Content deleted Content added
m →Energy Star qualification: clean up |
Rescuing 5 sources and tagging 0 as dead.) #IABot (v2.0.9.5 |
||
Line 17:
[[File:Chip-On-Board COB LED Module.JPG|thumb|An 80W [[Light emitting diode#Chip-on-board arrays|Chips on board]] (COB) LED module from an industrial light luminaire, thermally bonded to the heat sink]]
An '''LED lamp''' or '''LED light'''<ref>{{Cite web |date=2015-12-02 |title=LED revolution: The big switch |url=https://www.indiatoday.in/magazine/cover-story/story/20151214-climate-change-technologies-led-revolution-the-big-switch-820921-2015-12-02 |access-date=2025-04-11 |website=India Today |language=en}}</ref> is an [[electric light]] that produces [[light]] using [[light-emitting diode]]s (LEDs). LED lamps are significantly more [[Electrical efficiency|energy-efficient]] than equivalent [[Incandescent light bulb|incandescent lamps]] and [[fluorescent lamp]]s.<ref>{{Cite news |title=How Energy-Efficient Light Bulbs Compare with Traditional Incandescents |url=https://energy.gov/energysaver/save-electricity-and-fuel/lighting-choices-save-you-money/how-energy-efficient-light |archive-url=
LED lamps require an electronic [[LED circuit]] to operate from mains power lines, and losses from this circuit means that the efficiency of the lamp is lower than the efficiency of the LED chips it uses. The driver circuit may require special features to be compatible with lamp dimmers intended for use on incandescent lamps. Generally the current waveform contains some amount of distortion, depending on the luminaires' technology.<ref>{{Cite journal |last1=Ciugudeanu |first1=Calin |last2=Buzdugan |first2=Mircea |last3=Beu |first3=Dorin |last4=Campianu |first4=Angel |last5=Galatanu |first5=Catalin Daniel |date=12 December 2019 |title=Sustainable Lighting-Retrofit Versus Dedicated Luminaires-Light Versus Power Quality |journal=Sustainability |language=en |volume=11 |issue=24 |pages=7125 |doi=10.3390/su11247125 |issn=2071-1050 |doi-access=free|bibcode=2019Sust...11.7125C }}</ref>
Line 53:
[[File:Sct Mathias xmas illumination 2010-12-14.jpg|thumb|LEDs as Christmas illumination in [[Viborg, Denmark]]]]
In 2003, the first surgical goggles with LEDs were demonstrated.<ref name="auto1">{{Cite book|url=https://books.google.com/books?id=algLBgAAQBAJ|title=Light-Emitting Diodes (2nd Edition, 2006)|first=E. Fred|last=Schubert|date=1 January 2006|publisher=E. Fred Schubert|isbn=978-0-9863826-1-1 |via=Google Books}}</ref> Audi showed the [[Audi Nuvolari]] concept car with LED headlights.<ref name="auto2">{{Cite book|chapter-url=https://www.spiedigitallibrary.org/conference-proceedings-of-spie/5941/594101/LEDs-for-solid-state-lighting-and-other-emerging-applications/10.1117/12.625918.full|chapter=LEDs for solid state lighting and other emerging applications: status, trends, and challenges|first=M. George|last=Craford|editor-first1=Ian T. |editor-first2=John C. |editor-first3=Tsunemasa |editor-first4=Ian E. |editor-last1=Ferguson |editor-last2=Carrano |editor-last3=Taguchi |editor-last4=Ashdown |title=Fifth International Conference on Solid State Lighting |series=SPIE Proceedings |date=2 September 2005|publisher=SPIE|volume=5941|pages=594101|via=www.spiedigitallibrary.org|doi=10.1117/12.625918|s2cid=119804533 }}</ref><ref>{{Cite web|url=https://www.auto123.com/en/news/2003-audi-nuvolari-concept/43740/|title=2003 Audi Nuvolari Concept | Car News | Auto123|date=23 August 2003|website=auto123.com}}</ref><ref>{{Cite web |title=Audi Nuvolari quattro |url=https://www.autopista.es/noticias-motor/audi-nuvolari-quattro_80682_102.html |access-date=2025-04-11 |website=Autopista |language=es}}</ref> In 2004, [[Audi]] released the first car with LED daytime running lights and directionals, the 2004 [[Audi A8]] W12.<ref name="auto1" /><ref>{{Cite web|url=https://compoundsemiconductor.net/article-gen/83185|title=Lumileds LEDs used in Audi headlights - News|website=Compound Semiconductor}}</ref><ref>{{Cite news |title=Hella Develops Audi LEDs |url=https://www.photonics.com/Articles/Hella_Develops_Audi_LEDs/a18248 |archive-url=
