All sciences. №4, 2023
International Scientific Journal

Authors: Aliyev Ibratjon Xatamovich, Karimov Boxodir Xoshimovich, Karimov Shavkat Boxodirovich, Usmonov Yakub Usmonovich, Axmedov Tursun Axmedovich, Yuldoshaliyev Dilshod Quldoshaliyevich, Sayitov Shavkat Samiddinovich, Xolmatov Erkinjon Soliyevich, Obidov Foziljon Oripovich, Abdusalyamova Tilloxon, Karimova Dilorom Shavkatovna, Tulyaganov Abdumannop Abdujabbarovich, Baratov Mirodiljon Xamudjanovich, Begatov Jasurbek, Qo'shqorov Ahliddin Mirzoxidovich, Raxmonjonov Xasanboy, To'xtasinov Maqsadjon Murodjonovich

Editor-in-Chief Ibratjon Xatamovich Aliyev

Illustrator Ibratjon Xatamovich Aliyev

Illustrator Obbozjon Xokimovich Qo'ldashov

Illustrator Sultonali Mukaramovich Abduraxmonov

Illustrator Boxodir Xoshimovich Karimov

Cover Designer Ibratjon Xatamovich Aliyev

Cover Designer Ra'noxon Mukaramovna Aliyeva

Cover Designer Boxodir Xoshimovich Karimov

Scientific supervisor Boxodir Xoshimovich Karimov

Deputy Scientific Director Sultonali Mukaramovich Abduraxmonov

Economic Manager Farruh Murodjonovich Sharofutdinov

Economic Consultant Botirali Rustamovich Jalolov

Proofreader Gulnoza Muxtarovna Sobirova

Proofreader Abdurasul Abdusoliyevich Ergashev

Proofreader Ekaterina Aleksandrovna Vavilova

© Ibratjon Xatamovich Aliyev, 2023

© Boxodir Xoshimovich Karimov, 2023

© Shavkat Boxodirovich Karimov, 2023

© Yakub Usmonovich Usmonov, 2023

© Tursun Axmedovich Axmedov, 2023

© Dilshod Quldoshaliyevich Yuldoshaliyev, 2023

© Shavkat Samiddinovich Sayitov, 2023

© Erkinjon Soliyevich Xolmatov, 2023

© Foziljon Oripovich Obidov, 2023

© Tilloxon Abdusalyamova, 2023

© Dilorom Shavkatovna Karimova, 2023

© Abdumannop Abdujabbarovich Tulyaganov, 2023

© Mirodiljon Xamudjanovich Baratov, 2023

© Jasurbek Begatov, 2023

© Ahliddin Mirzoxidovich Qo'shqorov, 2023

© Xasanboy Raxmonjonov, 2023

© Maqsadjon Murodjonovich To'xtasinov, 2023

ISBN 978-5-0060-3821-9 (т. 4)

ISBN 978-5-0059-5900-3

Created with Ridero smart publishing system

PHYSICAL AND MATHEMATICAL SCIENCES

OPTICAL AND SOUND MEMORY IN LITHIUM NIOBATE CRYSTALS

UDC 535.215.31

Karimov Boxodir Xoshimovich

Candidate of Physical and Mathematical Sciences, Associate Professor of the Faculty of Physics and Technology of Fergana State University
Karimov Shavkat Bakhodirovich
Candidate of the Faculty of Physics and Technology of Fergana State University
Aliev Ibratjon Xatamovich
3rd year student of the Faculty of Mathematics and Computer Science of Fergana State University

Ferghana State University, Ferghana, Uzbekistan

Annotation. PHOTOEDC (or photovoltage) in semiconductors, regardless of its nature, cannot exceed the band gap width, i.e. several volts/cm.

Keywords: PHOTOEDC, photovoltaic current, crystals without a center of symmetry, semiconductors, third-rank tensors, Fermi-level energies.

Аннотация. Фото-ЭДС (или фотонапряжение) в полупроводниках независимо от ее природы не может превышать ширину запрещенной зоны, т.е. несколько Вольт/см.

Ключевые слова: фото-ЭДС, фотовольтаический ток, кристаллы без центра симметрии, полупроводники, тензоры третьего ранга, энергии уровня Ферми.

For example, in a homogeneous semiconductor, the Dember (diffusion) photo voltage for an arbitrarily high intensity of exciting light does not exceed the value [1].

(1)

where Eg is the band gap of the semiconductor, n1 and n0 are, respectively, nonequilibrium and equilibrium carrier concentrations, Nc is the density of states.

Another example is the resulting photovoltage during illumination of the p-n junction [2].

(2)

which also does not exceed Eg. Here nn and pp are, respectively, electron concentrations in the n—region and holes in the p—region. EFn and EFp are Fermi—level energies in the n— and p-regions.

