is typically 100k and C is 220 nF.
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...