This circuit was found in a 1970s American documentation. It can be applied to almost any regulator. The transistor used admits equivalent, depending on the circuit current.
This simple circuit causes an LED to light up when the battery voltage drops below the voltage set in the...
Obtained from a 1967 documentation, this circuit uses transistors from the time. The galvanometer can be a...
The figure shows how to implement an alarm buzzer in an LM3914 to warn about crossing the scale...