Light bulb refers to the lighting source that emits light and heat through electric energy. It was invented by Henry Goebbels in 1854, andThomas Alva Edison Found more suitable materials and developedIncandescent lamp。
With the development of society, the use of light bulbs has also changed. At first, it may be to provide convenience for production and life, but with the progress of society, there have also been obvious changes in the use of light bulbs, beginning to have different uses such as "cars, beautifying the environment, decoration"FunctionalityUse the lamp.
The bulb is made according to the principle of heat effect of electric current.After the bulb is connected to the rated voltage, the current is heated to the incandescent state (above 2000C) through the filament, so that it generates heat and emits light, thus converting electrical energy into internal energy and light energy during operation.
Light bulb:
Light is a form of energy, which is released by atoms. It is composed of many small particles, which have energy and momentum but no mass.These particles are called visible photons, which are the mostBasic unit。When the electron is excited, the atom will release visible photons.If you already know how atoms work, then you also know that electrons are negatively charged particles walking around the nucleus.Atomic electrons have different levels of energy, which mainly depends on several factors, including their speed and distance from the atomic nucleus.Different energy levels of electrons occupy different orbital functions and orbits.Generally speaking, electrons with large energy will be farther away from the atomic nucleus. When the atom gains or loses energy, the change is represented by the movement of electrons.When something transfers energy to atoms - take heat for example - electrons can be temporarily pushed into a higher orbit (away from the nucleus).The electron just stays in this orbital position for a very short time: it is almost immediately returned toNucleusTo reach its original orbit.At this time, the electrons emit extra energy in the form of photons.The wavelength of luminescence depends on how much energy is released, which also depends on the orbital position of the electron.Therefore, different kinds of atoms will release different kinds of visible photons.In other wordsColor of lightIt is determined by the type of excited atom.
The structure of the bulb is very simple.There are two metal contact points at its bottom, which are used to connect electricity.The metal contact point has two wires contacting a thin metal filament.The filament is located in the center of the bulb and supported by a glass.Wire and filament are wrapped ininert gasWhen the bulb is connected to the power supply, the current will flow from one contact point to another and then to the wire and filament.Solid conductorLine currentA large number offree electronFrom negativeCharged zoneMove to the positive charged area.The hopping electron in the vibrating atom may be temporarily pushed to a higher energy position.When theyFall backoriginalNormal positionThe electrons will release extra energy in the form of photons.Metal atoms release most ofinfraredvisible lightSon, people's eyes can see.But if they are heated to about 4000fahrenheitThe bulb will emit a lot of visible light.In almost allIncandescent light bulbsTungsten is used because it is the most ideal filament material.The metal must be heated to a very high temperature before it can emit useful visible light.In fact, most metals will melt before reaching this temperature, while tungsten wire is unusually highMelting temperature。However, tungsten filament will catch fire at such a high temperature. If conditions permit, two chemicals will react and cause combustion. The filament in the bulb is sealed by a sealed, oxygen free space to prevent combustion.The air in the bulb is sucked out to create a state close to vacuum -- that is, there is no substance in it.Since there is almost no gas or special substance in it, the substance will not burn.One problem with this method is that tungsten atomsEvaporation。At such a high temperatureVacuum bulbFree tungsten atoms shoot out in a straight line.As more and more atoms evaporate, the filament begins to decay and the glass begins to darken.This greatly reduces the life of the bulb.
Encyclopedia x Knowledgeable: Illustrated Incandescent Lamp
Used in modern light bulbsinert gasUsuallyargon This greatly reduces this loss of tungsten.When a tungsten atom evaporates, it will combine with an argonAtomic collisionAnd because the inert gas usually does not react with other elements, there is noCombustion reaction。Cheap and easy to use, light bulbs have proved a great success.Bulbs remain the most popular indoor lighting option.But it will eventually give way to more advanced technologies because it is not energy efficient.Most of the energy emitted by incandescent bulbs is emitted by visible photons with thermal infrared light -- only about 10% of the light produced isVisible spectrum。This wastes a lot of electricity.Warm light source, such asFluorescent lampandLED lightThey do not waste a lot of energy to generate heat and emit most of the visible light.As a result, they will gradually replace the bulbs.
