This circuit supplies a continuous voltage at its output, which is the peak value of the alternating input voltage. The circuit is from a 90's EDN, making use of Maxim integrated circuits of the time.
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...