Found in a 1990 Hobbyst Handbook this circuit has an output power of a few tens of watts and serves as reinforced for the car's sound. The speaker can be 2 or 4 ohm.
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...