This fast Schmitt trigger operates at frequencies from 10 Hz to 100 Hz, with very short rise time. The circuit is from an American documentation from 1968.
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...