Luminescent sources are called sources, the glow of which is based on the phenomenon of luminescence. Luminescence called spontaneous radiation, excess over thermal, if its duration significantly exceeds the oscillation period electromagnetic wave corresponding radiation. Luminescence is observed in gaseous, liquid and solid bodies.Luminescent and mixed radiation sources include all gas-discharge lamps. Classification of gas-discharge lamps is possible according to physical, design features, operational properties and areas of application. By physical features that determine the most important properties of gas discharge lamps: such as the spectrum and color of radiation, brightness, potential gradient, energy efficiency. For them, the determining factors are the composition of the gaseous medium (working substance), the partial pressure of the components of the gas mixture, and the current. Together with the type of discharge, the area of ​​glow used and the dimensions of the gas gap, they determine the power and voltage, dimensions and design of the gas-discharge lamp and its components, their thermal conditions, the choice of materials and related operating features and applications. According to the type of discharge, gas-discharge lamps are divided into arc, smoldering and pulsed. According to the composition of gases or vapors in which the discharge occurs, they are divided into lamps with a discharge: 1) in gases; 2) in metal vapors; 3) in vapors of metals and their compounds.
According to the working pressure, gas discharge lamps are divided into:
1) lamps low pressure approx. 0.1 to 104 Pa (up to 0.1 atm).2) Lamps high pressure from 3*104 to 106 Pa. (from 0.3 atm to 10 atm). 3) ultra-high pressure lamps over 106 Pa. (more than 10 atm).
According to the area of ​​​​the glow of the lamp: 1) with a pillar; 2) smoldering glow.
Depending on what is the main source of radiation,
gas discharge lamps are divided into: 1) gas or vapor-light, in which the radiation is caused by the excitation of atoms, molecules, or recombination of ions. 2) photoluminescent (called simply luminescent for short), in which the radiation is created by phosphors excited by the radiation of the discharge. 3) electric light, in which the radiation is created by electrodes, heated in a gas to a high temperature. For most type 2 and 3 lamps, discharge radiation is mixed with the main type of radiation, so they are essentially sources of mixed radiation. According to the shape of the bulb, gas discharge lamps with a column are divided into: 1) tubular or linear, in which the distance between the electrodes is 2 or more times the inner diameter of the tube; 2) capillary tubes with an inner diameter of less than 4 mm; 3) spherical tubes with a distance between the electrodes less than or equal to inner diameter bulbs (the bulbs of these lamps are often shaped like a ball or close to it, from which they get their name, they are also called short or medium arc gas discharge lamps.

"In the dark it is especially convenient to do all the dark deeds," but for light deeds in the dark, we need good visibility of objects. With the advent of "Ilyich's light bulb" into our lives, candles, torches, kerosene stoves and other non-environmentally friendly and impractical light sources have become very bad. And imagine modern house, illuminated by candles, somehow ridiculous and difficult. Let's see what the present industry can please us with and what sources it can offer to illuminate our home.

Three types of lamps are mainly used for indoor and outdoor lighting:

• incandescent;
• luminescent;
• LED.

Consider the advantages and disadvantages of each of these.

Incandescent lamps

What it is - probably everyone knows. This is a riddle about her: “A pear is hanging - you can’t eat it!”, She’s “Ilyich’s light bulb”. Although it was invented either by Edison or Lodygin. What can be said about it, in comparison with some new light sources? It “eats” a lot of electricity, it shines a little, it also serves a little (about 1000 hours).

The only advantage is that it is cheap, continuous spectrum, widespread and reliable like a Kalashnikov assault rifle: it shines equally well at direct or alternating current, at low or high temperature can work at low voltage. By the way, with a decrease in voltage significantly service life increases.This can be used for emergency lighting of undemanding places - for example, landings. You can turn on two identical bulbs in series, or you can turn it on through the corresponding semiconductor diode. In this case, they can last up to a million hours.

Fluorescent light sources

They are a white tube (straight or curved) with electrodes on the edges. Fluorescent lamps are much more efficient than incandescent lamps. With the same illumination, they consume five times less electricity, i.e. a 20-watt fluorescent will shine approximately like a 100-watt incandescent lamp.

The emission of luminescent light sources is much closer to natural, in addition, you can select the desired color shade of the lamp according to the glow temperature. Due to the fact that the entire surface of the tube glows, such sources emit diffused light and do not blind the eyes. The longer service life of fluorescent lighting lamps (2000 - 20000 hours) is highly dependent on the quality of the ballast (read the manufacturer) and the number of inclusions.

