An electric light is a device that produces visible light from electric current. It is the most common form of artificial lighting and is essential to modern society, providing interior lighting for buildings and exterior light for evening and nighttime activities. In technical usage, a replaceable component that produces light from electricity is called a lamp. Lamps are commonly called light bulbs; for example, the incandescent light bulb. Lamps usually have a base made of ceramic, metal, glass or plastic, which secures the lamp in the socket of a light fixture. The electrical connection to the socket may be made with a screw-thread base, two metal pins, two metal caps or a bayonet cap.
The three main categories of electric lights are incandescent lamps, which produce light by a filament heated white-hot by electric current, gas-discharge lamps, which produce light by means of an electric arc through a gas, and LED lamps, which produce light by a flow of electrons across a band gap in a semiconductor.
Before electric lighting became common in the early 20th century, people used candles, gas lights, oil lamps, and fires. Cornish chemist Humphry Davy developed the first incandescent light in 1802, followed by the first practical electric arc light in 1806. By the 1870s, Davy's arc lamp had been successfully commercialized, and was used to light many public spaces. The development of a steadily glowing filament suitable for interior lighting took longer, but by the early twentieth century inventors had successfully developed options, replacing the arc light with incandescents.
The energy efficiency of electric lighting has increased radically since the first demonstration of arc lamps and the incandescent light bulb of the 19th century. Modern electric light sources come in a profusion of types and sizes adapted to many applications. Most modern electric lighting is powered by centrally generated electric power, but lighting may also be powered by mobile or standby electric generators or battery systems. Battery-powered light is often reserved for when and where stationary lights fail, often in the form of flashlights, electric lanterns, and in vehicles.
Types of electric lighting include:
|Name||Optical spectrum||Nominal efficacy
|Incandescent light bulb||Continuous||4–17||2–20,000||2,400–3,400||Warm white (yellowish)||100|
|Halogen lamp||Continuous||16–23||3,000–6,000||3,200||Warm white (yellowish)||100|
|Fluorescent lamp||Mercury line + Phosphor||52–100 (white)||8,000–20,000||2,700–5,000*||White (various color temperatures), as well as saturated colors available||15–85|
|Metal-halide lamp||Quasi-continuous||50–115||6,000–20,000||3,000–4,500||Cold white||65–93|
|Sulfur lamp||Continuous||80–110||15,000–20,000||6,000||Pale green||79|
|High pressure sodium||Broadband||55–140||10,000–40,000||1,800–2,200*||Pinkish orange||0–70|
|Low pressure sodium||Narrow line||100–200||18,000–20,000||1,800*||Yellow, no color rendering||0|
|LED lamp||Line plus phosphor||10–110 (white)||50,000–100,000||Various white from 2,700 to 6,000*||Various color temperatures, as well as saturated colors||70–85 (white)|
|Electrodeless lamp||Mercury line + Phosphor||70–90 (white)||80,000–100,000||Various white from 2,700 to 6,000*||Various color temperatures, as well as saturated colors||70–85 (white)|
*Color temperature is defined as the temperature of a black body emitting a similar spectrum; these spectra are quite different from those of black bodies.
The most efficient source of electric light is the low-pressure sodium lamp. It produces, for all practical purposes, a monochromatic orange-yellow light, which gives a similarly monochromatic perception of any illuminated scene. For this reason, it is generally reserved for outdoor public lighting applications. Low-pressure sodium lights are favoured for public lighting by astronomers, since the light pollution that they generate can be easily filtered, contrary to broadband or continuous spectra.
The modern incandescent light bulb, with a coiled filament of tungsten, and commercialized in the 1920s, developed from the carbon filament lamp introduced about 1880. As well as bulbs for normal illumination, there is a very wide range, including low voltage, low-power types often used as components in equipment, but now largely displaced by LEDs
There is currently interest in banning some types of filament lamp in some countries, such as Australia, which has banned standard inefficient incandescent bulbs through a three-year phase out that started in 2009. Sri Lanka has already banned importing filament bulbs because of high use of electricity and less light. Less than 3% of the input energy is converted into usable light. Nearly all of the input energy ends up as heat that, in warm climates, must then be removed from the building by ventilation or air conditioning, often resulting in more energy consumption. In colder climates where heating and lighting is required during the cold and dark winter months, the heat byproduct has at least some value.
