Welding inverters vs welding transformers. Comparison of the main characteristics and features of welding inverters What is the difference between welding machines

In the construction industry, both traditional welding machines and more technologically advanced inverter ones are used. What is the specificity of both? What is the difference between a welding inverter and a welding machine classified as a conventional unit?

What is a welding inverter?

This type of welding machine is characterized by the ability to convert direct electric current into alternating current. This unit contains the following main components:

• rectifiers - network and frequency;
• filter;
• frequency converter - the actual inverter;
• transformer;
• Control block.

The welding inverter works like this.

Alternating current from the electrical network, which has a frequency of 50 Hz, is fed to the mains rectifier. After that, the current is respectively rectified and then smoothed by means of a filter. Then it is fed to the inverter, in which it is converted into an alternating frequency with a high frequency - about a few tens of kHz. After that, the voltage is reduced by means of a transformer to a level of about 50-60 V, while its strength increases to about 100-200 A. Then the current is rectified by means of a frequency rectifier - already in the process of arc welding.

The frequency converter - the inverter - can be regulated by the welder, due to which the optimal operating parameters of the unit are ensured. For this, another functional element of the inverter welding machine is involved - the control unit.

The main advantages of inverters:

• low weight and dimensions;
• high energy efficiency of welding;
• high precision welding.

Disadvantages of inverters:

• units in many cases require special storage conditions - in terms of temperature, air humidity;
• sensitivity to low temperatures;
• high price, high cost of maintenance and repair.

What is a traditional welding machine?

The "classic" welding machine is characterized primarily by its simple design. Its main functional element is a transformer.

The traditional welding machine works like this.

Alternating current from the electrical network is sent to the primary winding, as a result of which the magnetization of the transformer core is formed. Then the current passes through the secondary winding - in it the magnetic flux forms an alternating current, characterized by a lower voltage in comparison with what is supplied to the primary winding. Its voltage depends on the number of turns on the secondary winding.

The traditional welding machine functions, therefore, due to electromagnetic induction, at which a large current is generated - sufficient for welding, at its low voltage.

The main advantages of traditional welding units:

• no requirements for special storage conditions;
• lack of sensitivity to low temperatures;
• low price, low maintenance.

Disadvantages of the respective devices:

• large weight, dimensions;
• not the most outstanding energy efficiency and accuracy.

Comparison

The main difference between a welding inverter and a traditional type welding machine is the presence of a current converter in the first device. In addition, the units under consideration differ in the aspect:

• weight, dimensions;
• energy efficiency, welding accuracy;
• requirements for storage conditions;
• sensitivity to low temperatures;
• prices, services.

It can be noted that, as a rule, the use of traditional devices requires a higher qualification of the welder.

Having determined what is the difference between a welding inverter and a traditional type welding machine, we will reflect in a small table its main criteria in relation to the aspects discussed above.

Table

Among novice welders who get acquainted with the types of joining metals with an electric arc, the question arises: which is better, a transformer or an inverter? To choose the right device for yourself, you should understand their device and differences, as well as the advantages and disadvantages. The future use of the equipment also plays an important role (the most frequent specific types works and time of their execution). Below are the detailed answers for each item.

The most affordable tool for electric arc welding is a transformer. A good device is able to connect metal elements with a thickness of 1.5 to 30 mm. It can also be used to cut steel when the temperature from a propane-oxygen flame is not enough.

The welding transformer has a simple structure, which includes two windings. The first receives alternating voltage from a socket or shield. Devices can be designed for both single-phase and three-phase networks. For this reason, they are large and small. Due to electromagnetic induction, the current strength (A) increases significantly, and the voltage (V ) goes down. A current from 80 to 500 A is formed on the secondary winding. There are also more powerful models. The maximum for the transformer is 48 V at idle. This makes it safe to use when the welder is in contact with the product being worked on.

This allows you to weld carbon steel, aluminum, cast iron. The adjustment of the current strength in large models is carried out by removing or approaching the windings. In small devices, stepped switching is used, which cuts off part of the winding and reduces the voltage path.

Equipment advantages

Among the advantages of transformers are the following:

• simple device and the ability to independently repair;
• cheap cost of components;
• alternating current holds the arc well in a humid environment, therefore, when welding pipes with leaking water, the seam is easier to conduct;
• the ability to work as a transformer with electrodes with a diameter of 1.6 to 7 mm (large devices);
• high current strength (in portable models up to 300 A, and in stationary models more than 500 A), which allows welding thick metal;
• relatively cheap cost of store versions.

