Light-Emitting Diodes (LEDs)
Nick Poole, 
bboyho 
Introduction
LEDs are all around us: In our phones, our cars and even our homes. Any time something electronic lights up, there's a good chance that an LED is behind it. They come in a huge variety of sizes, shapes, and colors, but no matter what they look like they have one thing in common: they're the bacon of electronics. They're widely purported to make any project better and they're often added to unlikely things (to everyone's delight).
Unlike bacon, however, they're no good once you've cooked them. This guide will help you avoid any accidental LED barbecues! First things first, though. What exactly is this LED thing everyone's talking about?
LEDs (that's "ell-ee-dees") are a particular type of diode that convert electrical energy into light. In fact, LED stands for "Light Emitting Diode." (It does what it says on the tin!) And this is reflected in the similarity between the diode and LED schematic symbols:
In short, LEDs are like tiny lightbulbs. However, LEDs require a lot less power to light up by comparison. They're also more energy efficient, so they don't tend to get hot like conventional lightbulbs do (unless you're really pumping power into them). This makes them ideal for mobile devices and other low-power applications. Don't count them out of the high-power game, though. High-intensity LEDs have found their way into accent lighting, spotlights and even automotive headlights!
Are you getting the craving yet? The craving to put LEDs on everything? Good, stick with us and we'll show you how!
Suggested Reading
Here are some other topics that will be discussed in this tutorial. If you are unfamiliar with any of them, please have a look at the respective tutorial before you go any further.