Halogen lamps are usually much smaller than standard incandescent lamps, because for successful operation a bulb temperature over 200 °C is generally necessary. For this reason, most have a bulb of fused silica (quartz) or aluminosilicate glass. This is often sealed inside an additional layer of glass. The outer glass is a safety precaution, to reduce ultraviolet emission and to contain hot glass shards should the inner envelope explode during operation. Oily residue from fingerprints may cause a hot quartz envelope to shatter due to excessive heat buildup at the contamination site. The risk of burns or fire is also greater with bare bulbs, leading to their prohibition in some places, unless enclosed by the luminaire.
Those designed for 12- or 24-volt operation have compact filaments, useful for good optical control. Also, they have higher efficacies (lumens per watt) and better lives than non-halogen types. The light output remains almost constant throughout their life.
Fluorescent lamps consist of a glass tube that contains mercury vapour or argon under low pressure. Electricity flowing through the tube causes the gases to give off ultraviolet energy. The inside of the tubes are coated with phosphors that give off visible light when struck by ultraviolet photons. They have much higher efficiency than incandescent lamps. For the same amount of light generated, they typically use around one-quarter to one-third the power of an incandescent. The typical luminous efficacy of fluorescent lighting systems is 50–100 lumens per watt, several times the efficacy of incandescent bulbs with comparable light output. Fluorescent lamp fixtures are more costly than incandescent lamps, because they require a ballast to regulate the current through the lamp, but the lower energy cost typically offsets the higher initial cost. Compact fluorescent lamps are available in the same popular sizes as incandescent lamps and are used as an energy-saving alternative in homes. Because they contain mercury, many fluorescent lamps are classified as hazardous waste. The United States Environmental Protection Agency recommends that fluorescent lamps be segregated from general waste for recycling or safe disposal, and some jurisdictions require recycling of them.
The solid-state light-emitting diode (LED) has been popular as an indicator light in consumer electronics and professional audio gear since the 1970s. In the 2000s, efficacy and output have risen to the point where LEDs are now being used in lighting applications such as car headlights and brake lights, in flashlights and bicycle lights, as well as in decorative applications, such as holiday lighting. Indicator LEDs are known for their extremely long life, up to 100,000 hours, but lighting LEDs are operated much less conservatively, and consequently have shorter lives. LED technology is useful for lighting designers, because of its low power consumption, low heat generation, instantaneous on/off control, and in the case of single color LEDs, continuity of color throughout the life of the diode and relatively low cost of manufacture. LED lifetime depends strongly on the temperature of the diode. Operating an LED lamp in conditions that increase the internal temperature can greatly shorten the lamp's life.
Carbon arc lamps consist of two carbon rod electrodes in open air, supplied by a current-limiting ballast. The electric arc is struck by touching the rod tips then separating them. The ensuing arc produces a white-hot Plasma (physics)plasma between the rod tips. These lamps have higher efficacy than filament lamps, but the carbon rods are short-lived and require constant adjustment in use, as the intense heat of the arc erodes them. The lamps produce significant ultraviolet output, they require ventilation when used indoors, and due to their intensity they need protection from direct sight.
Invented by Humphry Davy around 1805, the carbon arc was the first practical electric light. It was used commercially beginning in the 1870s for large building and street lighting until it was superseded in the early 20th century by the incandescent light. Carbon arc lamps operate at high power and produce high intensity white light. They also are a point source of light. They remained in use in limited applications that required these properties, such as movie projectors, stage lighting, and searchlights, until after World War II.
A discharge lamp has a glass or silica envelope containing two metal electrodes separated by a gas. Gases used include, neon, argon, xenon, sodium, metal halide, and mercury. The core operating principle is much the same as the carbon arc lamp, but the term "arc lamp" normally refers to carbon arc lamps, with more modern types of gas discharge lamp normally called discharge lamps. With some discharge lamps, very high voltage is used to strike the arc. This requires an electrical circuit called an igniter, which is part of the electrical ballast circuitry. After the arc is struck, the internal resistance of the lamp drops to a low level, and the ballast limits the current to the operating current. Without a ballast, excess current would flow, causing rapid destruction of the lamp.
Some lamp types contain a little neon, which permits striking at normal running voltage, with no external ignition circuitry. Low pressure sodium lamps operate this way. The simplest ballasts are just an inductor, and are chosen where cost is the deciding factor, such as street lighting. More advanced electronic ballasts may be designed to maintain constant light output over the life of the lamp, may drive the lamp with a square wave to maintain completely flicker-free output, and shut down in the event of certain faults.
Many lamp units, or light bulbs, are specified in standardized shape codes and socket names. Incandescent bulbs and their retrofit replacements are often specified as "A19/A60 E26/E27", a common size for these kind of light bulbs. In this example, the "A" parameters describe the bulb size and shape while the "E" parameters describe the Edison screw base size and thread characteristics.
