This control for 1/15 HP motors with 5,000 rpm for 115 V power grid was suggested by a Motorola circuit manual from 1968. The SCR supports more modern equivalents.
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...