The first electric arc lamp was invented in 1802 by the Russian physicist V.V. Petrov. It was based on two coal rods, placed horizontally. One of them was connected to the positive pole of the electric battery, the other to the negative one. While warming up, the rods began to glow, and a glowing electric arc appeared between them. To obtain such an arc, it was necessary to separate the carbon rods at a strictly defined distance, which was technically difficult to implement.

In the middle of the XIX century. French physicist J. Foucault invented a regulator that automatically maintained the required distance between the coals. However, this complicated the design of the lamp. At the end of the XIX century. idea of \u200b\u200bmaking it easy to use light bulb, as they say, was in the air. P.N. Yablochkov was one of the first to tackle this problem.

The Yablochkov candle was distinguished by a simple design. The inventor placed carbon electrodes not horizontally, as was done before him, but; vertically, placing an insulator (porcelain insert) between them. When an electric current was passed through the "candle", a luminous arc appeared at the top, igniting the electrodes. To achieve uniform illumination, Yablochkov coated the electrodes with a layer of kaolin - white clay that served as an insulator. The lamps worked for an hour and then burned out. To make the lamp shine longer, Yablochkov increased the thickness of one carbon rod and also used alternating current.

Glory came to the inventor. In Paris, his lamps were the first to illuminate the Louvre store. Gas lanterns on the streets of the French capital were dismantled - they were replaced everywhere by "Yablochkov candles". Placed in white matte balls, they gave a pleasant bright light.

Yablochkov's lamps could be found not only in Paris: they burned on the central streets of all European capitals, in halls and restaurants best hotels, on the alleys of the largest parks in Europe. The enterprises of the partnership produced 10 thousand light bulbs a day, and they were bought up instantly (one light bulb cost 20 kopecks, which was not so cheap at that time).

But the triumph of the Russian inventor was short-lived. Soon they began to assert that in fact the light did not come from Russia, but from America, and that the Russian scientist specially made his lamps short-lived in order to get rich. But objectively, the future did not belong to the arc lamp, but to the incandescent lamp invented by our compatriot A.N. Lodygin and improved by T. Edison (we still use such a lamp).

In 1879 P.N. Yablochkov returned to Russia. In St. Petersburg, the production of arc lamps was established, but it was not possible to launch them into widespread consumption. Nevertheless, the merit of the inventor is beyond doubt. Thanks to the Yablochkov candle, a new era has begun in people's lives: electric light is no longer perceived as a miracle. Today we remember P.N. Yablochkov with deep respect for his arduous life and his invention.

100 Great Russian Inventions, Veche 2008

In modern power engineering, radio engineering, telecommunications, automation systems, the transformer is widely used, which is rightfully considered one of the most common types of electrical equipment. The invention of the transformer is one of the remarkable pages in the history of electrical engineering. Almost 120 years have passed since the creation of the first industrial single-phase transformer, on the invention of which scientists and engineers worked from the 30s to the mid-80s of the XIX century different countries.

Nowadays, thousands of different designs of transformers are known - from miniature to gigantic, for the transportation of which special railway platforms or powerful floating vehicles are required.

As you know, when transmitting electricity over a long distance, a voltage of hundreds of thousands of volts is used. But consumers, as a rule, cannot directly use such huge voltages. Therefore, the electricity generated at thermal power plants, hydroelectric power plants or nuclear power plants undergoes transformation, as a result of which the total capacity of transformers is several times higher than the installed capacity of generators at power plants. Energy losses in transformers should be minimal, and this problem has always been one of the main problems in their design.

The creation of the transformer became possible after the discovery of the phenomenon of electromagnetic induction by outstanding scientists of the first half of the 19th century. Englishman M. Faraday and American D. Henry. Faraday's experiment with an iron ring is widely known, on which two windings isolated from each other were wound, a primary connected to a battery, and a secondary one with a galvanometer, the arrow of which was deflected when the primary circuit was opened and closed. It can be considered that the Faraday device was a prototype of the modern transformer. But neither Faraday nor Henry were the inventors of the transformer. They did not study the problem of voltage conversion; in their experiments, the devices were powered by direct and not alternating current and acted not continuously, but instantly at the moments when the current in the primary winding was turned on or off.

The first electrical applianceswhich exploited the phenomenon of electromagnetic induction were induction coils. In them, when the primary winding was opened, a significant EMF was induced in the secondary, which caused large sparks between the ends of this winding. Several tens of such devices were patented during 1835-1844. The most perfect was the induction coil of the German physicist G.D. Rumkorf.

