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 preamp version uses BC109 transistors that are older versions of the current BC549 in plastic...
This circuit was obtained in a technical documentation from the 70s, but it can be assembled with...
This stepper motor control was originally designed to use a PC's parallel port and is quite simple...