In 2005, an LED lamp was installed to illuminate the [[Mona Lisa]].<ref>{{Cite web|url=http://www.ingelux.com/wp-content/uploads/2017/09/Lampe-Joconde-Toshiba-Ingelux-English.pdf|title=Lighting ''Mona Lisa'' with LEDs: details concerning innovating techniques|publisher=TOSHIBA Lamp|date=2013|first1=Marc|last1=Fontoynont|first2=Jean Pierre|last2=Miras|first3=Marco|last3=Angelini|first4=Jean|last4=Chanussot|first5=Christophe|last5=Marty|first6=Grégory|last6=Duchêne|first7=Leonid|last7=Novakovski|first8=Kazuaki|last8=Makita|first9=Tokayoshi|last9=Moriyama}}</ref> LEDs were in use at the Casino Breda in The Netherlands, the Vienna State Opera, and the venue for the Shanghai Grand Prix, for example. LED flashlights and headlamps for people were available.<ref name="auto2" /> In 2006, some of the first LED spotlights for use in stores were released.<ref>{{cite web | url=http://www.ledsmagazine.com/company-newsfeed/article/16689836/lumelextm-the-first-led-product-from-lighting-services-inc-launched-at-lightfair | title=LumeLEX™, the first LED product from Lighting Services Inc, launched at LightFair | date=6 June 2006 }}</ref> In 2007, Audi was the first car manufacturer to offer headlights that solely used LEDs, used in the [[Audi R8]].<ref>{{Cite web |last=Moore |first=Alina |date=2007-08-10 |title=Audi's first all-LED headlight in the world |url=https://www.topspeed.com/cars/car-news/audi-s-first-all-led-headlight-in-the-world/ |access-date=2025-06-05 |website=TopSpeed |language=en}}</ref>
Line 101:
==Applications==
LED lamps are used for both general and special-purpose lighting. Where colored light is needed, LEDs that inherently emit light of a single color require no energy-absorbing filters. LED lamps are commonly available as drop-in replacements for either bulbs or fixtures, replacing either an entire fixture (such as LED light panels replacing fluorescent [[troffer]]s or LED spotlight fixtures replacing similar halogen fixtures) or bulbs (such as LED tubes replacing fluorescent tubes inside troffers or LED HID replacement lamps replacing HID bulbs inside HID fixtures) The differences between replacing a fixture and replacing a bulb are that, when a fixture (like a troffer) is replaced with something like an LED panel, the panel must be replaced in its entirety if the LEDs or the driver it contains fail since it is impossible to replace them individually in a practical fashion<ref>{{Cite web |last=Nowicki |first=Michael |date=2015-06-18 |title=LED lighting: Replaceable or disposable? |url=https://www.bdcnetwork.com/home/news/55159469/led-lighting-replaceable-or-disposable |access-date=2025-04-11 |website=Building Design+Construction |language=en}}</ref> (although the driver is often separate and so it may be replaced), where as, if only the bulb is replaced with an LED replacement lamp, the lamp can be replaced independently of the fixture should the lamp fail. Some LED replacement lamps require the fixture to be modified such as by electrically removing the fixture's ballast, thus connecting the LED lamp directly to the mains supply; others can work without any modifications to the fixture.<ref>{{Cite web|url=https://www.ledsmagazine.com/smart-lighting-iot/white-point-tuning/article/16695188/how-do-plugandplay-t8s-stack-up-against-ballastbypass-led-lamps-magazine|title=StackPath|website=ledsmagazine.com|date=22 July 2014|access-date=14 July 2020|archive-date=15 July 2020|archive-url=https://web.archive.org/web/20200715005348/https://www.ledsmagazine.com/smart-lighting-iot/white-point-tuning/article/16695188/how-do-plugandplay-t8s-stack-up-against-ballastbypass-led-lamps-magazine|url-status=dead}}</ref>
[[File:DSC09917 BAPS Temple - E view by Volkan Yuksel.jpg|thumb|left|[[BAPS Shri Swaminarayan Mandir Atlanta]] illumination with color mixing LED fixtures]]
[[File:Muzeum Narodowe w Warszawie Galeria Sztuki XIX wieku.JPG|thumb|Computer-led LED lighting allows enhancement of unique qualities of paintings in the [[National Museum, Warsaw|National Museum]] in [[Warsaw]].<ref>{{cite web |title=Warsaw Top 10 |url=http://www.warsawtour.pl/sites/default/files/repozytorium/broszury/en/top_10_gb_2012.pdf |work=Warsaw tour Edition nr 5, 2012 |page=20 |access-date=1 March 2013 |quote=The National Museum in Warsaw is also one of the most modern in Europe. (...) The LED system allows to adjust the light to every painting so that its unique qualities are enhanced. |archive-url=https://web.archive.org/web/20130309204514/http://www.warsawtour.pl/sites/default/files/repozytorium/broszury/en/top_10_gb_2012.pdf |archive-date=9 March 2013 |url-status=dead }}</ref>]]
Line 295:
|}
