How The Inverter Welder Works

 The differences between traditional systems and new welding machines made with inverter technology, and the impact that the latter has had on the market.

The principle of operation of the welding systems is the same, regardless of the type of model and the technology on which it is based. In principle, we can say that an inverter welder works neither more nor less than a normal traditional welder.

It is obvious, however, that there are significant differences between traditional and new generation welding systems, which are based on inverter technology, but these differences are mainly concentrated in the efficiency, performance level, and versatility of use of the equipment. It should also be noted that this discussion refers in particular to electric-powered welding machines since welding is an operation that can also be performed with the use of a torch burner.

Leaving aside tin soldering, done with small equipment and used almost exclusively in the electronics sector, brazing and oxyacetylene welding, which require a torch and are used mostly in hydraulics, the welding systems that cover the most interest and occupy the largest market segment, are precisely those that exploit the electric arc.


Arc welding

The arched system allows to weld many different metals and alloys, and precisely for its versatility it finds a wide range of applications ranging from industrial and professional to artisan and hobby. The first power-supplied welding plants began to appear at the beginning of the twentieth century when generators with adequate power were created to generate a voltaic arc capable of melting iron.

Furthermore, arc welding requires direct current, while only alternating current is running in electrical networks; traditional welding machines consequently had to integrate a transformer, or alternatively a current rectifier, in order to convert the incoming alternating current into a direct current output flow.

The first thing that can be easily understood at this point is that traditional welding machines were decidedly bulky and also very heavy machines, due to the components necessary for their operation; despite this, thanks precisely to the versatility of use to which we have mentioned before and to the new needs of the metallurgical industry, at the time in full expansion, their diffusion on the market was very rapid.


Inverter technology

Already a few decades later, in fact, during the Second World War, the need to weld new alloys, such as aluminum, and to increase the quality of the joints, led to the development of new and more complex arc welding techniques, like TIG for example. This new type of welding, however, apart from the complexity of execution, required a much higher electrical power which is why they could only be used in the industrial sector.

On the other hand, inverter technology was first mentioned in 1925, when an article illustrating its operation appeared in a specialized magazine. In principle, the first inverters were nothing more than electronic devices in which an oscillator controlled a transistor, which generated a square wave by opening and closing a circuit.

Before the arc welding systems made the qualitative leap that led to the current and excellent inverter welding machine, however, it was necessary to wait almost another sixty years, because it was only in 1983 that they were finally developed and introduced on the market the first isolated gate bipolar transistors, or IGBTs, whose patent was older than three years.

The particularity of the IGBT, in fact, is that of being able to manage the conversion of high power voltages and currents, consequently the IGBT inverter technology applied to the welding machines has allowed to significantly increase their level of performance and power. The new inverter welding machines, therefore, including models intended for craft and hobby use, in addition to manual electrode welding performed with low and medium power current, are also able to perform high power TIG welding.

The additional advantage offered by the inverter welder , compared to the traditional one, is also given by the technological level of the hardware. The IGBT inverter is an extremely small and light electronic component, unlike the transformer, and this has made it possible to drastically reduce both the overall dimensions and the weight of the welding system; it is also able to handle much higher power loads without problems. Consequently, inverter welding machines have allowed the widespread diffusion of all those welding techniques that previously were relegated only to the industrial sector.


Various models and types

Not all inverter welding machines currently on the market are able to perform all types of welding, however; it is obvious that the various plants differ according to the price and the range of users for which they are intended.

The cheaper inverter welders, in fact, are mainly intended for hobby use, therefore they are limited to performing manual electrode welds MMA, or at most MMA, MIG, MAG, and WIG. This type of system is characterized by an installation power that rarely exceeds 3 or 4 kW, therefore they can also be used in the home; the economic range also includes some inverter continuous wire welding machines, therefore capable of performing high power TIG welding; however, these are basic models designed especially for beginner welders and hobbyists, so you can start practicing this complex welding technique without being forced to spend an excessive amount on the equipment.

The models belonging to the medium-high price range, on the other hand, are able to weld both electrode and continuous wire, consequently they require greater installation power, which can even reach 6 kW and more, as well as greater ability and experience from the operator. They are also characterized by additional technologies in addition to the IGBT inverter, such as the triggering of the high-frequency arc for example, or the possibility of welding also with pulsed current.

While offering a higher yield than economic models, both in terms of efficiency and power and versatility of use, the inverter welding machines belonging to the medium-high range are conditioned by a greater complexity of use, therefore they are mainly intended for welders who have gained some experience and skill.

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