Welding machine yourself. How to make a welding machine with your own hands: a step-by-step description of how to calculate and assemble a welding machine (110 photos)

Now it is difficult to see any work with metal without the use of a welding machine. This device freely cuts or connects iron parts, regardless of its thickness and dimensions. To engage in welding, you need to have some skills, and, in fact, the device itself. You can buy it, you can hire a welder to carry out the necessary work, or you can make the unit yourself.

Standard scheme of the welding machine and its types

Before you start creating a welding machine at home, you should understand its structure.

The main element of the welder, of which it consists, is a transformer that feeds the arc of the apparatus, controls the alternating voltage and controls the quality and magnitude of the current.

The designs of standard welding machines are very diverse, but the following main types can be distinguished:

• AC apparatus;
• Working with direct current;
• Three-phase;
• Inverter.

Welding with direct current is usually used for working with thin sheet material, automotive and roofing steel.

DC and AC welding devices are reliable, unpretentious in operation, heavy in weight and very sensitive to voltage drops. If it falls below 200 volts, it will be difficult to work, there will be problems with ignition and arc support.

These welding machines are very similar in design, and if we have AC welding, then by modifying it a little, we will get a device for working with direct current.

As for inverters, thanks to the use of electronic parts, their weight has become much lighter. They are not afraid of voltage drops, but at the same time they are very sensitive to overheating. These devices must be handled with care, otherwise they may break.

Homemade AC welding machine

The AC welding unit is one of the most common models. It is the easiest to use and easy to assemble at home compared to other types of welders.

What is needed for this:

• Wires for secondary and primary winding;
• winding core;
• Step-down transformer (you can take "LATRA").

What wires are needed? The optimal voltage during the operation of the device, created independently, is 60V with the optimal current - 120 -160A. Based on this, we understand that the minimum cross-section of copper wires to wind the primary should be 3-4 square meters. mm. Optimal - 7 square meters. mm, which takes into account possible additional load and power surges.

Do not use wires in PVC or rubber insulation, as they can overheat and cause a short circuit.

If there is no wire of the desired cross section, you can use thin wires wound together. True, the thickness of the winding will increase, which will entail an increase in the dimensions of the apparatus itself. To make the secondary winding, you can take a thick copper wire, consisting of many strands.

The core for homemade is made from a transformer steel plate, the thickness of which should be from 0.35 mm to 0.55 mm. They must be folded so that a core of the required thickness is obtained, and then the device is bolted to the corners. At the end of the work, the surface of the plates should be treated with a file and insulation should be made.

Then the winding starts. First, primary (about 240 turns can be done). In order to be able to regulate the passing current, you need to make several taps with an approximate step of 20-25 turns.

How much copper is needed for the secondary winding? Usually the number of turns is 65-70. The cross section of the wire is 30 - 35 sq. mm. As with the primary winding, taps must be made to regulate the current. Wire insulation must be reliable and resistant to heat.

Winding is done in one direction and each layer is isolated. The ends of the winding are bolted to the plate and we can assume that the homemade welder is ready.

If you need to increase the current, a voltage boost can help in this matter, or you can do it manually by reducing the number of turns of the primary winding and switching the wire to a contact with a smaller number of turns.

When creating a welding machine, you must not forget to ground it, according to safety precautions. And also always make sure that the welding machine does not overheat!

Simple DC Welding Machine

For welding cast iron and stainless steel, you will need a machine with direct current. You can create it in 15 minutes if you already have an AC device. In this case, the existing device will be upgraded.

Alteration of the change will consist in connecting a rectifier to the secondary winding, which is assembled on diodes. Diodes, in turn, must withstand a current of 200 A and be well cooled.

The rectifier will do its job better if you use 50V capacitors and a special choke to regulate the current.

What you need to know when connecting the device to the network permanently:

• Be sure to use a knife switch, which at any time can disconnect the device from the network;
• The cross section of the wire for connection must be greater than or equal to 1.5 square meters. mm, and the current consumption in the primary winding is a maximum of 25 A.

