Using the LM358 from Texas Instruments, this circuit uses LED indicators and can be powered with voltages of 5V or according to the analyzed logic.
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...