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 application circuit for the Texas Instruments LMV358A was obtained from the component's own...
This circuit generates pulses whose frequency depends on C1. The circuit can be powered by...
This circuit turns on your car's backlight when a vehicle coming from behind gets too close to it...