The time of this timer depends on C1. The circuit was found in the July 1994 Electronics Now magazine. The supply voltage depends on the relay and can go up to 12 V.
This highly sensitive light sensor was found in a 1970 General Electric documentation. The circuit...
The given number circuit is used to activate the relay by interrupting the light beam that hits...
This alarm circuit with sensors in series was found in the Electronics Now magazine of June 1994....