When we talk about welding machines, IGBTs refers to the type of transistors used in the inverter, which is the most important module in this type of machine tools.
IGBTs is an acronym in EnglishInsulated Gate Bipolar Transistors (Insulated Gate Bipolar Transistor)—and refers to a transistor that can operate at virtually any current level, making it unnecessary to connect them in parallel, thus greatly increasing their reliability. Among its outstanding features are the reduced weight of the power source, greater reliability, higher welding quality, more energy efficiency and, in the most advanced models, the possibility of programming the cycles of welding.
IGBT: what does it mean and what advantages does it offer?
Compared to the welding machines traditional, with power supply to transformer or generator and alternator, the welders with IGBT technology they make use of the switched source system for the generation of the electrical currents necessary to operate.
As we saw before, IGBTs it means Insulated Gate Bipolar Transistors (Insulated Gate Bipolar Transistor), and is part of what is commonly known as a power source inverter. This technology enables better performance and increased energy efficiency when using a solid-state power supply.
- The use of the rectifier provides a minimum voltage drop.
- Reduced noise emission.
- Longer work cycle time.
- Efficient energy consumption; energy is lost as heat only in those components where performance is non-ideal.
- Reduced weight compared to other previous technologies.
- Voltage and amperage limited only by breakdown voltage and size; virtually any output voltage or amperage can be achieved.
- Being a computer controlled source, the output can be modified in real time by a microprocessor, making it possible to create complex welding programs, allowing a level of automation not possible with traditional welders.
- The inverter technology allows to carry out welds cleaner, continuous, eliminating the hassle of electrode stuck.
- Minimal susceptibility to line voltage changes.
Let’s look at the most important advantages in more detail.
Thanks to the high frequency output and the microprocessor control of the characteristics of the arc in this type of welding, penetration and stability of the arc are guaranteed.
A better ignition of the arc is also achieved, which prevents the appearance of defects in the first attack with the electrode, and, thanks to the dynamic control of the inductance, a better wetting of the faces to be welded is achieved, and the almost total elimination of splashes.
Traditional welding machines achieve 60% energy efficiency at best. The inverter welders, especially those provided with the technology IGBTs, reach an efficiency of 90%, with which the energy saving is remarkable.
By eliminating the eddy currents that are unavoidable in the power supplies of traditional machines, and as it is a digital circuit that works at high frequency, these welding machines IGBTs can sustain welding current much longer than traditional ones; On average, it is possible to work 60% of the time that the machine is in operation.
Informatization and automation
The IGBT models that have a microprocessor allow loading specialized software for each type of material, electrode and technique of welding; In this way, it is possible to increase the quality of welding and production times to values impossible to achieve with traditional machines.
In turn, the incorporation of microprocessors opens the door to complete automation of the manufacturing process. welding, regardless of the technology used (SMAW, TIG, MIG, etc). It is then possible to program a team of welding by points so that it performs a weld every n milliseconds; in this way the current, the time of each cycle and the state of the electrode are controlled. The same can be achieved in robotic welding systems MIG-MAG, TIG, etc.
Many machines incorporate three basic modes to assist the welder:
- hot start, or hot start: it allows to prime the electrode in an easy way, for which the dexterity that is necessary with traditional equipment to prevent the electrode from sticking to the surface to be welded is not required.
- short bow: allows welding with the electrode close to the piece, which ensures wetting of the surfaces, less splashing and greater use of the electrode filler material.
- anti stick: it happens to all of us, with traditional equipment, that the new electrode paste to the surfaces to be welded when we start the operation, or resume it after a break. This is because the electrode is cold, and requires a certain amount of time in the arc to reach the melting temperature.
- Disconnect the machine from the mains before changing the electrodes. If this is inconvenient or impossible for you, wear rubber insulated safety shoes and gloves to prevent electrical shock from carelessness or distraction.
- Always use an approved eye protection mask.
- Wear suitable clothing: work overalls (overalls or overalls) and, if possible, a fireproof overall.
- Always keep a class ABC fire extinguisher always recharged and in working order.
- Before starting the welding check the surroundings of the work table and remove all combustible materials: paper, cardboard, flammable liquids and combustible or powdered metals (especially mixtures of aluminum and iron oxide).
- Read the instruction manual of your machine carefully welder before starting the tasks.
- Check that the electrical installation intended for the welder have the approved cutting elements: thermal key and circuit breaker.
- If you are going to work for long periods of time, wear a mask.
- Make sure that the place where you will carry out the work is properly ventilated and there are no dangerous vapors or gases.