They are also available in a compact version with coil or serpentine tube and are available with either E27 (large base) or E14 (small base) plinths. This allows them to be used as light sources in most household fixtures by simply replacing an incandescent bulb with an appropriate compact fluorescent bulb.

The disadvantages of fluorescent lighting sources include:

• flicker, but with the use of high-quality electronic ballast, this disadvantage is reduced;
• non-continuous emission spectrum;
• higher cost;
• the need for disposal, because contain mercury.

LED lighting lamps

Light sources based on ultra-bright LEDs are simply a storehouse of advantages, with the exception of one major significant drawback - the high price, which manufacturers are persistently trying to reduce. And they will lower it after some time! Are LED bulbs good for home lighting as follows:

• efficiency is higher than luminescent;
• durability (up to 100,000 hours);
• safety of use;
• mechanical strength;
• lack of mercury vapor;
• small ultraviolet and infrared radiation;
• various color shades;
• continuous spectrum;
• do not blink (lack of stroboscopic effect).

LED matrices and fixtures based on them are the most promising sources of artificial light in terms of energy efficiency and practical application both for home and street lighting. Most likely, LED light sources will be used in the future.

An example of a light source related to the first class. Incandescent lamp for general use in a transparent bulb

An example of a light source belonging to the second class. Arc sodium lamp in a transparent bulb

An example of a light source related to the third class. Lamp mixed type in a flask coated with a phosphor

An example of a light source related to the fourth class. LED lamp made in the form of an incandescent lamp for general use

Classification of light sources

There is not a single branch of the national economy where artificial lighting is not used. The beginning of the development of the light source industry was laid in the 19th century. The reason for this was the invention of arc lamps and incandescent lamps.

A body that emits light as a result of energy conversion is called a light source. Almost all types of light sources currently produced are electrical. This means that electric current is used as the primary energy expended to create light radiation. Light sources are devices with light emission not only in the visible part of the spectrum (wavelength 380 - 780 nm), but also in the ultraviolet (10 - 380 nm) and infrared (780 - 10 6 nm) regions of the spectrum.

There are the following types of light sources: thermal, fluorescent and LED.

Thermal radiation sources are the most common. The radiation in them appears due to the heating of the filament to a temperature at which not only thermal radiation appears in the infrared spectrum, but visible radiation is also observed.

Luminescent radiation sources are capable of emitting light regardless of the state of their radiating body. The glow in them arises through the transformation various kinds energy directly into optical radiation.

Based on the above differences, light sources are divided into four classes.

Thermal

This includes all kinds, including halogen, as well as electric infrared heaters and carbon arcs.

Fluorescent

These include the following types of electric lamps: arc lamps, various glow discharge lamps, low pressure lamps, arc lamps, pulsed and high-frequency discharge lamps, including those in which metal vapor is added or a phosphor coating is applied to the bulb.

mixed radiation

These types of lighting lamps simultaneously use thermal and fluorescent radiation. High intensity arcs are an example.

LED

TO LED sources lights include all types of lamps and lighting fixtures using light emitting diodes.

In addition, there are other features by which lamps are classified (by scope, design and technological features, and the like).

Basic parameters of light sources

The light, electrical and operational properties of electric light sources are characterized by a number of parameters. Comparison of the parameters of several light sources, for their use in a particular area of ​​application, allows you to choose the most suitable one. Comparing the parameters of individual copies of the same light source, paying attention to the place and time of manufacture, one can judge the quality and technological level of their production.

We list the main electrical characteristics lamps and in general all light sources:

Rated voltage- the voltage at which the lamp operates in the most economical mode and for which it was calculated for its normal operation. For an incandescent lamp, the rated voltage is equal to the voltage of the mains supply. This voltage is indicated U l.n. and is measured in volts. Discharge lamps do not have such a parameter, since the voltage of the discharge gap is determined by the characteristics of the ballast used to stabilize it.

Rated power P l.n - calculated value characterizing the power consumed by an incandescent lamp when it is turned on at rated voltage. For gas-discharge lamps, in the circuit of which ballasts are included, the rated power is considered the main parameter. Based on its value, through experiments, the remaining electrical parameters of the lamps are determined. It should be taken into account that in order to determine the power consumed from the network, it is necessary to add the power of the lamp and the ballast.

