Found in an American documentation from the 90s, this circuit uses small low voltage lamps (6 to 12 V0. The circuit can be adapted to use LED indicators.
This control for motors up to 1 A was found in a Siliconix documentation using its own component....
This filter rejects the hum of 60 Hz from power grid, being placed between the signal source and...
In the figure we have an interface using an optical coupler and the comparator LM339 or any...