Welding machine inverter DIY repair

In detail: do-it-yourself inverter welding machine repair from a real master for the site my.housecope.com.

If you know how to repair welding inverters with your own hands, then you can fix most of the problems yourself. Possession of information about other faults will prevent unreasonable costs for service maintenance.

Welding inverter machines provide high quality welding with minimum professional skills and maximum welder comfort. They have a more complex design than welding rectifiers and transformers and, accordingly, less reliable. Unlike the aforementioned predecessors, which are mostly electrical products, inverter devices are a rather complex electronic device.

Therefore, in the event of a failure of any component of this equipment, an integral part of diagnostics and repair will be checking the performance of diodes, transistors, zener diodes, resistors, and other elements of the inverter's electronic circuit. It is possible that you will need to be able to work not only with a voltmeter, digital multimeter, and other ordinary measuring equipment, but also with an oscilloscope.

The repair of inverter welding machines also differs in the following feature: there are often cases when it is impossible or difficult to determine the faulty element by the nature of the malfunction and you have to consistently check all the components of the circuit. From all of the above, it follows that for a successful self-repair, knowledge in electronics (at least at the initial, basic level) and little skills in working with electrical circuits are required. In the absence of these, do-it-yourself repairs can result in a waste of energy, time and even lead to additional malfunctions.

Video (click to play).

An instruction is included with each unit, which contains a complete list of possible malfunctions and the corresponding solutions to the problems that have arisen. Therefore, before doing anything, you should familiarize yourself with the recommendations of the manufacturer of the inverter.

All malfunctions of welding inverters of any type (household, professional, industrial) can be divided into the following groups:

caused by the wrong choice of the welding operating mode;
associated with the failure or malfunction of the electronic components of the device.

In any case, the welding process is difficult or impossible. Several factors can cause a problem with the machine. They should be identified sequentially, moving from a simple action (operation) to a more complex one. If all the recommended checks are completed, but normal operation of the welding machine has not been restored, then there is a high probability of a malfunction of the inverter module electrical circuit. The main reasons for the failure of an electronic circuit are:

Ingress of moisture into the device - most often occurs due to precipitation (snow, rain).
Dust accumulated inside the housing interferes with the normal cooling of the electronic components. As a rule, most of the dust gets into the machine when it is used on construction sites. To prevent this from causing damage to the inverter, it must be cleaned periodically.
Failure to comply with the manufacturer's mode of continuity of welding work can also lead to failure of the inverter electronics as a result of its overheating.

Most often, malfunctions are associated with external factors, settings and errors in the operation of the inverter. The most typical situations:

The welding arc is unstable or the work is accompanied by excessive spatter of the electrode material. This occurs when the wrong choice of current, which must correspond to the diameter and type of the electrode, as well as the welding speed. The manufacturer of the electrodes indicates recommendations for the selection of the current strength on the packaging. In the absence of such information, it is worth using the simplest formula: apply 20–40 A per 1 mm of the electrode diameter. If the welding speed is reduced, the current should be reduced.

The welding electrode sticks to metal - this can be caused by several reasons. Most often this happens due to a too low supply voltage of the network to which the device is connected, and in the case of an inverter with the ability to work at a reduced voltage, the latter is reduced when the load is connected to a level lower than the specified minimum. Another possible reason is poor contact of the device modules in the panel sockets. It is eliminated by tightening the fasteners or tighter fixing of the inserts (boards). A voltage drop at the input of the device can be caused by the use of a power strip, whose wire has a cross section of less than 2.5 mm 2, which also leads to a decrease in the supply voltage of the inverter during welding. Also, the reason may be too long an extension cord (with an extension wire length of more than 40 m, efficient operation is generally impossible due to very large losses in the supply circuit). Sticking can occur due to the burning or oxidation of contacts in the power supply circuit, which also leads to a significant "sagging" of the voltage. This problem can also manifest itself in the case of poor preparation of the products to be welded (the oxide film significantly worsens the contact of the part with the electrode).

Image - Welding machine inverter DIY repair

The inverter is on, its indicators are on, but no welding. Most often this occurs due to overheating of the device, when the glow of the control indicator or lamp (if available) is hardly noticeable, and the inverter does not have a sound signal. The second reason is spontaneous disconnection of welding cables or their breakage (damage).

