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Led applications

LEDs have many uses. Some of these are given here.

  1. thin, lightweight message displays, e.g. in public information signs (at airports and railway stations, among other places)
  2. status indicators, e.g. on/off lights on professional instruments and consumers audio/video equipment
  3. infrared LEDs in remote controls (for TVs, VCRs, etc.)
  4. clusters of LEDs are used in traffic signals, replacing ordinary bulbs behind coloured glass
  5. car indicator lights and bicycle lighting
  6. calculator and measurement instrument displays (seven segment displays), although now mostly replaced by LCDs
  7. red or yellow LEDs are used in indicator and [alpha]numeric displays in environments where night vision must be retained: aircraft cockpits, submarine and ship bridges, astronomy observatories, and in the field, e.g. night time animal watching and military field use
  8. red or yellow LEDs are also used in photographic darkrooms, for providing lighting which does not lead to unwanted exposure of the film
  9. illumination, e.g. flashlights (a.k.a. torches, UK), and backlighting for LCD screens
  10. signaling/emergency beacons and strobes
  11. movement sensors, e.g. in mechanical and optical computer mice and trackballs
  12. in LED printers, e.g. high-end colour printers

LEDs offer benefits in terms of maintenance and safety.

  1. The typical working lifetime of a device, including the bulb, is ten years, which is much longer than the lifetimes of most other light sources.
  2. LEDs fail by dimming over time, rather than the abrupt burn-out of incandescent bulbs.
  3. LEDs give off less heat than incandescent light bulbs and are less fragile than fluorescent lamps.
  4. Since an individual device is smaller than a centimetre in length, LED-based light sources used for illumination and outdoor signals are built using clusters of tens of devices.

Because they are monochromatic, LED lights have great power advantages over white lights where a specific colour is required. Unlike the white lights, the LED does not need a filter that absorbs most of the emitted white light. Coloured fluorescent lights are made, but they are not widely available. LED lights are inherently coloured, and are available in a wide range of colours. One of the most recently introduced colours is the emerald green (bluish green, wavelength of about 500 nm) that meets the legal requirements for traffic signals and navigation lights.

Interesting fact

The largest LED display in the world is 36 m high, at Times Square, New York, U.S.A.

There are applications that specifically require light that does not contain any blue component. Examples are photographic darkroom safe lights, illumination in laboratories where certain photo-sensitive chemicals are used, and situations where dark adaptation (night vision) must be preserved, such as cockpit and bridge illumination, observatories, etc. Yellow LED lights are a good choice to meet these special requirements because the human eye is more sensitive to yellow light.

The light emitting diode

  1. What is an LED?
  2. List 5 applications of LEDs.

Questions & Answers

what makes an atom to take part in a chemical reaction
Mwila Reply
what is an element
Mwila
what are molecules
Uyanda Reply
what are molecules
Itumeleng Reply
A group of two atoms tha the form smallest identifiable unit into which a pure substance.
El
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Mercy Reply
it's a topic in physics
Thabo
Anything that occupies space and has mass
Lisoga
what is the catalyst used in esterification reaction
ketina Reply
I think is sulfuric acid
Selby
what is equilibrium
Dabo Reply
It is a condition of a system when neither its state of motion nor its internal energy state tends to change with time. ... For a single particle, equilibrium arises if the vector sum of all forces acting upon the particle is zero.
susan
it is a dynamic change when the forward reaction is equals to the reverse reaction rate
Frank
what does organic mean
ntuthuko Reply
it means "from living thing"
Maqaqatu
What is a successful collision?
Refiloe Reply
It's a collision that results to a reaction
Tshepo
what is the factor and reaction rate of 20%HCL and 5%HCL
Kleng Reply
concentration and 0.05M/s
Tokozan
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Edelita Reply
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Edelita
besides the concentration what are the two conditions for the hydrogen half cell to function under standard conditions
Malwandla Reply
forces of non-concervative
Marlet Reply
What is the following process is likely to involve carbon burning?
Sofie Reply
Combustion
Luyanda
Which Statement is part of the cell theory?
Hananiya Reply
What is the second formal statement in the cell theory
Hananiya
🤔
Bontle
what is meant by ohmic
nthabiseng Reply
when someone is referred to as ohmic, it basically means that it obeys ohm's law
Tanaka
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Source:  OpenStax, Siyavula textbooks: grade 12 physical science. OpenStax CNX. Aug 03, 2011 Download for free at http://cnx.org/content/col11244/1.2
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