This circuit is from Ferranti documentation from 1967. The operational is of the time, but the configuration is valid for modern equivalent components, including higher current capacity.
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...