Message In The Bulb? Quick Answer

Clause said: I speak British English. I would say the lightbulb burned out. If the lightbulb exploded and the glass shattered and flew around the room, I would say, “The lightbulb blew up.” Click to expand…

I usually use the past participle. That is, “the bulb burned out” or “the light burned out”. I would also usually include a location, e.g. B. “The kitchen light has burned out”. The same goes for pretty much anything electronic, like “the fuse blew” or “the kettle blew”. For example “the outside bulb is off again”. “Burned out” is something I’ve never heard anyone say in the UK.

We’ve all seen the spiral, energy-efficient lightbulbs in stores, and some of us even have them in our homes. But it’s not always clear how they differ from other types — and which is the best lightbulb for the job.

There are three basic types of light bulbs on the market: incandescent, halogen and CFL (compact fluorescent). Mark Candido, co-owner of The Accessory Store in Stamford, Connecticut, explains the differences in terms of aesthetics and energy consumption.

lightbulbs

Lightbulbs are the traditional lightbulbs that we are all familiar with. They emit a warm glow but are the least efficient and need to be replaced most often. Use an incandescent bulb when you want a cozier effect or want to bring out the true color of a shade.

halogen bulbs

Halogen lamps are more efficient than incandescent lamps – they provide 25 to 30 percent more light with the same amount of electricity. However, they emit a whiter light and are therefore more suitable for offices, kitchens or lamps with warm tones. Also, they burn at a very high temperature, so don’t use them in a place where you could accidentally burn yourself.

CFL lamps (compact fluorescent lamps).

I’ve heard that a lightbulb has glass around it to keep air out of the filament. Can a lightbulb burn in space where there is no air with no glass around it?

Aug 2002

We may have all heard of interesting things that happen in space where there is a weightless environment (not free of gravity) or where there is no air. For example, what is the shape of a candle flame burning in a spacecraft air chamber? It is not tapered like here on Earth. Phenomena that we experience here on earth behave differently under the weightless conditions of “space”.

The typical lightbulb contains a thin wire (usually tungsten) called a filament that has a high electrical resistance. This filament gets very hot when an electric current is passed through it. The intense temperature makes the filament shine brightly. If oxygen were present, the red-hot filament would burn up. For combustion as we know it, oxygen must be present. To keep oxygen away from the filament of a lightbulb on Earth, some lightbulbs have most of the air removed, others are simply filled with an inert gas (a gas that does not burn or aid in combustion). Therefore, on Earth, the glass sphere around the filament is necessary to keep the filament isolated from the oxygen in the air. (It also protects us from the exposed wires and hot filament.)

Since there is no air (oxygen) in space, a filament without a glass cover would simply glow and not be consumed by conventional firing.

In fact, the filament gets so hot that it literally vaporizes atoms and electrons. Sometimes this material collects as a dark spot at the tip of the bulb. Eventually, the filament degrades, weakens, and breaks, ending the life of the bulb. In some cases, the presence of a gas can actually prevent the filament from deteriorating to some extent. When a gas is present, the atoms of the filament cannot easily vaporize, so the life of the filament is extended. In some lightbulbs, the filament can even burn hotter and thus emit more light when a certain type of gas is present in the lightbulb. Today, halogen gases are widely used in incandescent lamps to improve the quality of incandescent lamps. These bulbs are currently advertised as being more durable and brighter.

In summary, lightbulbs on Earth have removed most of the air, or are simply filled with an inert gas (a gas that does not burn or aid in combustion) to keep oxygen away from a lightbulb’s filament. Therefore, the globe is necessary to keep the filament insulated from the oxygen in Earth’s atmosphere. In space, an incandescent bulb could burn for a considerable amount of time, but the emptiness of space could accelerate the evaporation of the filament and eventually the filament would break, just like on Earth.

says it’s two words: “lightbulb”. says it’s two words: “lightbulb”. But says it’s one word: “lightbulb”. (a) the publisher specifies one, or (b) the author specifies one. But regardless of who chooses it, all spellings in any given book should conform to the use of a single dictionary (and yes, I know: Emerson was probably right when he said “A dumb consistency is the hobgoblin of little minds”). I always state which ones I use in my notes to the editor, and while I was at Tor I made it a habit to state (first the 10th edition, now the 11th, known in the industry as and respectively) what that was the editor’s preference, and I carried that over to the trilogy. And so the only reference to a lightbulb is written as a single word (although it looks wrong to me). But, man, you’d think we wouldn’t have any ambiguity about such a common term at this late date!

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A device that generates light from electricity

“Electric lamp” redirects here. For the piece of furniture see lamp

“Lightbulb” redirects here. For the music by Fujiya & Miyagi, see Lightbulbs (album)

Incandescent bulbs (left) and compact fluorescent bulbs (right) turned on

An electric light is a device that produces visible light from electric current. It is the most widespread form of artificial lighting and is essential to modern society[1] as it provides interior lighting for buildings and exterior lighting for evening and nocturnal activities. In technical parlance, a replaceable component that generates light from electricity is referred to as a lamp.[2] Lamps are commonly referred to as incandescent bulbs; for example the light bulb.[3] Lamps usually have a ceramic, metal, glass or plastic base that secures the lamp in a fixture’s socket. The electrical connection to the socket can be made with a threaded base, two metal pins, two metal caps or a bayonet cap.

The three main categories of electric lamps are incandescent lamps, which produce light by means of a filament incandescent when subjected to an electric current, gas-discharge lamps, which produce light by means of an arc through a gas, such as B. fluorescent lamps, and LEDs Lamps that generate 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 fire.[4] English chemist Humphry Davy developed the first incandescent lamp in 1802, followed by the first practical arc lamp in 1806. By the 1870s, Davy’s arc lamp was successfully commercialized and used to illuminate many public spaces.[5] The efforts of Joseph Swan and Thomas Edison led to commercial incandescent bulbs becoming widely available by the 1880s, and by the early 20th century had completely replaced arc lamps.

The energy efficiency of electric lighting has increased radically since arc lamps and the incandescent lamp were first demonstrated in the 19th century. Modern electric light sources come in a plethora of types and sizes suitable for many applications. Most modern electric lighting is powered by centrally generated electrical power, but lighting can also be powered by mobile or standby power generators or battery systems. Battery-powered lights are often reserved for the failure of parking lights, often in the form of flashlights or electric lanterns, and in vehicles.

Elaborate light in Denver, Colorado

Types [ edit ]

Lifetime and brightness test of electric light in an integrating sphere

Types of electric lighting include:

Different types of lamps have very different efficiencies and light colors.[6]

* Color temperature is defined as the temperature of a black body emitting a similar spectrum; these spectra are very different from those of black bodies.

The most efficient electric light source is the low-pressure sodium vapor lamp. It produces, for all practical purposes, a monochromatic orange-yellow light that gives a similarly monochromatic perception of any scene lit. For this reason it is generally reserved for outdoor public lighting applications. Low-pressure sodium lamps are preferred by astronomers for public lighting because the light pollution they produce can be easily filtered, unlike broadband or continuous spectra.

lightbulb [edit]

Sign with instructions on how to use lightbulbs

The modern incandescent lamp with a filament made of tungsten, which was commercialized in the 1920s, developed from the carbon filament lamp introduced in the 1880s.

Less than 3% of the energy supplied is converted into usable light. Almost all energy input ends up as heat, which in warm climates must then be removed from the building through ventilation or air conditioning, often resulting in higher energy consumption. In colder climates where heating and lighting are required during the cold and dark winter months, the heat by-product has some value. Incandescent lamps are being phased out in many countries due to their low energy efficiency.

In addition to incandescent lamps for normal lighting, there is a very wide range, including low-voltage, low-wattage types that are often used as components in appliances, but are now largely being superseded by LEDs.

Halogen lamp [ edit ]

Halogen lamps are generally significantly smaller than conventional incandescent lamps, as successful operation usually requires a bulb temperature of over 200 °C. For this reason, most have a bulb made of fused silica or aluminosilicate glass. This is often sealed in an additional layer of glass. The outer glass is a safety precaution to reduce UV emissions and contain hot glass fragments should the inner shell explode during operation. Oily residue from fingerprints can cause a hot quartz casing to shatter due to excessive heat build-up at the point of contamination. Also, the risk of burns or fire is greater with bare bulbs, leading to them being banned in some places unless enclosed by the fixture.

Those designed for 12 or 24 volt operation have compact filaments that are useful for good optical control. They also have higher efficiency (lumens per watt) and longer lifetime than halogen-free types. The light output remains almost constant over the entire service life.

Fluorescent lamp [ edit ]

Above two compact fluorescent lamps. Below two fluorescent tubes. A matchstick, left, is shown as a scale.