Induction coil protects Kronstadt

The first successful application of an induction coil was carried out in the early 1840s by the Russian academician B.S. Jacobi (1801-1874) for the ignition of powder charges of underwater electric mines. The minefields built under his leadership in the Gulf of Finland blocked the way to Kronstadt for two Anglo-French squadrons. It is known that during this war the defense of the Baltic coast was of great importance. A huge Anglo-French squadron, consisting of 80 ships with a total of 3,600 guns, unsuccessfully tried to break through to Kronstadt. After the flagship Merlin collided with an underwater electric mine, the squadron was forced to leave the Baltic Sea.

The enemy admirals admitted with regret: "The allied fleet cannot undertake anything decisive: a fight against the mighty fortifications of Kronstadt would only put the fate of the ships at a useless risk." The well-known English newspaper "Herald" laughed at Vice Admiral Nepir: "I came, saw and ... did not win ... The Russians laugh, and we are funny, in fact." Electric mines, unknown in Europe, forced to retreat the most magnificent fleet that ever appeared at sea, it, as another newspaper wrote, not only "did not advance the war, but returned without winning a single victory."

For the first time an induction coil was used as a transformer by the talented Russian electrical engineer-inventor Pavel Nikolaevich Yablokov (1847-1894).

In 1876, he invented the famous "electric candle" - the first source of electric light, widely used and known as "Russian light". Due to its simplicity, the "electric candle" spread throughout Europe for several months and even reached the chambers of the Persian Shah and the King of Cambodia.

For simultaneous connection to the electrical network a large number candles Yablochkov invented a system of "crushing electrical energy" by means of induction coils. He received patents for the "candle" and a scheme for their inclusion in 1876 in France, where he had to leave Russia in order not to end up in a "debt" prison. (He owned a small electrical workshop and was fond of experimenting with devices that he took for repairs, not always paying creditors on time.)

In the system of "crushing electrical energy" developed by Yablochkov, the primary windings of the induction coils were connected in series to the AC network, and a different number of "candles" could be included in the secondary windings, the operating mode of which did not depend on the mode of others. As stated in the patent, such a scheme allowed "to carry out separate power supply of several lighting devices with different light intensities from a single source of electricity." It is quite obvious that in this circuit the induction coil was operating in transformer mode.

If a generator was connected to the primary network direct current, Yablochkov provided for the installation of a special breaker. Patents for the inclusion of candles by means of transformers were obtained by Yablochkov in France (1876), Germany and England (1877), in Russia (1878). And when a few years later a dispute began about who had priority in the invention of the transformer, the French society "Electric Lighting", which issued a message on November 30, 1876, confirmed the priority of Yablochkov: in the patent "... the principle of operation and methods of turning on the transformer was described." ... It was also reported that "Yablochkov's priority is recognized in England as well."

The scheme of "crushing electrical energy" by means of transformers was demonstrated at electrical exhibitions in Paris and Moscow. This installation was the prototype of a modern electrical network with the main elements: prime mover - generator - transmission line - transformer - receiver. Yablochkov's outstanding merits in the development of electrical engineering were awarded the highest award of France - the Order of the Legion of Honor.

In 1882, a laboratory assistant at Moscow University I.F. Usagin demonstrated at the Industrial Exhibition in Moscow Yablochkov's “crushing” scheme, but included various receivers in the secondary windings of the coils: an electric motor, a heating coil, an arc lamp, and electric candles. With this, he first demonstrated the versatility of alternating current and was awarded a silver medal.

As already noted, in the Yablochkov installation, the transformer did not have a closed magnetic circuit, which completely satisfied technical requirements: with sequential switching on of the primary windings, the switching on and off of some consumers in the secondary windings did not affect the operating mode of others.

Yablochkov's inventions gave a powerful impetus to the use of alternating current. In different countries, electrical engineering enterprises began to be created for the manufacture of alternators and the improvement of devices for its transformation.

When it became necessary to transmit electricity over long distances, the use of high-voltage direct current for these purposes turned out to be ineffective. The first power transmission to alternating current was carried out in 1883 to illuminate the London Underground, the length of the line was about 23 km. The voltage was increased to 1500 V with the help of transformers, created in 1882 in France by L. Golyard and D. Gibbs. These transformers also had an open magnetic circuit, but they were already intended for voltage conversion and had a transformation ratio different from unity. Several induction coils were fixed on a wooden support, the primary windings of which were connected in series. The secondary winding was sectioned, and each section had two leads for connecting receivers. The inventors provided for the extension of the cores to regulate the voltage on the secondary windings.

