LEDs are an astounding new invention that will soon replace almost all other light sources on the planet. Because they're unlike the light bulbs you've known, choosing and using them successfully requires a new set of skills and knowledge. Patented by a GE engineer in 1962, LEDs were such an astounding invention, other engineers in the company called them "the magic thing." Originally used as tiny red dots to indicate a device was turned on, it took another 20 years to figure out how to make LEDs in other colors. And more time to make them brighter. All those problems have been solved now. They use about one-tenth the electricity to produce the same brightness incandescent lights would. They don't get hot, so they don't increase air conditioning costs. And their life expectancy is 30 to 40 times longer than standard light bulbs. They have a few limitations, and you should know more about them before you start converting your lighting to LEDs. That's what this book is about.