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.
We found this circuit in an English magazine in 1975, but it can be easily assembled, as the...
Found in a 90s Popular Electronics, this circuit uses a 741 to generate frequencies from 0.1 to 30...
This circuit is from an 80's documentation. The circuit makes use of a component of the era, the...