Turning off the mains voltage during welding - an incorrectly selected circuit breaker is installed in the electrical panel. This device must be rated for up to 25 A.

The inverter does not turn on - low voltage in the network, insufficient for the operation of the device.

Stopping the operation of the inverter during prolonged welding - most likely the temperature protection has tripped, which is not a malfunction. After a pause of 20-30 minutes, welding can be resumed.

Serious damage to the inverter module may be indicated by the smell of burning or smoke coming from the casing. In this case, it is better to seek help from service specialists. Do-it-yourself repair of welding inverters requires certain skills and knowledge.To identify and eliminate the cause of the malfunction, the body of the device is opened and its filling is visually inspected. Sometimes the whole point is only in poor-quality soldering of parts, wires, other contacts on the circuit boards, and it is enough to re-solder them to make the device work. At first, they try to identify damaged parts visually - they may be cracked, have a darkened case or pins burned out on the board, electrolytic capacitors will be swollen at the top. All identified faulty elements are soldered and replaced with the same or similar ones with suitable characteristics. The selection is made according to the markings on the case or according to tables. When soldering parts, the use of a soldering iron with suction will provide maximum speed and convenience of work. Image - Welding machine inverter DIY repair

If the visual inspection did not bring any result, then proceed to ringing (testing) the parts using an ohmmeter or multimeter. The most vulnerable elements of inverter modules are transistors. Therefore, the repair of the apparatus usually begins with their inspection and verification. Power transistors rarely fail by themselves - as a rule, this is preceded by a failure of the elements of the "swinging" circuit (driver), the details of which are checked first. In the same way, by means of the tester, they call the rest of the board elements.

On the board, it is necessary to check the condition of all printed conductors for the absence of breaks and burns. The burnt areas are removed and the jumpers are soldered, as in the case of breaks, with a PEL wire (with a cross section corresponding to the board conductor). You should also check and, if necessary, clean (with a white eraser) the contacts of all connectors in the device.

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Rectifiers (input and output), which are conventional diode bridges mounted on a heatsink, are considered to be quite reliable components of inverters. But sometimes they fail. It is most convenient to check the diode bridge after unsoldering the wires from it and removing it from the board. If the entire group of diodes rings for a short time, then you should look for a broken (faulty) diode.

The key management board is checked last. In the inverter module, this is the most complex element and the operation of all other components of the apparatus depends on its functioning. The final stage in the repair of the inverter welding device should be to check the presence of control signals coming to the busbars of the gates of the key block. Diagnose this signal using an oscilloscope.

In cases that are unclear and more complex than those described above, the intervention of specialists will be required. Trying to fix the malfunction yourself is not worth it, especially when the inverter is under warranty.