Rated lamp current I l.n - the current consumed by the lamp at rated voltage and rated power.

Type of current- variable or constant. This parameter is standardized only for gas discharge lamps. It affects other parameters (besides those previously mentioned) that change with the type of current, and this applies to lamps operating only on direct or only on alternating current.

The main light parameters of light sources are:

Light flow emitted by the lamp. For measuring luminous flux incandescent lamps include it at rated voltage. For gas discharge lamps, the measurement is made when it is operating at rated power. The luminous flux is denoted by the letter F (Latin phi). The unit of luminous flux is lumen (lm).

The power of light. For some types, instead of the luminous flux, the parameters are the average spherical luminous intensity or the brightness of the filament. For such lamps, they are the main lighting parameters. Used symbols for luminous intensity Iv, I vΘ , for brightness - L, their units are candela (cd) and candela per square meter(cd / m 2).

Luminous efficacy of the lamp, is the ratio of the luminous flux of the lamp to its power

Unit of light output- unit of measurement of the parameter lumens per watt (Lm / W). With this parameter, you can evaluate the effectiveness of the use of light sources in lighting installations. However, another parameter is used as a characteristic of irradiating lamps - the value of the return of the radiation flux.

Luminous flux stability- percentage of the amount of luminous flux reduction at the end of the lamp life to the initial luminous flux.

The operational parameters of light sources include parameters that characterize the efficiency of the source in certain operating conditions:

Full service lifeτ total - the duration of burning in hours of the light source, switched on under nominal conditions, until complete failure (burnout of an incandescent lamp, failure to ignite for most gas discharge lamps).

Useful lifeτ p is the duration of burning in hours of the light source, switched on under nominal conditions, until the luminous flux decreases to a level at which its further operation becomes economically unprofitable.

Average service lifeτ is the main operating parameter of the lamp. It is the arithmetic mean of the total lifetimes of groups of lamps (at least ten) provided that the average value of the luminous flux of the lamps of the group by the time the average service life is reached remains within the useful lifetime, that is, at a given stability of the luminous flux. This parameter is especially important for incandescent lamps, since an increase in their luminous efficiency, other things being equal, leads to a reduction in service life. Since the experimental determination of the service life leads to the failure of the tested lamps, this parameter is determined on a certain number of lamps with a given degree of probability calculated according to the laws of mathematical statistics.

Dynamic durability- a parameter characterizing the service life of incandescent lamps under conditions of vibration and shaking. Lamps with the required dynamic life must withstand a certain number of test cycles over a specified frequency range.

To clarify the performance of lamps, in addition to the concept of average service life, the concept of a warranty service life is used, which determines the minimum burning time of all lamps in a batch. This concept is sometimes given a commercial meaning, considering guarantee period service time during which any lamp should be lit.

The relatively limited duration of burning of light sources, especially incandescent lamps, sets the requirement for their interchangeability, which can only be achieved if the parameters of individual lamps are repeatable.

To ensure the efficiency of the lighting installation, both the initial luminous flux of the lamp and the dependence of its decay on the operating time are important. With an increase in the duration of operation of the lighting installation, the role of capital costs in the cost of light energy decreases. It follows that lighting installations with a small number of burning hours per year should be made using cheaper incandescent lamps and, conversely, in industrial lighting installations where the burning time is 3000 hours or more, it is rational to use gas discharge sources that are more expensive than incandescent lamps. light with high luminous efficacy. The cost of a unit of light energy is also determined by the electricity tariff. At low tariffs, the use of lamps with a relatively low luminous efficiency and an increased service life in lighting installations is justified.

Introduction

1. Types of artificial lighting

2 Functional purpose of artificial lighting

3 Sources of artificial lighting. Incandescent lamps

3.1 Types of incandescent lamps

3.2 Construction of an incandescent lamp

3.3 Advantages and disadvantages of incandescent lamps

4. Discharge lamps. general characteristics. Application area. Kinds

4.1 Sodium discharge lamp

4.2 Fluorescent lamp

4.3 Mercury discharge lamp

Bibliography

Introduction

The purpose of artificial lighting is to create favorable conditions visibility, maintain a person's well-being and reduce eye fatigue. Under artificial lighting, all objects look different than under daylight. This happens because the position, spectral composition and intensity of radiation sources change.