Its exact technical name isIncandescent lamp, which is a kind of thin wire (usuallyTungsten wire）A lamp heated to incandescence and used to give light.The periphery of the bulb is made of glass to keep the filament in a vacuum, or low pressureinert gasThe function is to prevent the filament from oxidation under high temperature.With reference to incandescent lamps, it is generally believed that electric lamps are made by AmericansThomas Alva Edison Invention.But if serious research, another American Henry·Goebbels(Heinrich G ö bel) has invented the same principle and materials decades earlier than Edison.In 1801, David, a British chemist, electrified the platinum wireAlso inIt was invented in 1810Electric candle, using twoCarbon rodArc lighting between.In 1854, Henry Goebbels used a carbonizedBamboo silk, placed in vacuumGlass bottlesLower power on and light up.His invention is the first one with practical effect todayIncandescent lamp。The bulb he tested at that time could last for 400 hours, but he did not immediately apply for a design patent.
Light bulb:
The biggest problem with light bulbs isfilamentThe sublimation of.Because of the tiny resistance difference on the tungsten wire, the temperature varies. In places with high resistance, the temperature rises higher, and the tungsten wire also sublimates faster, which causes the tungsten wire to become thinner and the resistance to further increase;Finally, the tungsten wire is burnt out.Later, it was found that the sublimation of tungsten wire could be slowed down by replacing vacuum with inert gas.Most light bulbs today are filled with nitrogen, argon or krypton.Modern incandescent lamps generally have a lifetime of about 1000 hours.
spare parts
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The bulb is mainly composed offilament, glass shell, lamp cap, etc.In bulbMetallic materialsAll are conductors, while the plastic part of the glass shell and lamp cap isinsulator。
Main categories
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Tungsten wire
W-filament bulb
A light source widely used by people. It can emit warm and yellow light. It is what most of us think of as a light bulb.It's cheap, so,W-filament bulb It also has various styles to match different lamps.However, the service life of tungsten filament bulb is not long, and it does not save power. It also emits a high temperature, so it should not be too close to paper, textiles or plastic products.
W91 tungsten wire is suitable for making filament, impact resistant filament and other high-temperature resistance devices.
W71 tungsten wire is suitable for manufacturing lampsfilamentAnd other shockproof devices.
W61 tungsten wire is suitable for manufacturingHelical coilFilament.
W41 type tungsten wire is suitable for manufacturing stranded tungsten wire, tungstenHeating element。
W42 tungsten wire is suitable for manufacturing stranded tungsten wire, tungsten heating element and other equipment without special temperature requirements.
W11 tungsten wire is suitable for making electrode and lead.
Tungsten halogen
tungsten-halogen bulb
The life of foam is longer than that of ordinaryTungsten wireLight bulbs have come for a long time, but they are also expensive.Tungsten wireHalogen lampThe generated light cord is also whiter and closer than the ordinary tungsten filament bulbNatural light。
There are two types of halogen lamps: high voltage type, which is usually only used for sky lamps;The other is low voltage type, which is mainly used for downward illumination.Both bulbs can adjust the light.
Halogen sky lamps with adjustable light intensity are particularly practical for ordinary families, because these lamps are smooth in shape, and the light is projected upward toceilingOr reflected off the wall,Lighting effectSoft.At least the halogen bulb is smaller and more power saving, so it is often used in spotlights as lamps that project light upward or downward.
One of the main advantages of halogen lamps is that the maximum light energy can be emitted from the filament of a small needle.Therefore, the shape of the lamp can become very smooth and mini, saving more space.
Because it saves electricityHalogen bulbWidely used in storeslightingChinese - You can recognize them from those tiny blinking bulbs.
fluorescence
Fluorescent lamp
The light it emits is cooler, rougher and bluish than the tungsten filament bulb, but the lamp is very power saving and durable, so it is often an economical choice on the right.They also have many improvements at present and can be used in smaller lamps.In addition, the light generated by these improved lamps is also warmer than the old ones, so they become the best choice for kitchens and studios.But all in all, this kind of lamp is helpful for creating the atmosphere in the home.
Metal halide
Metal halide bulb
This is the light source developed and manufactured at present. It is not only cheap, but also won't damage the color of the room.It is most often used for garden needsHigh brightnessThe place.Because of the sodium content, it will emit light orange light.Today, metals are the most widely usedHalogen lampThe main consideration is the advantage of electricity saving.But they are also gradually used in indoor lighting.
LED
LED bulb
LEDIt will be invented by EdisonbulbSince then, the great light revolution will begin again.