The scheme of work of the welder is such that from time to time he needs to be given a rest. It doesn't matter if it's a semi-auto or a handbrake. However, if the device works on electrodes with a diameter of less than 3 mm, then you can not interrupt.

Inverter: how to make a welding machine with your own hands

The inverter itself can be assembled from small parts and wiring from a Soviet TV or vacuum cleaner.

Features of the inverter:

• The device works with direct current and its smooth adjustment from 40 to 130 A;
• The largest current for the primary winding is 20A, the electrodes used should be no more than 3 mm;
• The electric holder must have a button, by pressing which voltage will go into the device.

All elements of the inverter are located on a special printed circuit board, and for better heat removal from the diodes, they are fixed on a special heat sink, which is screwed to the board. The board itself is usually made of fiberglass, with an approximate thickness of 1.5 mm.

For additional cooling of the circuit, you can use a fan fixed directly to the case in which the inverter is located.

With the help of such an apparatus, you can safely cook non-ferrous and ferrous metals, blanks from a thin sheet.

Three-phase welding machines are usually used for welding in production conditions, so it does not make sense to make them at home.

Timval, Budyonny and thyristor welders are especially popular.

Tips on how to make a welding machine at home: spot welding

One of the most convenient and economical mini-welding has recently become spot welding, which takes place by contact. In everyday life, such a thing is used for repairing household appliances and welding batteries.

Heating occurs with the help of an impulse, and the impulse moment does not exceed one tenth of a second, that is, everything happens very quickly.

Such a mini-welding is created using a transformer from an old microwave oven, which will be finalized in the process of creating the apparatus. The goal is to be able to get a short-term pulse of at least 1000A at the output.

The processing goes like this:

• Everything is removed from the transformer except the core and primary winding;
• A wire with a cross section of at least 100 square meters is wound in place of the secondary winding. mm;
• The main thing here is to wind the wire very tightly around the core.

As a result, the output should be about 5 volts, but if the power is too low, you can take another transformer. Then you need to check the voltage again. If it is not more than 2000 A, the micro welding machine is ready for use.

When performing simple and small-scale welding work at home, everyone can assemble.

For assembly, you do not have to spend a lot of money, effort and time. Also, you do not need to purchase unreasonably expensive models of such equipment.

To make a mini welding machine with your own hands from improvised means, without much financial cost and effort, you need to understand how the equipment functions, after which you can start producing it at home.

First of all, it is worth determining the required current supply power of home-made equipment for welding. The connection of parts of a massive structure requires a greater current intensity, and welding work with thin metal surfaces requires a minimum.

The current value is related to the selected electrodes to be used in the process. When welding products up to 5 mm, it is necessary to use rods up to 4 mm, and in a design with 2 mm thickness, the rods should be 1.5 mm.

When using electrodes of 4 millimeters, the current strength is regulated up to 200 amperes, in 3 millimeters up to 140 amperes, in 2 millimeters - up to 70 amperes and for the smallest up to 1.5 millimeters - up to 40 amperes.

You can form an arc for the welding process yourself, using the mains voltage, which is obtained due to the operation of the transformer.

This equipment includes:

• magnetic circuit;
• winding - primary and secondary.

Also, the transformer can be made independently. For the magnetic circuit, plates made of steel or other durable material are used. The windings are necessary in order to directly perform welding work and be able to connect the welding unit to a 220 volt network.

Transformer for welding.

Specialized equipment has additional devices that improve the quality and power of the arc, which makes it possible to independently adjust the current values.

You should not go deep enough into this topic, since one of the easiest ways to assemble a do-it-yourself welding machine is.

Its feature is work with alternating current, which ensures the performance of a high-quality seam when welding metal surfaces. Such equipment can cope with any household work where it is necessary to weld metal or steel structures.

To make it you need to prepare:

1. Several meters of cable with a large thickness.
2. Material for the core, which will be located in the transformer.
   The material itself must have increased permeability with magnetization.