The history of artificial lighting began when man began to use fire. Bonfire, torch and torch became the first artificial light sources. Then came oil lamps and candles. IN early XIX centuries have learned to emit gas and refined petroleum products, a kerosene lamp appeared, which is used to this day.

When the wick is lit, a luminous flame is produced. A flame emits light only when a solid body is heated by this flame. It is not combustion that generates light, but only substances brought to a red-hot state emit light. In a flame, light is emitted by incandescent particles of soot. This can be verified by placing the glass over the flame of a candle or a kerosene lamp.

Lighting oil lamps appeared on the streets of Moscow and St. Petersburg in the 30s of the 18th century. Then the oil was replaced with an alcohol-turpentine mixture. Later, kerosene began to be used as a combustible substance and, finally, lighting gas, which was obtained artificially. The light output of such sources was very low due to the low color temperature of the flame. It did not exceed 2000K.

By color temperature artificial light is very different from daylight, and this difference has long been noticed by the change in color of objects when going from daylight to evening artificial lighting. First of all, a change in the color of the clothes was noticed. In the twentieth century, with the widespread use of electric lighting, the change in color during the transition to artificial lighting decreased, but did not disappear.

Today, a rare person knows about the factories that produced lighting gas. The gas was produced by heating hard coal in retorts. Retorts are large metal or clay hollow vessels that are filled with charcoal and heated in a furnace. The released gas was purified and collected in facilities for storing lighting gas - gas holders.

More than a hundred years ago, in 1838, the St. Petersburg Gas Lighting Society built the first gasworks. By the end of the 19th century, gas tanks appeared in almost all large cities of Russia. The gas illuminated the streets, railway stations, businesses, theaters and residential buildings. In Kyiv, engineer A.E. Struve installed gas lighting in 1872.

The creation of direct current generators driven by a steam engine made it possible to widely use the possibilities of electricity. First of all, the inventors took care of the light sources and paid attention to the properties of the electric arc, which was first observed by Vasily Vladimirovich Petrov in 1802. dazzling bright light allowed to hope that people would be able to give up candles, a torch, a kerosene lamp and even gas lamps.

In arc lamps, it was necessary to constantly move the electrodes put "nose" to each other - they quickly burned out. At first they were shifted by hand, then dozens of regulators appeared, the simplest of which was the Archro regulator. The luminaire consisted of a fixed positive electrode fixed on a bracket and a movable negative electrode connected to a regulator. The regulator consisted of a coil and a block with a load.

When the lamp was turned on, current flowed through the coil, the core was drawn into the coil and diverted the negative electrode from the positive one. The arc was ignited automatically. With a decrease in current, the retracting force of the coil decreased and the negative electrode rose under the action of the load. This and other systems have not received wide distribution due to low reliability.

In 1875, Pavel Nikolaevich Yablochkov proposed a reliable and simple solution. He arranged the carbon electrodes in parallel, separating them with an insulating layer. The invention was a tremendous success, and the "Yablochkov candle" or "Russian Light" was widely used in Europe.

Artificial lighting is provided in rooms where there is not enough natural light, or to illuminate the room during the hours of the day when there is no natural light.

1. Types of artificial lighting

Artificial lighting can be general(all production facilities are illuminated with the same type of lamps, evenly spaced above the illuminated surface and equipped with lamps of the same power) and combined(local illumination of work places is added to general lighting with lamps located near the apparatus, machine tool, instruments, etc.). The use of only local lighting is unacceptable, since the sharp contrast between brightly lit and unlit areas tires the eyes, slows down the process of work and can cause accidents and accidents.

2.Functional purpose of artificial lighting

By functional purpose artificial lighting is divided into working , duty , emergency .

Work lighting mandatory in all premises and in illuminated areas to ensure the normal work of people and traffic.

Emergency lighting included outside of business hours.

Emergency lighting It is provided to ensure minimum illumination in the production room in case of a sudden shutdown of the working lighting.

In modern multi-span one-story buildings without skylights with one side glazing in daytime day use both natural and artificial lighting (combined lighting). It is important that both types of lighting are in harmony with one another. For artificial lighting in this case, it is advisable to use fluorescent lamps.

