A light emitting diode (LED) is a semi conductor light source. When a semi conductor diode is switched on, it can release energy in the form of photons. This effect is named as Electroluminescence.
This effect was first discovered in 1907, by H.J.Round of Marconi Labs. No practical use was made of this discovery for several decades.
The first practical visible spectrum of LED was developed in 1962, by Nick Holonyak Jr, rightfully called “The father of LED”. In 1962, LED was introduced as a practical electronic component. Early LED emitted very low intensity light.
Until 1968, LED was extremely costly and had very little use. The first commercial LED was a replacement for incandescent and neon lamps. Later LED was used in T.V, radio, telephone, calculator and watches.
Very bright modern versions of LED are available now, in the visible, infrared as well as ultraviolet wave lengths. Today LED is used for aviation lighting, automobile lighting, in indicators and traffic signal lights.
The compact size of the LED has made it possible to develop new text and video displays and sensors. The faster switching frequency is useful in advanced communication technology. Infra red LED is used in the remote control units of the T.Vs, DVD players and other domestic appliances.
Visalakshi Ramani
Pages
- A Prayer
- Why these Articles?
- I. THE FIRST OF ITS KIND!
- II. SPIRIT AND SUCCESS!
- III. LUCKY ACCIDENTS
- IV. FICTION AND FACTS
- V. NURSERY RHYMES
- #05. An Introduction
- 46. Ring a Ring o’ Roses
- 47. Mary Mary
- 48. Jack And Jill
- 49. Rain Rain Go Away
- 50. Sing a Song
- 51. London Bridge
- 52. Ding Dong Bell
- 53. For Want Of a Nail
- 54. Goosey Goosey
- 55. Hey Diddle Diddle
- 56. Little Miss Muffet
- 57. Old Mother
- 58. Little Tommy
- 59. Pussy Cat
- 60. Elephant Rhyme
- 61. An Apple a Day
- 62. A Wise Old Owl
- 63. Hot Cross Buns
- 64. Twinkle Twinkle
- 65. Wee Willie Winkie
- VI. DESERT BLOSSOMS
- VII. WONDERFUL BODY
- #07. An Introduction
- 76. The Human Aura
- 77. The Homunculus
- 78. Personalities
- 79. Brain Asymmetry!
- 80. “Use it or Lose it”
- 81. Why S.A.D?
- 82. Pain Gate Theory
- 83. A Rare Disorder!
- 84. A King’s Touch!
- 85. Is Fever a Favor?
- 86. Phytochemical Boosters
- 87. Why regain weight?
- 88. How do we see?
- 89. Tasty Bites!
- 90. “Feeling Left out”?
- 91. Artificial Blood
- 92. Artificial Skin!
- 93. Is Sleep a Luxury?
- 94. Aromatherapy
- 95. Garlic Pearls.
- VIII. MIRACULOUS MIND
- #08. An Introduction
- 96. Genius and Genes!
- 97. Anima and Animus
- 98. Body Language
- 99. Types of Thinking
- 100. Types of Intelligence
- 101. Memory Techniques
- 102. Types of Listening
- 103. Selective Listening
- 104. Commonest Phobia!
- 105. Agoraphobia
- 106. The Fear Of Size!
- 107. Dreamy Discoveries
- 108. Why do we day dream?
- 109. Brain Washing!
- 110. When we tell a lie…
- 111. Escapism
- 112. PSI Phenomena
- 113. Personal Space
- 114. Why Sensitive?
- 115. Drugs and Drinks!
- IX. MATHEMAGIC
- X. SCIENCE SPECIALS
- XI. UNUSUAL ANIMALS
- XII. FLIGHTLESS BIRDS
- XIII. INSECTS
- XIV. WATER KINGDOM
- XV. GENERAL INTEREST
- 182. Bloomer.
- 183. Joyful Jacuzzi
- 184. Laudable Lipogram
- 185. The Royal Car
- 186. A Taj Mahal in U.K!
- 187. Steady as a rock?
- 188. Holy Swastika defiled!
- 189. The King of Games!
- 190. Sky Writing!
- 191. Death defying jumps
- 192. Fresh Water at Sea
- 193. Milky Myths
- 194. Pride and Punishment
- 195. Nicotiana
- 196. Soothing Sleep
- 197. Silent Movies.
- 198. The Virus Day
- 199. Popeye’s Strength
- 200. The Ten-in-One man
- 201. Fertility and Eggs
- XVI. HOME SWEET HOME
- XVII. Some Useful Info
- 211. Anniversary gifts
- 212. Birth-month-gem
- 213. Birth-Month-Flower
- 214. The Scratch Test
- 215. Gems And Planets
- 216. Week Days And Gems.
- 217. Gems for Elements
- 218. The Seven Colors
- 219. Ruby
- 220. Natural Pearl
- 221. Red Coral
- 222. Emerald
- 223. Sapphire
- 224. Diamond
- 225. Blue Sapphire
- 226. Hessonite
- 227. Cat’s Eye
- 228. Alexandrite
- 229. Coin Collectors
- XVIII. Styles of Art
- CONCLUSION.
- Reviews