Cons of equipment

Among the disadvantages of this equipment for welding can be identified:

• Step adjustment in small models. This does not allow you to fine-tune the device for a specific metal thickness. For example, in mode "4" the current strength is not enough for full penetration, and in mode "5" burns already appear. To get out of the situation, welders use a spring located between the product and the mass cable, which creates additional resistance and reduces the current.
• Welding with a transformer has a stronger rumble. This noise during the day can annoy the welder. To reduce its impact, the machine must be located away from the place of work, but this requires longer cables.
• Splashing of molten metal occurs to a large extent, which leads to excessive consumption of electrodes.
• Most devices are able to lower the current only to a certain value, usually around 80 A. This creates difficulties when welding thin sheet iron. In such situations, you have to use additional resistance.

Features of inverters

The welding inverter refers to a more "advanced" device that has gained popularity recently. It greatly increases the frequency of the incoming voltage and converts it to direct current. This is achieved through the operation of the transformer in combination with capacitors, key transistors and diodes. Thanks to modern technologies achieved minimum dimensions device that allows you to hang them on your shoulder and work for a long time.

Equipment advantages

Inverters have the following advantages:

• due to direct current, less metal spatter occurs, which saves consumables;
• the surface of the seam is smoother with small scales;
• arc burning is calm and stable;
• the inverter can weld not only carbon steel, but also stainless steel and aluminum;
• the device supports work with electrodes with a diameter of 1.6 to 5 mm;
• compact models that fit in a small suitcase;
• current settings are smooth, which allows you to set any required value;
• due to the minimum current value of 20 A, it is possible to work with thin parts without additional resistance;
• energy savings (all inverters operate from 220V, and power consumption is 6-9 kW);
• some devices are equipped with additional functions that facilitate the ignition of the electrode and prevent it from sticking to the surface.

Cons of inverters

There are few drawbacks to this equipment. One of them is the higher cost relative to the transformer. But the device fully justifies this money. In the event of a breakdown, repairs are more expensive due to the numerous components. A complex electrical circuit makes it difficult to troubleshoot the problem yourself.

Semiautomatic devices based on transformers and inverters

In the creation of semi-automatic devices, a transformer or inverter is used as the main source of welding current, which melts the feed wire in a shielding gas environment. Their use is characterized by the following features:

• The transformer semi-automatic is more suitable for welding carbon steel. Most often they are used in the repair work of car bodies. It's cheap and reliable way weld cracks in thin metal. The large dimensions of the equipment allow it to be operated on the territory of a workshop or workshop. The movement is carried out on a small trolley, where a gas cylinder is also placed.
• The inverter semiautomatic device has small dimensions, and it can be carried by hand, provided the gas hose is long. Constant voltage makes it possible to weld carbon steel, stainless steel and aluminum (when installing a wire of the appropriate composition). Although spatter is high on alloy metals, the welds are of good quality.

How to choose a device

The cost of transformers and inverters is different. But when choosing, it is necessary to start mainly not from the price of the equipment, but from the future use. The transformer is perfect for personal use in the country or in a private house. They can repair the fence, build a greenhouse in the spring, weld the canopy that has fallen off the gate. Semi-automatic machines based on transformers are suitable for repair work on car bodies in your own garage.

An inverter is worth buying if frequent welding work is planned. It can be:

• heating welding;
• plumbing;
• production of stainless steel containers;
• creation of new doors and gates.

The seams on such products will be better and more beautiful. The subsequent surface treatment is also reduced.

An inverter-based semi-automatic machine can be bought for regular work on the manufacture of tanks (for water, fuel, chemical environment), filters, welding of stainless metals, or for a large service station.

Choosing welding equipment is easy when you understand its features and advantages for future work. It is good if before buying there will be an opportunity to cook with both devices, and compare the quality of the result and your own feelings in terms of ease of use.

It can be said that in the recent past century, one of the most cherished desires of any master, closely associated with the repair of machines or any other metalworking, was to have a welding machine at hand. Let it be a home-made transformer model, but this equipment, in addition to the indescribable benefits, has always inspired pride in its owner. Now, with a high pace of technology development, the shelves of electrical equipment stores are crammed with various models of welding machines that differ in purpose, functions, and, of course, in price. And for those who are faced with the choice of an RDS welding machine for domestic needs or for production, the first question that arises is “What to choose an inverter or transformer welder?”.

Therefore, in this article we will present some of the pros and cons of these devices, so that you can clearly determine which type of device you need - an inverter or a transformer. We warn you that this material will only talk about manual arc welding machines.