Life expectancy for many types of lamp is defined as the number of hours of operation at which 50% of them fail, that is the median life of the lamps. Production tolerances as low as 1% can create a variance of 25% in lamp life, so in general some lamps will fail well before the rated life expectancy, and some will last much longer. For LEDs, lamp life is defined as the operation time at which 50% of lamps have experienced a 70% decrease in light output.
Some types of lamp are also sensitive to switching cycles. Rooms with frequent switching, such as bathrooms, can expect much shorter lamp life than what is printed on the box. Compact fluorescent lamps are particularly sensitive to switching cycles.
The total amount of artificial light (especially from street light) is sufficient for cities to be easily visible at night from the air, and from space. This light is the source of light pollution that burdens astronomers and others.
Due to their nonlinear resistance characteristics, tungsten filament lamps have long been used as fast-acting thermistors in electronic circuits. Popular uses have included:
In circuit diagrams lamps usually are shown as symbols. There are two main types of symbols, these are:
A New World Record is the sixth studio album by Electric Light Orchestra (ELO). It was released in September 1976 on United Artists Records in the U.S., and on 19 November 1976 on Jet Records in the United Kingdom. A New World Record marked ELO's shift towards shorter pop songs, a trend which would continue across their career.
Their second album to be recorded at Musicland Studios in Munich, the LP proved to be the band's breakthrough in the UK; after their previous three studio recordings failed to chart in their home market, A New World Record became their first top ten album in the UK. It became a global success and reached multi-platinum status in the US and UK, The album sold five million units worldwide within its first year of release. The cover art features the ELO logo, designed by Kosh, for the first time. This logo would be included on most of the group's subsequent releases. The album yielded four hit singles, including "Livin' Thing", the transatlantic Top Ten hit "Telephone Line", which became the band's first gold US single, the UK Top Ten hit "Rockaria!", and the US number 24 hit "Do Ya", a remake of the 1972 single by The Move, of which Lynne was a member between 1970 and 1972.
In 1977, four of the album's songs were featured on the soundtrack of the film Joyride. In 2006, the album was remastered and released with bonus tracks on Sony's Epic/Legacy imprint. "Surrender" was also issued as a promotional single and an iTunes download single, which entered the top 100 download chart. The track was originally written in 1976 for a cancelled film soundtrack and was finished in 2006. In July 2012, the all vinyl record company Music on Vinyl re-released A New World Record on 180 gram vinyl with an embossed cover.Bev Bevan
Beverley Bevan (born 25 November 1944) is an English rock musician, who was the drummer and one of the original members of The Move and Electric Light Orchestra (ELO). After the end of ELO in 1986, he founded ELO Part II.
Bevan also served as the touring drummer for Black Sabbath during the Born Again Tour, and later played percussion on The Eternal Idol album in 1987. Bevan was inducted into the Rock and Roll Hall of Fame in 2017 as a member of Electric Light Orchestra.Discovery (Electric Light Orchestra album)
Discovery is the eighth studio album by English rock band Electric Light Orchestra (ELO). It was released on 31 May 1979 in the United Kingdom by Jet Records, where it topped record charts, and on 8 June in the United States on Jet through Columbia Records distribution.ELO Part II
ELO Part II were a band formed by Electric Light Orchestra drummer and co-founder Bev Bevan. The band also included former ELO bassist Kelly Groucutt, and violinist Mik Kaminski for most of its career, along with conductor Louis Clark who toured as a guest with ELO in its later years.
After Bevan left the band in late 1999, he sold his half of the rights to the Electric Light Orchestra name back to Jeff Lynne, and the band changed its name to The Orchestra.Eldorado (Electric Light Orchestra album)
Eldorado (subtitled as A Symphony by the Electric Light Orchestra) is the fourth studio album by the Electric Light Orchestra (ELO). It was released in the United States in September 1974 by United Artists Records and in the United Kingdom in October 1974 by Warner Bros. Records.Electric Light Orchestra
The Electric Light Orchestra (ELO) are an English rock band formed in Birmingham in 1970, by songwriters/multi-instrumentalists Jeff Lynne and Roy Wood with drummer Bev Bevan. Their music is characterised by a fusion of Beatlesque pop, classical arrangements, and futuristic iconography. After Wood's departure in 1972, Lynne became the band's leader, arranging and producing every album while writing virtually all of their original material. For their initial tenure, Lynne, Bevan and keyboardist Richard Tandy were the group's only consistent members.
