This circuit for cars with mechanical ignition systems was found in the Electronics Experimenter handbook from 1991. It inhibits the ignition system, preventing theft.
This is another practical idea found in a 1997 documentation. This circuit allows a DJ to change the...
This circuit uses two 4001 ports to drive a relay. The circuit is from Electronics Now magazine, July...
This circuit is based on an LM3900 transconductance operational amplifier, found in 1992...