The best option is when the core in the form of a rod has the letter "P". In some cases, it is allowed to use this part in a more modified form, for example, a round stator made from a damaged electric motor.

Scheme of the device of the welding transformer.

However, it is worth paying attention that it is more difficult to wind the windings on this form. Best of all, when the core cross-section for classic do-it-yourself welding equipment used for domestic purposes had an area of ​​\u200b\u200babout 50 cm2.

In order for the equipment to have an affordable weight, it is not necessary to increase the cross section in volume, however, the technical effect will not be at the highest level. If the cross-sectional area does not suit you, then you can calculate it yourself using special schemes and formulas.

The primary winding must be made of copper wire, which will have enhanced characteristics: thermal resistance, since during the operation of the structure this part heats up very much.

Such a part must have cotton or fiberglass insulation. In extreme cases, it is possible to use insulated rubber wire or rubber cloth, but beware of PVC winding.

The insulation is also made by hand, using cotton or fiberglass, or rather, its parts are 2 cm wide. Thanks to these pieces, it will be possible to wrap the wire, and then impregnate it with any varnish with an electrical purpose. Such insulation will not overheat after regular operation.

Similarly to the above calculations, it will be possible to calculate which cross-sectional area of ​​\u200b\u200bthe winding - primary and secondary - will be the most optimal. Often the secondary winding has an area of ​​about 30 mm2, and the primary winding up to 7 mm2, using a rod 4 mm in diameter.

In addition, in a simple way, you need to determine how much a piece of copper wire will stretch and how many turns it will take to wind two windings. After that, the coils are wound, and the frame is made using the geometric parameters of the magnetic circuit.

The main thing is to make sure that there are no difficulties when putting on the magnetic circuit. First of all, you need to choose the right core size. It is best made using electrical cardboard or textolite.

Using the same analogy, it will be possible to make a structure for welding small parts. For the home, you can use a small “mini” welding machine.

Welding Machine Manufacturing

Today it is almost impossible and rather difficult to weld metal or process it in the proper way without using welding equipment. After you make a welding machine with your own hands, you can do any work with metal products.

Scheme of a transformer with a separate choke.

To make a high-quality unit, you need to have the knowledge and skills that will help you understand the circuit of a DC or AC welding machine, which are two options for assembling equipment.

For the purpose of home use, it is best to learn how to make mini welding.

It is more convenient to call a wizard or purchase a ready-made unit, but sometimes it can be too costly, since it is quite difficult to determine the number of volts per welding machine when choosing a model for various parameters, such as the weight for the welding machine.

There are several types of welding machines: working on alternating current, direct, having three phases or inverter. To choose one of the options and start the assembly, it is necessary to consider each scheme of the first 2 types. During the preparatory process, you need to pay attention to the voltage stabilizer.

On alternating current

To make home-made welding machines, you need to select a voltage indicator, the best is 60 volts, the current is best regulated from 120 to 160 amperes.

You can independently determine the cross-sectional value of the required wire for the manufacture of the primary winding of the transformer, which must be connected to a 220-volt network.

The cross section according to the area parameters should not be more than 7 mm2, since it is worth noting the possible voltage drop and possible additional load.

Based on the calculations, the optimal size of the diameter of the copper core for the primary winding, which reduces the action of the mechanism, is 3 millimeters. When choosing aluminum for the wire, the cross section is multiplied by a value of 1.6.

It is worth noting that the wires must be wrapped with a rag, as they must be insulated. The fact is that as the temperature rises, the wire can melt and a short circuit will occur.

In the absence of the necessary wire, it is possible to replace it with a slightly thinner residential wire, winding it in pairs. However, it must be remembered that the winding thickness will increase, due to which the dimensions of the welding equipment will be large. Under the secondary winding, a thick wire with a large number of strands of copper is used.

DC

Electrical circuit of a DC welder.

Some welding machines work with direct current. Thanks to this unit, it is possible to weld cast iron products and stainless steel structures.

