Una luz eléctrica es un dispositivo que produce luz visible a partir de energía eléctrica . Es la forma más común de iluminación artificial y es esencial para la sociedad moderna, [1] proporcionando iluminación interior para edificios y luz exterior para actividades nocturnas. En el uso técnico, un componente reemplazable que produce luz a partir de electricidad se llama lámpara . [2] Las lámparas se denominan comúnmente bombillas ; por ejemplo, la bombilla incandescente . [3] Las lámparas suelen tener una base de cerámica., metal, vidrio o plástico, que asegura la lámpara en el casquillo de un artefacto de iluminación . La conexión eléctrica al enchufe se puede realizar con base roscada, dos clavijas metálicas, dos tapas metálicas o una tapa de bayoneta .
Las tres categorías principales de luces eléctricas son las lámparas incandescentes, que producen luz mediante un filamento calentado al rojo vivo por corriente eléctrica, las lámparas de descarga de gas , que producen luz mediante un arco eléctrico a través de un gas, como las lámparas fluorescentes , y LED. Lámparas , que producen luz mediante un flujo de electrones a través de una banda prohibida en un semiconductor .
Antes de que la iluminación eléctrica se volviera común a principios del siglo XX, la gente usaba velas , luces de gas , lámparas de aceite y fuegos . [4] El químico inglés Humphry Davy desarrolló la primera luz incandescente en 1802, seguida de la primera luz de arco eléctrico práctica en 1806. En la década de 1870, la lámpara de arco de Davy se comercializó con éxito y se utilizó para iluminar muchos espacios públicos. [5] Esfuerzos de Joseph Swan y Thomas Edisoncondujo a que las bombillas incandescentes comerciales se volvieran ampliamente disponibles en la década de 1880 y, a principios del siglo XX, habían reemplazado por completo a las lámparas de arco. [1] [4]
La eficiencia energética de la iluminación eléctrica ha aumentado radicalmente desde la primera demostración de las lámparas de arco y la bombilla incandescente del siglo XIX. Las fuentes de luz eléctrica modernas vienen en una gran variedad de tipos y tamaños adaptados a muchas aplicaciones. La mayor parte de la iluminación eléctrica moderna funciona con energía eléctrica generada de forma centralizada, pero la iluminación también puede funcionar con generadores eléctricos móviles o de reserva o sistemas de baterías. Batería potenciada por la luz a menudo se reserva para cuando y donde las luces estacionarias fallan, a menudo en forma de linternas o eléctricos linternas , así como en vehículos.
Tipos [ editar ]
Los tipos de iluminación eléctrica incluyen:
- Bombilla incandescente , un filamento calentado dentro de una envoltura de vidrio.
- Las lámparas halógenas son lámparas incandescentes que utilizan una envoltura de cuarzo fundido lleno de gas halógeno.
- Lámpara LED , una lámpara de estado sólido que utiliza diodos emisores de luz (LED) como fuente de luz.
- Lámpara de arco
- Lámpara de arco de carbono
- Lámpara de arco de xenón , utilizada en muchos flashes de cámara, estroboscopios y proyectores de cine digital
- Lámpara de arco de mercurio-xenón
- Lámpara de ultra alto rendimiento , una lámpara de arco de vapor de mercurio de ultra alta presión utilizada en muchos proyectores de video
- Lámpara de descarga de gas , una fuente de luz que genera luz enviando una descarga eléctrica a través de un gas ionizado.
- Lámpara fluorescente
- Lámpara fluorescente compacta , una lámpara fluorescente diseñada para reemplazar una lámpara incandescente
- Lámpara de neón
- Lámpara de vapor de mercurio
- Lámpara de vapor de sodio
- Lámpara de azufre
- Lámpara de halogenuros metálicos
- Lámpara de descarga de alta intensidad
- Lámpara sin electrodos , una lámpara de descarga de gas en la que la energía se transfiere a la lámpara a través de campos electromagnéticos u ondas de radio.
- Lámpara de plasma
- Lámpara fluorescente
Los diferentes tipos de luces tienen una eficacia y un color de luz muy diferentes . [6]
| Nombre | Espectro óptico | Eficacia nominal ( lm / W ) | Vida útil ( MTTF ) (horas) | Temperatura de color ( kelvin ) | Color | El color de renderizado índice |
|---|---|---|---|---|---|---|
| Bombilla incandescente | 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 | 10–200[7] (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.
Incandescent light bulb[edit]
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.
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 some value. Incandescent bulbs are being phased out in many countries due to their low energy efficiency.
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.
Halogen lamp[edit]
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 lamp[edit]
Las lámparas fluorescentes consisten en un tubo de vidrio que contiene vapor de mercurio o argón a baja presión. La electricidad que fluye a través del tubo hace que los gases emitan energía ultravioleta. El interior de los tubos está recubierto con fósforos que emiten luz visible cuando son golpeados por fotones ultravioleta . [8] Tienen una eficiencia mucho mayor que las lámparas incandescentes. Para la misma cantidad de luz generada, generalmente usan alrededor de un cuarto a un tercio de la potencia de una incandescente. La típica eficacia luminosa 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.[9]
LED lamp[edit]
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.
