This circuit is from a 1976 Motorola CMOS manual. It can be implemented with modern Darlingtons like those in the Texas TIP series. The load current depends only on the Darlington transistor.
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...