LED bulbAt present, LED lights are mainly high-powerWhite LEDMainly single lamp, the current top three LED lighting manufacturers in the world have a three-year warranty, and large particles per wattGreater than or equal to100 lumens, small particles shall be more than or equal to 110 lumens per watt.luminous attenuationLarge particles are less than 3% per year, and light attenuation small particles are less than 3% per year.
Xenon lamp, also known as HID gas discharge headlamp.It's wrapped inQuartz tubeThe high-pressure xenon inside replaces the traditional tungsten wire, providing higher color temperature and more concentrated lighting.
Luminescence principle is based on UV cut antiultraviolet rayscrystalQuartz glass tubeFilled with various chemical gases, most of which arexenonXenon andIodideWait, then go throughSupercharger（Ballast）Put the 12 voltDC voltageInstantly boost to 23000 volts, through high voltageamplitude of the earthquake waveThe xenon electron in the quartz tube is excited to dissociate, and a light source is generated between the two electrodes. This is calledgas discharge 。And the white produced by xenon is super strongElectric arc light, can improve the light color temperature value, similar to the sunlight in the daytime, which is required for HID operationCurrentOnly 3.5A, the brightness is traditionalHalogen bulbIts service life is 10 times longer than that of traditional halogen bulbs.
History of Invention
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Bulb d e ngp à o (ENBulb)，It is reported that Henry of the United States was the first person to use itGoebbels。The most famous inventor is the American scientistThomas Alva Edison It is well known that Edison successfully trial produced the bulb on October 21, 1879.
In the development process, Thomas Alva Edison carefully analyzed theGas lampandArc lampHis main direction of attack is to find a heat-resistant material.The electric current burns it to incandescence and emits incandescent light without breaking or melting.He accidentally found the cotton thread suddenly in the airFiringAsh, while the carbon cotton thread is put into the treated glass ball and emits incandescent light.Unfortunately, the light only lasted a few minutes and then disappeared.He mistakenly gave up the experiment and tried cesium, nickel, platinum (platinum)Platinum iridium alloy1600 kinds of different heat-resistant materials have yielded little.
Thomas Alva Edison returned to the study of carbon.In October that year, he experimented with a 20 cm long, 0.15 cm diameterCarbon rodIts heat resistance reaches 5.5 hours, and he continues to improve the carbonization method and air extraction treatment.
Light bulb:
On October 21, 1879, he used a carbonized cotton thread with a diameter of 0.025 cm as the filament. Its brightness was bright and stableIlluminance, 1 hour, 2 hours... 45 hours of light.After more than a year of efforts and thousands of experiments, the long-awaited electric lamp was finally born.
In October of the same year, Thomas Alva Edison changed to carbonized cardboard to greatly improve the life of electric lamps, and the manufacturers could not wait to put it into production.On the New Year's Eve in 1880, 3000 people went toNew YorkWatch this new invention on the street.Success did not stop Thomas Alva Edison.The next year, he made a bamboo filament lamp that can light for 1200 hours continuously.It was not until 1904 that the Austrians invented a lamp three times stronger than the bamboo filament lamptungsten lampThe former is replaced.Tungsten filament lamps have been used since 1907.
Before the invention of the light bulb, it was a laborious and dangerous thing to light a place after sunset. Candles or torches were used for lighting, althoughoil lampNot bad, but it always leaves soot.
In the middle of the 18th century, electrical science really developed. At that time, inventors everywhere loudly called for the invention of a practical household lighting device.British inventor Swan and American inventor Edison inventedbulbIn the modern light bulb and the light bulb invented by Edison that year, there is no essential change but some additional parts.
It is generally believed that the electric light is made by Americansthomas edison Invention.However, if we carefully study, another American, Henry Goebbels, has invented the same principle and material and reliable electric light bulb decades earlier than Edison, and many other people have also made many contributions to the invention of electric light bulb before Edison.
In 1801, British chemistDavidThe platinum wire is electrified for luminescence.
In 1810, David inventedElectric candleThe arc between two carbon rods is used for illumination.
In 1854, Henry Goebbels used a carbonized bamboo wire to put it under a vacuum glass bottle to generate electricity and light.His invention today seems to be the first practical incandescent lamp.The bulb he tested at that time could last for 400 hours, but he did not immediately apply for a design patent.
In 1850, Joseph Wilson Swan, an Englishman（Joseph WilsonSwan) began to study electric lights.
In 1878, Joseph Wilson Swan used it in a vacuumCarbon filamentThe electrified bulb was patented in the UK, and began to set up a company in the UK to install electric lights in families.