Differences between the welding process of an inverter and a transformer

Let's take a look at the welding process itself and the difference between an inverter and a transformer in this matter. And here, the main drawback of conventional transformers is the insufficient stability of the arc along with the low stability of the mode, which is completely dependent on fluctuations in the electrical network. Welding inverters have an undeniable advantage here, since inverter sources provide a stabilized constant welding current, which is independent of fluctuations in the input voltage and thus provides a more stable arc and minimal metal spatter during welding. A more technologically savvy inverter differs from a transformer at least in the presence of a smooth adjustment of the welding current, not to mention the presence of special functions that are present in the arsenal even of a budget model, such as Hot-Start, Anti-Sticking, Arc-Force, etc.

In addition to all of the above, the welding inverter consumes much less electricity and can operate from autonomous power sources - gasoline and diesel generators (on our website you can find current models of generators). For example, the power consumption of an inverter when working with an electrode with a diameter of 3 mm is equivalent to the consumption of two electric kettles, which is quite within the household norms. Based on all of the above, welding with an inverter is much more profitable, more pleasant, and most importantly easier than with a transformer.

Weight and dimensions

An important advantage of a welding inverter over a transformer is its low weight and rather small dimensions. All this is made possible by increasing the frequency of the voltage: after all, if the frequency is increased by 1000 times, the size of the transformer is reduced by ten times. For some inverter models, the transformer itself is smaller than a cigarette pack; the main mass is occupied by a radiator. It is not surprising that such an inverter can be easily hung on the shoulder and cooked in hard-to-reach places: with a mass of less than 4 kilograms, some inverter models make it easy to work with electrodes even up to 3-4 mm in diameter (for example, the inverter of the domestic brand Svarog ARC 200 Easy). And again, in the rivalry between 2 types of equipment, the inverter wins, as they say, you can't carry a 40-kilogram transformer on your shoulder.

money question

Frankly, often transformers are still two or more times cheaper than inverters. And the repair of transformers in the post-Soviet space is usually cheaper. However, from the experience of European colleagues, interesting data can be drawn: every 1000 Euro of the cost of welding in manual arc welding can be divided into the following cost categories:

• 35% wages for welders
• 35% cost of electrodes
• 28% cost of electricity
• And only 2% of equipment and accessories (the cost of the device, cables, etc.)

As you can see, the cost of welding equipment only slightly affects the total cost of welding. In this regard, it becomes profitable to buy equipment that uses the latest developments: even with a higher cost of the inverter, the reduction in electricity costs in the future gives a total saving of the total cost of welding by 5-8% percent!

Summing up

Apparently, modern welding inverters are really more practical, more economical, and most importantly more profitable to use, unlike classic transformers. Nevertheless, it is important to remember that the guarantee of high-quality welding to a greater extent depends not on the “fancy” equipment, but on the skills and training of the master, namely, the person!

Welding machines come in two popular varieties - transformer and inverter. What are the features of both? What is the difference between "inverter" and "transformer" in the context of the designation of certain types of welding equipment?

What is an "inverter"?

« inverter» refers to innovative devices for welding. The principle of its operation lies in the ability to convert the electric current supplied through alternating networks (the most common) into a rectified constant, and then an alternating one with the desired frequency, as well as a force sufficient for high-quality welding. To do this, use the built-in rectifier "inverter".

Let us examine in more detail the principles of operation of the inverter unit.

After rectification, the current is smoothed out by a special filter, which is present in the design of the device in question. After - by means of special transistors it is again converted into an alternating one, but with a very high frequency - several tens of kHz. For comparison: electric current propagates through networks with a frequency of 50 Hz. The high-frequency current voltage in the "inverter" decreases to about 70-90 V, while the current increases - to about 100-200 A.

This technology allows you to generate current for welding by means of devices with small dimensions, and, moreover, consuming relatively little electricity.

Modern inverter machines, as a rule, provide significantly higher quality welding than many other types of units. Moreover, according to some experts, "inverters" are more convenient to use than their counterparts. These units are well suited for beginners with little experience welders. Although, of course, the use of appropriate apparatus requires sufficient high level employee training.

The unit with relatively small dimensions and weight - about 4 kg falls into the hands of the welder. It is convenient to carry it from one place to another, to carry out welding in hard-to-reach areas of buildings.

Among the most remarkable properties of the welding machines in question is the ability to function even with a not very stable network, and, if necessary, be powered by autonomous home power plants.

"Inverters" provide the most stable supply of welding current. The fact that there may be voltage fluctuations at the input does not matter. As a result, a sufficiently stable welding arc is formed. In addition, this welding technology significantly reduces the scattering of drops of molten metal.

