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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 is different between work and power in details
Andiswa Reply
When a force is exerted to an object and causes it to move in the direction of the force the work is done whereas power is the rate at which work is done.
ISRAEL
Why is alcohol flameable?
Moloto Reply
What is interconversion reaction for? ... under substitution reaction
Moloto
how can u tell whether the compound is an alkane, alkene or alkyne
Imagine Reply
alkane compounds are saturated, consists of single bonds between atoms and alkenes are unsaturated consists of one double bond between two adjacent carbon atoms .alkynes are also unsaturated but they consists of a triple bond between 2 adjacent carbon atoms.
Andile
you can tell simple by looking at the bonds which exist between the carbon-carbon atoms of the compound, so if a compound consists of double bond between its carbon-carbon atoms it is an alkene etc.
Tatyana
can it say it cause I understand it better
Tobeka Reply
Hey, what is momentum?
Inocent Reply
the product of mass n its velocity
Albert
And what's simple harmonic?
Inocent
What is organic compounds
Gaba Reply
are compounds which consists of carbon atoms
Mkhize
Thanks bro
Gaba
How many industrial processes are there?
Sheron Reply
A homologous group is a group with the same amount of electrons in the outermost shell.
Duncan Reply
What are hydrocarbons
Lindiwe Reply
Its a compound of hydrogen and carbon atoms
Luyanda
do hydrocarbons get unsaturated?
Mandi Reply
yes
Thembi
they are saturated
Sinoty
Yes
Gugu
what is monomer
Vuyo Reply
what is polymerism
Tobeka
I think a polymer is a chemical compound with molecules bonded together in long, repeating chains. Because of their structure, polymers have unique properties that can be tailored for different uses.
Kagiso
what about a monomer ?
Louis
which essays are expected in march exams
Qiniso Reply
what do you look at when you want to successfully compare the boiling points of two|three organic molecules
FIN Reply
1-check the homologous group 2-number of carbons or chain length n their intermolecular forces between the bonds
Lesego
why are alkanes none as primary
Babulele Reply
meant to say known as primary alchols
Babulele
because there is only 1 OH attached to carbon and carbon
Sinoty
intermoleculer forces
Bwn Reply

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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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