In keeping with the long life claimed for LED lamps, long warranties are offered. However, currently there are no standardized testing procedures set by the Department of Energy in the United States to prove these assertions by each manufacturer.<ref>{{Cite web |title=Standards Development for Solid-State Lighting {{!}} Department of Energy |url=https://energy.gov/eere/ssl/standards-development-solid-state-lighting |archive-url=
Incandescent and halogen lamps naturally have a [[power factor]] of 1, but Compact fluorescent and LED lamps use input [[rectifier]]s and this causes lower power factors. Low power factors can result in surcharges for commercial energy users; CFL and LED lamps are available with driver circuits to provide any desired power factor, or site-wide [[Power factor|power factor correction]] can be performed. EU standards require a power factor better than 0.4 for lamp powers between 2 and 5 watts, better than 0.5 for lamp powers between 5 and 25 watts and above 0.9 for higher power lamps.<ref>[https://www.ledon.at/wissensbeitrage/was-ist-der-leistungsfaktor/ PF vs. Power in EU] {{Webarchive|url=https://web.archive.org/web/20180801124713/https://www.ledon.at/wissensbeitrage/was-ist-der-leistungsfaktor/ |date=1 August 2018 }}. ledon.at</ref><ref>{{Cite web|url=https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2012:342:0001:0022:en:PDF|title=Commission Regulation (EU) No 1194/2012|date=14 December 2012|access-date=5 October 2019|website=EUR-Lex|format=PDF|page=13}}</ref>
Line 325:
LED emitters are inherently suitable for dimming, because they can operate over a wide range of currents without significant change of color. However, the circuits in LED lamps must be explicitly designed to be dimmable and compatible with particular types of dimmer switch.<ref name="dimming">{{Cite web|url=http://luxreview.com/article/2015/07/dos-and-dont-s-for-led-dimming|title=Dimming LED lamps: the dos and don'ts|website=luxreview.com|access-date=28 January 2017|archive-date=8 September 2018|archive-url=https://web.archive.org/web/20180908223933/http://luxreview.com/article/2015/07/dos-and-dont-s-for-led-dimming|url-status=dead}}</ref> Otherwise damage to the lamp and/or the dimmer may result. Color rendering is not identical to that of incandescent lamps, which emit close to perfect [[black-body radiation]], as does the sun. A measurement unit called [[color rendering index|CRI]] is used to record how a light source renders eight color sample chips, on a scale from 0 to 100.<ref>[http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/lightsources/appendixB.asp Appendix B: Calculating color rendering metrics]. lrc.rpi.edu</ref> LEDs with CRI below 75 are not recommended for use in indoor lighting.<ref>[http://www.energystar.gov/ia/partners/product_specs/program_reqs/SSL_prog_req_V1.1.pdf Energy Star Program Requirements for Solid State Lighting Luminaires]. (PDF). Retrieved 2 June 2012.</ref> Badly designed LED lamps may flicker. The effect can be seen on a slow motion video of such a lamp. The extent of flicker is based on the quality of the DC power supply built into the lamp structure, usually located in the lamp base. Longer exposures to flickering light contribute to headaches and eye strain.<ref>{{Cite news |last=Keeping |first=Steven |date=2012-07-17 |title=rattan pendant light |url=https://indochinalight.com/collections/rattan-pendant-lights |access-date=2025-04-11 |work= |language=en}}</ref><ref>"A Review of the Literature on Light Flicker: Ergonomics, Biological Attributes, Potential Health Effects, and Methods in Which Some LED Lighting May Introduce Flicker", IEEE Standard P1789, February 2010.</ref><ref>Open letter from Alex Baker, Lighting Program Manager, Energy Star, dated 22 March 2010.</ref> LED life span as a function of [[lumen maintenance]] drops at higher temperatures. [[Thermal management of high-power LEDs]] is a significant factor in design of solid state lighting equipment. LED lamps are sensitive to excessive heat, like most [[Solid-state electronics|solid state]] electronic components. Also, the presence of incompatible [[volatile organic compound]]s can impair the performance and reduce lifetime.<ref>"Cree XLamp LEDs Chemical compatibility" URL: https://www.cree.com/led-components/media/documents/XLamp_Chemical_Comp.pdf</ref> The long life of LEDs, expected to be about 50 times that of the most common incandescent lamps and significantly longer than fluorescent types, is advantageous for users but will affect manufacturers as it reduces the market for replacements in the distant future.<ref name=":0" />