Lámpara de arco de carbón [ editar ]
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 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.
Inventado por Humphry Davy alrededor de 1805, el arco de carbono fue la primera luz eléctrica práctica. Se utilizó comercialmente a partir de la década de 1870 para edificios grandes y alumbrado público hasta que fue reemplazada a principios del siglo XX por la luz incandescente. Las lámparas de arco de carbono funcionan a alta potencia y producen luz blanca de alta intensidad. También son una fuente puntual de luz. Permanecieron en uso en aplicaciones limitadas que requerían estas propiedades, como proyectores de películas , iluminación de escenarios y reflectores , hasta después de la Segunda Guerra Mundial.
Lámpara de descarga [ editar ]
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.
Form factors[edit]
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.
Lamp life expectancy[edit]
La esperanza de vida de muchos tipos de lámparas se define como el número de horas de funcionamiento en las que el 50% de ellas fallan, es decir, la vida media de las lámparas. Las tolerancias de producción tan bajas como el 1% pueden crear una variación del 25% en la vida útil de la lámpara, por lo que, en general, algunas lámparas fallarán mucho antes de la esperanza de vida nominal y algunas durarán mucho más. Para los LED, la vida útil de la lámpara se define como el tiempo de funcionamiento en el que el 50% de las lámparas han experimentado una disminución del 70% en la salida de luz.
Algunos tipos de lámpara también son sensibles a los ciclos de conmutación. Las habitaciones con cambios frecuentes, como los baños, pueden esperar una vida útil de la lámpara mucho más corta que la impresa en la caja. Las lámparas fluorescentes compactas son especialmente sensibles a los ciclos de conmutación.
Alumbrado público [ editar ]
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.
Uses other than illumination[edit]
Electric lamps can be used as heat sources, for example in incubators, as infrared lamps in fast food restaurants and toys such as the Kenner Easy-Bake Oven.
Due to their nonlinear resistance characteristics, tungsten filament lamps have long been used as fast-acting thermistors in electronic circuits. Popular uses have included:
- Stabilization of sine wave oscillators
- Protection of tweeters in loudspeaker enclosures; excess current that is too high for the tweeter illuminates the light rather than destroying the tweeter.
- Automatic volume control in telephones
A stylized depiction of a light bulb features as the logo of the Turkish AK Party.[10][11]
Circuit symbols[edit]
In circuit diagrams lamps usually are shown as symbols. There are two main types of symbols, these are:
The cross in a circle usually represents a lamp as an indicator. (ANSI/IEEE Std 315A-1986)
The semicircular dent in a circle, which usually represents a lamp as a source of light or illumination.
Cultural symbolism[edit]
In Western culture, a lightbulb — in particular, the appearance of an illuminated lightbulb above a person's head — signifies sudden inspiration.
See also[edit]
- Light tube
- List of light sources
- Flameless candle
References[edit]
- ^ a b Reisert, Sarah (2015). "Let There be Light". Distillations Magazine. 1 (3): 44–45. Retrieved 22 March 2018.
- ^ "Lamp". Dictionary.com. Retrieved November 9, 2014.
- ^ "Light bulb". Merriam-Webster. Retrieved September 18, 2017.
- ^ a b Freebert, Ernest (2014). The Age of Edison: Electric Light and the Invention of Modern America. Penguin Books. ISBN 978-0-14-312444-3.
- ^ Guarnieri, M. (2015). "Switching the Light: From Chemical to Electrical" (PDF). IEEE Industrial Electronics Magazine. 9 (3): 44–47. doi:10.1109/MIE.2015.2454038. hdl:11577/3164116. S2CID 2986686.
- ^ Brown, Martin T. (2003) Memorandum from Martin T Brown. UK Parliament
- ^ "Dubai Lamp | Philips Lighting". Philips.ae. Retrieved 2 August 2019.
- ^ Perkowitz, Sidney; Henry, A. Joseph (23 November 1998). Empire of Light:: A History of Discovery in Science and Art. Joseph Henry Press. ISBN 978-0-309-06556-6.
- ^ United States Environmental Protection Agency, OSWER (2015-07-23). "Hazardous Waste". US EPA. Retrieved 3 November 2018.
- ^ Thomson Reuters (2013-06-29). "A protester holds a light bulb, the official symbol of Turkey's ruling AK Party (AKP), with a Nazi swastika sign painted on it during an anti-government protest at Taksim Square in Istanbul". news.trust.org. Retrieved 2018-11-03.
- ^ Kutlugun, Satuk Bugra and Akcay, Ahmet Sait (14 August 2016). "15 years of Turkey's Justice and Development Party". Anadolu Agency.CS1 maint: multiple names: authors list (link)