The exception to this rule was only semiconductor textures in which the effect of abnormally high photo voltages (AFN effect) is observed, due to the addition of elementary photo-EMF of the Dember (1) or elementary photo-EMF (2), developing at individual p-n transitions of the texture [3].

In such textures from sprayed layers of CdTe, Ge, Si, GaAs, PbS, CdSe, etc., photo voltages can reach values of the order of several hundred Volts per centimeter of length in the direction of addition of elementary photo-EMF (1) or (2).

In recent years it has become clear that currents are possible in thermodynamic nonequilibrium conditions of a different nature, due to the absence of a center of symmetry environment. The most important of this class of effect is the anomalous photovoltaic effect (AF effect).

The AF effect is that with uniform illumination of a short-circuited ferroelectric, a stationary current flows through it, which in [4,5] was called photovoltaic. It has been shown that it is the photovoltaic current that leads to the anomalous photovoltaic effect (AF effect) in ferroelectrics.

The anomalous photovoltaic effect detected for ferroelectrics for the first time in [4,5] is a special case of the AF effect described for crystals without a center of symmetry by the third rank aijk tensor [5,6]:

(3)

According to (3), with uniform illumination by linearly polarized light of homogeneous crystals without a center of symmetry (ferroelectric, pyro, or piezoelectric crystal), a photovoltaic current Ji arises in it, the sign and magnitude of which depend on the orientation of the polarization vector of light with projections EJ, EK*.

The components of the aijk tensor are nonzero for 20 acentric symmetry groups. If the electrodes of the crystal are opened, the photovoltaic current Ji generates photovoltaic voltages

where σt and σf, respectively, are dark and photoconductivity, l is the distance between the electrodes. Generated photovoltage in crystals without a center of symmetry of the order (103—105). In/see In accordance with (3) and the symmetry of the point group of the crystal, expressions can be written for the photovoltaic current Ji. Comparison of the experimental angular dependence Ji (b) with (3) makes it possible to determine the photovoltaic tensor aij or the photovoltaic coefficient

(a* is the light absorption coefficient).

In [10], the photovoltaic coefficient in lithium niobate crystals of the order K = (2-3) * 10—9A * cm* (W) -1 was determined.

This paper reviews and discusses photovoltaic, optical (photorefractive) and sound memory in lithium niobate crystals.

Use in holographic recording in LiNbO3:Fe gives advantages. In this case, the recording is carried out by the photovoltaic effect (FE) corresponding to the photovoltaic current.

Lithium niobate is widely used in holography and storage devices due to its excellent ferroelectric and piezoelectric properties. Just as magnetic materials «remember» the magnetic field, ferroelectrics can «remember» the electric field under certain conditions.

1. OPTICAL MEMORY IN LITHIUM NIOBATE CRYSTALS

The effect of nonequilibrium carriers on birefringence in ferroelectric and piezoelectric crystals has been called the photorefractive effect (FR effect) in the literature and has found wide use for the registration of volumetric holograms. The FR effect is as follows. As a result of local illumination of a ferroelectric or piezoelectric crystal by intense transmitted light (focused laser beam), a reversible change in birefringence occurs in the crystal volume inside the light beam, mainly due to a change in the refractive index of the extraordinary beam ne. The magnitude of this change reaches 10-4 -10-3 for some pyroelectrics (LiNbO3 LiTa03), and its lifetime can vary widely, from milliseconds in BaTiO3 to months in LiNbO3. The hologram is recorded due to the volumetric modulation of the Dn value corresponding to the modulation of the recording beam. The recording resolution is exceptionally high, 102-104 lines/mm. [7, 9].

The main advantage of this optical memory method in comparison with photographic layers is the possibility of parallel recording, reading and erasing.

As shown by the sign, and the magnitude of the photovoltaic current depends on the symmetry of the crystal and the polarization of light. Photovoltaic current leads to the generation of abnormally large photovoltaic voltages in the same direction. Thus, during the exposure time t, a macroscopic field appears in the crystal.

(5)

Due to the linear electric effect, the field leads to the FR effect:

(6)

where rij are electro—optical coefficients. Equation (6) is written in the main coordinate system. After illumination, the field remains in the crystal for a long time due to the capture of nonequilibrium electrons and holes. This capture mechanism is responsible for optical memory.

Use in holographic recording in LiNbO3:Fe gives advantages. In this case, the recording is carried out by the photovoltaic effect (FE) corresponding to the photovoltaic current. The generated photon voltage of the order (103-105) V/cm is responsible for the optical memory in LiNbO3:Fe crystals.

Erasure can be carried out by annealing the crystal at 1700C. There are other methods of erasing.