Modern transformers have a closed magnetic circuit and their primary windings are connected in parallel. With parallel connection of receivers, the use of an open magnetic circuit is not technically justified. It has been found that a closed-circuit transformer has better performance, lower losses and higher efficiency. Therefore, as the transmission range increased and the voltage in the lines increased, they began to design a closed-magnet transformer in 1884 in England by brothers John and Edward Hopkinson. The magnetic circuit was assembled from steel strips isolated from each other, which reduced eddy current losses. On the magnetic core, alternating high and low voltage coils were located. On the inexpediency of operating a transformer with a closed magnetic circuit when serial connection The primary windings were first pointed out by the American electrical engineer R. Kennedy in 1883, stressing that a change in the load in the secondary circuit of one transformer will affect the operation of other consumers. This can be eliminated by connecting the windings in parallel. The first patent for such transformers was received by M. Deri (in February 1885). In subsequent high voltage power transmission schemes, the primary windings began to be connected in parallel.

The most advanced single-phase transformers with a closed magnetic circuit were developed in 1885 by Hungarian electrical engineers: M. Deri (1854-1934), O. Blati (1860-1939) and K. Zipernovsky (1853-1942). They also used the term "transformer" for the first time. In their patent application, they pointed out the important role of the closed laminated magnetic circuit, especially for powerful power transformers. They also proposed three modifications of transformers that are still in use: ring, armored and rod. Such transformers were serially produced by the Ganz & Co electrical engineering plant in Budapest. They contained all the elements of modern transformers.

The first autotransformer was created by an electrician of the American firm "Westinghouse" W. Stenley in 1885, its successful test took place in Pittsburgh.

The introduction of oil cooling (late 1880s, D. Swinburne) was of great importance for improving the reliability of transformers. Swinburne placed the first transformers in ceramic vessels filled with oil, which significantly increased the reliability of winding insulation. All this contributed to the widespread use of single-phase transformers for lighting purposes. The most powerful plant by Ganz & Co was built in Rome in 1886 (15,000 kVA). One of the first power plants built by the firm in Russia was a station in Odessa to illuminate a new opera house widely known in Europe.

AC Triumph. Three-phase systems

80s of the XIX century. went down in the history of electrical engineering under the name of "transformer battles". The successful operation of single-phase transformers has become a convincing argument for the use of alternating current. But the owners of large electrical companies that produced DC equipment did not want to lose profits and did their best to prevent the introduction of alternating current, especially for long-distance transmission.

Generously paid journalists spread fables about alternating current. The famous American inventor T.A. Edison (1847-1931). After the creation of the transformer, he refused to attend its test. “No, no,” he exclaimed, “alternating current is nonsense with no future. Not only do I not want to inspect the AC motor, but I also do not want to know about it! " Edison's biographers argue that, having lived a long life, the inventor was convinced of his erroneous views and would give a lot to get his words back.

The well-known Russian physicist A.G. Stoletov in 1889 in the Electricity magazine: “I involuntarily recall the persecution that transformers were subjected to in our country regarding the recent project of the Gants & Co firm to illuminate a part of Moscow. Both in oral reports and in newspaper articles, the system was denounced as something heretical, irrational and, of course, disastrous: it was proved that transformers were completely banned in all decent Western states and were only tolerated in some Italy, which is susceptible to cheapness. " Not everyone knows that the introduction of the electric chair in New York State in 1889 using high voltage alternating current electrical businessmen also sought to use life-threatening alternating current to compromise.

The development of reliable single-phase transformers paved the way for the construction of power plants and single-phase transmission lines, which became widely used for electric lighting. But in connection with the development of industry, the construction of large plants and factories, the need for a simple economical electric motor began to be felt more and more. As you know, single-phase AC motors do not have an initial starting torque and could not be used for electric drive purposes. So in the mid-80s of the XIX century. a complex energy problem arose: it was necessary to create installations for the economical transmission of high voltage electricity over long distances and to develop a design for a simple and highly economical AC motor that met the requirements of an industrial electric wire.

Thanks to the efforts of scientists and engineers from different countries, this problem has been successfully solved on the basis of multiphase electrical systems. Experiments have shown that the most expedient of these is a three-phase system. The greatest success in the development of three-phase systems was achieved by the outstanding Russian electrical engineer M.O. Dolivo-Dobrovolsky (1862-1919), forced to live and work in Germany for many years. In 1881 he was expelled from the Riga Polytechnic Institute for participating in the student revolutionary movement without the right to enter a higher educational institution in Russia.

In 1889, he invented a surprisingly simple three-phase asynchronous squirrel cage motor, the design of which, in principle, has survived to this day. But for the transmission of electricity at high voltage, three single-phase transformers were needed, which significantly increased the cost of the entire installation. In the same 1889 Dolivo-Dobrovolsky, showing an outstanding retailer, created a three-phase transformer.

