This circuit generates a constant current given by R1. The load is on the high side of the feed (High Side). The circuit admits equivalent operationals and the source must be symmetrical.
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...