2. SOUND MEMORY IN LITHIUM NIOBATE CRYSTALS

Slightly yellowish single crystals of lithium niobate LiNbO3 have been used in technology for quite a long time. This is a surprisingly "talented" material: ferroelectric (its permittivity depends on the electric field strength, temperature and pre-polarization). The crystal contains special microscopic regions – ferroelectric domains that differ in the direction of polarization. The dimensions of the domains are 10-7-10-5 m, or 0.1—10 microns. By acting with an electric field, the domains can be moved around the crystal, in a strong field, the direction of polarization of all domains can be made the same (the crystal becomes monodomain). When the temperature rises to a certain value, the ability to polarize and form domains disappears. Lithium niobate has a very high temperature (Curie point) of 1210°C. Polarization occurs as a result of the mismatch of the "centers of gravity" of positive and negative charges in the crystal, a small and consistent displacement of ions from the position at which the charges completely compensate each other.

Physicists from the University of Mississippi M. McPherson, I. Ostrovsky and M. Breazil. studying the passage of short pulses of ultrasound through a thin plate of lithium niobate (LiNbO3), a new physical effect of "sound memory" in crystals was discovered [11].

Unexpectedly, scientists discovered that another ultrasonic signal with the same frequency and phase is emitted by the crystal seventy milliseconds after the passage of the main pulse. The study showed that the volume of the "echo" depends on the temperature of the crystal and the frequency of ultrasound. The effect is maximal at 26 megahertz and disappears at temperatures above 75 degrees Celsius, but it was reproduced at lower temperatures.

The acoustic quirk of lithium niobate may be related to its very unusual and extremely useful electrical properties: when compressed, it creates an electric field. Electric fields change the trajectory of light passing through it. Therefore, the substance is used in fiber-optic communication media and in holographic memory.

Each lithium niobate crystal consists of patches of so-called ferroelectric domains. Brizil suspects that the frequency of the delayed echo generated by the crystal is related to the size of these domains, which determine the suitability of the material for various purposes.

Just as magnetic materials "remember" the magnetic field, ferroelectrics can "remember" the electric field under certain conditions. This feature is widely used in the manufacture of electromagnetic detectors and other devices.

According to scientists, it is closely related to the properties of domains (regions with the same electrical polarization) inside the crystal and is explained by the formation and subsequent relaxation of electric charges near the boundaries of the domains.

The effect has not yet found a reliable theoretical explanation and needs to be rechecked, but it is already clear that it can be successfully used to control the quality of lithium niobate plates.

It appears that lithium niobate stores sound energy temporarily. How this happens is not yet clear, but researchers and we note that the sound wave compresses the substance through which it passes. This creates electric fields in the crystal, which moves the electrically charged atoms that the crystal contains. When the incoming sound from the outside stops, the ions return back, but not all in the same direction – the movement is divided by domains that define the boundaries at which the direction changes.

According to the law of conservation of energy, when the ions return, they release the received energy in the form of a delayed acoustic wave. This makes every domain sound. A stronger echo is associated with the resonance frequency of the domains, which depends on their size.

It is assumed that the magnitude of the echo depends on the concentration of domains and that the effect can be used to determine the quality of crystals. What the actual nature of the effect is remains to be seen.

Maybe the stones will really talk?

CONCLUTION

This paper reviews and discusses photovoltaic, optical (photorefractive) and sound memory in lithium niobate crystals. Coefficients in lithium niobate crystals of the order K = (2-3) × 10—9A ×cm× (W) -1.

Use in holographic recording in LiNbO3: Fe. gives advantages. In this case, the recording is carried out by the photovoltaic effect (FE) corresponding to the photovoltaic current. The generated photon voltage in LiNbO3:Fe crystals of the order (103-105) V/cm is responsible for optical memory.

Lithium niobate is widely used in holography and storage devices due to its excellent ferroelectric and piezoelectric properties. Just as magnetic materials «remember» the magnetic field, LiNbO3 ferroelectric can «remember» the electric field under certain conditions.

LITERATURE

1. Ryvkin. S. M. Photoelectric phenomena in semiconductors. M.: Fizmatgiz. 1963. 494C.

2. Bub R. Photoconductivity of solids. M.: ILL. 1962. 558C.

3. E.I.Adirovich. Photoelectric phenomena in semiconductors and optoelectronics. Tashkent: Fan. 1972. 343 P.

4. Glass A.M., Voh der Linbe D., Nerren T.J.//High- voltage Bulk Photovoltaic effect and the Photorefractive process in LiNbO3. J. Appl. Phys. Let, 1974. N4. v.25. p.233-236.

5. Fridkin V. M. Photosegnetoelectrics. M.: Nauka. 1979. pp.186—216.

6. V.I. Belinicher. Studies of photovoltaic effects in crystals. Diss. for the job application. Doctor of Physical and Mathematical Sciences. Novosibirsk. 1982. 350S.

7. Levanok A. P., Osipov V. V. Mechanisms of the photorefractive effect. // Izv. An. Russia, 1977. Vol.41. No. 4. C.752—769.

8. Sturman B. I., Fridkin V. M. Photovoltaic effects in media without an inversion center. M.: Nauka. 1992. 208 P.

9. Friedkin V. M. //Volumetric photovoltaic effect in crystals without a center of symmetry. Crystallography. 2001. Vol. 46 No.4. pp.722—726.