Inverter welding machines are gaining more and more popularity among master welders due to their compact size, low weight and reasonable prices. Like any other equipment, these devices can fail due to improper operation or due to design flaws. In some cases, the repair of inverter welding machines can be carried out independently by examining the inverter device, but there are breakdowns that are eliminated only at the service center.Welding inverters, depending on the models, operate both from a household electrical network (220 V) and from a three-phase (380 V). The only thing to consider when connecting the device to a household network is its power consumption. If it exceeds the capabilities of the wiring, then the unit will not work with a sagging network.So, the following main modules are included in the device of an inverter welding machine.Just like diodes, transistors are installed on radiators for better heat dissipation from them. To protect the transistor unit from voltage surges, an RC filter is installed in front of it.Below is a diagram that clearly shows the principle of operation of the welding inverter.So, the principle of operation of this module of the welding machine is as follows. The primary rectifier of the inverter is supplied with voltage from the household electrical network or from generators, gasoline or diesel. The incoming current is alternating, but passing through the diode block, becomes permanent... The rectified current is fed to the inverter, where it is converted back to alternating current, but with changed frequency characteristics, that is, it becomes high-frequency. Further, the high-frequency voltage is reduced by a transformer to 60-70 V with a simultaneous increase in the current strength.At the next stage, the current again enters the rectifier, where it is converted to DC, after which it is supplied to the output terminals of the unit. All current conversions controlled by a microprocessor control unit.Modern inverters, especially those based on the IGBT module, are quite demanding on the rules of operation. This is explained by the fact that when the unit is operating, its internal modules give off a lot of heat... Although both radiators and a fan are used to remove heat from power units and electronic boards, these measures are sometimes not enough, especially in inexpensive units. Therefore, you need to strictly follow the rules that are indicated in the instructions for the device, implying periodic shutdown of the installation for cooling.This rule is usually referred to as the “Duty Cycle” (Duty Cycle), which is measured as a percentage. Not observing the PV, overheating of the main units of the apparatus occurs and their failure occurs. If this happens with a new unit, then this breakdown is not subject to warranty repair.Also, if the inverter welding machine is working in dusty rooms, dust settles on its radiators and interferes with normal heat transfer, which inevitably leads to overheating and breakdown of electrical components. If it is impossible to get rid of the presence of dust in the air, it is required to open the inverter case more often and clean all the components of the device from accumulated dirt.But most often inverters fail when they work at low temperatures. Breakdowns occur due to the appearance of condensation on the heated control board, as a result of which a short circuit occurs between the parts of this electronic module.A distinctive feature of inverters is the presence of an electronic control board, therefore, only a qualified specialist can diagnose and eliminate a malfunction in this unit.... In addition, diode bridges, transistor blocks, transformers and other parts of the electrical circuit of the apparatus can fail. To carry out diagnostics with your own hands, you need to have certain knowledge and skills in working with measuring instruments such as an oscilloscope and a multimeter.From the above, it becomes clear that, without the necessary skills and knowledge, it is not recommended to start repairing the device, especially electronics. Otherwise, it can be completely disabled, and repairing the welding inverter will cost half the cost of a new unit.As already mentioned, inverters fail due to external factors affecting the “vital” units of the apparatus. Also, malfunctions of the welding inverter can occur due to improper operation of the equipment or errors in its settings. The most common malfunctions or interruptions in inverter operation are as follows.Very often, this breakdown is caused by faulty network cable apparatus. Therefore, first you need to remove the cover from the unit and ring each wire of the cable with a tester. But if everything is in order with the cable, then more serious diagnostics of the inverter will be required. Perhaps the problem lies in the standby power source of the device. The repair technique for the “duty room” using the example of a Resant brand inverter is shown in this video.This malfunction can be caused by an incorrect setting of the amperage for a certain diameter of the electrode.You should also consider and welding speed... The smaller it is, the lower the current value must be set on the control panel of the unit. In addition, to match the current strength to the diameter of the additive, you can use the table below.If the welding current is not regulated, the cause may be breakdown of the regulator or violation of the contacts of the wires connected to it. It is necessary to remove the cover of the unit and check the reliability of the connection of the conductors, and, if necessary, ring the regulator with a multimeter.If everything is in order with him, then this breakdown can be caused by a short circuit in the choke or a malfunction of the secondary transformer, which will need to be checked with a multimeter. If a malfunction is found in these modules, they must be replaced or rewound to a specialist.Excessive power consumption, even when the device is not loaded, most often causes turn-to-turn closure in one of the transformers. In this case, you will not be able to repair them yourself. It is necessary to take the transformer to the master for rewinding.This happens if the voltage drops in the network... To get rid of the sticking of the electrode to the parts to be welded, you will need to correctly select and set up the welding mode (according to the instructions for the device). Also, the voltage in the network may sag if the device is connected to an extension cord with a small wire cross-section (less than 2.5 mm 2).

It is not uncommon for a voltage drop that causes the electrode to stick when using a power strip that is too long. In this case, the problem is solved by connecting the inverter to the generator.

Quite often, home craftsmen are faced with the need to perform welding. To do this, they need special welding equipment.

Today, welding inverters are a fairly common type of similar apparatus, which can increasingly be found among many owners. However, at a certain moment, this equipment may fail, which makes one think about repairs.

Moreover, in this case, it is not necessary to contact specialists; in some cases, you can return the welding machine to working condition on your own. The main thing is to know what exactly led to the malfunction and how you can eliminate it yourself without incurring unnecessary service costs.

One of the main qualities that ensured the popularity of inverter welding machines is high quality welding, which can be provided by any person who does not have sufficient skills in handling it. At the same time, the operating conditions of this unit themselves are distinguished by a high level of convenience.

It should be mentioned that this equipment has a more complex design when compared with welding rectifiers and transformers. This, in turn, negatively affects their reliability. It should also be said that the predecessors listed above are electrical devices. In contrast, inverter devices are one of the varieties of complex electronic devices.