It may take no more than half an hour to create a DC welding machine with your own hands. In order to convert homemade products with alternating current, it is necessary that the secondary winding be connected, which is assembled on a diode.

In turn, the diode must withstand a current of 200 amperes and have good cooling. To trim the current value, you can use capacitors that have certain characteristics and voltage features. After that, the unit is assembled sequentially according to the scheme.

Chokes are used to regulate the current, and contacts to attach the holder. Additional parts are used in the transmission of current from an external carrier to the welding site.

In order to operate the welding machine for its intended purpose, it is necessary, first of all, to kindle an electric arc. This process is easy and is carried out by the following actions: we bring the tip of the electrode under a certain slope from the side of the metal coating and strike it on the surface of the structure.

If the action is performed correctly and successfully, a small flash occurs, and the material is melted, after which the necessary elements can be welded.

When making a mini welding machine with your own hands, you must be guided by the recommendations for working with it. To weld elements, you need to hold the rod in such a position that it is at a certain distance from each other of the parts to be welded. This distance can be equal to the cross section of the selected electrode.

Often a metal such as carbon steel is connected with a direct polar current. However, some alloys can only be welded with reverse current polarity. In addition, it is necessary to carefully control the quality of the seam and how the structure is melted.

Scheme of a simple welding machine.

It is worth emphasizing that the alternating current, located, can be regulated efficiently and smoothly. Often, no difficulties arise with setting the unit to the required parameters.

With a small current strength indicator, the seam will come out of poor quality, but you should not set an increased value, as there is a risk of burning the surface.

If it is necessary to weld surfaces of small thickness, then the rods will fit with a size of 1 to 3 millimeters, while the current strength should vary with marks of 20-60 A. Using large-section electrodes, metal products up to 5 millimeters can be welded, however, in this case, the current should be 100 A.

Upon completion of the welding process, using a homemade product, it is necessary to carefully remove the scale with light movements that appears on the seam, after which it is cleaned with a special brush.

Thanks to this action, you will be able to maintain a pleasant aesthetic appearance of your device. Do not worry if the cleaning of the equipment does not work out very well in the first couple. This skill is gained through experience and subject to the implementation of all recommendations for the competent operation of the structure.

Outcome

Summing up, it is worth noting that DC welding machines are much easier to assemble and they are also easy to use, due to their low power.

According to experts, making a welding machine with your own hands is not difficult.

However, to make it, you need to have a clear idea for what, for what work it will be used.

A home-made device is completed and assembled from available components and parts. As an option for craftsmen, a plasma mechanism can also be considered.

Practice shows that with an accurate selection of components, the device will serve for a long time and reliably.

It is important that the electrical circuit is as simple as possible. Sometimes they even use a microwave transformer.

The device must be operated from a 220 V AC household mains.

If you choose 380 V as the operating voltage, then the circuit and design of the device will become noticeably more complicated.

Structural diagram of the welding machine

For the production of welding works, devices operating on alternating and direct current are used.

The circuit of any apparatus includes a transformer (it is possible to use a transformer from a microwave oven), a rectifier, a choke, a holder, an electrode. It is in this sequence that electric current flows through a closed circuit.

The circuit is completed when an electric arc occurs between the electrode and the metal pieces to be connected.

In order for the quality of the welded joint to be high, it is necessary to ensure stable burning of this arc.

And to set the required combustion mode, a current regulator is used.

DC machines are used for welding elements made of thin sheet metal. With this welding method, any electrodes and electrode wire without ceramic coating can be used.

The electrode holder is connected to the rectifier through a choke. This is done in order to smooth out voltage ripples.

The inductor is a coil of copper wires, which is wound on any core. The rectifier, in turn, is connected to the secondary winding of the transformer.

The transformer is connected to the household electrical network. The connection sequence is simple and clear.

AC voltage conversion is performed using a step-down transformer.

