This equalizer has automatic level control, being designed by Sanyo for cassette recorders and radio. The maximum supply voltage of the LA3210 is 15 V and the typical idle current of 1.4mA.
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...