For this reason, if the owner is faced with malfunctions in the operation of the welding inverter, in order to find the cause of the malfunction and carry out the repair itself, it is necessary to make sure that its constituent elements are working: diodes, transistors, zener diodes, resistors, as well as other elements of the inverter electronic circuit.You should also be prepared for the fact that the user will be faced with the need to use devices such as a voltmeter, digital multimeter, as well as other ordinary measuring equipment, including an oscilloscope.

When starting to repair inverter welding machines, you need to remember the following point: it is often difficult to understand, focusing only on the nature of the problem that has arisen, what exactly led to the termination of the operation of the machine.

In such a situation, the owner has no choice but to take turns check each element of the circuit... Therefore, in order for the repair to justify the efforts and time spent on it and to ensure the necessary result, the owner of such a device must have certain knowledge of electronics, as well as at least minimal skills in working with electrical circuits.

If he does not understand this plan, then, having decided on an independent repair of the inverter welding machine, he only risks wasting time in vain, without having achieved his goal. It is possible that his initiative may worsen the operation of the device, and the actions performed by him will cause new problems.

If we consider all the problems that are diagnosed during the operation of welding inverters of any type, then they can be classified into several groups:

malfunctions resulting from an illiterate choice of the welding operating mode;
malfunctions caused by a malfunction or improper operation of the electronic components of the equipment.

Regardless of the nature of the malfunction, such a situation will not allow the owner to continue welding in the usual mode. Various factors can cause a malfunction in the operation of the welding inverter. To determine the exact cause, it is necessary to check each of them in turn, and at the beginning they start with simple operations and gradually move on to more complex ones. After carrying out all the recommended diagnostic procedures, it may happen that the welding machine is still inoperative. In this case, it can be assumed that the problem is related to the inoperative electrical circuit of the inverter module. The most common failure of an electronic circuit occurs for the following reasons:

Penetration of moisture into the device. In most cases, precipitation contributes to this.
In the event of dust accumulation under the housing, favorable conditions arise for disrupting the correct cooling of the components of the electronic circuit. Equipment used on construction sites is most often at greatest risk of contamination. To prevent damage to the inverter under these operating conditions, clean it regularly.
Disregard of the manufacturer's recommendations regarding the proper use of the inverter without interruption. This can also be one of the causes of malfunctions in the operation of the electronics of the equipment, arising against the background of its overheating.

Usually, inverter devices fail due to external factors, as well as incorrect settings and neglect of the recommendations for using the device. Among such situations, the following can most often be observed:

A burning odor from the cabinet of the unit may be a sign of a serious problem with the inverter module. In such a situation, the best solution would be service call... To fix such a malfunction with your own hands, the owner must have certain skills and knowledge.

The do-it-yourself repair procedure consists in gaining access to the body of the device, further examining its filling. In some cases, the cause of the malfunction may be poor soldering of elements, cables, and other contacts on the circuit boards.

Therefore, in such a situation, return the device to working condition. can be by soldering... At the initial stage, you need to try to find out which elements are out of order. This may be indicated by cracks, dark spots on the case, or signs of burnout on the terminal board, as well as swelling of the top of the electrolytic capacitors.

After it was possible to establish the faulty nodes, they must be evaporated, then replaced with parts identical or similar to them in terms of characteristics. When choosing replacement parts, pay attention to the markings on the body, or use tables. When removing damaged elements, it is recommended to use a soldering iron with suction. This will allow you to complete the work with a minimum amount of time and avoid serious problems.

In some cases, the survey may not produce results. In a situation like this, it makes sense to start ring out elementsusing an ohmmeter or multimeter. Transistors have the lowest level of protection. For this reason, during the repair of the device, it is necessary first of all to examine them and check their operability. Most power transistors are highly reliable. And if, nevertheless, they turned out to be faulty, then the most often favorable factor for this is the failure of the elements of the "swinging" their circuit. The elements of the latter must be checked at the very beginning. After completing the check, it is necessary to subject the nickname and other elements of the board.

When examining the board, attention should be paid to the state each printed conductorwhere you need to make sure that they do not have breaks and burns. If burnt areas were found, they must be removed and the jumpers soldered. This operation is performed by hand in the same way as in the case of damage to the PEL cable. If necessary, then the contacts of each of the connectors present in the device should also be checked. In some cases, they will need to be cleaned.