Among the disadvantages of "inverters":

• high price;
• the possibility of failures in operation at temperatures below minus 15 degrees.

In addition, a feature of many inverter welding units is the need to use a power cable, the length of which does not exceed 2.5 meters.

What is a "transformer"?

Transformer units for welding operate on alternating current and in the general case do not straighten it before applying to the electrode. This feature predetermines often not the highest quality of formation of seams during welding.

In order to optimize the result of the work, the welder can use an external rectifier. But you need to keep in mind that such a unit is not cheap: its price can be comparable to the cost of a "transformer". In addition, the installation of a rectifier noticeably makes the welding system heavier, and therefore it is not easy to transfer it from one place to another as easily and quickly as in the case of an “inverter”.

"Transformers" work without failures and provide good quality welding under the condition of a stable supply of electricity. Not all types of units related to transformers function correctly when connected to the same autonomous power plants. The use of a "transformer" requires a particularly high qualification of the welder, who has considerable experience in working with this equipment.

The units under consideration do not always allow smooth adjustment of the welding current supply. They are less economical than "inverters". Their weight is much greater than that of the first type of welding machines: it can be about 40 kg.

Among the undeniable advantages of the "transformer" is simplicity. This device functions by converting the current supplied to the transformer - primary - into a secondary one, characterized by a relatively low voltage and high current strength. In this case, the principle of electromagnetic induction is involved. It involves the formation of the conversion coefficient due to the difference between the indicators of the number of turns in different sections of the winding - primary and secondary.

Thus, the unit in question is very reliable, easy to install.

"Transformers" are relatively inexpensive. They are not characterized by a strong sensitivity to frost - as is the case with "inverters". Therefore, in many areas of application of welding machines, "transformers" are indispensable.

Comparison

There is, of course, more than one difference between an “inverter” and a “transformer” in the context of welding technology. The difference between the types of aggregate under consideration is especially obvious when they are compared in the aspect:

• current supplied to the electrode;
• used sources of electricity;
• sizes;
• weight;
• welding quality;
• prices;
• frost resistance.

To more clearly reflect what is the difference between an "inverter" and a "transformer", a small table will help us.

Table

Welding inverters..Sometimes they are mistakenly called invectors, or even inventory .. How often do we hear this phrase, but how do inverters fundamentally differ from conventional transformer welding?

Inverter-type welding machines are designed for manual arc welding of metals and metal structures made of black steel. These invertersare characterized by convenient operation, easy maintenance and portable size. Moreover, due to their design, the inverters do not “sink” the network, and can work in an unstable network.

The welding inverter is usually composed of a rectifier, a converter, a transformer, an output rectifier and a control circuit.

Let's start with a little theory. The principle of operation of a welding inverter lies in one of the laws of electrical engineering, which states: The higher the voltage frequency, the less dimensions and the mass of the transformer to transfer the same amount of power. So, with an increase in the frequency of the electric current by a factor of 1000, the dimensions decrease by a factor of 10. Active developments in the field of inverter welding began at the beginning of the 20th century, and they received a recognizable appearance since the 90s of the last century, when special power transistors began to be actively introduced. With their help, it was possible to raise the frequency of the current to great heights, while reducing the size of the devices.

So, for example, the welding inverter tss sai-200 operates at a frequency of 100 kHz, while having this mass of only 7 kg. For comparison, for conventional devices, the characteristic showing the ratio of the welding current to the mass of the device varies between 1-1.5 A / kg, while for modern inverters, this value has already reached 4-5 A / kg /

Welding inverters have gained a leading position in the welding equipment market due to their excellent technical specifications, ease of transportation and reliability in operation. The main advantages of inverters are:

- Light weight of welding equipment;

- Low power consumption; (relative to transformer welding machines)

- Reduced spark spatter area during welding;

- Possibility of regulation of force of welding current;

- Possibility of work from the moment of inclusion;

- High quality weld.

Moreover,inverter - this is the safest and most easy-to-use device among all devices designed for welding a variety of metals.

When working with inverters, it is enough to follow a few simple recommendations, following which you will significantly extend the life of your welding machine:

- Do not place the inverter in a dusty environment. When working outdoors, place it on a stand to prevent dust from entering.

- Do not overload the inverters during operation. In the instruction manual for each device, a special characteristic “PV” is indicated. It shows how many percent of the time the inverter can operate in maximum mode. This parameter is usually calculated for 10 minutes.

- After finishing welding work, let the inverter cool down a little. When the power is turned off, the fan cooling the radio components stops, and if it is turned off immediately, then some elements of the circuit may burn out and fail.