But he did not come immediately to the design, which, like an asynchronous motor, has in principle been preserved to the present day. Initially, it was a device with a radial arrangement of cores. Its design still resembles an electric machine without an air gap with protruding poles, and the rotor windings are transferred to the rods. Then there were several designs of the "prismatic" type. Finally, in 1891, the scientist received a patent for a three-phase transformer with a parallel arrangement of cores in one plane, similar to the modern one.

The general test of a three-phase system using three-phase transformers was the famous Laufen-Frankfurt power transmission, built in 1891 in Germany with the active participation of Dolivo-Dobrovolsky, who developed for it necessary equipment... Near the town of Laufen, near a waterfall on the Neckar River, a hydroelectric power station was built, the turbine of which could develop a net power of about 300 hp. The rotation was transmitted to the shaft of a three-phase synchronous generator. By means of a three-phase transformer with a capacity of 150 kVA (no one had previously manufactured such transformers), electricity at a voltage of 15 kV was transmitted via a three-wire transmission line over a huge distance for that time (170 km) in Frankfurt am Main, where an international technical exhibition was opening. The transmission efficiency exceeded 75%. A three-phase transformer was installed at the exhibition site in Frankfurt, which reduced the voltage to 65 V. The exhibition was illuminated by 1000 electric lamps... A three-phase asynchronous motor with an output of about 75 kW was installed in the hall, driving a hydraulic pump that supplied water for a brightly lit decorative waterfall. There was a kind of energy chain: an artificial waterfall was created by the energy of a natural waterfall, 170 km away from the first. Impressive visitors to the exhibition were amazed at the wonderful powers of electrical energy.

This transmission was a true triumph for three-phase systems, worldwide recognition of M.O.'s outstanding contribution to electrical engineering. Dolivo-Dobrovolsky. Modern electrification began in 1891.

With the growth of the power of transformers, the construction of power plants and energy systems begins. The electric drive, electric transport, and electrical technology are emerging and rapidly developing. It is interesting to note that the first most powerful power plant in the world with three-phase generators and transformers was the service station of the first industrial enterprise in Russia with three-phase electrical equipment. It was the Novorossiysk elevator. The power plant's synchronous generators were 1200 kVA, three-phase asynchronous motors power from 3.5 to 15 kW were driven various mechanisms and cars, and some of the electricity was used for lighting.

Gradually, electrification affected more and more new branches of TVE, communications, everyday life, medicine - this process deepened and expanded, electrification took on a mass character.

During the XX century. In connection with the creation of powerful interconnected energy systems, an increase in the transmission range of electrical energy, an increase in the voltage of transmission lines, the requirements for the technical and operational characteristics of transformers increased. In the second half of the XX century. significant progress in the production of powerful power transformers was associated with the use of cold-rolled electrical steel for magnetic cores, which made it possible to increase induction and reduce the cross-section and weight of the cores. The total losses in transformers were reduced to 20%. It was possible to reduce the size of the cooling surface of the oil tanks, which led to a reduction in the amount of oil and a reduction in the total weight of the transformers. The technology and automation of the production of transformers was continuously improved, new methods were introduced for calculating the strength and stability of windings, the resistance of transformers to the effects of forces during short circuits. One of urgent problems modern transformer engineering - achieving dynamic resistance of powerful transformers.

Great prospects for increasing the power of power transformers are opening up when using superconducting technology. The use of a new class of magnetic materials - amorphous alloys, according to experts, can reduce energy losses in cores by up to 70%.

Transformer in the service of radio electronics and telecommunications

After the discovery by G. Hertz (1857-1894) in 1888 of electromagnetic waves and the creation in 1904-1907 of the first electronic tubes, real prerequisites appeared for the implementation of wireless, the need for which was growing. A transformer has become an integral part of circuits for generating high voltage and high frequency electromagnetic waves, as well as for amplifying electromagnetic oscillations.

One of the first scientists to study Hertz waves was the talented Serbian scientist Nikola Tesla (1856-1943), who owned more than 800 inventions in the field of electrical engineering, radio engineering and telemechanics and whom the Americans called the "king of electricity." In a lecture given at Franklin University in Philadelphia in 1893, he quite definitely spoke about the possibility practical application electromagnetic waves. “I would like, - said the scientist, - to say a few words about a subject that is always on my mind, which affects the well-being of all of us. I mean the transmission of meaningful signals, perhaps even energy, over any distance without wires at all. Every day I am more and more convinced of the practical feasibility of this scheme. "

Experimenting with high frequency vibrations and striving to implement the idea of \u200b\u200b"wireless communication", Tesla in 1891 created one of the most original devices of his time. The scientist came up with a happy idea - to combine in one device the properties of the "resonance-transformer" transformer, which played a huge role in the development of many branches of electrical engineering, radio engineering and is widely known as "Tesla's transformer". By the way, with the light hand of French electricians and radio operators, this transformer was simply called "Tesla".