3. Sources of artificial lighting. Incandescent lamps.

In modern lighting installations designed to illuminate industrial premises, incandescent, halogen and gas-discharge lamps are used as light sources.

incandescent lamp- an electric light source, the luminous body of which is the so-called filament body (the filament body is a conductor heated by the flow of electric current to a high temperature). Tungsten and alloys based on it are currently used almost exclusively as a material for the manufacture of a heating body. IN late XIX- the first half of the XX century. The heating body was made from a more affordable and easy-to-process material - carbon fiber.

3.1 Types of incandescent lamps

The industry produces various types of incandescent lamps:

vacuum , gas-filled(filler mixture of argon and nitrogen), coiled, from krypton content .

3.2 The design of the incandescent lamp

Fig.1 Incandescent lamp

The design of a modern lamp. In the diagram: 1 - flask; 2 - the cavity of the flask (vacuum or filled with gas); 3 - glow body; 4, 5 - electrodes (current inputs); 6 - hooks-holders of the body of heat; 7 - lamp leg; 8 - external link of the current lead, fuse; 9 - base case; 10 - base insulator (glass); 11 - contact of the bottom of the base.

The design of the incandescent lamp is very diverse and depends on the purpose. specific type lamps. However, the following elements are common to all incandescent lamps: filament body, bulb, current leads. Depending on the characteristics of a particular type of lamp, filament body holders can be used. various designs; Lamps can be made without bases or with bases. various types, have an additional external flask and other additional structural elements.

3.3 Advantages and disadvantages of incandescent lamps

Advantages:

low cost

small size

The uselessness of ballasts

When turned on, they light up almost instantly.

The absence of toxic components and, as a result, the absence of the need for infrastructure for the collection and disposal

Ability to work as DC(any polarity), and on an alternating

The ability to manufacture lamps for a wide variety of voltages (from fractions of a volt to hundreds of volts)

No flicker or buzz when running on AC

Continuous emission spectrum

Electromagnetic Impulse Immunity

Ability to use brightness controls

Normal operation at low temperature environment

Disadvantages:

Low light output

Relatively short service life

Sharp dependence of luminous efficiency and service life on voltage

The color temperature lies only in the range of 2300-2900 K, which gives the light a yellowish tint.

Incandescent lamps represent fire hazard. 30 minutes after turning on the incandescent lamps, the temperature outer surface reaches the following values ​​depending on the power: 40 W - 145°C, 75 W - 250°C, 100 W - 290°C, 200 W - 330°C. When lamps come into contact with textile materials their flask heats up even more. Straw touching the surface of a 60 W lamp flares up after about 67 minutes.

The luminous efficiency of incandescent lamps, defined as the ratio of the power of the rays of the visible spectrum to the power consumed from the electrical network, is very small and does not exceed 4%

4. Discharge lamps. General characteristics. Application area. Kinds

IN Lately It is customary to call gas-discharge lamps discharge lamps. They are divided into high and low pressure discharge lamps. The vast majority of discharge lamps operate in mercury vapor. Possess high efficiency converting electrical energy into light. Efficiency is measured in Lumens/Watt.

Discharge light sources (gas-discharge lamps) are gradually replacing the previously familiar incandescent lamps, however, the line emission spectrum, fatigue from flickering of light, the noise of ballasts (ballasts), the harmfulness of mercury vapor if it enters the room when the flask is destroyed, the impossibility of instant re-ignition for lamps remain shortcomings high pressure.

With the continuing rise in energy prices and the rise in the cost of lighting fixtures, lamps and accessories, the need to introduce technologies that reduce non-manufacturing costs is becoming increasingly urgent.

General characteristics of gas discharge lamps

Service life from 3000 hours to 20000.

Efficiency from 40 to 150 lm/W.

Emission color: warm white (3000 K) or neutral white (4200 K)

Color reproduction: good (3000 K: Ra>80), excellent (4200 K: Ra>90)

The compact size of the radiating arc allows you to create high-intensity light beams

Areas of application of gas-discharge lamps.

Shops and showcases, offices and public places

Decorative outdoor lighting: building and pedestrian lighting

Artistic lighting of theaters, cinemas and stage (professional lighting equipment)

Types of gas discharge lamps.

To date, the most efficient discharge lamps in sodium vapor. In addition to this type of discharge lamps, there are widespread fluorescent lamps(low pressure discharge lamps), metal halide lamps , arc mercury fluorescent lamps. Less common xenon vapor lamps .

