How does an inverter welder work?

The three-phase or single-phase utility frequency (50-60Hz) AC power, and after filtering, obtain a relatively smooth DC voltage. Then through the inverter circuit composed of high-frequency switching electronic components (MOSFET or IGBT), the direct current is converted into an intermediate frequency alternating current of tens of KHZ. After step-down transformation by the main transformer, the smoothed DC output welding current is obtained through rectification and filtering.

The transformation sequence can be simply expressed as:

Power frequency AC (rectified and filtered) → DC (inverted) → intermediate frequency AC (step-down, rectified, filtered) → DC.

That is: AC→DC→AC→DC.

The high frequency switching in the inverter module can be done by either MOSFETS (metal-oxide semiconductor field effect transistors) or preferably IGBTs (insulated-gate bipolar transistor).

According to the structure of the welding machine, the number of MOS tubes used in the inverter power supply is relatively large, and the single amperage is 9-20A. For a larger type of welding machine, the number of MOS tubes used is 32-40 at 400A or 500A. The time is prone to the problem of irregular frequency. IGBT is generally two modules, you only need to select the module amperage according to the welding machine model. Besides the high voltage, high current handling capability of IGBT, the most important advantage of IGBT is that IGBT is less susceptible to fluctuations in main power supply and generator power, making it more reliable and less prone to damage or failure. Therefore, the MOS cost is low, but the decapower welding machines all use the IGBT solution.

What are the advantages of an inverter welder?

Inverter-based products offer many advantages over conventional transformer-based devices:

Weight and size: This is the most significant and impressive advantage of inverter welders over conventional machines. The DECAPOWER INVERTER MIG series does not weigh more than 30 lbs, and some can even be slung over the shoulder. This compact design makes the inverter welding machine suitable for different working environments, easy to carry and move.

Efficiency: The high efficiency of the inverter welding machine is one of its outstanding features. A good quality inverter welder has an efficiency rating of around 80-90%, compared to 50% or less for conventional welders. This is because the larger transformers in traditional machines have larger resistances and therefore lose a lot of power (or energy) through heat dissipation.

Duty cycle: Generally, inverter-based machines can achieve higher duty cycles, that is, welding operations can be performed continuously for a longer period of time. This is also due to the difference in transformer size. Although the smaller components in an inverter heat up quickly, they can cool down more easily and quickly. In a traditional  transformer welder, the components are much larger and therefore tend to store heat and take longer to cool.

DC output: Many traditional transformer MMA welders only have an AC output, which means they are limited in the types of electrodes they can weld. However, with inverter-based machines, the current is more easily rectified to DC, which means they are capable of welding a wide variety of different welding electrodes. For example, Decapower MMA series welding machines can use the Lift Tig function.

Performance: The performance of premium inverter welders is significantly better than traditional welders. This is especially evident in MMA welding, where operators find welding much easier and they don’t have to “fight” the arc. This is mainly due to the fact that inverter machines are able to have higher open circuit voltage and have functions such as hot start, anti-sticking and arc force.

FAQS:

1. What are the advantages of inverter welding machine?

Due to the high operating frequency of the inverter, the cross-sectional area of the core of the main transformer and the number of turns of the coil are greatly reduced. Therefore, the inverter welding machine can save metal materials to a large extent, reduce the overall size and weight, and greatly reduce the power loss. The important thing is that the inverter welding machine can adjust the output current within the time of microseconds, so it can realize the ideal control process required by the welding process and obtain a satisfactory welding effect.

2. Is an inverter welder better than an arc welder?

Characteristics of inverter power supply: The basic characteristic of arc welding inverter is high operating frequency, which brings many advantages. Compared with the traditional arc welding power source, its main features are as follows:

1. Small size, light weight, material saving, easy to carry and move.

2. High efficiency and energy saving, the efficiency can reach 80%~90%, saving more than 1/3 of the traditional welding machine.

3. Good dynamic characteristics, easy arc ignition, stable arc, beautiful weld shape and small spatter.

4. It is suitable for combining with robots to form an automatic welding production system.

5. One machine can be used for multiple purposes to complete various welding and cutting processes.

3. Is a cheap inverter welder worth it?

Choosing a cheap inverter welder is worth it depending on your needs, budget, and usage scenario. You need to consider the following factors:

Budget: A cheap inverter MIG welder might be more attractive in terms of price, but ensure that you’re not sacrificing quality and performance. Lower-quality welders may develop issues over prolonged use, leading to more repairs and a shorter lifespan.

Frequency of Use and Projects: If you only occasionally undertake small welding projects and don’t require high strength and quality welds, a cheap inverter welder might suffice. However, if you engage in welding work frequently, especially in industrial or commercial environments, investing in a higher-quality welder might provide more value.

Performance and Features: Cheaper welders may have limitations in terms of performance and features. Ensure that the selected welder can meet your needs, such as the type and thickness of materials to be welded, as well as the required welding settings and controls.

Safety and Reliability: Welding involves high temperatures and potential hazards. Prioritize safety by selecting a welder with adequate safety features and protective measures to ensure your safety and that of your work environment.

If possible, it’s best to choose a brand with a reputable track record in terms of quality and reliability. Regardless of the type of inverter welder chosen, always ensure adherence to safety operations and usage guidelines.

4. What can I weld with an inverter welder?

Inverter welders can be used to weld various materials, including steel, stainless steel, aluminum, and some other metals.