This circuit, designed on request, has proven to be useful to indicate when the voltage in a power supply line is changing from 120V to 240Vac. It can be used in different circumstances and circuits, ...

If you’re working with 3.3V or 5V circuits, it’s easy for you to throw on a power or status LED here or there. [Tom Gralewicz] has found himself in a pickle, though, often working on projects with ...

You’ve got an apparently simple design requirement on your latest AC-line powered project: provide a distinctly illuminated indicator to show that the unit is plugged into the line and that power is ...