This anti-theft circuit was found in a 1985 documentation. It uses common components that can still be found easily. The relay is 12 V and the circuit has timings of 3 minutes and 20 seconds.
This old 4-channel circuit was found in the December 1994 Electronics Now magazine. The circuit uses...
The 78xx series is manufactured by several semiconductor companies that present ideas for use in...
This circuit that converts very low currents into voltage was obtained in the 80's used component...