This immobilizer circuit for vehicles was found in a 80’s Hands On Electronics. The circuit shortens the platinum to prevent its operation and thus the operation of the engine when started.
This circuit triggers the LED when the monitored battery voltage drops below 9 V for 12 V...
We found this circuit in a Radio Electronics from January 1967. The SCR is already the C106, which...
This power source with silicon diodes at a time when valves were still used was found in Radio...