In Tesla's device, the primary and secondary windings were tuned to resonance. The primary winding was connected through an arrester with an induction coil and capacitors. During a discharge, a change in the magnetic field in the primary circuit causes a very high voltage and frequency current in the secondary winding, which consists of a large number of turns.

Modern measurements have shown that high quality voltages with amplitudes of up to one million volts can be obtained with a resonant transformer. Tesla pointed out that by changing the capacitance of a capacitor, you can get electromagnetic oscillations with different wavelengths.

The scientist proposed using a resonance transformer to excite a "conductor-emitter", raised high above the ground and capable of transmitting high-frequency energy without wires. It is obvious that Tesla's "emitter" was the first antenna to find the widest application in radio communications. If a scientist created a sensitive receiver of electromagnetic waves, he would have come up with the invention of radio.

Tesla's biographers believe that before A.S. Popov and G. Marconi Tesla was closest to this discovery.

In 1893, a year before Roentgen, Tesla discovered "special rays" penetrating objects that were opaque to ordinary light. But he did not complete these studies, and a friendly relationship was established between him and Roentgen for a long time. In the second series of experiments, Roentgen used.

In 1899, Tesla, with the help of friends, managed to build a scientific laboratory in Colorado. Here, at an altitude of two thousand meters, he began to study lightning discharges and establish the presence electric charge land. He came up with the original design of the "amplifying transmitter", resembling a transformer and allowing to receive voltages up to several million volts at a frequency of up to 150 thousand periods per second. He attached a mast about 60 m high to the secondary winding.When he turned on the transmitter, Tesla was able to observe huge lightning, a discharge up to 135 feet long, and even thunder. He again returned to the idea of \u200b\u200busing high-frequency currents for "lighting, heating, movement of electric vehicles on the ground and in the air," but, naturally, he could not realize his ideas at that time. Tesla's resonance transformer found its application in radio receiving technology at the beginning of the 20th century. Its constructive modification was manufactured by the Marconi company under the name "jigger" (sorter) and was also used to clear the signal from interference.

Communication range problems were solved with the advent of amplifiers. The transformer has been widely used in amplifier circuits based on the use of Ldion, invented in 1907 by the American radio engineer.

In the XX century. electronics has come a long way from bulky tube devices to semiconductor technology, microelectronics and optoelectronics. And the transformer has always remained an unchanged element of power supplies and various conversion circuits. For many decades, the technology of manufacturing low-power (from a fraction of a watt to several watts) transformers has improved. Their mass production required the use of special electrical materials, in particular ferrites, for the manufacture of magnetic circuits, as well as coreless transformers for high-frequency installations. Research continues to find more efficient designs using the latest advances in science and technology.

Electrification has always been the basis of scientific and technological progress. On its basis, technologies in industry, transport, agriculture, communications and construction are continuously being improved. The mechanization and automation of production processes has achieved unprecedented success. Achievements in the world energy sector would not have been possible without the introduction of various and highly efficient power and special transformers.

But from the objective laws of the development of science and technology, it follows that no matter how perfect designs are created today, they are only a step on the way to creating even more powerful and unique transformers.

Ultra-high pressure arc lamps (LSVD) include lamps operating at a pressure of 10 × 10 5 Pa and above. When high pressures gas or metal vapor with a strong approach of the electrodes, the cathode and anode regions of the discharge are reduced. The discharge is concentrated in a narrow spindle-shaped region between the electrodes, and its brightness, especially near the cathode, reaches very high values.

This arc discharge is an indispensable light source for projector and projector types, as well as for a number of special applications.

The use of mercury vapor or inert gas in lamps gives them a number of features. The production of mercury vapor at an appropriate pressure, as can be seen from the examination of high pressure made in the article "", is achieved by dosing mercury in the lamp bulb. The discharge ignites as a low pressure mercury discharge at ambient temperature. Then, as the lamp burns out and heats up, the pressure increases. The working pressure is determined by the steady-state temperature of the bulb, at which the electric power supplied to the lamp becomes equal to the power dissipated in the surrounding space by radiation and heat transfer. Thus, the first feature of ultra-high pressure mercury lamps is that they are fairly easy to ignite but have a relatively long burn-up period. When they go out, reignition can be carried out, as a rule, only after complete cooling. When the lamps are filled with inert gases, the discharge after ignition almost instantly enters a steady state. Ignition of a discharge in a gas at high pressure presents certain difficulties and requires the use of special igniting devices. However, after extinguishing, the lamp can be re-lit almost instantly.

