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 ...

APEM Inc. is expanding its line of LED indicators to feature HYPERBRIGHT LED indicators for daytime viewing and for applications where battery life and low power consumption are critical. APEM Inc. is ...