This amplifier circuit with gain between 0 and 96 was found in the December 1983 issue of Radio Electronics magazine. The power supply must be 15 V.
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...