ELO was formed out of Lynne's and Wood's desire to create modern rock and pop songs with classical overtones. It derived as an offshoot of Wood's previous band, The Move, of which Lynne and Bevan were also members. During the 1970s and 1980s, ELO released a string of top 10 albums and singles, including two LPs that reached the top of British charts: the disco-inspired Discovery (1979) and the science-fiction-themed concept album Time (1981). In 1986, Lynne lost interest in the band and ceased its operation. Bevan responded by forming his own band, ELO Part II, which later became the Orchestra. With the exception of a short-lived reunion in 2000–01, ELO remained largely inactive until the 2010s. In 2014, Lynne re-formed the band again with Tandy as Jeff Lynne's ELO, where he resumed concert touring and new recordings under the moniker.
During ELO's original 14-year period of active recording and touring, they sold over 50 million records worldwide, collecting 19 CRIA, 21 RIAA, and 38 BPI awards. For a period in the mid 1970s, the band saw more success in the United States, where they were billed as "the English guys with the big fiddles". From 1972 to 1986, ELO accumulated twenty Top 20 songs on the UK Singles Chart, and fifteen Top 20 songs on the US Billboard Hot 100. The band also holds the record for having the most Billboard Hot 100 Top 40 hits (20) without a number one single of any band in US chart history. In 2017, the ELO line-up of Wood, Lynne, Bevan, and Tandy were inducted into the Rock and Roll Hall of Fame..Electric Light Orchestra discography
Below is the complete Electric Light Orchestra discography including imports, videos, and hit singles. ELO's back catalogue is unusual since their compilation albums far outweigh their studio output in number, owing to the large number of hit singles primarily written by Jeff Lynne. From 1972 to 1986, ELO accumulated more combined UK and US Top 40 hits than any other band in the world, and also generated the third most UK and US separate Top 40 hits.Jeff Lynne
Jeffrey Lynne (born 30 December 1947) is an English songwriter, singer, record producer, and multi-instrumentalist from Birmingham who co-founded the rock band Electric Light Orchestra (ELO). The group formed in 1970 as an offshoot of the Move, of which Lynne was also a member. Following the departure of Roy Wood in 1972, Lynne took over ELO's leadership and wrote, arranged and produced virtually all of the band's subsequent records. Before, Lynne was also involved with the Idle Race as a founding member and principal songwriter.
After ELO's original disbandment in 1986, Lynne released two solo albums: Armchair Theatre (1990) and Long Wave (2012). Additionally, he began producing various artists. In 1988, under the pseudonyms Otis Wilbury and Clayton Wilbury, he co-founded the supergroup Traveling Wilburys with George Harrison, Bob Dylan, Roy Orbison, and Tom Petty. Lynne's songwriting and production collaborations with former Beatles led him to co-produce their Anthology reunion singles "Free as a Bird" (1995) and "Real Love" (1996). In 2014, Lynne reformed ELO and resumed concert touring under the moniker "Jeff Lynne's ELO".
Lynne produced all fifteen ELO singles that rose to the Top 10 record charts in the UK. His production credits also include the UK or US Top 10 albums Cloud Nine (Harrison, 1987), Mystery Girl (Orbison, 1989), Full Moon Fever (Petty, 1989), Into the Great Wide Open (Petty, 1991), Flaming Pie (Paul McCartney, 1998) and Get Up! (Bryan Adams, 2015). In 2014, Lynne received a star on the Birmingham Walk of Stars, and in 2015, was awarded a star on the Hollywood Walk of Fame. He received three Ivor Novello Awards including the award for Outstanding Services to British Music. In 2017, Lynne was inducted into the Rock and Roll Hall of Fame as a member of ELO.List of light sources
This is a list of sources of light, including both natural and artificial processes that emit light. This article focuses on sources that produce wavelengths from about 390 to 700 nanometers, called visible light.Mr. Blue Sky
"Mr. Blue Sky" is a song by British rock group Electric Light Orchestra (ELO), featured on the band's seventh studio album Out of the Blue (1977). Written and produced by frontman Jeff Lynne, the song forms the fourth and final track of the "Concerto for a Rainy Day" suite, on side three of the original double album. "Mr. Blue Sky" was the second single to be taken from Out of the Blue, peaking at number 6 in the UK Singles Chart and number 35 in the United States.Musselburgh and District Electric Light and Traction Company
Musselburgh and District Electric Light and Traction Company operated a passenger tramway service in Musselburgh between 1904 and 1928.Out of the Blue (Electric Light Orchestra album)
