This Motorola circuit is from 1965. Collector currents must be 7 and 12 A for transistors. Equivalents may be used. The circuit is for contact breaker cars.
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...