4.1 Sodium discharge lamp

Sodium discharge lamp(NL) - an electric light source, the luminous body of which is gas discharge in sodium vapor. Therefore, the resonant radiation of sodium is predominant in the spectrum of such lamps; lamps give a bright orange-yellow light. This specific feature of NL (monochromaticity of radiation) causes unsatisfactory color rendering quality when illuminated by them. Due to the characteristics of the spectrum, NL are mainly used for street lighting, utilitarian, architectural and decorative. The use of NL for lighting industrial and public buildings is extremely limited and is usually determined by the requirements of an aesthetic nature.

Depending on the magnitude of the partial pressure of sodium vapor, lamps are divided into low pressure sodium lamps(NLND) and high pressure sodium lamps(NLVD)

Historically, the first of the sodium lamps were created low pressure sodium lamps (NLND). In the 1930s this type of light sources began to spread widely in Europe. In the USSR, experiments were conducted to master the production of NLND, there were even models that were mass-produced, but their introduction into the practice of general lighting was interrupted due to the development of more technologically advanced DRL lamps, which, in turn, began to be replaced by NLVD.

NLND differ in a number of features that significantly complicate both their production and operation. First, sodium vapor at a high arc temperature acts very aggressively on the glass of the bulb, destroying it. Because of this, NLND burners are usually made of borosilicate glass. Secondly, the efficiency of NLND strongly depends on the ambient temperature. To ensure acceptable temperature regime burner, the latter is placed in an external glass flask, which plays the role of a "thermos".

Creation high pressure sodium lamps(NLVD) required a different solution to the problem of protecting the burner material from the effects of sodium vapor: a technology was developed for manufacturing tubular burners from aluminum oxide A l2 O 3 . Such a ceramic burner made of a thermally and chemically stable and well-transmitting material is placed in an outer flask made of heat-resistant glass. The cavity of the outer flask is evacuated and thoroughly degassed. The latter is necessary to maintain the normal temperature regime of the burner and protect the niobium current inputs from the effects of atmospheric gases.

The NLVD burner is filled with a buffer gas, which is gas mixtures different composition, as well as sodium amalgam (an alloy with mercury) is dosed into them. There are NLVD "with improved environmental properties" - mercury-free.

4.2 Fluorescent lamp

Fluorescent Lamp- gas-discharge light source, the luminous flux of which is determined mainly by the glow of phosphors under the influence of ultraviolet radiation of the discharge; the visible glow of the discharge does not exceed a few percent.

Fluorescent lamps are widely used for general lighting, while their luminous efficiency is several times greater than that of incandescent lamps for the same purpose. The service life of fluorescent lamps can be up to 20 times longer than the service life of incandescent lamps, provided that sufficient quality of the power supply, ballast and restrictions on the number of switching are observed, otherwise they quickly fail. The most common type of such sources is a mercury fluorescent lamp. It is a glass tube filled with mercury vapor, coated with inner surface phosphor layer.

Fluorescent lamps are the most common and economical source of light for creating diffused lighting in public buildings: offices, schools, educational and design institutes, hospitals, shops, banks, and enterprises. With the advent of modern compact fluorescent lamps, designed to be installed in conventional E27 or E14 lampholders instead of incandescent lamps, they began to gain popularity in everyday life. The use of electronic ballasts (ballasts) instead of traditional electromagnetic ones makes it possible to improve the characteristics of fluorescent lamps - to get rid of flicker and hum, to further increase efficiency, and increase compactness.

4.3 Mercury discharge lamp

Mercury discharge lamps are an electric light source in which a gas discharge in mercury vapor is used to generate optical radiation. To name all types of such light sources in domestic lighting engineering, the term "discharge lamp" is used, which is included in the International Lighting Dictionary approved by the International Commission on Illumination.

Depending on the filling pressure, there are low pressure discharge lamps(RLND), (RLVD) and ultra high pressure discharge lamps(RLSVD).

TO low pressure discharge lamps include mercury lamps with a partial pressure of mercury vapor in steady state less than 100 Pa. For low-pressure discharge lamps, this value is about 100 kPa, and for ultra-high pressure discharge lamps, it is 1 MPa or more.

For general lighting of workshops, streets, industrial enterprises and other objects that do not impose high requirements on the quality of color reproduction are used high pressure discharge lamps DRL type.