Inverter welding machines can greatly simplify the welding procedure for various products. The failure of this equipment can upset any owner. However, you should not contact the service center specialists ahead of time. In some cases, you can return the device to a working condition with your own hands. Often this equipment has quite simple faultsthat can be easily eliminated. The main thing is to clearly understand what exactly led to the failure of the device and how to properly repair it.

It is well known that the repair of welding machines in the overwhelming majority of cases can be organized and carried out independently. The only exception is the restoration of the efficiency of the electronic inverter, the complexity of the circuit of which does not allow for full repairs at home.

Even an electrical engineer can be confused by just trying to turn off the protection of an inverter. So in this case, it is best to seek help from a specialized workshop.

The main manifestations of malfunctions in electric arc welding machines are:

the device does not turn on when connected to the mains and started;
sticking of the electrode with a simultaneous hum in the area of the converter;
spontaneous shutdown of the welding machine in case of overheating.

Repair always begins with an inspection of the welding machine, checking the supply voltage. It is not difficult to repair transformer welding machines, moreover, they are not picky to maintain. In inverter devices, it is more difficult to determine the breakdown, and repair at home is often impossible.

However, if handled correctly, inverters will last a long time and will not break down. Protect from dust, high humidity, frost, store in a dry place.There are the most typical malfunctions of welding machines, which can be eliminated by hand.

In this case, first of all, you need to make sure that there is voltage in the network and the integrity of the fuses installed in the transformer windings. If they are in good working order, use the tester to ring the current windings and each of the rectifier diodes, thereby checking their performance.

If one of the current windings breaks, it will need to be rewound, and in the event of a failure of both, it is easier to replace the entire transformer. A damaged or "suspicious" diode is replaced with a new one. After repair, the welding machine is turned on again and checked for serviceability.

Sometimes the filter capacitor fails. In this case, the repair will consist in checking it and replacing it with a new part.

If all the elements of the circuit are working properly, it is necessary to deal with the mains voltage, which can be greatly underestimated and is simply not enough for the normal functioning of the welding machine.

Electrode sticking and arc interruption can be caused by a voltage drop due to a short circuit in the transformer windings, diode failure, or loose connection contacts. A breakdown of the capacitor filter or short circuiting of individual parts to the body of the welding machine is also possible.

For reasons of an organizational nature, due to which the device does not cook as it should, it is possible to attribute the excessive length of the welding wires (more than 30 meters).

If sticking is accompanied by a strong hum of the transformer, this also indicates an overload in the load circuits of the device or a short circuit in the welding wires.

One of the repair options with the elimination of these effects can be the restoration of the insulation of the connecting cables, as well as the tightening of loose contacts and terminal blocks.

In some cases, repairs can be carried out independently if the device starts to shut down spontaneously. Most models of welding machines are equipped with a protective circuit (automatic) that is triggered in a critical situation, accompanied by a deviation from normal operation. One of the options for such protection involves blocking the operation of the device when the ventilation module is turned off.

After spontaneous shutdown of the welding machine, first of all, you should check the state of protection and try to return this element to working condition..

If the protective unit re-operates, it is necessary to proceed to troubleshooting according to one of the methods described above, associated with short circuits or malfunction of individual parts.

In this situation, first of all, you should make sure that the cooling unit of the unit is working properly, and that overheating of the internal spaces is excluded.

It also happens that the cooling unit does not cope with its functions due to the fact that the welding machine has been under a load exceeding the permissible norm for a long time. The only correct decision in this case is to give it a "rest" for about 30-40 minutes, and then try to turn it on again.

In the absence of internal protection, the circuit breaker can be installed in the electrical panel. To maintain the normal functioning of the welding unit, its settings must correspond to the selected modes.

So, some models of such machines (welding inverter, in particular), in accordance with the instructions, should work according to a schedule that assumes a break for 3-4 minutes after 7-8 minutes of continuous welding.

Before repairing an inverter welding machine with your own hands, it is advisable to familiarize yourself with the principle of operation, as well as with its electronic circuit. Their knowledge will allow you to quickly identify the causes of breakdowns and try to eliminate them in a timely manner.

The operation of this device is based on the principle of double conversion of the input voltage and obtaining a constant welding current at the output by rectifying a high-frequency signal.

The use of an intermediate high-frequency signal makes it possible to obtain a compact impulse device that has the ability to effectively adjust the value of the output current.