Fluorescent lamps consist of a glass tube containing low-pressure mercury vapor or argon. Current flowing through the tube causes the gases to emit ultraviolet energy. The inside of the tubes are coated with phosphors that emit visible light when struck by ultraviolet photons.[7] They are much more efficient than incandescent bulbs. They typically use about a quarter to a third of the wattage of an incandescent bulb for the same amount of light produced. The typical light output of fluorescent lighting systems is 50-100 lumens per watt, several times the efficiency of incandescent lamps with comparable light output. Fluorescent lamp fixtures are more expensive than incandescent lamps because they require a ballast to regulate the current through the lamp, but the lower energy costs typically offset the higher initial cost. CFLs are available in the same popular sizes as incandescent bulbs and are used in the home as an energy-saving alternative. Because they contain mercury, many fluorescent lamps are classified as hazardous waste. The US Environmental Protection Agency recommends that fluorescent lamps be segregated from general waste for recycling or safe disposal, and some jurisdictions require their recycling.[8]

LED lamp [ edit ]

The solid state light emitting diode (LED) has been popular as an indicator light in consumer electronics and professional audio equipment since the 1970s. In the 2000s, efficiency and performance increased to such an extent that LEDs are now used in lighting applications such as car headlights and brake lights, in flashlights and bicycle lights, and in decorative applications such as holiday lighting. Indicator LEDs are known for their extremely long lifespans of up to 100,000 hours, but illumination LEDs are much less economical to operate and consequently have a shorter lifespan. LED technology is useful to 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 manufacturing cost. The LED lifetime is highly dependent on the temperature of the diode. Operating an LED lamp in conditions that increase the internal temperature can significantly reduce lamp life.

Carbon arc lamp[ edit ]

Carbon arc lamps consist of two outdoor carbon rod electrodes powered by a current-limiting ballast. The arc is ignited by touching and then separating the rod tips. The resulting arc creates a white-hot plasma between the rod tips. These lamps are more efficient than incandescent lamps, but the carbon rods are short-lived and require constant adjustment with use as the intense heat of the arc erodes them. The lamps produce significant UV radiation, must be ventilated when used indoors and, due to their intensity, must be protected from direct view.

Invented by Humphry Davy around 1805, the carbon arc was the first practical electric light. It was used commercially for large buildings and street lighting from the 1870s until it was superseded by the incandescent lamp in the early 20th century. Carbon arc lamps operate at high power and produce high intensity white light. They are also a point light source. They remained in use in limited applications that required these properties until after World War II, such as: B. film projectors, stage lighting and searchlights.

discharge lamp [ edit ]

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 working principle is largely the same as the carbon-arc lamp, but the term “arc lamp” usually refers to carbon-arc lamps, with more modern types of gas-discharge lamps usually referred to as discharge lamps. Some discharge lamps use a very high voltage to start the arc. This requires an electrical circuit called the igniter which is part of the ballast electrical circuit. After the arc is ignited, the internal resistance of the lamp falls to a low level and the ballast limits the current to the operating current. Without a ballast, an overcurrent would flow that would quickly destroy the lamp.

Some lamp types contain a small amount of neon, which allows ignition at normal operating voltage without external ignition circuitry. Low-pressure sodium lamps work in this way. The simplest ballasts are just an inductor and are chosen where cost is the deciding factor, such as B. in street lighting. More advanced electronic ballasts can be designed to maintain a constant light output over the life of the lamp, drive the lamp with a square wave to maintain completely flicker-free performance, and shut down in the event of certain faults.

Form Factors[ edit ]

Many lamp units or bulbs are specified in standardized shape codes and socket names. Incandescent bulbs and their aftermarket replacements are often listed as “A19/A60 E26/E27”, a common size for this type of bulb. 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[ edit ]

The life expectancy of many lamp types is defined as the number of operating hours in which 50% of them fail, i.e. the average lifespan of the lamps. Manufacturing tolerances as little as 1% can cause a 25% variance in lamp life, so in general some lamps will fail well before rated life and some will last much longer. For LEDs, lamp life is defined as the operating time at which 50% of the lamps have experienced a 70% drop in light output. In the 1900s, the Phoebus Cartel was formed to shorten the lifespan of lightbulbs, an example of planned obsolescence

Some lamp types are also sensitive to switching cycles. In rooms with frequent changes, such. B. bathrooms, a much shorter lamp life can be expected than stated on the packaging. Compact fluorescent lamps are particularly sensitive to switching cycles.

Public lighting[ edit ]

The total amount of artificial light (especially from street lamps) is enough for cities to be clearly visible from the air and from space at night. This light is the source of the light pollution that plagues astronomers and others.

In this composite image from October 2012, man-made lights highlight particularly developed or populated areas of the Earth’s surface, including the coasts of Europe, the eastern United States, India, Japan and South Korea.

Uses other than lighting[edit]

A 60W clear glass bulb

Electric lamps can be used as heat sources, for example, in incubators, as infrared lamps in fast-food restaurants, and as toys such as the Kenner Easy-Bake Oven.

Because of their non-linear resistance characteristics, tungsten filament lamps have long been used as fast-acting thermistors in electronic circuits. Popular uses were:

Stabilization of sine wave oscillators

protection of tweeters in speaker cabinets; Overcurrent that is too high for the tweeter will make the light glow instead of destroying the tweeter.

Automatic volume control in phones

A stylized depiction of a lightbulb is the logo of the Turkish AK party.[9][10]

Circuit symbols[ edit ]

In circuit diagrams, lamps have two main types of symbols that indicate their respective functions. These are:

The cross in a circle usually represents a lamp indicator. (ANSI/IEEE Std. 315A-1986)

The semi-circular dent in a circle that most often represents a lamp as a source of light or illumination.

Cultural symbolism[ edit ]

In Western culture, a lightbulb — specifically, the appearance of a glowing lightbulb over a person’s head — signifies sudden inspiration.

See also[edit]

1. The world’s longest-lasting lightbulb has been in use for over a century

The aptly named Centennial Light of the Livermore/Pleasanton Fire Department in California is the world’s longest-lasting lightbulb. The lightbulb has been in use since 1901 which means that as of 2021 the lightbulb has surpassed its original title and has been burning for 120 years! The bulb is almost never turned off and does not retain its original functionality as it burns at only 4 watts as opposed to the 30 watts when it was originally installed.

2. The process of inventing the lightbulb didn’t start with Edison

Many credit Thomas Edison alone as the inventor of the lightbulb, but as many as 22 inventors came before him, creating a chain of research, experiments, and prototypes that led Edison to patent his invention in 1879.

It all started with the Italian inventor Alessandro Volta, who became the first method of generating electricity with his invention, the voltaic column. From there, Humphrey combined Davy Volta’s earlier invention with carbon electrodes to create the world’s first electric lamp. With further improvements made by several scientists including Warren de la Rue and William Staite, Edison’s last invention came closest to Joseph Swan’s in 1860, but Edison stepped in and corrected a problem with the filament in Swan’s design, and and so it went on. The lightbulb as we know it today was born.

3. Light bulbs can affect concentration

A study conducted in 2009 by Mark Winterbottom and Arnold Wilkins of the University of Cambridge and the University of Essex¹ of UK schools concluded: “80% of classrooms are lit by 100 Hz fluorescent lights, which cause headaches and can impair vision”.

While flicker often goes unnoticed by the human eye, it appears to have a significant impact on our ability to focus.

4. The human brain runs on one-fifth the wattage of a standard light bulb

In an article published by Scientific American², using the resting metabolic rate (RMR) of the normal human body, it was calculated that the average human brain runs at 12.6 watts. This corresponds to about one-fifth of the power required to operate a conventional 60-watt light bulb.

5. The UK has more lightbulbs than you might think

There are an estimated 600 million lightbulbs currently in use in the UK, which is an average of 25 lightbulbs per household. That also means there are just under 9 lightbulbs for every person in the UK population.

From their original invention to the feat of your own brain, we hope these facts gave you some aha moments.

To shop our full range of lighting, find out more here.

References:

https://www.sciencedirect.com/science/article/abs/pii/S0272494408001011?via%3Dihub

https://www.scientificamerican.com/article/thinking-hard-calories/

Great invention in the electrical field – lightbulb The lightbulb is one of the most influential inventions in the world. It makes us more productive at night and helps us enjoy more activities at night. It is significantly changing the lives of people around the world. The birth of the lightbulb also helped us by making more inventions related to light like telephones, televisions and computers. By using lightbulbs we have actually reduced the likelihood of fire accidents because when we don’t have a lightbulb we use candles instead which can easily cause fires. There are many more benefits we get from the lightbulb and all of these are credited to Thomas Alva Edison. Thomas Alva Edison is a well-known American inventor. He invented about 1093 devices that greatly influenced us, such as the lightbulb, microphone, telephone receiver, universal stock ticker, phonograph, kinetoscope (for viewing moving images), rechargeable battery, electric pen and mimeograph. Edison also improved many other existing devices. In the period 1878-1880, Thomas Edison began serious research into developing a practical incandescent lamp. Edison and his collaborators worked on at least three thousand different theories to develop an efficient incandescent lamp. In 1878 Edison built his first high resistance electric light bulb. Incandescent lamps produce light by using electricity to heat a thin strip of material (called a filament) until it is hot enough to glow. Many inventors had tried to perfect incandescent lamps to “compartmentalize” electric light, or make it smaller and dimmer than the existing arc lamps, which were too bright to be used for small spaces like the rooms in a house the lamp would go out a filament dated January 27, 1880 in the center of the paper……in our attic. It is a product of the continuous improvements Edison made to the 1879 lightbulb. Despite being over a hundred years old, this lightbulb looks very similar to the lightbulbs currently lighting your home. The base or socket of this 19th century lamp is similar to those still in use today. It was one of the most important features of Edison’s lamp and electrical system. The label on this bulb reads: From a discovery made by one of his associates, he patented the Edison effect (now called the thermionic diode), which is the basis of all electron tubes. Edison will forever be remembered for his contributions to the lightbulb. While he didn’t come up with the first lightbulb ever made, and technology changes every day, Edison’s work with lightbulbs was a brilliant spark on the invention timeline.

