We found this circuit in the October 1996 Electronics Now magazine. The circuit uses LDRs as sensors and drives relays. The relays must have voltages according to the power supply.
This timer, from an old American publication, uses indicator lamps, but can be modified to use...
This didactic circuit from a 1977 Radio Shack documentation shows how to use the 741 as a...
Found in an 80's Hands On Electronics, this circuit turns on a light when it gets dark and goes...