The second feature that distinguishes an ultra-high pressure mercury discharge with a short arc from the corresponding gas discharge is its electrical mode. Due to the large difference between the potential gradients in mercury and inert gases at the same pressure, the combustion voltage of such lamps is significantly higher than with gas filling, due to which, at equal powers, the current of the latter is much higher.

The third significant difference is the emission spectrum, which in gas-filled lamps corresponds in spectral composition to daylight.

These features have led to the fact that arc lamps are often used for filming and film projection, in simulators of solar radiation and other cases when correct color rendering is required.

Lamp device

The spherical shape of the lamp bulb was selected to ensure high mechanical strength at high pressures and small distances between the electrodes (Figures 1 and 2). The quartz glass spherical flask has two diametrically spaced long cylindrical legs, in which the inputs connected to the electrodes are sealed. A long leg is necessary to remove the lead from the hot bulb and prevent it from oxidizing. Some types of mercury lamps have an additional ignition electrode in the form of a tungsten wire soldered into the bulb.

Figure 1. General view of ultra-high pressure mercury-quartz lamps with a short arc of various power, W:
and - 50; b - 100; in - 250; r - 500; d - 1000

Figure 2. General view of xenon ball lamps:
and - constant current lamp with a power of 100 - 200 kW; b - 1 kW AC lamp; in - AC lamp with a power of 2 kW; r - constant current lamp with a power of 1 kW

Electrode designs differ depending on the type of current that powers the lamp. When operating on alternating current, for which mercury lamps are intended, both electrodes have the same design (Figure 3). They differ from the electrodes of tubular lamps of the same power in greater massiveness, due to the need to reduce their temperature.

Figure 3. Electrodes for short arc AC mercury lamps:
and - for lamps up to 1 kW; b - for lamps up to 10 kW; in - solid electrode for high-power lamps; 1 - core from tornated tungsten; 2 - tungsten wire sheathing coil; 3 - oxide paste; 4 - getter; 5 - base made of sintered tungsten powder with addition of thorium oxide; 6 - forged tungsten part

When lamps are operated on direct current, the position of the lamp burning, which should be only vertical, becomes important - the anode upwards for gas lamps and preferably the anode downwards for mercury lamps. The location of the anode at the bottom reduces the stability of the arc, which is important due to the counterflow of electrons directed downwards and hot gases rising upward. The upper position of the anode forces to increase its dimensions, since in addition to its heating due to the higher power dissipated at the anode, it is additionally heated by a stream of hot gases. For mercury lamps, the anode is placed at the bottom in order to ensure more uniform heating and, accordingly, reduce the burn-up time.

Due to the small distance between the electrodes, mercury ball lamps can operate on alternating current from a mains voltage of 127 or 220 V. The working pressure of mercury vapor in lamps with a power of 50 - 500 W, respectively (80 - 30) × 10 5, and in lamps with a power of 1 - 3 kW - (20 - 10) × 10 5 Pa.

Ultra-high pressure lamps with a ball bulb are most often filled with xenon due to the convenience of its dosage. The distance between the electrodes is 3 - 6 mm for most lamps. Xenon pressure in a cold lamp (1 - 5) × 10 5 Pa for lamps with a power of 50 W to 10 kW. Such pressures make ultra-high pressure lamps explosive even when inoperative and require special enclosures to store them. Due to the strong convection, the lamps can only work in an upright position, regardless of the type of current.

Radiation lamps

High brightness of mercury ball lamps with a short arc is obtained due to an increase in the current and stabilization of the discharge at the electrodes, which prevent the expansion of the discharge channel. Depending on the temperature of the working part of the electrodes and their design, different brightness distributions can be obtained. When the temperature of the electrodes is insufficient to provide the arc current due to thermionic emission, the arc contracts at the electrodes into bright luminous points of small sizes and takes on a spindle shape. The brightness near the electrodes reaches 1000 Mcd / m² and more. The small size of these areas leads to the fact that their role in the total radiation flux of lamps is insignificant.

When the discharge contracts at the electrodes, the brightness increases with increasing pressure and current (power) and with decreasing distance between the electrodes.

If the temperature of the working part of the electrodes ensures the receipt of the arc current due to thermionic emission, then the discharge, as it were, spreads over the surface of the electrodes. In this case, the brightness is more evenly distributed along the discharge and still increases with increasing current and pressure. The radius of the discharge channel depends on the shape and design of the working part of the electrodes and almost does not depend on the distance between them.

The light output of lamps increases with an increase in their power density. With a spindle-shaped discharge, the light output has a maximum at a certain distance between the electrodes.

The radiation of mercury ball lamps of the DRSh type has a line spectrum with a strongly pronounced continuous background. The lines are greatly expanded. There is no radiation with wavelengths shorter than 280 - 290 nm at all, and due to the background, the proportion of red radiation is 4 - 7%.