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If a light bulb burns out in a series circuit, the circuit is broken. This is because each device in a daisy chain must function properly for the circuit to be complete. So, unlike a parallel circuit where each light has its own circuit, even if one light bulb burns out, the remaining light bulbs will still work.

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If one of the bulbs in a series circuit goes out, the circuit is broken. A series connection is only complete if all parts work properly. In a parallel circuit, each bulb has its own circuit, so if one bulb burned out, the others could still work.

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says it’s two words: “lightbulb”. says it’s two words: “lightbulb”. But says it’s one word: “lightbulb”. (a) the publisher specifies one, or (b) the author specifies one. But regardless of who chooses it, all spellings in any given book should conform to the use of a single dictionary (and yes, I know: Emerson was probably right when he said “A dumb consistency is the hobgoblin of little minds”). I always state which ones I use in my notes to the editor, and while I was at Tor I made it a habit to state (first the 10th edition, now the 11th, known in the industry as and respectively) what that was the editor’s preference, and I carried that over to the trilogy. And so the only reference to a lightbulb is written as a single word (although it looks wrong to me). But, man, you’d think we wouldn’t have any ambiguity about such a common term at this late date!

Tags: writing

At M&M Lighting in Houston, we pride ourselves on offering some of the finest lighting options in all of Texas. From decorative pendants and chandeliers to outdoor lights and sconces, we stock a wide range of lighting products to complement any room in your home. Before you start shopping for a new kitchen chandelier or bedside lamp, it can be beneficial to understand how lightbulbs actually work. In this blog we take a closer look at lightbulbs and how they work.

Lightbulbs: Understanding their history

Before the invention of the lightbulb, trying to light up the world after sunset was a messy and dangerous task. While Thomas Edison is often credited with inventing the lightbulb, this famous American inventor wasn’t the only one who helped develop this revolutionary technology. Let’s take a closer look at how the lightbulb came about.

The history of the lightbulb began long before Edison patented his first commercially successful lightbulb in 1879. In 1800, an Italian inventor named Alessandro Volta developed the first practical method of generating electricity known as the voltaic pile. Made from alternating discs of zinc and copper (interspersed with layers of cardboard soaked in salt water), these unique elements conducted electricity when a copper wire was connected to both ends. This was actually known as the forerunner of the modern battery, and Volta’s glowing copper wire was thought to be one of the earliest manifestations of incandescent lighting.

It was not until 1850 that an English chemist named Joseph Swan developed an incandescent lightbulb that used carbon paper filaments instead of other platinum models. Swan received a patent in the UK in 1978 and demonstrated a working lamp in February. Edison realized that the problem with Swan’s design was the filament, and he discovered that a thin filament with a high electrical resistance would make a lamp more practical since it would require a small amount of current to light it.

After Edison made this discovery, Swan incorporated these improvements into his light bulbs and started an electric lighting company in England. Edison quickly sued for patent infringement, but since Swan’s patent was a strong claim, the two inventors eventually joined forces to form Edison-Swan United. The two inventors became one of the world’s largest manufacturers of light bulbs, according to the Museum of Unnatural Mystery.

How do lightbulbs work?

Light bulbs have a very simple design structure. At the base, they have two metal contacts that connect to the ends of an electrical circuit. These metal contacts are also connected to two stiff wires, which are then attached to a thin metal thread. The filament sits in the center of the bulb and is held in place by a glass holder filled with an inert gas such as argon. When the light bulb is connected to a power supply, an electric current flows from one contact to the other.

the filament

The filament inside the lightbulb is in the form of a coil. It is made through a process known as drawing, where tungsten is mixed with the material. Tungsten is a natural solid metal and chemical element that when used raw has the ability to naturally heat light.

wires and stem

In the center of a lightbulb is a central stem made of glass. The stem is used to support the filament in place. The connecting wires are there to ensure the steady flow of current through the other components of the bulb.

the base

The lightbulb base has four main functions. Its first task is to securely support the bulb within an electrical source unit, much like a lamp or lamp socket. The base’s second job is to carry the power from the main power source to the actual lightbulb itself. In addition to these tasks, the base serves to protect the internal insulation of the bulb and to secure all components of the bulb itself.

As you can see, there must be multiple working parts for a lightbulb to work. If you are looking for new pendant lights, wall lights or outdoor lighting online, visit the M&M Lighting Houston showroom today!

Note: The thin tungsten wire held by the other two thicker wires is the element of a lightbulb that produces light. Current flows through the thin wire, which ultimately leads to the conversion of thermal energy into light energy, thereby causing the light bulb to glow.

Complete step-by-step answer:

The light bulb (incandescent lamp) consists of a sphere, the filament, connecting wires and a shaft, a base and inert gases filled inside.

The thin wire inside the lightbulb is called the lightbulb filament. It is made of tungsten.

When we say that an electric current flows through the lightbulb, we essentially mean that it flows through the filament, which is connected to two thicker wires that have metal contacts attached. Since it is a conductor, the current heats the filament. This thermal energy is converted into light, causing the light bulb to light up.

Additional information: The base of the light bulb is connected to an electrical circuit via two metal contacts. The metal contacts are attached to two wires, which are then connected to the filament. The filament is held in the center of the bulb by a glass stem. The wires, shaft, and filament are enclosed in a glass envelope called a sphere, which is filled with an inert gas (argon).

Note: In metals, the electric current is generated by the movement of free electrons present in the atoms. The moving electrons collide with each other, causing the atoms to vibrate. This leads to heating of the filament. The vibrating atoms mainly emit infrared radiation, but when heated to say 2200°C, visible light is emitted. Since the filament is thin and therefore has a high resistance, it can easily heat up.

Electric light with a filament that is heated until it glows

A 230 volt light bulb with a medium sized E27 (Edison 27mm) male thread base. The filament is visible as a mostly horizontal line between the vertical leads.

Elaborate light in Denver, Colorado

An incandescent light bulb, incandescent lamp, or incandescent lamp is an electric light with a wire filament that is heated until it glows. The filament is sealed in a glass flask with vacuum or inert gas to protect the filament from oxidation. Power is supplied to the filament through connectors or wires embedded in the glass. A bulb socket provides mechanical support and electrical connections.

Incandescent lamps are manufactured in a wide range of sizes, light outputs and voltage ratings from 1.5 volts to around 300 volts. They require no external control equipment, have low manufacturing costs, and work equally well with AC or DC power. As a result, the incandescent lamp has been widely used in household and commercial lighting, for portable lighting such as table lamps, car headlights, and flashlights, and for decorative and advertising lighting.

Incandescent lamps are much less efficient than other types of electric lighting, converting less than 5% of the energy they use into visible light.[1] The remaining energy is lost as heat. The luminous efficacy of a typical incandescent lamp operating at 120V is 16 lumens per watt, compared to 60 lm/W for a compact fluorescent lamp or 150 lm/W for some white LED lamps.[2]

Some applications use the heat generated by the filament. Heat lamps are made for uses such as incubators, lava lamps, and the Easy-Bake Oven toy. Quartz tube halogen infrared heaters are used for industrial processes such as paint curing or room heating.

Incandescent bulbs typically have a short lifespan compared to other types of lighting; about 1,000 hours for incandescent bulbs for home use versus typically 10,000 hours for CFLs and 20,000-30,000 hours for LED lighting. Most incandescent lamps can be replaced with fluorescent lamps, high-intensity discharge lamps and light-emitting diode (LED) lamps. In some areas, the use of incandescent lamps has been phased out to reduce energy consumption.

history [edit]

Historians Robert Friedel and Paul Israel list inventors of incandescent lamps before Joseph Swan and Thomas Edison. [Failed Verification] They conclude [citation needed] that Edison’s version was able to outperform the others due to a combination of three factors: an effective glow material, a higher vacuum than others could achieve (by using the Sprengel pump), and a high Resistance that made power distribution from a central source economically viable.

Historian Thomas Hughes has credited Edison’s success to his development of a complete, integrated system of electric lighting.

The lamp was a small component in his electric lighting system, and no more critical to its effective functioning than the Edison jumbo generator, Edison main and feeder lines, and parallel distribution system. Other generator and light bulb inventors of comparable ingenuity and excellence have long been forgotten because their creators did not direct their introduction to a lighting system. Thomas P. Hughes, in Technology at the Turning Point, edited by W. B. Pickett[4][5]

Timeline of the early development of the lightbulb[6]

Early pre-commercial research[edit]

Original carbon filament lamp from Thomas Edison’s shop in Menlo Park

In 1761, Ebenezer Kinnersley demonstrated heating a wire to white heat.[7]

In 1802, Humphry Davy used what he described as “a battery of immense size”[8] consisting of 2,000 cells housed in the basement of the Royal Institution of Great Britain[9] to produce an incandescent light by he passed the current through a thin strip of platinum, chosen because the metal had an extremely high melting point. It wasn’t bright enough or lasted long enough to be practical, but it set the precedent behind the efforts of dozens of experimenters over the next 75 years.[10]

In the first three quarters of the 19th century many experimenters worked with various combinations of platinum or iridium wires, carbon rods and evacuated or semi-evacuated housings. Many of these devices have been demonstrated and some patented.