According to Ohm's law, the voltage that is induced on the secondary winding of the transformer decreases, and the current increases from 4 amperes to 40 or more.

Approximately this value is required for welding. In principle, this device can be called the simplest welding machine.

And with the help of wires, attach the electrode holder to it. But it is impossible to use the holder for practical purposes, since the circuit does not contain other necessary elements.

And most importantly - it does not have a current magnitude regulator. As well as a rectifier and other elements.

The transformer is considered the main element of the welding machine. It can be bought or adapted already used.

Many craftsmen use a transformer from a microwave oven that has served its time. Due to its dimensions and weight, the micropulse element always takes up a lot of space in the structure.

If we consider the welding unit as a whole, then we can distinguish three main blocks that it includes:

• power unit;
• rectifier block;
• inverter block.

A home-made inverter apparatus can be arranged in such a way that it has minimal dimensions and weight.

Such devices, designed for use in the household, are now sold in stores.

The advantages of the inverter apparatus over traditional units are obvious. First of all, it should be noted the compactness of the device, ease of use, reliability.

Only one component in the parameters of this device is of concern - its high cost.

The most general calculations confirm that making such an apparatus with your own hands is easier and more profitable.

The main elements, in practice, can always be found among electrical machines and devices that ended up in storerooms. Or in a landfill.

The simplest current regulator can be made from a piece of heating coil, which is used in household electric stoves. Choke - from a piece of copper wire.

Radio amateurs came up with the simplest pulse welding method according to the scheme. It is used to attach wires to a metal board.

No complicated fixtures - just a choke and a couple of wires. The current regulator is also not needed. Instead, a fusible link is included in the circuit.

One electrode is connected to the board through a choke.

As the second, a crocodile clip is used. The plug with wires is included in the socket of a household network.

The clamp with the wire is sharply applied to the board in the place where it needs to be welded. A welding arc occurs and at this moment the fuses in the electrical panel may blow.

This does not happen because the fusible link burns out faster. And the wire remains securely welded to the board.

Product package

Homemade is going to do small jobs in the household.

All elements, electronic devices, wires and metal structures must be assembled in a specific place. Where the product will be assembled.

The choke can be used from the fittings of a fluorescent lamp. The number of wires, preferably copper, of different sections, you need to stock up more.

If the throttle in finished form could not be found, then it must be made independently.

This will require a steel magnetic circuit from an old starter and several meters of copper wires with a cross section of 0.9 squares.

Power Supply

The main element of the power supply in the inverter is a transformer.

It can be converted from a laboratory autotransformer or used to remake a microwave oven transformer that has already served its time.

It is very important not to damage the primary winding when removing the transformer from the microwave oven.

The secondary winding is removed and redone. The number of turns and the diameter of the copper wires are calculated depending on the pre-selected power of the welding machine.

The spot welding method is well implemented by an apparatus made on a microwave transformer.

The rectifier is used to convert AC voltage to DC voltage. The main elements of this device are diodes.

It is switched into certain circuits, most often bridges. An alternating current is supplied to the input of such a circuit, and a direct current is removed from the output terminals.

Diodes are selected with such power to withstand the initially specified loads. For their cooling, special radiators made of aluminum alloys are used.

When marking the installation board, it is advisable to provide a place for a choke, which is designed to smooth out the pulses. The rectifier is assembled on a separate board, from getinax or textolite.

Inverter block

The inverter converts the direct current coming from the rectifier into alternating current, which has a high oscillation frequency.

The conversion is performed using electronic circuits on thyristors or powerful transistors.

If a voltage of 220 volts with a frequency of 50 Hz is applied to the input terminals of the transformer, then a direct current of up to 150 amperes and a voltage of 40 volts is fixed at the output terminals of the inverter.

These current parameters allow you to weld metal parts from various alloys.

The electronic regulator allows you to select the mode corresponding to a particular operation.

Practice shows that a home-made welding machine, in terms of its characteristics, is not inferior to factory products.

