This circuit turns off a relay after a time determined by C1. The circuit was found in the December 1974 Radio Electronics magazine. The relay is rated according to the supply voltage.
This switching power supply was found in an Electronic Design from the 90s. The components are...
This burglar alarm is highly efficient, depending of course on the care with which it is...
This circuit is from a 1969 Electronics World. The transistors may be modern general-purpose...