The basic circuit illuminates up to ten LEDs in sequence, following the rhythm of music or speech picked-up by a small microphone. The expanded version can drive up to ten strips, formed by up to five ...

Controlling LEDs is really quite simple. As you know, they need to be current limited which is as easy as applying Ohm’s law to your given set of values. To make things even more even there’s a slew ...

Discover how to build a simple wireless power transfer system at home using readily available components like enameled copper wire, an LED, a 2N2222A transistor, and a 9V battery. This step-by-step ...

Let’s say you want to blink an LED. You might grab an Arduino and run the Blink sketch, or you might lace up a few components to a 555. But you needn’t go so fancy! [The Design Graveyard] explains how ...

Transistors, the tiny switches that flip on and off inside computer chips, have long been the domain of electricity. But scientists are beginning to develop chip components that run on light. Last ...