10. Fridkin V. M., Magomadov R. M. Anomalous photovoltaic effect in LiNbO3: Fe in polarized light. //w. Pisma ZhETF. 1979.t30.P.723-726.

11. Encyclopedia. The entry was published on 27.09.2002 at 00:00 in the following headings: …news archive 2002—2007.

TECHNICAL SCIENCES

TECHNOLOGY OF OBTAINING AND STUDYING A FILM THERMOGENERATOR

UDC 621.362

Yuldashaliev Dilshod Kuldoshalievich

lecturer of the Department of "Professional Education" of Fergana State University
Usmanov Yakub
Associate Professor of the Department of "Professional Education" of Fergana State University
Akhmedov Tursunakhmedovich
Associate Professor of the Department of "Professional Education" of Fergana State University
Karimov Bahodir Hashimovich
Associate Professor of the Department of "Professional Education" of Fergana State University

Ferghana State University, Ferghana, Uzbekistan

Annotation. The Seebeck effect (thermo-EMF) is used to convert thermal energy into electrical energy. The transfer of heat by electric current (Peltier effect) underlies the action of solid-state cooling and thermostatic devices. Thermoelectric energy converters have unique combinations of design and operational characteristics, such as the absence of moving parts, working fluids and gases, high reliability, the ability to operate for several years without maintenance or with minimal periodic maintenance, etc.

Keywords: thermogenerator, thermoelements, Peltier effect, thermoelectric materials, film thermogenerator, thermo-EMF, application of film thermogenerator.

Аннотация. Эффект Зеебека (термо-ЭДС) используется для преобразования тепловой энергии в электрическую. Перенос тепла электрическим током (эффект Пельтье) лежит в основе действия твердотельных охлаждающих и термостатирующих устройств. Термоэлектрические преобразователи энергии обладают уникальными сочетаниями конструктивных и эксплуатационных характеристик, таких, как отсутствие движущихся деталей, рабочих жидкостей и газов, высокая надёжность, возможность эксплуатации в течение нескольких лет без обслуживания или при минимальном периодическом обслуживании и др.

Ключевые слова: термогенератор, термоэлементы, эффект Пельтье, термоэлектрические материалы, плёночный термогенератор, термо-ЭДС, применение плёночного термогенератора.

These advantages determine the variety of use of thermogenerators as power sources, mainly for autonomous systems – in space, in hard-to-reach areas of land and sea, etc. Thermoelectric refrigerators and thermostats are used in instrumentation, IR technology, medicine, biology, household appliances. There is also a wide range of applications of thermoelectric devices in measuring technology, thermometry, pyrometry, electrical measurements, etc.

Many of the tasks that practice sets for developers of thermoelectric devices can be successfully solved with the use of film thermogenerators (PTG). The obvious advantage of PTG is the ability to fundamentally increase the number of elements while maintaining the volume of the converter, and, if necessary, create microminiature devices. Small-sized power supplies, low-current micro-coolers and thermostats, highly sensitive and sufficiently low-inertia temperature and heat flow sensors, etc. can be manufactured on the basis of PTG. Vacuum technology significantly simplifies the assembly process and shortening the manufacturing time of thermogenerators, allows combining elements and circuits of radio and optoelectronics with thermoelectric devices in a single design and manufacturing in a single technological cycle.

The results of physical and technological research, design developments have made significant progress in the field of film thermoelectric converters.

To date, the fundamental possibility of creating PTGS with energy characteristics close to volumetric ones has been proven, the technology of their mass production has been developed, a number of devices based on them have been created. The new thermoelectric temperature and radiant flux sensors have an order of magnitude higher sensitivity.

The successes achieved in the creation of highly efficient PTGS will undoubtedly lead to their wide technical application, which in turn will require further development of physical and technological research, expansion of the front of design developments. In this regard, it is urgent to develop a technology for obtaining PTG and new design developments, as well as to investigate electro and thermophysical properties.

The working substance in modern thermoelectric converters are semiconductors, the selection and optimization of the properties of which are based on the theory developed by academician A.F.Ioffe. The quality of the material is characterized by thermoelectric efficiency z = α2 σ/χ, where α is the coefficient of thermo-EMF, σ and χ are their specific electrical and thermal conductivity. The higher the value of the dimensionless parameter zT (T is the operating temperature), the greater the efficiency of the thermogenerator.

The technology for producing a film thermogenerator is based on the thermal evaporation of semiconductor materials in vacuum or in an atmosphere of various gases.