The human [[circadian rhythm]] can be [[light effects on circadian rhythm|affected by light]] sources.<ref>{{cite journal|title=Blue light from light-emitting diodes elicits a dose-dependent suppression of melatonin in humans|first1=Kathleen E.|last1=West|first2=Michael R.|last2=Jablonski|first3=Benjamin|last3=Warfield|first4=Kate S.|last4=Cecil|first5=Mary|last5=James|first6=Melissa A.|last6=Ayers|first7=James|last7=Maida|first8=Charles|last8=Bowen|first9=David H.|last9=Sliney|first10=Mark D.|last10=Rollag|first11=John P.|last11=Hanifin|first12=George C.|last12=Brainard|date=1 March 2011|journal= Journal of Applied Physiology|volume=110|issue=3|pages=619–626|doi=10.1152/japplphysiol.01413.2009|pmid=21164152|s2cid=23119076}}</ref><ref>{{cite journal|title=Evening exposure to a light-emitting diodes (LED)-backlit computer screen affects circadian physiology and cognitive performance |first1=Christian|last1=Cajochen|first2=Sylvia|last2=Frey|first3=Doreen|last3=Anders|first4=Jakub|last4=Späti|first5=Matthias|last5=Bues|first6=Achim|last6=Pross|first7=Ralph|last7=Mager|first8=Anna|last8=Wirz-Justice|first9=Oliver|last9=Stefani|date=1 May 2011|journal= Journal of Applied Physiology|volume=110|issue=5|pages=1432–1438|doi=10.1152/japplphysiol.00165.2011|pmid=21415172|s2cid=4140748 |url=https://zenodo.org/record/1184290}}</ref> The effective [[color temperature]] of [[daylight]] is ~5,700K<ref>{{cite web |last=Williams |first=D. R. |year=2004 |title=Sun Fact Sheet |url=https://nssdc.gsfc.nasa.gov/planetary/factsheet/sunfact.html |publisher=[[NASA]] |access-date=4 February 2018}}</ref> (bluish white) while [[incandescent light bulb|tungsten lamps]] are ~2,700K (yellow).<ref>{{Cite web |title=Evident Scientific {{!}} Life Science and Industrial Measurement Solutions |url=https://evidentscientific.com/en/ |access-date=2025-06-05 |website=evidentscientific.com}}</ref> People who have [[circadian rhythm sleep disorder]]s are sometimes treated with [[light therapy]] (exposure to intense bluish white light during the day) and [[dark therapy]] (wearing amber-tinted goggles at night to reduce bluish light).<ref>{{Cite web|url=https://www.nigms.nih.gov/Education/Pages/Factsheet_CircadianRhythms.aspx|title=Circadian Rhythms|website=nigms.nih.gov|access-date=7 August 2016|archive-date=13 March 2020|archive-url=https://web.archive.org/web/20200313000520/https://www.nigms.nih.gov/education/pages/factsheet_circadianrhythms.aspx|url-status=dead}}</ref><ref>{{cite journal|title=Circadian rhythm sleep disorders and phototherapy|first1=Christopher D.|last1=Fahey|first2=Phyllis C.|last2=Zee|date=1 December 2006|journal= Psychiatric Clinics of North America|volume=29|issue=4|pages=989–1007; abstract ix|doi=10.1016/j.psc.2006.09.009|pmid=17118278}}</ref><ref>{{cite journal|title=Controlling light–dark exposure patterns, rather than sleep schedules, determines circadian phase|first1=Kenneth|last1=Appleman|first2=Mariana G.|last2=Figueiro|first3=Mark S.|last3=Rea|date=1 May 2013|journal= Sleep Medicine|volume=14|issue=5|pages=456–461|doi=10.1016/j.sleep.2012.12.011|pmid=23481485|pmc=4304650}}</ref>
Some organizations recommend that people should not use bluish-white lamps at night. The American Medical Association argues against using bluish-white LEDs for municipal street lighting.<ref>{{cite web|url=https://www.ama-assn.org/ama-adopts-guidance-reduce-harm-high-intensity-street-lights|title=AMA Adopts Community Guidance to Reduce the Harmful Human and Environmental Effects of High Intensity Street Lighting|website=ama-assn.org|date=14 June 2016 |access-date=4 February 2018}}</ref> Research suggests that the shift to LED street lighting attracts 48% more flying insects than [[sodium-vapor lamp#High-pressure sodium|HPS]] lamps, which could cause direct ecological impacts as well as indirect impacts such as attracting more [[Lymantria dispar dispar|gypsy moths]] to port areas.<ref>{{cite journal|last1=Pawson|first1=S.|last2=Bader|first2=M.|title=LED lighting increases the ecological impact of light pollution irrespective of color temperature|journal=Ecological Applications|date=October 2014|volume=24|issue=7|pages=1561–1568|access-date=6 January 2017|doi=10.1890/14-0468.1|pmid=29210222|url=https://www.researchgate.net/publication/267070067|doi-access=free|bibcode=2014EcoAp..24.1561P }}</ref>
| |||