Figure 4. Distribution of brightness along ( 1 ) and across ( 2 ) axis of discharge of xenon lamps

The discharge cord of DC ball xenon lamps, when operating in a vertical position with the anode up, has the shape of a cone, resting with its tip on the tip of the cathode and expanding upward. A small cathode spot of very high brightness is formed near the cathode. The distribution of brightness in the discharge cord remains the same when changing the discharge current density in a very wide range, which makes it possible to construct uniform curves of the brightness distribution along and across the discharge (Figure 4). The brightness is directly proportional to the power per unit length of the arc discharge. The ratio of luminous flux and luminous intensity in a given direction to the arc length is proportional to the ratio of the power to the same length.

The emission spectrum of ultrahigh pressure xenon ball lamps differs little from the emission spectrum.

Powerful xenon lamps have an increasing current-voltage characteristic... The slope increases with increasing electrode spacing and pressure. The anode-cathode potential drop for short-arc xenon lamps is 9-10 V, with the cathode being 7-8 V.

Modern ultra-high pressure ball lamps are produced in various designs, including those with collapsible electrodes and water cooling. The design of a special metal collapsible lamp-lamp of the DKsRM55000 type and a number of other sources used in special installations has been developed.

Almost in parallel with the development of chemical light sources, electrical ones developed, and they appeared even a little earlier than gas burners.

In 1799, the Italian physicist Alessandro Volta created the first chemical current source, which was called the "voltaic pillar".

So, the next class of light sources is electrical, that is, devices that use electricity as a source of energy, and the energy source is not included in technical systems. The main classes will be:

Arc lamps, where, under the action of an electric discharge, gas glows between the electrodes;

Incandescent lamps, in which light is emitted by a heated filament;

Gas lamps, where a glow discharge is used, which is formed at low gas pressure and low current;

Electrodeless lamps (microwave);

LEDs.

Arc lamps

At first, systems began to evolve that used an electric arc. This phenomenon was observed simultaneously by H. Davy in England and V. Petrov in Russia, which once again confirms the inevitability of inventions. It is interesting to note that both the burning of an electric arc and the glow of a hot wire under the action of a current were observed in the same year.

However, it was only 42 years later that the French physicist Foucault created the first arc lamp with manual adjustment of the arc length, which was widely used. However, manual control was extremely inconvenient, and on the days of coronation celebrations in Moscow, arc lamps with automatic regulation of the distances between the coals were lit on the Kremlin towers - the brainchild of the inventor Alexander Shpakovsky (not to be confused with Nikolai!).

Soon Pavel Yablochkov improved the design by placing the electrodes vertically and separating them with an insulator layer. This design was called "Yablochkov's candle" and was used all over the world: for example, with the help of such "candles" the Paris Opera House was illuminated.

Arc lamps were, although bright, but not very economical, so incandescent lamps soon began their triumphant march. However, arc lamps did not disappear at all, but took their own, quite definite niche, which once again casts doubt on the conclusions about the "death of technical systems".

The main problem was the rapid combustion of the electrodes. More than once the inventors had the idea of \u200b\u200benclosing a voltaic arc in an oxygen-deprived atmosphere. After all, thanks to this, the lamp could burn much longer. The American Jandus was the first to come up with the idea of \u200b\u200bnot placing the entire lamp under the dome, but only its electrodes. When a volt arc occurred, the oxygen contained in the vessel quickly reacted with the hot carbon, so that a neutral atmosphere soon formed inside the vessel. Although oxygen continued to flow through the gaps, its influence was greatly weakened, and such a lamp could burn continuously for about 200 hours.

From the use of vacuum, they soon switched to the use of inert gases. Mercury and xenon arc gas-discharge lamps are now used as sources of particularly bright light.

Most gas-discharge lamps use radiation from the positive column of an arc discharge, in flash lamps, a spark discharge that turns into an arc. There are arc discharge lamps with low [from 0.133 N / m2 (10-3 mm Hg)], for example, a low pressure sodium lamp, high (from 0.2 to 15 at, 1 at \u003d 98066.5 N / m2) and ultra-high (from 20 to 100 atm and more, for example, xenon gas-discharge lamps) pressure.

The color of the received light depends on the substance, the vapor of which is in the lamp. Comparative characteristics gas discharge lamps are presented in the table.

Comparative characteristics of arc lamps

The low pressure sodium lamp is characterized by the highest efficiency of all light sources - about 200 lm / W.