In 1835, James Bowman Lindsay demonstrated a constant electric light at a public meeting in Dundee, Scotland. He stated he could “read a book a foot and a half away”. However, he did not develop the electric light any further.[12]

In 1838, the Belgian lithographer Marcellin Jobard invented an incandescent lamp with a vacuum atmosphere using a carbon filament.

In 1840, British scientist Warren de la Rue enclosed a coiled platinum wire in a vacuum tube and passed an electric current through it. The design was based on the concept that platinum’s high melting point would allow it to work at high temperatures and that the evacuated chamber would contain fewer gas molecules to react with the platinum, improving its longevity. Although it was a viable design, the cost of platinum made it impractical for commercial use.

In 1841 Frederick de Moleyns of England received the first patent for an incandescent lamp with a design containing platinum wires in a vacuum bulb. He also used carbon.

In 1845, the American John W. Starr patented a light bulb using carbon filaments.[16][17] His invention was never commercially produced.[18]

In 1851, Jean Eugène Robert-Houdin publicly demonstrated light bulbs at his estate in Blois, France. His light bulbs are on display in the Château de Blois museum.[a]

In 1859 Moses G. Farmer built an electric light bulb with a platinum filament.[19] Thomas Edison later saw one of these bulbs in a Boston store and asked farmers for advice on the electric light business.

In 1872, the Russian Alexander Lodygin invented an incandescent lamp and received a Russian patent in 1874. He used as a burner two carbon rods of reduced cross-section in a hermetically sealed glass container filled with nitrogen, electrically arranged so that the current could be passed on to the second carbon when the first was consumed.[20] He later lived in the USA, changed his name to Alexander de Lodyguine and applied for and received patents for incandescent lamps with chromium, iridium, rhodium, ruthenium, osmium, molybdenum and tungsten filaments[21] and an incandescent lamp with Molybdenum filament demonstrated at the 1900 World’s Fair in Paris.[22]

On July 24, 1874, Henry Woodward and Mathew Evans filed a Canadian patent for a lamp consisting of carbon rods mounted in a nitrogen-filled glass cylinder. They were unsuccessful in commercializing their lamp and sold rights to their patent (US Patent 0,181,613) to Thomas Edison in 1879.

On March 4, 1880, just five months after Edison’s lightbulb, Alessandro Cruto created his first lightbulb. Cruto prepared a filament by depositing graphite on thin platinum filaments by heating them with an electric current in the presence of gaseous ethyl alcohol. Heating this platinum to high temperatures leaves thin strands of platinum coated with pure graphite. By September 1881 he had achieved a successful version of this first synthetic filament. The light bulb invented by Cruto lasted five hundred hours as opposed to the forty of Edison’s original version. At the 1882 Munich Electrical Exhibition in Bavaria, Germany, Cruto’s lamp was more efficient than Edison’s and produced better white light.[25]

Heinrich Göbel claimed in 1893 that he designed the first incandescent lamp in 1854, using a thin, high-resistance carbonized bamboo filament, platinum lead-in wires in an all-glass envelope, and a high vacuum. Judges from four courts expressed doubts about the alleged Göbel anticipation, but a decision was never reached in a final hearing because Edison’s patent had expired. A research paper published in 2007 concluded that the history of the Göbel lamps in the 1850s is a legend.[26]

Commercialization[ edit ]

Carbon filament and vacuum[ edit ]

Carbon filament lamps showing bulb dimming

Joseph Swan (1828–1914) was a British physicist and chemist. In 1850 he began working with carbonized paper threads in an evacuated glass flask. By 1860 he was able to demonstrate a working device, but the lack of a good vacuum and adequate power supply resulted in a short bulb life and an inefficient light source. By the mid-1870s better pumps were available and Swan returned to his experiments.[27]

Historic plaque at Underhill, the first house to be lit with electric lights

In 1878, with the help of Charles Stearn, an expert in vacuum pumps, Swan developed a processing method that avoided early piston blackening. This received a British patent in 1880.[28] On 18 December 1878 a lamp with a slender carbon rod was shown at a meeting of the Newcastle Chemical Society and Swan gave a working demonstration at their meeting on 17 January 1879. It was also shown to 700 people attending a meeting of the Literary Society and Philosophical Society of Newcastle upon Tyne on 3 February 1879.[29] These lamps used a carbon rod from an arc lamp rather than a slender filament. Hence they were of low resistance and required very large conductors to deliver the required current, making them commercially impractical, although they demonstrated the possibilities of incandescent lighting using relatively high vacuum, a carbon conductor, and platinum lead wires. This bulb lasted about 40 hours.[29] Swan then devoted himself to making a better carbon filament and the means of attaching its ends. In the early 1880s he developed a process for treating cotton to produce “parchmentized threads” and was awarded British Patent 4933 in the same year.[28] From that year he began installing lightbulbs in houses and landmarks in England. His home, Underhill, Low Fell, Gateshead, was the first in the world to be lit by an incandescent bulb. In the early 1880s he had founded his company.[30] In 1881 the Savoy Theater in the City of Westminster, London, was lit by Swan bulbs, becoming the first theater and first public building in the world to be lit entirely by electricity.[31] The first street in the world to be lit by a lightbulb was Mosley Street in Newcastle upon Tyne, UK. It was lit by Joseph Swan’s bulb on February 3, 1879.

Comparison of Edison, Maxim and Swan lightbulbs, 1885

Edison carbon filament lamps, early 1880s

Thomas Edison began serious research into developing a practical incandescent lamp in 1878. Edison filed his first patent application for “Improvement in Electric Lights” on October 14, 1878.[34] After many experiments, first with carbon in the early 1880s and then with platinum and other metals, Edison finally returned to a carbon filament.[35] The first successful test took place on October 22, 1879 and lasted 13.5 hours. Edison continued to improve on this design and filed a US patent on November 4, 1879 for an electric lamp that “uses a carbon filament or strip coiled and … connected to platinum contact wires”. Edison and his team later found that a carbonized bamboo filament could last more than 1200 hours by making the carbon filament using “cotton and linen threads, wood shavings, and paper wrapped in various ways.” In 1880, the Oregon Railroad and Navigation Company steamer, Columbia, became the first application for Edison’s electric light bulbs (it was also the first ship to use a dynamo).

Albon Man, a New York attorney, formed the Electro-Dynamic Light Company in 1878 to exploit his and William Sawyer’s patents.[43][44] Weeks later, the United States Electric Lighting Company was formed.[43][44][45] This company did not make its first commercial installation of incandescent lamps until the fall of 1880 at the Mercantile Safe Deposit Company in New York City, some six months after the Edison incandescent lamps were installed on the Columbia. Hiram S. Maxim was the chief engineer at the United States Electric Lighting Company.[46] After the great success in the United States, Edison’s patented lightbulb began to gain great popularity in Europe as well; Among other things, the first Edison light bulbs in the Nordic countries were installed in the weaving hall of Finlayson’s textile mill in Tampere, Finland, in March 1882.[47]

Lewis Latimer, then employed by Edison, developed an improved process for heat treating carbon filaments that reduced breakage and allowed them to be formed into novel shapes, such as the distinctive “M” shape of Maxim filaments. On January 17, 1882, Latimer received a patent for the “Process of Manufacturing Carbons,” an improved process for making filaments, which was purchased by the United States Electric Light Company.[48] Latimer patented other improvements such as a better way of attaching filaments to their wire mounts.[49]

In the UK, the Edison and Swan companies merged to form the Edison and Swan United Electric Company (later known as Ediswan and eventually incorporated into Thorn Lighting Ltd.). Edison was initially opposed to this combination, but after Swan sued him and won, Edison was eventually forced to cooperate, and the merger went through. Eventually, Edison acquired all of Swan’s shares in the company. Swan sold his US patent rights to the Brush Electric Company in June 1882.

The United States Patent Office ruled on October 8, 1883 that Edison’s patents were based on the prior art of William Sawyer and were invalid. The legal battle lasted several years. Finally, on October 6, 1889, a judge ruled that Edison’s electric light improvement claim was valid for “a high-resistance carbon filament”.

In 1896, Italian inventor Arturo Malignani (1865–1939) patented an evacuation process for mass production that made it possible to obtain economical light bulbs with a lifespan of 800 hours. The patent was acquired by Edison in 1898.[27]

In 1897, German physicist and chemist Walther Nernst developed the Nernst lamp, a form of incandescent lamp that used a ceramic sphere and did not require a vacuum or inert gas.[51][52] Nernst lamps were twice as efficient as carbon filament lamps and were briefly popular until being overtaken by metal filament lamps.

Metal filament, noble gas [ edit ]

Hanaman (left) and Just (right), the inventors of the tungsten bulb

Wire lamp with drawn wire – indestructible. 1906 Hungarian advertisement for the Tungsram lightbulb. This was the first lightbulb to use a filament made of tungsten instead of carbon. The inscription reads:

Spectrum of an incandescent lamp at 2200 K showing most of its emission as invisible infrared light.