Some time ago, welding mini inverters appeared in the trading network. It took years for manufacturing companies to achieve this miniaturization.

While craftsmen have long been able to make a do-it-yourself plasma welding machine.

This step was prompted by local conditions - tightness in the workshop and the significant weight of factory inverters. A plasma machine is a great way out of this situation.

And the fact that instead of copper wires the secondary winding of the transformer is made of copper sheet has also long been known.

Assembly sequence of the welding machine

When placing elements on a metal or textolite basis, a certain order must be observed. The rectifier must be located near the transformer.

The inductor is on the same board as the rectifier. The current regulator must be located on the control panel. The body of the apparatus can be made of sheet steel or aluminium.

Or adapt the chassis from an old oscilloscope and even a computer system unit. It is very important not to "sculpt" the elements as close to one another as possible.

It is imperative to make holes in the walls for the installation of cooling fans and a constant flow of air.

The board with thyristors and other elements is placed as far as possible from the transformer, which gets very hot during operation. Just like a rectifier.

The welding machine is used in some types of body work to connect metal parts. However, work using these devices is usually carried out in the presence of serious damage to the body, which are relatively rare. Therefore, it is not advisable to purchase a new relatively expensive device for one-time use. For domestic use, you can make a welding machine with your own hands.

Peculiarities

It should be borne in mind that it is profitable to manufacture a welding machine on your own only if there are some initial components. This is because, although it is not difficult to assemble the simplest model of the device in question, the materials required for this are very expensive. Therefore, if you purchase them separately specifically for the manufacture of this device with your own hands, in terms of the final cost it may turn out to be close to a new branded tool, which, of course, will surpass the home-made welding machine in terms of technical characteristics.

The basis of the tool in question is a transformer that serves as a source of energy. It consists of two coils of copper wire wound on a metal core. Moreover, the coils differ in the number of turns. The one that is connected to the mains is called the primary. In the secondary coil, a current of less voltage, but more amperage, arises due to induction.

It should be borne in mind that a welding machine with a low amperage produces poor quality welding, while an excessively high amperage leads to burning of the electrodes and cutting the metal.

The welding machine can be equipped with a transformer, for example, from a microwave oven. However, since a voltage of about 2000 volts appears on its secondary winding, it is necessary to make some changes to the design with your own hands in order to lower the voltage, namely, to reduce the number of turns.

To reduce the voltage, the secondary winding is sawn in two places and pulled out of the coil. In this case, care must be taken not to damage the primary winding. Then the secondary winding is rewound with a thicker wire or a PEV wire with enamel insulation or thermal paper 0.05 mm thick. It is advisable to use the third option, as this avoids the appearance of the skin effect, which manifests itself in the case of using a conventional wire. It consists in the displacement of high-frequency currents, which leads to overheating of the conductor.

The created winding is covered with thin-insulating varnish. Parameters such as number of turns and thickness are calculated for each transformer model. However, the optimal values ​​are also derived: the thickness of the winding is 0.3 mm, the width is 40 mm, the thickness of the wire is 0.5-0.7 mm.

If there is no transformer from a microwave oven or any other device, you can assemble it yourself. This will require a core with a cross section of 25-55 cm² made of transformer iron, which is characterized by high magnetic permeability, a copper wire several tens of meters long, and insulating materials.

As for the wire, heat-resistant copper wire with fiberglass, cotton or, in extreme cases, rubber insulation is considered the best option. You can make your own insulation. To do this, cut the insulating material into strips of 2 cm and wrap the wire around them.

The final stage is impregnation with electrical varnish. The better the insulation, the lower the possibility of overheating the tool. The winding parameters are calculated based on the technical characteristics of the device. The open-circuit output voltage of a home-made welding machine ranges from 60 to 65 V, the operating voltage is from 18 to 24 V. At the highest power and an electrode with a diameter of 4 mm, the power in the secondary winding is 3.5-4 kW, in the primary - about 5 kW , taking into account losses. The current in this case is about 25 A.

