I needed a simple LED indicator showing that a particular voltage level had been reached—specifically, that a capacitor had charged to a particular potential. I was convinced that there must be a way ...

This LED DC voltage indicator circuit is a voltmeter, rather than simply a battery tester. As such it may measure voltages as low as 3V. It utilizes venerable LM741 operational amplifiers applied as ...

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 ...

The QRM Series, rear-mounting LED indicators from APEM Inc. is suitable for a wide range of applications, from heavy machinery to military devices, and the QRM-NV series, including night vision (NVIS) ...

The S18DLH and S22DLH high-intensity indicator lights are designed with highly visible LEDs to provide bright, clear indication in environments with high levels of ambient light, including direct ...