In 1902, Siemens developed a tantalum lamp filament that was more efficient than even graphitized carbon filaments because they could operate at higher temperatures. Because tantalum metal has a lower resistivity than carbon, the tantalum lamp filament was quite long and required several internal supports. The metal thread gradually shortened with use; The filaments were installed with large slack loops. Lamps used for hundreds of hours became quite fragile.[53] Metal filaments had a tendency to break and rejoin, although this would usually reduce resistance and shorten the life of the filament. General Electric acquired the rights to use tantalum filaments and produced them in the USA until 1913.[54]

From 1898 to around 1905, osmium was also used as a lamp filament in Europe. The metal was so expensive that used broken lamps could be returned for a partial credit.[55] It could not be made for 110V or 220V, so several lamps were connected in series for use on standard voltage circuits.

Tungsten filament[edit]

On December 13, 1904, a Hungarian patent (No. 34541) was granted to the Hungarian Sándor Just and the Croatian Franjo Hanaman for a tungsten filament lamp that lasted longer and gave a brighter light than the carbon filament.[27] Tungsten filament lamps were first introduced to the market in 1904 by the Hungarian company Tungsram. This type is often referred to as the Tungsram bulb in many European countries.[56] Filling a flask with an inert gas such as argon or nitrogen slows the vaporization of the tungsten filament compared to operating in a vacuum. This allows higher temperatures and thus greater efficiency with less reduction in filament life.[57]

In 1906, William D. Coolidge developed a process for making “ductile tungsten” from sintered tungsten that could be made into filaments while working for the General Electric Company. By 1911, General Electric had begun selling ductile tungsten wire incandescent lamps.[59]

In 1913, Irving Langmuir found that filling a lamp with inert gas instead of a vacuum resulted in twice the luminous efficacy and less blackening of the bulb.

In 1917, Burnie Lee Benbow received a patent for the coiled-coil filament, which involves winding a coiled filament itself into a bobbin using a mandrel. In 1921, Junichi Miura created the first double-coil incandescent lamp using a filament tungsten filament while working for Hakunetsusha (a predecessor of Toshiba). At that time there were no machines to mass produce coiled-coil filament. Hakunetsusha developed a process for mass production of coiled-coil filaments in 1936.[62]

Between 1924 and the outbreak of World War II, the Phoebus Cartel attempted to set prices and sales quotas for lightbulb manufacturers outside of North America.[63]

In 1925, Marvin Pipkin, an American chemist, patented a process for matting the inside of lamp bulbs without weakening them.[64] In 1947 he patented a process for coating the inside of lamps with silica.[65]

In 1930, the Hungarian Imre Bródy filled lamps with krypton gas instead of argon and developed a process for extracting krypton from the air. Production of krypton-filled lamps based on his invention began in 1937 in Ajka in a factory co-designed by Polányi and Hungarian-born physicist Egon Orowan.

By 1964 improvements in the efficiency and production of incandescent lamps had reduced the cost of providing a given amount of light by a factor of thirty compared to the cost when Edison’s lighting system was introduced.

The consumption of light bulbs increased rapidly in the USA. In 1885 an estimated 300,000 lamps for general lighting were sold, all with carbon filaments. When tungsten filament was introduced, there were about 50 million lampholders in the United States. In 1914 88.5 million lamps were used (only 15% with carbon filaments) and by 1945 the annual sales of lamps were 795 million (more than 5 lamps per person per year).[68]

Effectiveness and efficiency[ edit ]

Xenon halogen lamp with E27 base that can replace a halogen lamp

More than 95% of the energy used by a typical lightbulb is converted to heat rather than visible light.[1] Other electric light sources are more effective.

Thermal image of a lightbulb. 22-175°C = 71-347°F.

For a given amount of light, an incandescent lamp uses more electricity and gives off more heat than a fluorescent lamp. In buildings where air conditioning is used, the heat dissipation from incandescent light bulbs increases the load on the air conditioning system.[69] While the heat from lamps reduces the need to run a building’s heating system, the latter can typically produce the same amount of heat at a lower cost than incandescent lamps.

Compared to other types of incandescent lamps (halogen-free), halogen incandescent lamps emit the same amount of light with lower power consumption and a more constant performance over time at low dimming.[70]

The luminous efficacy of a light source is the ratio of visible light to the total power input of the source, e.g. a lamp.[71] Visible light is measured in lumens, a unit defined in part by the human eye’s varying sensitivity to different wavelengths of light (see luminosity function). Not all wavelengths stimulate the human eye equally well. The unit of luminous efficacy is lumens per watt (lpw). By definition, the maximum efficiency is 683 lm/W for monochromatic green light. A white light source, where all visible wavelengths are present, has a lower efficiency, around 250 lumens per watt.

Luminous efficacy is defined as the ratio of luminous efficacy to the theoretical maximum luminous efficacy of 683 lpw for green light.[72][73]

The table below lists the luminous efficacy and efficiency values ​​for some generic 120 volt incandescent lamps with a 1000 hour lifespan and several idealized light sources. A longer table of luminous efficacy compares a wider range of light sources.

Type Total Luminous Efficacy Total Luminous Efficacy (lm/W) 40 W Tungsten Incandescent 1.9% 12.6[1] 60 W Tungsten Incandescent 2.1% 14.5[1] 100 W Tungsten Incandescent 2.6% 17.5[1] Glass Halogen 2, 3% 16 Quartz halogen 3.5% 24 Photographic and projection lamps with very high filament temperatures and short lifetimes 5.1% 35[74] Ideal blackbody radiator at 4000K 7.0% 47.5 Ideal blackbody radiator at 7000K 14% 95 Ideal monochromatic 555 nm (green) source 100% 683

The spectrum emitted by a blackbody radiator at incandescent temperatures does not match the properties of the human eye, with most of the radiation lying in the range that the eye cannot see. An upper limit for the luminous efficacy of incandescent lamps is around 52 lumens per watt, the theoretical value emitted by tungsten at its melting point.[67]

Color rendering[edit]

The spectrum of light produced by an incandescent lamp is very close to that of a black body radiator at the same temperature.[75] The basis for light sources used as a standard for color perception is a tungsten filament lamp operating at a defined temperature.[76]

Spectral power distribution of a 25 W incandescent lamp.

Light sources such as fluorescent lamps, high-intensity discharge lamps and LED lamps have a higher luminous efficiency. These devices produce light by luminescence. Their light has bands of characteristic wavelengths, without the “tail” of invisible infrared emissions, instead of the continuous spectrum produced by a thermal source. By careful selection of fluorescent phosphor coatings or spectral distribution modifying filters, the emitted spectrum can be tuned to mimic the appearance of incandescent sources or other different color temperatures of white light. When these sources are used for color-sensitive tasks, such as B. film lighting, certain techniques may be required to duplicate the appearance of incandescent lamps.[77] Metamerism describes the effect of different distributions of the light spectrum on color perception.

Cost of lighting[edit]

The initial cost of an incandescent light bulb is small compared to the cost of the energy it consumes over its lifetime. Incandescent bulbs have a shorter lifespan than most other lighting, an important factor when replacement is cumbersome or expensive. Some types of lamps, including incandescent and fluorescent lamps, emit less light as they age; This can be a disadvantage or shorten the effective life due to lamp replacement before catastrophic failure. A comparison of the cost of running an incandescent lamp versus other light sources must include the lighting requirements, the cost of the lamp and the labor cost of replacing the lamps (taking into account the effective lamp life), the cost of the electricity consumed, and the impact of lamp operation on heating and air conditioning systems. In residential and commercial lighting, the energy lost through heat can significantly increase the energy demand of a building’s air conditioning system. During the heating season, the heat generated by the light bulbs is not wasted,[78] although in most cases it is cheaper to obtain heat from the heating system. Regardless, a more efficient lighting system saves energy over the course of a year in almost all climates.[79]

Measures to prohibit use[ edit ]

Because incandescent bulbs use more energy than alternatives such as CFLs and LED bulbs, many governments have implemented measures to ban their use by setting minimum efficiency standards that are higher than incandescent bulbs can achieve. Measures to ban light bulbs have been implemented in the European Union, the United States, Russia, Brazil, Argentina, Canada and Australia, among others. In Europe, the European Commission has calculated that the ban will contribute 5 to 10 billion euros to the economy and save 40 TWh of electricity each year, resulting in a reduction in CO 2 emissions of 15 million tonnes.[80]

Objections to banning the use of incandescent lamps include the higher initial cost of alternatives and the lower light quality of fluorescent lamps.[81] Some people have concerns about the health effects of fluorescent lighting.

efforts to improve effectiveness

Some research has been done to improve the effectiveness of commercial incandescent lamps. In 2007, General Electric announced a project for high-efficiency incandescent (HEI) lamps, which they claimed would eventually be four times more efficient than current incandescent lamps, although their initial production goal was to be roughly twice as efficient. 83] The college program was discontinued in 2008 due to slow progress.[84][85]

US Department of Energy research at Sandia National Laboratories originally suggested the potential for dramatically improved photonic grating filament efficiency.[82] However, later work indicated that initially promising results were wrong.[86]

Stimulated by laws in different countries requiring higher lightbulb efficiency, Philips hybrid lightbulbs were introduced. The Halogena Energy Saver bulbs can produce around 23 lm/W; about 30 percent more efficient than traditional incandescent bulbs by using a reflective capsule to reflect formerly wasted infrared radiation back to the filament, part of which is re-emitted as visible light.[81] This concept was developed by Duro-Test in 1980 with a commercial product that produced 29.8 lm/W.[87][88] More advanced reflectors based on interference filters or photonic crystals can theoretically lead to higher efficiencies, up to a limit of about 270 lm/W (40 % of the maximum possible efficiencies).[89] Laboratory proof-of-concept experiments have produced up to 45 lm/W, which is close to the efficiency of CFLs.[89][90]

construction [edit]

Incandescent lamps consist of an airtight glass housing (the envelope or bulb) with a filament of tungsten wire inside the bulb through which an electric current is passed. Contact wires and a base with two (or more) conductors make electrical connections to the filament. Incandescent bulbs typically contain a stem or glass mount that is anchored to the base of the bulb and allows the electrical contacts to pass through the envelope without air or gas leaks. Small wires embedded in the shaft, in turn, support the filament and its lead wires.