The technological mode of obtaining a film thermogenerator depends on a large number of parameters, such as the temperature of the evaporator and the substrate, the thickness of the film, the composition and pressure of residual gases in the vacuum chamber, the conditions of thermal and chemical treatment of films after spraying. At the same time, each semiconductor material has its own optimal mode, and often small deviations from it even by one of the parameters lead to the disappearance of the thermal effect in the manufactured films. For this reason, the development of a technology for obtaining a film thermogenerator from a particular material requires a lot of experimental work, a large number of test spraying with successive variation of several technological parameters, their combinations and finding parameters specific to obtaining a tarmoeffect on films from this semiconductor material.

We have developed a technology for producing a thermogenerator from Bi-Sb materials.

Film thermogenerators were obtained by spraying a semiconductor material from a crucible in a vacuum of ~10-5 mmHg on various substrates (aluminum, honey, brass, iron, mica, sapphire and ceramics) heated from 20-250 ° C and located at an angle of 90 ° in the direction of the molecular beam.

An optimal mode has been developed and a substrate for a Bi-Sb-based film thermogenerator has been selected.

The resulting thermogenerators generate 60 mA and 50 mV at a temperature of 200-2500 C.

The front of design developments is expanding and the electro and thermophysical properties of the obtained thermogenerators based on Bi-Sb are being investigated.

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36. Aliyev I. H. The behavior of an electron in an atom. Exact science. – №63. Publishing house "Pluto". 2019. – pp. 37-39.

37. Aliyev I. H. Electron and its features. Exact science. – №71. Publishing house "Pluto". 2020. – pp. 2-5.

38. Aliyev I. H. Entangled micro-friends. «Uyda qoling!» shiori ostida «Oliy ta’lim islohorlari: yuruqlar, muammolar, yechimlar» mavzusidagi respublika miqyusida onlayn ilmiy maqolalar hamda innovatsion ixtirolar tanlovining ilmiy maqolalar to’plami. Tashkent. 2020. – pp. 164—178.

MATHEMATICAL MODEL FOR CONTROLLING THE FORCE OF PRESSING THE TERMINAL TO THE WINDOW IN THE SOLDERING PROCESS

UDC 004.94

Sayitov Shavkatjon Sameddinovich

Lecturer of the Department of "Electronics and Instrumentation" of the Faculty of Computer Design Systems of the Fergana Polytechnic Institute

Ferghana Polytechnic Institute, Ferghana, Uzbekistan

Annotation. Speaking of the necessary devices for the soldering process, it is definitely possible to note as such a device the soldering device itself, better known as a soldering iron and along with this is most often a hand tool used during tinning and soldering to heat parts, flux, melt solder and make it into the contact point of soldered parts. The working part of the soldering iron can be noted the tip, which is heated either by flame, a vivid example of this is heating from a blowtorch, or by electric current.

Keywords: soldering iron, soldering, mathematical apparatus, mathematical modeling, pressing force.

Аннотация. Говоря же о необходимых устройствах для осуществления процесса пайки, однозначно можно отметить в качестве такого устройства непосредственно само паяльное устройство, более известное как паяльник и наряду с этим чаще всего являющееся ручным инструментом, применяющийся при лужении и пайке для нагрева деталей, флюса, расплавления припоя и внесении его в место контакта спаиваемых деталей. Рабочей частью паяльника можно отметить жало, которое нагревается либо пламенем, яркий тому пример нагрев от паяльной лампы, либо при помощи электрического тока.

Ключевые слова: паяльник, пайка, математический аппарат, математическое моделирование, сила нажатия.

The main large types of such a device include two large classes of soldering irons with periodic or constant heating. The first class includes hammer and end soldering irons, which are a massive working tip mounted on a long metal handle, the length of which ensures safe operation of the tool. To perform this type of work, these soldering irons are equipped with special shaped tips or shaped stings. Such soldering irons are heated mainly from external heat sources, in the person of which fire from gas or gasoline burners can mainly act. This type of soldering iron is the oldest and has been known since ancient times.

The next type of soldering iron – arc, was quite popular in the XIX century, which follows from its name. And also another consequence of the name of this type is the use of a method for heating it to create an electric arc, periodically excited between a carbon electrode placed between the soldering iron itself and the tip. For example, an arc soldering iron can have a tip mass of 1 kg and heat up to 500 degrees Celsius, at a voltage of 24 Volts for 3 minutes, with a power consumption of about 1.5—2 kW.

Soldering irons with constant heating are more modern. These also include electric soldering irons with a built-in electric heating element that operates from the mains, that is, directly, or through a step-down transformer, or from batteries.

The gas type of soldering irons also works constantly, thanks to the built-in gas burner, where the combustible gas is supplied from the built-in canister, with pre-liquefied gas. However, although much less often, gas can be supplied via a hose from an external source. To another type of soldering irons, it is possible to include soldering irons on liquid fuel, which still have the honor to be called liquid fuel. They are similar to gas, but heating is already carried out by the flame of burning liquid fuel, which is also known.