Film "Arc lamp”Was filmed by XX Century Fox with the participation of United Pictures and was released on the US screens on December 27, 2012.
Its world premiere took place three days later. As it was easy to find out from magazines like Empire or Cinema, the film's budget broke the record of all three Terminators combined. The number of Oscar nominations announced six weeks later was greater than for Titanic: not only for special effects, but also for the main ones - for Best Film, Best Director, Best Cinematography "...
The fees of the first-plan actors were estimated at tens of millions of dollars. This was all the more revealing that surprisingly few really famous actors appeared in the film. In one of the numerous interviews that became part of the pre-release preparation organized by the film studios, the director said that this was due to the desire to show the world the faces not of "familiar stars", but "people like you and me." He himself was also a figure unexpected for a picture of this scale and with such a budget.
But the director, who had previously shot several that received limited popularity and hardly paid off, turned out to be really talented. The film grossed over a quarter of its gigantic budget on its first weekend in the US, Overseas Territories and Canada.
The second quarter was received over the next two days, which came almost perfectly - on New Year's Eve and the New Year itself. And this, too, was only collected from North American cinemas. By the time the Christmas / New Year holidays in Europe ended, that is, by Sunday January 6, 2013, the painting paid off almost entirely, and by January 9, it had already begun to make a net profit. It is significant that after a short period of decline by the beginning of the third week of distribution, there was even a slight tendency towards an increase in the number of viewers who decided to watch this film. But this was already a sign of his quality. It was becoming clear that Arc Lamp was one of the most successful films in the history of American and world cinema.
Published in 1984 and which became the basis for the script, Eric Harry's novel received not very favorable criticism at the time. In 2012-2013, its new, "enlarged cover" edition (copyright - Simon & Schuster) bought, according to some estimates, up to five percent of those who watched the movie, which in itself was an impressive figure. After interest in the film began to decline, the publisher threw the same book into the market in a standard pocket format, and then reprinted the second novel by the same author, Invasion, in a hurry to rake up the rest of the profit.
It must be admitted that the novel really was "nothing special." Until two-thirds of the links on Amazon and Barnes & Nobles, dating from the second half of the 1990s (that is, based on the text of the book), did not rate the novel above two stars. Factual errors, such as the mention of the M60 machine gun on the M1A1 Abrams tank (in fact, the M240 was installed in the place of the loader) and others, were corrected in the new edition, but that was not the point. The film gave the book not just a "second wind" - it breathed into it bright colors, terrible in their realism. The silent white flashes of nuclear explosions sweeping away the wheat fields of Oklahoma, turning the forests of Alaska cut by frozen rivers to glass - all of this was filmed and presented in such a way that the viewer's heart sank. Not a single monster from horror films, not a single alien with fangs and claws in all films of category "B" taken together did not cause such shock and fear that the strong-willed, courageous face of General Zorin caused the viewer, pressing the input button of the command to apply the "limited nuclear strike "on the United States ... A strike considered" retaliatory "after the Russians, who lost control of their own satellites, decided that the explosions of Chinese nuclear warheads over their country were an American strike. Bloody, savage in its ruthlessness putsch with armored personnel carriers crushing people on the streets of Moscow, the horror of the nameless, shown only for 5-6 seconds of a person who saw a shining white rising above the Fort Valley airbase projected against the horizon in silence a ball, but has not yet felt the tremor of the earth from the approach of a shock wave ... The audience has never seen this before, but this alone would never have written the "Arc Lamp" into history.
There were no expected cliches in the film. The Russian soldiers shown in it were not wearing earflaps and did not wear a Gold Star on their chest each. The American president was not black with the philosophically sad eyes of a sage: he was normal and similar to the real, just as everyone who played in this outstanding film looked like their conventional prototypes. A stunning drive that has been achieved so far by few people did not let go of everyone who came to the cinema hall, who bought a movie on a DVD disc, ordered it to be watched on pay channel cable television to the very end: to the massacre on the Far Eastern beaches, where "people like you and I" fell silently into the cold sand, trying to overcome the continuous river of current fire, to the battle on the Polish border, where the American army retaliated that no evil will remain unpunished until the breakthrough to Moscow, when for the first time the eyes of a ranger, blackened with fatigue and burning, leaned on the armor shield of the turret machine gun of the head "HAMVI" of the American column, looked at the towers of the old Russian fortress, pink from the evening sun.
The main message to the audience, which the filmmakers so successfully conveyed, was simple and accessible: "Russians cannot have nuclear weapons." Then, later, some began to count down from this very moment, from 12/27/2012, from the release of the film that has become so popular on the screens of American cinemas. In fact, it was, of course, nonsense.
The real and also by no means a preliminary countdown began many months earlier.

Such a movie DOES NOT EXIST in reality. This is in the alternative reality of S. Anisimov, he is present, invented by the author himself, and all of the above is an excerpt from the book "The Day Before the Day After Tomorrow", book 1