Out of the Blue is the seventh studio album by the British rock group Electric Light Orchestra (ELO), released in October 1977. Written and produced by ELO frontman Jeff Lynne, the double album is among the most commercially successful records in the group's history, selling about 10 million copies worldwide.Roll Over Beethoven
"Roll Over Beethoven" is a 1956 hit single written by Chuck Berry, originally released on Chess Records, with "Drifting Heart" as the B-side. The lyrics of the song mention rock and roll and the desire for rhythm and blues to replace classical music. The title of the song is an imperative directed at the composer Ludwig van Beethoven to roll over in his grave in reaction to the new genre of music that Berry was promoting. The song has been covered by many other artists, including the Beatles and the Electric Light Orchestra. Rolling Stone magazine ranked it number 97 on its list of the "500 Greatest Songs of All Time".Roy Wood
Roy Wood (born 8 November 1946) is an English singer-songwriter and multi-instrumentalist. He was particularly successful in the 1960s and 1970s as member and co-founder of the Move, Electric Light Orchestra and Wizzard. As a songwriter, he contributed a number of hits to the repertoire of these bands. Collectively, hit records by the Move, Electric Light Orchestra, Wizzard, and Wood's own solo singles demonstrated an impressive chart run for an individual, both as composer and performer. Altogether he had more than 20 singles in the UK Singles Chart under various guises, including three UK No. 1 hits.
The BBC has described Wood as being "responsible for some of the most memorable sounds of the Seventies" and "credited as playing a major role in the glam rock, psychedelic and prog rock movements". In 2008, Wood was awarded an honorary doctorate for his contribution to rock and pop by the University of Derby. In 2015, his long and eclectic career was recognised with the "Outer Limits" award at the Progressive Music Awards in London.Wood was inducted into the Rock and Roll Hall of Fame in 2017 as a member of Electric Light Orchestra.Secret Messages
Secret Messages is the tenth studio album by Electric Light Orchestra (ELO), released in 1983 on Jet Records. It was the last ELO album with bass guitarist Kelly Groucutt, conductor Louis Clark and real stringed instruments, and the last ELO album to be released on the Jet label. It was also the final ELO studio album to become a worldwide top 40 hit upon release.The Electric Light Orchestra (album)
The Electric Light Orchestra is the eponymous debut studio album by English rock band Electric Light Orchestra (ELO), released in December 1971 in the United Kingdom by Harvest Records. In the United States, the album was released in early 1972 as No Answer, after a misunderstood telephone message made by a United Artists Records executive asking about the album name; the caller, having failed to reach the ELO contact, wrote down "no answer" in his notes, and this was misconstrued to be the name of the album.Xanadu (Olivia Newton-John and Electric Light Orchestra song)
"Xanadu" is the title song from the soundtrack album Xanadu, and is the title song from the 1980 film of the same name. The song is performed by the Electric Light Orchestra (ELO) and Olivia Newton-John. Newton-John sings the primary vocals, with ELO lead singer Jeff Lynne adding "parenthetic" vocals in the style of their other songs on the Xanadu soundtrack, along with ELO providing the instrumentation. It is Jeff Lynne's favourite song of all that he has written.The single reached number one in several countries, and was the band's only UK number one single, when it peaked there for two weeks in July 1980. It was certified as "silver" by the British Phonographic Industry. The song peaked at number eight on the Billboard Hot 100 in the US.Xanadu (soundtrack)
Xanadu is the soundtrack of the 1980 musical film of the same name, featuring the Australian singer Olivia Newton-John and the British group Electric Light Orchestra (ELO). It was released in June 1980 on MCA Records in the United States and July 1980 by Jet Records in the United Kingdom. The original LP release featured on side one the songs of Newton-John, and on side two the songs of ELO. In 2008 the soundtrack album was digitally remastered as a bonus CD as part of the film's DVD release entitled Xanadu – Magical Musical Edition.
Although the film was a critical and commercial disappointment, the soundtrack was a worldwide success and received positive reviews from music critics going double platinum in the US and Canada. The hit singles "Magic" and "Xanadu", peaked at number one in the United States and United Kingdom, respectively. Both singles also went to number one in the Netherlands and Italy, respectively. It was the 5th most popular US soundtrack in 1981.Zoom (Electric Light Orchestra album)
Zoom is the twelfth studio album by British symphonic rock band Electric Light Orchestra (ELO), released on 12 June 2001 on Epic Records. It was the first official ELO album since 1986's Balance of Power.