Breakdowns of all welding inverters can be conditionally divided into the following types:

malfunctions associated with errors in the choice of the welding mode;
failures in operation due to the failure of the electronic (conversion) module or other parts of the device.

The method for detecting inverter malfunctions associated with malfunctions in the operation of the circuit involves the sequential execution of operations performed according to the principle "from simple damage to more complex breakdown." The nature and cause of breakdowns, as well as repair methods, can be found in more detail in the summary table.

It also contains data on the main parameters of welding, providing a trouble-free (without turning off the inverter) operation of the device.

Maintenance and repair of inverter-type welding machines is distinguished by a number of features associated with the complexity of the circuitry of these electronic units. Repairing them will require certain knowledge, as well as the ability to handle measuring instruments such as a digital multimeter, oscilloscope, and the like.In the process of repairing an electronic circuit, a visual inspection of the boards is first carried out in order to identify burnt or "suspicious" elements in the composition of individual functional modules.

If during the inspection no irregularities can be found, the troubleshooting continues by detecting irregularities in the operation of the electronic circuit (checking the voltage levels and the presence of a signal at its control points). Image - Welding machine inverter DIY repair

To do this, you will need an oscilloscope and a multimeter, which you should start working with only if you have full confidence in your abilities. If you have any doubts about your qualifications, the only correct solution would be to take (carry) the device to a specialized workshop.

Specialists in the repair of complex impulse devices will quickly find and eliminate the malfunction that has arisen, and at the same time will carry out maintenance of this unit.

If you decide to repair the board yourself, we recommend using the following advice from experienced specialists.

If burnt wires and parts are found during a visual inspection, they should be replaced with new ones, and at the same time all connectors should be plugged in, which will eliminate the option of losing contact in them.

If such a repair did not lead to the desired result, you will have to start a block-by-block inspection of the electronic signal conversion circuits.

To do this, it is necessary to find sources in which the diagrams of voltages and currents are given, intended for a more complete understanding of the operation of this unit.

Based on these diagrams using an oscilloscope, you can sequentially check all the electronic circuits and identify the node in which the normal signal conversion picture is disturbed.

One of the most complex components of an inverter welding machine is considered to be an electronic key control board, which can be checked for serviceability using the same oscilloscope.

If you have doubts about the performance of this board, you can try to replace it with a serviceable one (from another working inverter) and try to start the welding machine again.

In case of a favorable outcome, it remains only to give your board for repair or replace it with a purchased new one. The same should be done when there is a suspicion that all other modules or blocks of the welding machine are in good working order.

In conclusion, we recall that the repair of any welding units (and inverters, in particular) is considered a rather complex procedure that requires certain skills and ability to handle complex measuring equipment.If you have the slightest doubt about your professionalism, you should use the help of specialists and give them the opportunity to return the faulty device to work.Repair of welding inverters, despite its complexity, in most cases can be done independently. And if you are well versed in the design of such devices and have an idea of what is more likely to fail in them, you can successfully optimize the costs of professional service.Replacement of radio components in the process of repairing a welding inverterThe main purpose of any inverter is to generate a constant welding current, which is obtained by rectifying a high-frequency alternating current. The use of a high-frequency alternating current, converted by means of a special inverter module from a rectified mains supply, is due to the fact that the strength of such a current can be effectively increased to the required value using a compact transformer. It is this principle underlying the operation of the inverter that allows such equipment to be compact in size with high efficiency.Functional diagram of the welding inverterThe welding inverter circuit, which determines its technical characteristics, includes the following main elements:

a primary rectifier unit, the basis of which is a diode bridge (the task of such a unit is to rectify an alternating current supplied from a standard electrical network);

an inverter unit, the main element of which is a transistor assembly (it is with the help of this unit that the direct current supplied to its input is converted into an alternating current, the frequency of which is 50–100 kHz);

a high-frequency step-down transformer, on which, due to a decrease in the input voltage, the output current is significantly increased (due to the principle of high-frequency transformation, a current can be generated at the output of such a device, the strength of which reaches 200–250 A);

output rectifier, assembled on the basis of power diodes (the task of this block of the inverter includes rectifying an alternating high-frequency current, which is necessary for performing welding).

The welding inverter circuit contains a number of other elements that improve its operation and functionality, but the main ones are the ones listed above.