DRL(Arc Mercury Phosphor) - the designation of the RLVD adopted in domestic lighting technology, in which to correct the color of the light flux, aimed at improving color rendering, the radiation of a phosphor applied to the inner surface of the bulb is used.

Device DRL lamps

The first DRL lamps were made with two electrodes. To ignite such lamps, a source of high-voltage pulses was required. As it was used the device PURL-220 (Starting Device for Mercury Lamps for a voltage of 220 V). The electronics of those times did not allow the creation of sufficiently reliable igniting devices, and the PURL included a gas discharger, which had a shorter service life than the lamp itself. Therefore, in the 1970s. industry has gradually ceased production of two-electrode lamps. They were replaced by four-electrode ones that do not require external igniters.

For agreement electrical parameters lamps and a power source, almost all types of radars that have a falling external current-voltage characteristic require the use of a ballast, which in most cases is a choke connected in series with the lamp.

Fig.1 High pressure mercury lamp.

The four-electrode lamp DRL consists of outer glass flask(1) equipped with screw base(2). On the leg of the lamp is mounted on the geometric axis of the external flask quartz burner (discharge tube)(3) filled with argon with mercury addition. Four-electrode lamps have main electrodes(4) and located next to them auxiliary (igniting) electrodes(five). Each ignition electrode is connected to the main electrode located at the opposite end of the discharge tube through current-limiting resistance(6). Auxiliary electrodes facilitate lamp ignition and make its operation more stable during the start-up period.

Recently, a number of foreign firms have been manufacturing three-electrode DRL lamps equipped with only one ignition electrode. This design differs only in greater manufacturability in production, having no other advantages over four-electrode ones.

Operating principle

The lamp burner is made of refractory and chemically resistant transparent material (quartz glass or special ceramics) and is filled with strictly metered portions of inert gases. In addition, metallic mercury is introduced into the burner, which in cold lamp has the form of a compact ball or settles in the form of a coating on the walls of the flask and (or) electrodes. The luminous body of the RLVD is a column of arc electric discharge.

The ignition process of a lamp equipped with ignition electrodes is as follows. When a supply voltage is applied to the lamp, a glow discharge occurs between the closely spaced main and ignition electrodes, which is facilitated by a small distance between them, which is significantly less than the distance between the main electrodes, therefore, the breakdown voltage of this gap is also lower. The appearance in the cavity of the discharge tube of a sufficiently large number of charge carriers (free electrons and positive ions) contributes to the breakdown of the gap between the main electrodes and the ignition of a glow discharge between them, which almost instantly turns into an arc discharge.

Stabilization of the electrical and light parameters of the lamp occurs 10 - 15 minutes after switching on. During this time, the lamp current significantly exceeds the rated current and is limited only by the resistance of the ballast. The duration of the starting mode is highly dependent on the ambient temperature - the colder, the longer the lamp will flare up.

An electrical discharge in the burner of a mercury arc lamp produces visible blue or violet (rather than white as is commonly believed) radiation, as well as powerful ultraviolet radiation. The latter excites the glow of the phosphor deposited on the inner wall of the outer bulb of the lamp. The reddish glow of the phosphor, mixing with the white-greenish radiation of the burner, gives a bright light close to white.

A change in the mains voltage up or down causes a corresponding change in the luminous flux. The deviation of the supply voltage by 10 - 15% is acceptable and is accompanied by a change in the luminous flux of the lamp by 25 - 30%. When the supply voltage drops below 80% of the rated voltage, the lamp may not light up, and the burning lamp may go out.

When burning, the lamp becomes very hot. This requires the use of heat-resistant wires in lighting devices with mercury arc lamps, and imposes serious requirements on the quality of cartridge contacts. Since the pressure in the burner of a hot lamp increases significantly, its breakdown voltage also increases. The voltage of the supply network is insufficient to ignite a hot lamp. Therefore, before re-ignition, the lamp must cool down. This effect is a significant disadvantage of arc mercury lamps high pressure, since even a very short interruption of the power supply extinguishes them, and a long pause for cooling is required for re-ignition.

Traditional applications of DRL lamps

Lighting of open areas, industrial, agricultural and warehouse premises. Wherever this is due to the need for great energy savings, these lamps are gradually being replaced by NLVD (lighting cities, large construction sites, high production halls, etc.).

Bibliography

1. Life safety. Lecture notes. Part 2 / P.G. Belov, A.F. Koziakov. S.V. Belov and others; Ed. S.V. Belova. – M.: VASOT. 1993.