An electric current heats the filament to typically 2,000 to 3,300 K (1,730 to 3,030 °C; 3,140 to 5,480 °F), well below tungsten’s melting point of 3,695 K (3,422 °C; 6,191 °F). Filament temperatures depend on the filament type, shape, size, and amount of current drawn. The heated filament emits light that approximates a continuous spectrum. The usable portion of the emitted energy is visible light, but most of the energy is dissipated as near-infrared heat.

Lightbulbs[edit]

Most lightbulbs have either clear or coated glass. Bei beschichteten Glaskolben ist Kaolinton eingeblasen und elektrostatisch auf der Innenseite des Kolbens abgeschieden. Die Pulverschicht streut das Licht vom Filament. Dem Ton können Pigmente zugesetzt werden, um die Farbe des emittierten Lichts einzustellen. Kaolin-Diffusionslampen werden aufgrund ihres vergleichsweise sanften Lichts häufig in der Innenbeleuchtung verwendet. Es werden auch andere Arten von farbigen Glühbirnen hergestellt, einschließlich der verschiedenen Farben, die für “Partybirnen”, Weihnachtsbaumbeleuchtungen und andere dekorative Beleuchtung verwendet werden. Diese entstehen durch Einfärben des Glases mit einem Dotierstoff; das ist oft ein Metall wie Kobalt (blau) oder Chrom (grün).[91] Neodymhaltiges Glas wird manchmal verwendet, um ein natürlicheres Licht zu erzeugen.

Umriss des Glaskolbens Niederdruck-Inertgas (Argon, Stickstoff, Krypton, Xenon) Wolframfaden Kontaktdraht (geht in den Schaft) Kontaktdraht (geht aus dem Schaft) Stützdrähte (ein Ende im Schaft eingebettet; leitet keinen Strom) Schaft (Glas Halterung) Kontaktdraht (geht aus dem Schaft) Kappe (Hülse) Isolierung (Vitrite) Elektrischer Kontakt

Der Glaskolben einer Allgebrauchslampe kann Temperaturen zwischen 200 und 260 °C (392 und 500 °F) erreichen. Lampen, die für den Hochleistungsbetrieb bestimmt sind oder zu Heizzwecken verwendet werden, haben Umhüllungen aus Hartglas oder Quarzglas.[67]

Wenn eine Glühbirnenhülle leckt, reagiert der heiße Wolframfaden mit Luft und ergibt ein Aerosol aus braunem Wolframnitrid, braunem Wolframdioxid, violettblauem Wolframpentoxid und gelbem Wolframtrioxid, das sich dann auf den nahe gelegenen Oberflächen oder im Inneren der Glühbirne ablagert.

Gasfüllung [ bearbeiten ]

Die meisten modernen Glühlampen sind mit einem Inertgas gefüllt, um die Verdunstung des Glühfadens zu reduzieren und seine Oxidation zu verhindern. Das Gas hat einen Druck von etwa 70 kPa (0,7 atm).[92]

Das Gas verringert die Verdunstung des Filaments, aber die Füllung muss sorgfältig ausgewählt werden, um das Einbringen erheblicher Wärmeverluste zu vermeiden. Für diese Eigenschaften sind chemische Trägheit und ein hohes Atom- oder Molekulargewicht wünschenswert. Das Vorhandensein von Gasmolekülen stößt die freigesetzten Wolframatome zurück zum Filament, reduziert seine Verdampfung und ermöglicht den Betrieb bei höheren Temperaturen, ohne seine Lebensdauer zu verkürzen (oder verlängert bei Betrieb bei derselben Temperatur die Lebensdauer des Filaments). . Andererseits führt das Vorhandensein des Gases durch Wärmeleitung und Wärmekonvektion zu einem Wärmeverlust aus dem Filament – ​​und daher zu einem Effizienzverlust aufgrund einer verringerten Glühung.

Frühe Lampen verwendeten nur ein Vakuum, um den Glühfaden vor Sauerstoff zu schützen. Das Vakuum erhöht die Verdampfung des Filaments, eliminiert jedoch zwei Wärmeverlustarten. Einige kleine moderne Lampen verwenden ebenfalls Vakuum.

Die am häufigsten verwendeten Füllungen sind:[93]

Vakuum, verwendet in kleinen Lampen. Sorgt für die beste Wärmeisolierung des Filaments, schützt jedoch nicht vor dessen Verdunstung. Wird auch in größeren Lampen verwendet, bei denen die Oberflächentemperatur des Außenkolbens begrenzt werden muss.

Argon (93 %) und Stickstoff (7 %), wobei Argon wegen seiner Trägheit, geringen Wärmeleitfähigkeit und geringen Kosten verwendet wird und der Stickstoff hinzugefügt wird, um die Durchbruchspannung zu erhöhen und Lichtbögen zwischen Teilen des Filaments zu verhindern [92]

Stickstoff, der in einigen Lampen mit höherer Leistung verwendet wird, z. projection lamps, and where higher breakdown voltage is needed due to proximity of filament parts or lead-in wires

Krypton, which is more advantageous than argon due to its higher atomic weight and lower thermal conductivity (which also allows use of smaller bulbs), but its use is hindered by much higher cost, confining it mostly to smaller-size bulbs.

Krypton mixed with xenon, where xenon improves the gas properties further due to its higher atomic weight. Its use is however limited by its very high cost. The improvements by using xenon are modest in comparison to its cost.

Hydrogen, in special flashing lamps where rapid filament cooling is required; its high thermal conductivity is exploited here.

Small amounts of halogen gases, mixed with inert gas, are used in halogen lamps, a distinct type of incandescent lamp.

The gas fill must be free of traces of water, which greatly accelerates bulb blackening (see below).

The gas layer close to the filament (called the Langmuir layer) is stagnant, with heat transfer occurring only by conduction. Only at some distance does convection occur to carry heat to the bulb’s envelope.

The orientation of the filament influences efficiency. Gas flow parallel to the filament, e.g., a vertically oriented bulb with vertical (or axial) filament, reduces convective losses.

The efficiency of the lamp increases with a larger filament diameter. Thin-filament, low-power bulbs benefit less from a fill gas, so are often only evacuated.

Early light bulbs with carbon filaments also used carbon monoxide, nitrogen, or mercury vapor. However, carbon filaments operate at lower temperatures than tungsten ones, so the effect of the fill gas was not significant as the heat losses offset any benefits.

Manufacturing [ edit ]

The 1902 tantalum filament light bulb was the first one to have a metal filament. This one is from 1908.

Early bulbs were laboriously assembled by hand. After automatic machinery was developed, the cost of bulbs fell. Until 1910, when Libbey’s Westlake machine went into production, bulbs were generally produced by a team of three workers (two gatherers and a master gaffer) blowing the bulbs into wooden or cast-iron molds, coated with a paste.[94] Around 150 bulbs per hour were produced by the hand-blowing process in the 1880s at Corning Glass Works.[94]

The Westlake machine, developed by Libbey Glass, was based on an adaptation of the Owens-Libbey bottle-blowing machine. Corning Glass Works soon began developing competing automated bulb-blowing machines, the first of which to be used in production was the E-Machine.[94]

Ribbon machine [ edit ]

Corning continued developing automated bulb-production machines, installing the Ribbon Machine in 1926 in its Wellsboro, Pennsylvania, factory.[95] The Ribbon Machine surpassed any previous attempts to automate bulb production and was used to produce incandescent bulbs into the 21st century. The inventor, William Woods, along with his colleague at Corning Glass Works, David E. Gray, had created a machine that by 1939 was turning out 1,000 bulbs per minute.[94]

The Ribbon Machine works by passing a continuous ribbon of glass along a conveyor belt, heated in a furnace, and then blown by precisely aligned air nozzles through holes in the conveyor belt into molds. Thus the glass bulbs or envelopes are created. A typical machine of this sort can produce anywhere from 50,000 to 120,000 bulbs per hour, depending on the size of the bulb.[96][97] By the 1970s, 15 ribbon machines installed in factories around the world produced the entire supply of incandescent bulbs.[98] The filament and its supports are assembled on a glass stem, which is then fused to the bulb. The air is pumped out of the bulb, and the evacuation tube in the stem press is sealed by a flame. The bulb is then inserted into the lamp base, and the whole assembly tested. The 2016 closing of Osram-Sylvania’s Wellsboro, Pennsylvania plant meant that one of the last remaining ribbon machines in the United States was shut down.[98]

Filament [ edit ]

How a tungsten filament is made

The first commercially successful light bulb filaments were made from carbonized paper or bamboo. Carbon filaments have a negative temperature coefficient of resistance—as they get hotter, their electrical resistance decreases. This made the lamp sensitive to fluctuations in the power supply, since a small increase of voltage would cause the filament to heat up, reducing its resistance and causing it to draw even more power and heat even further.

