This circuit is a driver for R-2R network of AD converters. We found it in manufacturer documentation from the 1980s. The configuration can be adapted to be used with modern operationals.
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...