Another type of soldering irons with constant heating can be attributed to thermal air types of soldering irons, in such types, parts are heated, and the solder melts by blowing them with a jet of hot air, which resembles an industrial hair dryer, but unlike it, a thin high-temperature air jet is used in this case. And also, along with this type, it is possible to bring very logically, correctly, the type cited is infrared.

In it, as can also be seen from the name, heating is carried out by an infrared radiation source. A variety of such soldering irons are infrared laser soldering irons. And if these were only the main varieties, then it is worth paying attention to the types of various soldering irons, which include soldering stations, rod and most often common soldering irons, pulse soldering irons and finally induction soldering irons.

Now, if you familiarize yourself with each of these types, it can be noted that the rapidly developing technology of miniaturization of electronic components, improvement in sensitivity to high temperature, as well as the use of lead-free solders with a higher melting point has led to the appearance of soldering stations with additional functions such as:

· The ability to select an arbitrary temperature, thermostating, or more precisely, the ability to hold a certain temperature of the tip, rapid heating, which occurs in less than 15 seconds;

· The possibility of using stingers of various shapes, allowing replacement literally on the fly;

· The presence of a standby mode with low temperature and auto-off with the use of a ball tilt sensor, also known as an accelerometer.

In such types of stations, one can also observe the fact that a film heater on a ceramic substrate placed in a sealed housing made of heat-conducting ceramics can be used as a heating element.

The main positive aspects of this type of heaters are a relatively long service life and reliable electrical insulation of the tip from the heating circuit. Along with this, it can also be noted the act of having such soldering systems with hot air, in which infrared radiation is mainly possible, they are more favorable for dismantling parts, due to which they are also equipped with special parts for solder suction or devices for automatic or semi-automatic solder and flux feeding. Speaking of a rod soldering iron, it can be pointed out that the design of the most common soldering iron in everyday life is very simple and is a metal casing equipped with a plastic or wooden handle, in which a tubular heating element, aka a heater, is placed.

Inside such a heater, a displaced copper rod is placed at one end, this is the sting sharpened on the protruding end. In general, taking the form of a cone or a dihedral angle. The end of the sting is a tinned working end.

The heater itself is a wire made of nichrome or another alloy with a high resistivity and resistance to oxidation at high temperature wound on a ceramic pipe or a metal pipe wrapped with sheet mica. In modern soldering irons of this type, a film heater mounted on a ceramic tubular base or a ceramic volumetric heater is most often used. The heater itself is connected to a live wire passing through the handle and connected to the mains or a step-down transformer.

A pulsed soldering iron is one of the varieties of a household soldering iron, sometimes presented in the form of a soldering gun, at the end of which there are 2 electrical contacts and almost always a source of illumination of the soldering zone. The contacts are connected to the secondary winding of the transformer located in the body of the soldering iron itself and surprisingly, the winding has only 1 or 2 turns of copper wire. A piece of thick copper wire with a thickness of about 1-2 mm and a length of 3-5 cm is attached to the terminals of these contacts, which is both a heating element and a soldering iron sting. When the tool is turned on, the secondary winding current, reaching several tens of amperes, quickly heats up the copper wire to the operating temperature in a few seconds.

In pulsed soldering irons, instead of a massive transformer operating at an industrial frequency of 50-60 Hz, a pulsed electronic converter is used, with a frequency of tens of kHz, which reduces their weight and dimensions, and therefore makes their use much more convenient, which is achieved in the end.

And finally, the last type of soldering iron – induction by its nature is based on the idea of heating by inducing electric currents with a high-frequency electromagnetic field created by an inductor coil. Inside the sting itself, in fact, there is a ferromagnetic core that heats up due to hysteresis losses and, to a lesser extent, due to eddy currents, most often referred to as Foucault currents. In such soldering irons, only the tip itself is heated, which allows you to make the soldering iron extremely light and miniature. Speaking of their thermal stabilization, it is worth saying that this is feasible either in the traditional way, for example, by thermocouples or thermistors, or by choosing the material of the ferromagnetic core at a Curie temperature equal to the required tip temperature.

And in order to understand how well the soldering process went, it is worth considering it in more detail, realizing that initially, as soon as the terminal is lowered, a layer of solder – tin is fed under it in a simplified model (a more complicated one will be considered later). Under the same layer there is a silver layer of a metal heater, and already under it a layer of rear-view glass.

Empirically, it was found that the energy of the gap between the silver layer and the glass is 100 N. It may follow from this that the sum of the rupture forces between the solder and the terminal, as well as between the solder and the silver layer, is less than this value, since if it were greater than or equal to this value, the terminal itself would have sufficient force to carry the entire system with it when it breaks. But it is also clear that for rupture, that is, for deformation by the elastic force (3.2.1), where stiffness is determined through the Young’s modulus (3.2.2), its energy is equal to the energy of destruction of the crystal lattice, that is, the product of the specific heat of melting and the amount of matter (3.2.3), is equal to the potential energy of deformation (3.2.4).