Carbon filaments were “flashed” by heating in a hydrocarbon vapor (usually gasoline), to improve their strength and uniformity. Metallized or “graphitized” filaments were first heated to high temperature to transform them into graphite, which further strengthened and smoothed the filament. These filaments have a positive temperature coefficient, like a metallic conductor, which stabilized the lamps operating properties against minor variations in supply voltage.

Metal filaments displaced carbon starting around 1904. Tungsten has the highest available melting point. By 1910, a process was developed by William D. Coolidge at General Electric for production of a ductile form of tungsten. The process required pressing tungsten powder into bars, then several steps of sintering, swaging, and then wire drawing. It was found that very pure tungsten formed filaments that sagged in use, and that a very small “doping” treatment with potassium, silicon, and aluminium oxides at the level of a few hundred parts per million greatly improved the life and durability of the tungsten filaments.[99]

Coiled coil filament [ edit ]

To improve the efficiency of the lamp, the filament usually consists of multiple coils of coiled fine wire, also known as a coiled coil. Light bulbs using coiled coil filaments are sometimes referred to as ‘double-coil bulbs’. For a 60-watt 120-volt lamp, the uncoiled length of the tungsten filament is usually 580 millimetres (22.8 in),[67] and the filament diameter is 0.046 millimetres (0.0018 in). The advantage of the coiled coil is that evaporation of the tungsten filament is at the rate of a tungsten cylinder having a diameter equal to that of the coiled coil. The coiled-coil filament evaporates more slowly than a straight filament of the same surface area and light-emitting power. As a result, the filament can then run hotter, which results in a more efficient light source while lasting longer than a straight filament at the same temperature.

Manufacturers designate different forms of lamp filament with an alphanumeric code.[100]

Electrical filaments are also used in hot cathodes of fluorescent lamps and vacuum tubes as a source of electrons or in vacuum tubes to heat an electron-emitting electrode. When used as a source of electrons, they may have a special coating that increases electron production.

Reducing filament evaporation [ edit ]

During ordinary operation, the tungsten of the filament evaporates; hotter, more-efficient filaments evaporate faster.[101] Because of this, the lifetime of a filament lamp is a trade-off between efficiency and longevity. The trade-off is typically set to provide a lifetime of 1,000 to 2,000 hours for lamps used for general illumination. Theatrical, photographic, and projection lamps may have a useful life of only a few hours, trading life expectancy for high output in a compact form. Long-life general service lamps have lower efficiency, but prior to the development of incandescent and LED lamps they were useful in applications where the bulb was difficult to change.

Irving Langmuir found that an inert gas, instead of vacuum, would retard evaporation. General service incandescent light bulbs over about 25 watts in rating are now filled with a mixture of mostly argon and some nitrogen,[102] or sometimes krypton.[103] While inert gas reduces filament evaporation, it also conducts heat from the filament, thereby cooling the filament and reducing efficiency. At constant pressure and temperature, the thermal conductivity of a gas depends upon the molecular weight of the gas and the cross sectional area of the gas molecules. Higher molecular weight gases have lower thermal conductivity, because both the molecular weight and cross sectional area are higher. Xenon gas improves efficiency because of its high molecular weight, but is also more expensive, so its use is limited to smaller lamps.[104]

Filament notching is due to uneven evaporation of the filament. Small variations in resistivity along the filament cause “hot spots” to form at points of higher resistivity;[68] a variation of diameter of only 1% will cause a 25% reduction in service life.[67] Since filament resistance is highly temperature-dependent, spots with higher temperature will have higher resistance, causing them to dissipate more energy, making them hotter – a positive feedback loop. These hot spots evaporate faster than the rest of the filament, permanently increasing the resistance at that point. The process ends in the familiar tiny gap in an otherwise healthy-looking filament.

Lamps operated on direct current develop random stairstep irregularities on the filament surface which may cut lifespan in half compared to AC operation; different alloys of tungsten and rhenium can be used to counteract the effect.[105][106]

Since a filament breaking in a gas-filled bulb can form an electric arc, which may spread between the terminals and draw very heavy current, intentionally thin lead-in wires or more elaborate protection devices are therefore often used as fuses built into the light bulb.[107] More nitrogen is used in higher-voltage lamps to reduce the possibility of arcing.[102]

Bulb blackening [ edit ]

In a conventional lamp, the evaporated tungsten eventually condenses on the inner surface of the glass envelope, darkening it. For bulbs that contain a vacuum, the darkening is uniform across the entire surface of the envelope. When a filling of inert gas is used, the evaporated tungsten is carried in the thermal convection currents of the gas, and is deposited preferentially on the uppermost part of the envelope, blackening just that portion of the envelope. An incandescent lamp that gives 93% or less of its initial light output at 75% of its rated life is regarded as unsatisfactory, when tested according to IEC Publication 60064. Light loss is due to filament evaporation and bulb blackening.[108] Study of the problem of bulb blackening led to the discovery of the Edison effect, thermionic emission and invention of the vacuum tube.[109][110]

A very small amount of water vapor inside a light bulb can significantly increase lamp darkening. Water vapor dissociates into hydrogen and oxygen at the hot filament. The oxygen attacks the tungsten metal, and the resulting tungsten oxide particles travel to cooler parts of the lamp. Hydrogen from water vapor reduces the oxide, reforming water vapor and continuing this water cycle.[68] The equivalent of a drop of water distributed over 500,000 lamps will significantly increase darkening.[67] Small amounts of substances such as zirconium are placed within the lamp as a getter to react with any oxygen that may bake out of the lamp components during operation.[citation needed]

Some old, high-powered lamps used in theater, projection, searchlight, and lighthouse service with heavy, sturdy filaments contained loose tungsten powder within the envelope. From time to time, the operator would remove the bulb and shake it, allowing the tungsten powder to scrub off most of the tungsten that had condensed on the interior of the envelope, removing the blackening and brightening the lamp again.[111]

Halogen lamps [ edit ]

Close-up of a tungsten filament inside a halogen lamp . The two ring-shaped structures left and right are filament supports.

The halogen lamp reduces uneven evaporation of the filament and eliminates darkening of the envelope by filling the lamp with a halogen gas at low pressure, along with an inert gas. The halogen cycle increases the lifetime of the bulb and prevents its darkening by redepositing tungsten from the inside of the bulb back onto the filament. The halogen lamp can operate its filament at a higher temperature than a standard gas filled lamp of similar power without loss of operating life. Such bulbs are much smaller than normal incandescent bulbs, and are widely used where intense illumination is needed in a limited space. Fiber-optic lamps for optical microscopy is one typical application.

Incandescent arc lamps [ edit ]

A variation of the incandescent lamp did not use a hot wire filament, but instead used an arc struck on a spherical bead electrode to produce heat. The electrode then became incandescent, with the arc contributing little to the light produced. Such lamps were used for projection or illumination for scientific instruments such as microscopes. These arc lamps ran on relatively low voltages and incorporated tungsten filaments to start ionization within the envelope. They provided the intense concentrated light of an arc lamp but were easier to operate. Developed around 1915, these lamps were displaced by mercury and xenon arc lamps.[112][113][114]

Electrical characteristics [ edit ]

Comparison of efficacy by power 120-volt lamps[115] 230-volt lamps[116] Power (W) Output (lm) Efficacy (lm/W) Output (lm) Efficacy (lm/W) 5 25 5 15 110 7.3 25 200 8.0 230 9.2 40 500 12.5 430 10.8 60 850 14.2 730 12.2 75 1,200 16.0 100 1,700 17.0 1,380 13.8 150 2,850 19.0 2,220 14.8 200 3,900 19.5 3,150 15.8 300 6,200 20.7 5,000 16.7 500 8,400 16.8

Power [ edit ]

Incandescent lamps are nearly pure resistive loads with a power factor of 1. Unlike discharge lamps or LED lamps, the power consumed is equal to the apparent power in the circuit. Incandescent light bulbs are usually marketed according to the electrical power consumed. This depends mainly on the operating resistance of the filament. For two bulbs of the same voltage, and type, the higher-powered bulb gives more light.

The table shows the approximate typical output, in lumens, of standard 120 volt incandescent light bulbs at various powers. Light output of similar 230 V bulbs is slightly less. The lower current (higher voltage) filament is thinner and has to be operated at a slightly lower temperature for the same life expectancy, which reduces energy efficiency.[117] The lumen values for “soft white” bulbs will generally be slightly lower than for clear bulbs at the same power.

