Used with infrared remotes at the time, this circuit was found in a 1991 RE Experimenter Handbook. It may not work with the faster remotes control used today.
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...