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.
The frequency of this circuit is determined by the 100 uF capacitors. These components can be...
This crystal-controlled 1000 kHz oscillator was found in 1980s American documentation. The...
This circuit was obtained from an American documentation from 1976. The circuit has a dynamic...