In 1874,CanadaTwo electricians of the company applied for a patent for electric light.They filled the glass bubble with nitrogen to make the electrified carbon rod glow.But they didn't have enough money to continue developing the invention, and sold the patent to Thomas Edison in 1875.
In 1879, Edison changed to make light bulb with carbon filament, which lasted for 13 hours successfully.
Light bulb:
Edison's carbonization in 1880Bamboo filament bulbIt has been successfully maintained in the laboratory for 1200 hours.But in Britain,SwanHe sued Edison for patent infringement and won the lawsuit.Edison's electric light company in Britain was forced to let Swan join as a partner.But later Swan sold his rights and patents to Edison.In the United States, Edison's patents were also challenged.The United States Patent Office once ruled that his invention had a criminal record and was invalid.Finally, after years of litigation, Edison got thepatent right。
In 1906, General Electric invented a method to manufacture tungsten wire for electric lamps.Finally, the method of making tungsten wire cheaply was solved, and tungsten wire light bulbs have been used so far.
In 1910, Cooley Hall in the United States was made of tungsten wirefilament, inventedW-filament bulb 。
In 1913, Ramir of the United StatesGlass shellIt is filled with gas to prevent the filament from evaporating. Inflation is inventedTungsten wireLight bulb:
In 1925, Japan's Bupoju San invented the inner wallFrosted bulb。
In 1932, Shunichi Miura of Japan invented the double helix tungsten filament bulb.
The use of light bulbs makes the world more colorful and dazzling.
Development trend
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People's opinions on light bulbsproduct qualityThe requirements for consistency with photoelectric parameters are getting higher and higher, andTungsten wireThe consistency of performance is the key factor to ensure the performance of the bulb.
Light bulb development trend
Influence on various aspects of tungsten wire
Continuous improvement of performance and stability
The recrystallization performance is improved, the distribution of potassium foam is controlled, and it can be remanufactured
energy conservation
Coil positioning and stability
Compact fluorescent lamp
Control internal stress
Infrared coating lamp
Control the size and distribution of potassium bubbles
miniaturization
New technology (coil winding)
High precision size - silk size control
High chemical purity - less pollution, smaller wire size - to prevent uneven wire diameter and scratches
environmental protection
Waste acid and waste water treatment of tungsten products production, and substitute materials without radioactive thorium;Restricting the use of hazardous substances
Diversity
Best special applications for tungsten properties
Maintenance method
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Bulb maintenance methods mainly include:
one
Do not switch the power supply of the lamp too frequently.
two
Do not let the bulb light continuously for too long.
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Do not connect too many appliances in parallel on the wiring board.
four
Do not plug in or unplug the power supply when the light is on, or even unscrew the bulb.
five
Do not bring a hot bulb to the cold environment immediately, and vice versa.
Candlelight bulb
Key points of installation
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The bulb shall be free from external interference, beautiful, practical, firm and safe.
one
The connection of wires shall be standardized and reasonable.
two
The switch shall control the live wire.
three
The screw sleeve of the screw socket can only be connected to the zero line.
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The two wires in the lamp holder shall be insulated from each other and equipped with safety buckles.
Main defects
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Bulb blackening
Although technical measures have been taken to prevent tungsten sublimation at high temperatures, in fact, tungsten can sublimate at high temperatures, directly changing from solid to gaseous.Hot tungsten vapor condenses into solid state after being cooledcrystalLamp attachedInternal surfaceOn.So the bulb will turn black and dark.In addition, the results of sublimation and condensation make the filament thinner, and the formula R=ρ（resistivity）L/S (π r ²) can be analyzed, the radius r becomes smaller, the filament resistance R becomes larger, while the voltage at both ends of the lamp remains unchanged, P=U ²/R, so the power of the lamp becomes smaller and the brightness becomes darker.
Lamp damage
Conductor resistance and conductor materialCross-sectional area, length and temperature.commonlyMetallic materialsThe resistance of the tungsten filament increases with the temperature, and the tungsten filament has the same property.At the moment of turning on the light,Filament temperatureLow resistance, so the filament is easy to overheat and fuse.After working for a period of time, the filament temperature increases, and the resistance increases with the increase of temperature. The current and power of the lamp are close to each otherRating, so it is difficult to damage.A "220V, 60W" filament lamp is calculated by the formula R=U ²/PThermal resistanceIt's 807 euro, not workingCold resistanceMeasured valueIt's 63 Ohms.
