CONTENTS INTRODUCTION 5 CHAPTER ONE WHAT ARE LEDs 6 CHAPTER TWO DIFFERENT TYPES OF LEDs 14 CHAPTER THREE ADVANTAGES OF LEDs 23 CHAPTER FOUR THE FUTURE OF LEDs 28 EXPERIMENT BATTLE OF THE BULBS 34 Solve It Answer Key 35 Glossary 36 Selected Bibliography 37 Further Information 38 Index 39
LEDs are used with sensors in touch screens for TVs phones and other devices
INTRODUCTION What if you could have a lightbulb that was as bright as any other bulb saved you money didn’t need much energy to work was usually cool to the touch and lasted practically forever Well it already exists It’s called a light-emitting diode or LED LEDs are used in toys streetlights flashing signs cell phones TV remotes computers and much more Maybe you’re using a book light containing an LED to read this very page LEDs are truly changing the way we light our world They differ from standard lightbulbs in many ways and in the coming years they will be used more and more to light homes cities and even spacecraft So let’s check out what LEDs are made of and how they work You’ll see how they’re used in items ranging from digital alarm clocks to giant screens at sports stadiums You’ll also learn why LEDs are the best options to solve some serious lighting problems as well as how they’re likely to be used in the future 5