To determine the rupture force, which is already a priori the sum of the rupture forces between silver and solder, as well as between the terminal and solder, it is sufficient to use (3.2.5), where the distance is determined from the constancy of the area and the value of the volume change, which is calculated depending on the temperature (3.2.6), and from here the rupture force (3.2.7).

Now that the force of the rupture has been calculated, we can stop a little at the moment of pressing. From such a calculation, it became possible to determine that with a specific heat of 7.19 kJ/mol, with an amount of substance of the order of 0.0434 mol and 0.005149 grams and a density of the order of 7190 kg/m3, the area is 7.04424 *10-7 m2, with a side of 0.8393 mm, from which the temperature coefficient of 0.0042 K-1 is taken into account, with a resultant force of 99.99886267 N, that meets all the specified conditions.

Speaking of the pressing force, it can be noted that due to the attraction energy of the liquid flow of the alloy, it can be comparatively determined on the scale of the difference between the boundaries between the resulting force and the boundary force, from which a value of 0.001137328 N is obtained.

Used literature

1. Abdurakhmonov S. M., Sayitov S. S. Automated design for soldering the terminal of the rear window heating system of the car. Scientific-technical journal (STJ FerPI, FerPI ITJ, NTJ FerPI, 2021, Vol.23, special Issue No. 3), pp. 197-201.

2. Abdurakhmonov S. M., Sayitov G. S., Oshchepkova E. A., Rakhmonov D. H., Khuriboeva M. S. A new design for soldering the terminal of the rear window heating system the car. Current science. International Scientific Journal. Moscow, 2019 No. 9 (26), pp. 22-28.

3. Abdurakhmonov S. M., Sayitov S. S., Yuldasheva E. N. Automated soldering installation for terminal heating systems in auto-glass. Scientific-technical journal (STJ FerPI, FerPI ITJ, NTJ FerPI, 2021, Vol.25, No.6), pp. 256-259.

4. Abdurakhmonov S. M., Sayitov S. S. On the technology of soldering contact to heating systems of auto-glass // All sciences: international Scientific Journal. – 2022. – No.5, 2022. – pp. 95-115.

5. Toyirov N. S., Kholikov A. A., Sayitov S. S. Energy saving when using hybrid solar power plants in the oil and gas industry // All sciences: International Scientific journal. – 2022. – №6, 2022. – C. 253-260.

6. Akhmadzhonov A. E., Kholikov A. H., Sayitov S. S. Improving efficiency the use of thermal energy through the use of energy-efficient technologies at industrial enterprises // All Sciences: International Scientific Journal. – 2022. – №6, 2022. – 387-396 S.

7. Abdurakhmonov S. M., Sayitov S. S. Avtovil oynalarini isitish tizimlariga terminal kavshirlash technologiyasi tugrisida //. All Sciences: International Scientific Journal. – 2023. – №2, 2023. C. 22-32.

8. Evgeny Konstantinov. Get out of the twilight // Science and Life. – 2015. – No. 11. – pp. 112—119.

GENERAL OVERVIEW OF THE DEVICE AND THE PHYSICAL COMPONENT OF A DC ELECTROMAGNET

UDC 621.318.3

Kholmatov Erkinjon Salievich

Lecturer of the Department of "Electronics and Instrumentation" of the Faculty of Computer Design Systems of the Fergana Polytechnic Institute

Ferghana Polytechnic Institute, Ferghana, Uzbekistan

Annotation. The use of a powerful force, obedient, easy to handle, which is applicable in a variety of cases, which illuminates, heats, drives machines as forces of the most powerful attraction is a very topical issue that requires very detailed consideration. Of course, the image of such a performance is precisely the electromagnetic design, the physics of which is built from the initial ideas about electromagnetism. There is also a large number of phenomena of this kind, each of which requires its own analysis in all parameters. This paper is devoted to the description of the algorithm created at the moment for such cases.

Keywords: electromagnet, magnetic field, magnetic induction vector, magnetic field inductance, conductor, magnetic field strength, solenoid, Maxwell equations for electromagnetism, electromagnetic induction.

Аннотация. Использование могущественной силы, послушной, простой в обращении, которая применима в самых различных случаях, которая освещает, отапливает, приводит в движение машины в качестве сил мощнейшего притяжения весьма актуальный вопрос, который требует весьма подробного рассмотрение. Разумеется, образом такого исполнения является именно электромагнитная конструкция, физика которой строиться от первоначальных представлений об электромагнетизме. Существует также большое количество явлений подобного рода, каждая из которых требует наличие своего разбора по всем параметрам. Описанию созданного на данный момент алгоритма для таких случаем и посвящена настоящая работа.

Ключевые слова: электромагнит, магнитное поле, вектор магнитное индукции, индуктивность магнитного поля, проводник, напряжённость магнитного поля, соленоид, уравнения Максвелла для электромагнетизма, электромагнитная индукция.