2. Life safety / N.G. Zanko. G.A. Korsakov, K. R. Malayan and others. Ed. IS HE. Rusaka. - S.-P.: Publishing House of the St. Petersburg Forestry Academy, 1996.

3. Reference book on lighting engineering / Ed. Yu.B. Eisenberg. Moscow: Energoatomizdat, 1995.

IN public buildings, schools, kindergartens, offices, fluorescent lighting source is optimal view. Fluorescent lighting lamps (further L.L.) refer to GRLND(to discharge lamps low pressure). In terms of lighting characteristics, they are superior to ordinary ones, both in luminous flux (by 2–3 times) and in duration of burning (by 8–10 times).

Lighting characteristics of a fluorescent lamp

The principle of operation of a fluorescent light source

There are two electrodes inside the tubular glass bulb. Introduced into the volume of the flask itself inert gases and discharged mercury vapor. During connection to the electrical network, an electrical discharge is formed between the spiral electrodes. The current passing between the electrodes also passes through the gas mixture and mercury vapor, thereby creating UV (ultraviolet radiation). It is not visible to the human eye. For this reason, on the inside glass surface apply phosphor. It absorbs UV and converts it into visible light to the human eye through the luminescence effect.

Turning on LL

Like DRL and HPS, fluorescent lighting lamps cannot be connected to the network directly, but only through ballasts (ballasts). There are only two types of ballast, EMPRA and electronic ballast, electromagnetic and electronic ballast, respectively.

The principle of switching on a fluorescent lamp with an ECG

In this switching circuit, a starter is used, which is connected in parallel with a fluorescent lighting lamp. Inside it there are two electrodes, one of which is fixed, and the second is made of a bimetallic plate, it bends depending on the current passing through it. When the light is not on electrical network, the electrodes are open. When connected to the network, voltage is supplied to both the lamp and the starter. This voltage is not enough for a discharge to occur between the electrodes. L.L, but it is enough to cause a glow discharge in the starter. When the discharge passes through the bimetallic electrode, it bends and the contacts close. Electricity flows through the electrodes of the lamp and heats them accordingly. At the same time, the starter electrodes cool down, since the rated current that passes through them does not create heat. As a result, they open, and a power surge occurs, which is enough to form an electric discharge in a fluorescent lighting lamp.

The principle of operation of the electronic ballast

In this case, there is no starter in the circuit. The electronic ballast heats the lamp electrodes with an alternating voltage of increased frequency.

The main advantages and disadvantages of fluorescent lighting lamps

• The power of the luminous flux is much greater than that of incandescent lamps (L.N.)
• The color range of light radiation has a wide range
• The burning time of hours per year (on average 7,000 - 10,000) is an order of magnitude longer than that of L.N.

The disadvantages include:

• In case of depressurization of the tube, L.L. (crashed), they are environmentally hazardous, because inside their mercury vapor
• Wear over time of the phosphor, resulting in a change in color gamut
• Twinkle L.L. with a frequency of 100 Hz. For this reason, a stroboscopic effect occurs. It gives the false impression that the moving parts can appear as one object.
• The bulkiness of the luminaire, since ballast is required for operation

Fluorescent lamp marking

Lamps that complete domestic fixtures are marked as follows. In the first place is the letter "L", which naturally means luminescent. In second and third place, the type of light, for example, LB(white shade of light) and so on LD, LHB, LTB(daylight, cold white, warm white). If at the end of the marking is the letter " C" or several " CC", it means. What's on inside L.L. applied phosphor "de-luxe" and "super de-luxe", respectively.

Due to the fact that L.L. wide spectral characteristics, they are used in various production processes and special rooms. It depends on the temperature of the light.

• For offices, administrative premises, schools, shops, a fluorescent lighting source is used similar to daylight(temperature 6 300 – 6 600 TO).
• At a temperature 5 500 - 6 600 K the spectral range of light is most suitable for the formation of photobiological processes and this makes this light source optimal for the naturalness of the background. And for the same reason, they are used for lighting in aquariums to give a natural background to corals and their inhabitants.
• When staining the tube or applying different colors phosphor kind of light make green, yellow and so on.

In addition, fluorescent lamps are used in the textile and food industries, they are used by criminalists and at the post office.

It should be noted that since the tube contains mercury vapor, there are certain requirements for operation and storage.