The number of turns is determined on the basis of voltage, taking into account the cross-sectional area of ​​\u200b\u200bthe core of the magnetic circuit of 2 cm. For 1 V with a high-quality wire, there are 0.9 - 1.1 turns. The total is obtained by dividing the voltage level by the frequency. In this way, the indicators for both windings are calculated. Based on this, you can determine the required length of wire by multiplying the length of one turn by their total number. In this case, you need to take some stock.

Before winding the coils, it is necessary to make frames from textolite or electrical cardboard, which are freely put on the core. Between the primary and secondary windings, it is necessary to lay insulation in the form of fiberglass, electrical or ordinary cardboard.

Frame

The welding machine should be equipped with a housing in which the transformer is placed to protect it from external factors. When choosing or manufacturing it, it must be taken into account that due to electromagnetic radiation, not all materials are suitable for this. The best options are considered to be a fully curved rigid steel case or a case made of dielectric materials. The second option is more difficult to find or assemble with your own hands, besides it is less durable, but it avoids vibration and energy loss in the structural elements of transformers caused by eddy currents, which are excited by strong stray magnetic fields near the windings.

In cases made of other materials, these negative phenomena can be somewhat reduced (by 30-50%, depending on the design and material of the case), if longitudinal cuts are made on the case.

Most homemade welding tools do not have a one-piece body. This avoids problems associated with it, such as vibrations, eddy currents and energy losses. However, in this case, the welding machine is exposed to external factors, which leads to a sharp decrease in the reliability and safety of work. In addition, it must be taken into account that the above-mentioned losses amount to a few percent, which is almost imperceptible against the background of resistance in power lines and voltage fluctuations in the network.

In addition, it is desirable to equip the machine with secondary voltage regulation for smooth regulation of the welding current. This will compensate for losses in long wires, which is especially important when working away from the mains. In branded tools there is a step voltage adjustment by switching the windings. A home electric welding machine can be equipped with a voltage rectification circuit built on thyristors.

A do-it-yourself welding machine, in most cases, is not as reliable as a branded counterpart. Therefore, in the manufacture should take some measures to improve it.

Overheating is considered the main factor leading to premature failure of the devices in question. To reduce the possibility of its occurrence, first of all, it is necessary to make effective insulation. This requires reliable winding wires with a current density of up to 5-7 A / sq. mm. However, this may not be enough.

For rapid cooling of the wire, it is necessary to ensure interaction with air. To do this, you need to make slots in the windings. After the first layer of wire and every two subsequent layers, getenax or wooden planks of 5-10 mm are inserted from the outside.

This ensures that each layer of wire is in contact with air on one side. If the welding machine does not have fans, the slots are oriented vertically to ensure constant air circulation. In this case, cold air enters from below, warm air goes up.

A more efficient option for providing cooling to the transformer of the welding machine, of course, is a fan. Its blowing has almost no effect on the heating rate, but significantly accelerates cooling. However, it should be borne in mind that for a transformer with closed windings, the problem of overheating will not be solved even when a powerful fan is installed. In this case, it can be avoided only by a moderate mode of operation.

There is another solution to the problem of transformer overheating. It consists in immersing it in transformer oil. This liquid not only removes heat, but also is an additional insulator. In this case, the transformer housing must be a sealed container.

The most problematic in terms of overheating are toroidal transformers. They heat up quickly and cool down slowly. Also, a rather serious problem of home-made transformers is the vibration that occurs during operation due to the attraction of metal elements by the alternating magnetic field they create. Because of this, friction of the wires occurs, which leads to the destruction of the insulation, as well as the destruction and punching of the windings at the corners of the frame. To reduce the effects of vibration, it is necessary to make high-quality insulation. It is also necessary to firmly fix all fixed elements.

Avoid storage and use of the welding machine in high humidity conditions. Water condensing in the cracks of the insulation is a current conductor. The tool must be checked before use. If the voltage goes beyond 60 - 65 V, increase or decrease the winding.