Difference between "inverter" and "transformer".

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

What is an “inverter”?

“ Inverter ” refers to innovative welding devices. The principle of its operation lies in the ability to convert an electric current supplied via alternating networks (the most common) into a rectified direct current, and then an alternating one with the required frequency, as well as a force sufficient to carry out high-quality welding. For this, the built-in "inverter" rectifier is used.

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

After rectification, the current is smoothed by a special filter, which is present in the design of the apparatus under consideration. 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 voltage of the high-frequency current in the "inverter" decreases to about 70-90 V, while the current increases to about 100-200 A.

This technology allows the formation of a 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 machines. Moreover, according to some experts, "inverters" are more convenient to use than analogs. These units are well suited for beginners with little experience, welders. Although, of course, the use of appropriate devices requires a fairly high level of professional training of the employee.

A 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 when the network is not the most stable, and, if necessary, to be powered by autonomous home power plants.

"Inverters" provide the most stable welding current. The fact that there may be voltage fluctuations at the input is irrelevant. The result is a sufficiently stable welding arc. In addition, this welding technology significantly reduces the spread of molten metal droplets.

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 welders is the need to use a power cable that does not exceed 2.5 meters in length.

What is a "transformer"?

Transformer units for welding operate on alternating current and generally do not straighten it before being fed to the electrode. This feature often predetermines not the highest quality of weld formation during welding.

In order to optimize the work result, the welder can use an external rectifier. But it should be borne 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 the rectifier significantly increases the weight of the welding system, 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 interruption and provide good welding quality provided there is a stable supply of electricity. Not all types of transformer units function correctly when connected to the same autonomous power plants. The use of a "transformer" requires a particularly high qualification of the welder, having considerable experience with this equipment.

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

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

Thus, the considered unit 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 irreplaceable.

Comparison

There is certainly more than one difference between “inverter” and “transformer” in the context of welding technology. The difference between the types of aggregate under consideration is especially obvious when comparing them in the aspect:

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

A small table will help us to more clearly reflect the difference between an "inverter" and a "transformer".

Table