This analog ammeter circuit was found in documentation from the 1980s. The components admit equivalents and the scales are determined by the values of the components in the range selection.
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...