Current and resistance [ edit ]

The resistance of the filament is temperature dependent. The cold resistance of tungsten-filament lamps is about 1/15 the resistance when operating. For example, a 100-watt, 120-volt lamp has a resistance of 144 ohms when lit, but the cold resistance is much lower (about 9.5 ohms).[67][b] Since incandescent lamps are resistive loads, simple phase-control TRIAC dimmers can be used to control brightness. Electrical contacts may carry a “T” rating symbol indicating that they are designed to control circuits with the high inrush current characteristic of tungsten lamps. For a 100-watt, 120-volt general-service lamp, the current stabilizes in about 0.10 seconds, and the lamp reaches 90% of its full brightness after about 0.13 seconds.

Physical characteristics [ edit ]

Security [edit]

The filament in a tungsten light bulb is not easy to break when the bulb is cold, but filaments are more vulnerable when they are hot because the incandescent metal is less rigid. An impact on the outside of the bulb may cause the filament to break or experience a surge in electric current that causes part of it to melt or vaporize. In most modern incandescent bulbs, part of the wire inside the bulb acts like a fuse: if a broken filament produces an electrical short inside the bulb, the fusible section of wire will melt and cut the current off to prevent damage to the supply lines.

A hot glass bulb may fracture on contact with cold objects. When the glass envelope breaks, the bulb implodes, exposing the filament to ambient air. The air then usually destroys the hot filament through oxidation.

Bulb shapes [ edit ]

Incandescent light bulbs come in a range of shapes and sizes.

Bulb shape and size designations are given in national standards. Some designations are one or more letters followed by one or more numbers, e.g. A55 or PAR38, where the letters identify the shape and the numbers some characteristic size.

National standards such as ANSI C79.1-2002, IS 14897:2000[119] and JIS C 7710:1988[120] cover a common terminology for bulb shapes.

Examples Description SI Inch Details “Standard” lightbulb A60 E26 A19 E26 ⌀60 mm (~⌀19/8 in) A series bulb, ⌀26 mm Edison screw Candle-flame bulb CA35 E12 CA11 E12 ⌀35 mm (~⌀11/8 in) candle-flame shape, ⌀12 mm Edison screw Flood light BR95 E26 BR30 E26 ⌀95 mm (~⌀30/8 in) flood light, ⌀26 mm Edison screw Halogen track-light bulb MR50 GU5.3 MR16 GU5.3 ⌀50 mm (~⌀16/8 in) multifaceted reflector, 5.33 mm-spaced 12 V bi-pin connector

Common shape codes [ edit ]

General Service Light emitted in (nearly) all directions. Available either clear or frosted. Types: General (A), Mushroom, elliptical (E), sign (S), tubular (T) 120 V sizes: A17, 19 and 21 230 V sizes: A55 and 60[c]

High Wattage General Service Lamps greater than 200 watts. Types: Pear-shaped (PS)

Decorative lamps used in chandeliers, etc. Smaller candle-sized bulbs may use a smaller socket. Types: candle (B), twisted candle, bent-tip candle (CA & BA), flame (F), globe (G), lantern chimney (H), fancy round (P) 230 V sizes: P45, G95

Reflector (R) Reflective coating inside the bulb directs light forward. Flood types (FL) spread light. Spot types (SP) concentrate the light. Reflector (R) bulbs put approximately double the amount of light (foot-candles) on the front central area as General Service (A) of same wattage. Types: Standard reflector (R), bulged reflector (BR), elliptical reflector (ER), crown-silvered 120 V sizes: R16, 20, 25 and 30 230 V sizes: R50, 63, 80 and 95[c]

Parabolic aluminized reflector (PAR) Parabolic aluminized reflector (PAR) bulbs control light more precisely. They produce about four times the concentrated light intensity of general service (A), and are used in recessed and track lighting. Weatherproof casings are available for outdoor spot and flood fixtures. 120 V sizes: PAR 16, 20, 30, 38, 56 and 64 230 V sizes: PAR 16, 20, 30, 38, 56 and 64 Available in numerous spot and flood beam spreads. Like all light bulbs, the number represents the diameter of the bulb in 1 ⁄ 8 of an inch. Therefore, a PAR 16 is 51 mm (2 in) in diameter, a PAR 20 is 64 mm (2.5 in) in diameter, PAR 30 is 95 mm (3.75 in) and a PAR 38 is 121 mm (4.75 in) in diameter.

A package of four 60-watt light bulbs

Multifaceted reflector (MR) Multifaceted reflector bulbs are usually smaller in size and run at a lower voltage, often 12 V.

Left to right: MR16 with GU10 base, MR16 with GU5.3 base, MR11 with GU4 or GZ4 base

HIR/IRC “HIR” is a GE designation for a lamp with an infrared reflective coating. Since less heat escapes, the filament burns hotter and more efficiently.[121] The Osram designation for a similar coating is “IRC”.[122]

Lamp bases [ edit ]

40-watt light bulbs with standard E10, E14 and E27 Edison screw base

The double-contact bayonet cap on an incandescent bulb

Large lamps may have a screw base or a bayonet base, with one or more contacts on the base. The shell may serve as an electrical contact or only as a mechanical support. Bayonet base lamps are frequently used in automotive lamps to resist loosening by vibration. Some tubular lamps have an electrical contact at either end. Miniature lamps may have a wedge base and wire contacts, and some automotive and special purpose lamps have screw terminals for connection to wires. Very small lamps may have the filament support wires extended through the base of the lamp for connections. A bipin base is often used for halogen or reflector lamps.[123]

In the late 19th century, manufacturers introduced a multitude of incompatible lamp bases. General Electric’s “Mazda” standard base sizes were soon adopted across the US.

Lamp bases may be secured to the bulb with a cement, or by mechanical crimping to indentations molded into the glass bulb.

Lamps intended for use in optical systems have bases with alignment features so that the filament is positioned accurately within the optical system. A screw-base lamp may have a random orientation of the filament when the lamp is installed in the socket.

Contacts in the lightbulb socket allow the electric current to pass through the base to the filament. The socket provides electrical connections and mechanical support, and allows changing the lamp when it burns out.

Light output and lifetime [ edit ]

Incandescent lamps are very sensitive to changes in the supply voltage. These characteristics are of great practical and economic importance.

For a supply voltage V near the rated voltage of the lamp:

Light output is approximately proportional to V 3.4

output is approximately proportional to Power consumption is approximately proportional to V 1.6

consumption is approximately proportional to Lifetime is approximately proportional to V −16

is approximately proportional to Color temperature is approximately proportional to V 0.42[101]

A 5% reduction in voltage will double the life of the bulb, but reduce its light output by about 16%. Long-life bulbs take advantage of this trade-off in applications such as traffic signal lamps. Since electric energy they use costs more than the cost of the bulb, general service lamps emphasize efficiency over long operating life. The objective is to minimize the cost of light, not the cost of lamps.[67] Early bulbs had a life of up to 2500 hours, but in 1924 the Phoebus cartel agreed to limit life to 1000 hours.[124] When this was exposed in 1953, General Electric and other leading American manufacturers were banned from limiting the life.[125]

The relationships above are valid for only a few percent change of voltage around standard rated conditions, but they indicate that a lamp operated at low voltage could last much longer than at rated voltage, albeit with greatly reduced light output. The “Centennial Light” is a light bulb that is accepted by the Guinness Book of World Records as having been burning almost continuously at a fire station in Livermore, California, since 1901. However, the bulb emits the equivalent light of a four watt bulb. A similar story can be told of a 40-watt bulb in Texas that has been illuminated since 21 September 1908. It once resided in an opera house where notable celebrities stopped to take in its glow, and was moved to an area museum in 1977.[126]

Photoflood lamps used for photographic lighting favor light output over life, with some lasting only two hours. The upper temperature limit for the filament is the melting point of the metal. Tungsten is the metal with the highest melting point, 3,695 K (3,422 °C; 6,191 °F). A 50-hour-life projection bulb, for instance, is designed to operate only 50 °C (122 °F) below that melting point. Such a lamp may achieve up to 22 lumens per watt, compared with 17.5 for a 750-hour general service lamp.[67]

Lamps of the same power rating but designed for different voltages have different luminous efficacy. For example, a 100-watt, 1000 hour, 120-volt lamp will produce about 17.1 lumens per watt. A similar lamp designed for 230 V would produce only around 12.8 lumens per watt, and one designed for 30 volts (train lighting) would produce as much as 19.8 lumens per watt.[67] Lower voltage lamps have a thicker filament, for the same power rating. They can run hotter for the same lifetime before the filament evaporates.

The wires used to support the filament make it mechanically stronger, but remove heat, creating another tradeoff between efficiency and long life. Many general-service 120-volt lamps use no additional support wires, but lamps designed for “rough service” or “vibration service” may have as many as five. Low-voltage lamps have filaments made of heavier wire and do not require additional support wires.

Very low voltages are inefficient since the lead wires would conduct too much heat away from the filament, so the practical lower limit for incandescent lamps is 1.5 volts. Very long filaments for high voltages are fragile, and lamp bases become more difficult to insulate, so lamps for illumination are not made with rated voltages over 300 volts.[67] Some infrared heating elements are made for higher voltages, but these use tubular bulbs with widely separated terminals.

The Centennial Light is the longest-lasting light bulb in the world.

Various lighting spectra as viewed in a diffraction grating. Upper left: fluorescent lamp, upper right: incandescent bulb, lower left: white LED, lower right: candle flame.

See also[edit]

Explanatory notes [ edit ]