We found this circuit in a 70s RCA manual. The circuit uses an LDR by directly driving a sensitive relay. Resistor R1 is 5.6 ohms and R2 is 25k. The pot is 10k of wire.
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...