Initially, it is worth noting that the design of the electromagnet itself consists of a core and, most often, a metal wire, due to good electrical conductivity. This design itself is also similar to an elementary resistor or load, the function of which it can also perform, due to the determined resistance according to the regularity (1).

If we analyze the physics of this process, it turns out that in this case the charges begin to move, provided that it is a direct current, attracted by an electric field, which is created due to the potential difference at the output and input of the electromagnet winding. And after its resistance has been determined, and also provided that the flowing amount of charge (2) is known, it is possible to determine the passing current (3), where the velocity of the flying particles due to a correspondingly small potential difference, otherwise it would cause too strong an increase in temperature, is equal to the thermal velocity (5) for of the classical form and in (6) for the relativistic formulation, calculated in terms of energy (4).

And, accordingly, after that, it will be possible to come to the regularity of determining this magnitude of the potential difference, through the data obtained thanks to (7—10).

However, when using such a design, not only the elementary function of the resistor comes into play, but also something else. Any charge has some parameters, namely the value in Coulombs, as well as the magnitude of the electric field that it creates around itself. By itself, a charge a priori cannot create such a substance as a magnetic field, the proof of which will be given below, but it can be generated by an electric field. In a stationary state, a charge also has this property, and when a large number of charges in a conductor begin to move, they, by definition, both create and are subject to this very electric field. As a result, a vortex magnetic field is created around this very conductor.

The electric field is subject to its measurement due to such a concept as intensity (12), which is characterized by the effect on the fields of a certain charge at a certain distance on the probe charge due to the Coulomb force (11).

The magnetic field has the same ability to calculate, for it this value is called magnetic induction, measured in units – Tesla, named after the great and most brilliant Serbian scientist of his time Nikola Tesla. Since the cause of the magnetic field was previously explained, its first definition is calculated using Maxwell’s equations and their consequences (13—16), which are discussed in more detail below.

In addition, if certain exceptions are made due to the property of the action of the magnetic field, in particular, and in statics, then the laws for them will be similar to Coulomb’s laws (17—18), and also in a certain field will be a consequence of the field geometry condition, which is initially assumed by the theorem of Mr. Andre Marie Ampere on the circulation of the magnetic field (19).

However, all these parameters were given only for a general view, but if we turn to specific examples, then first of all it is worth giving a definition of the magnetic induction vector of a straight wire with a known current and a known distance from it is determined by (20).

It is important to note that in order to determine the magnetic induction vector, it is necessary to determine the magnetic permeability of the medium – this is the parameter demonstrating the ability of a material to conduct a magnetic field. Practically the same can be said about such an object as a solenoid – a real electromagnet consisting of a spiral wire and a core, as mentioned above at the very beginning of the description.

And here, it is worth taking a closer look, because the pattern for determining magnetic induction for a solenoid looks like this (21).

In this case, the number of turns plays a big role, and on the one hand, it would be possible to make a conversion to (20) by approving the diameter for the spiral and taking into account all past indicators for magnetic permeability and flowing current (22), but this pattern will not be true, because in this case, a non-linear, namely, a rotational electric field, which creates a direct magnetic field directly inside the solenoid, leading to the correct formula (21).

Before continuing, it is worth noting an important point – if the field being created is variable by definition, it creates an alternating electric field, which in turn again creates a parasitic magnetic field, but already opposite to the first and relatively smaller in magnitude. Such an additional magnetic field reduces the effectiveness of the original magnetic field, therefore it is called a parasitic field, however, it also creates a parasitic field for itself, and then in turn for itself, etc. In sum, any alternating magnetic field consists of a large number of small moles, represented by its parent rows.

And since the magnetic field, unlike the electric one, always simply has to be closed, it closes around the solenoid, continuing further. It is in this way that a magnetic field is created, which has, in addition to the magnetic induction index, also an indicator of the magnetic field strength (23).

But since there is such a tension and the process of creating a magnetic field with the help of charges is explained, it is interesting to consider the reverse moment of the effect of the created magnetic field on the charges. It is worth pointing out here that for the formation of a magnetic field, you can also use natural magnets, with an initially high concentration of internal charges and their movements, due to the nature of the alloy itself, or by using other methods of changing the shape of the electromagnet, for example, using Hermann Helmholtz coils for various transformations, namely for the total modulus of magnetic field induction from the Bio-Savard-Laplace law (24) or (25) for a single turn or for n turns (26), for the case that the distance along the axis from the coil to the center is equal to half the radius (27), for two coils (28—29), or a round solenoid, the so – called type of electromagnet – toroid (30), provided that there is no magnetic field inside it, but it is only inside the rounded conductor on which the wire is wound.

Thus, if a free charge enters a magnetic field, then it falls under the influence of the magnetic induction force under the action of a certain Lorentz force (31), under the action of which, taking into account the created centrifugal force (32), the charge begins its rotation with a radius (33).

Moreover, there is also a relativistic form of recording the same pattern (34—35).

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