Found in 1969 documentation, this circuit supplies a load after an interval given by R1 and C1. These components can be changed to other times.
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...