A huge amount of equipment has already been created for welding work. These devices can be operated with coated electrodes or with a special wire that is continuously fed into the working area. These are effective devices, and among the shortcomings, only heavy weight and bulky dimensions are noted. Also, this equipment will be difficult to master for beginners in this business.
Besides, not all work can be done with the help of such transformer devices.
Relatively recently, a new type of equipment has appeared - a semi-automatic welding inverter. Let's try to understand the principles of operation, find out the scheme of this device, as well as the features of this group of devices.
The principle of operation of inverter equipment
This is one of the youngest and very promising devices. Their serial production began only in the 80s. These were rectifiers equipped with a transistor inverter. In this device, electricity can change its characteristics up to several times. Scheme of a semi-automatic welding machineallows you to see all this more clearly.
First, the current is rectified as it passes through the semiconductor elements. Then smoothing occurs using a system of filters. Further, the direct current of the standard frequency changes its state to an alternating one, but its frequency is already much higher. After the frequency changes, the current is fed to a small transformer, where the voltage decreases and the current increases. Then high-frequency filters and rectifiers are connected, which form an electric arc.
Advantages of Inverter Welding Machines
Among the pluses is the weight. These are fairly compact devices. Various types of electrodes can be used here. This allows you to work on cast iron and non-ferrous metals. Inverters also have higher efficiency. It can reach 85%. Cost-effectiveness is also one of the advantages, and the ability to smoothly adjust the operating current, a stable arc is suitable for all types of operations.
For beginners, an inverter-type semi-automatic welding machine can greatly simplify work. In the hands of a professional, this high-frequency device is capable of producing high-quality and most reliable seams.
Flaws
The main drawback is the rather high price.
The cost is usually much higher than the price of transformer equipment. It will also be expensive to repair if the device suddenly fails. For example, a block of power transistors isa third of the cost of the device.
Besides, the device does not like dust. Coolers for cooling are installed in the case - dust is sucked into it in huge quantities. There may be metal dust in the air, which can cause short circuits.
Still among the shortcomings, professionals note complex electronics, which is very sensitive to low air temperatures and moisture. There is a risk of condensation buildup. There may also be some problems with operation in winter, and the device also requires proper storage.
Semiautomatic inverter welding
Semi-automatic devices differ from simple inverter welding devices by the presence of a mechanism for supplying a special electrode wire to the welding site. To start the feed, the specialist presses a special trigger. The area where the work is carried out must be blown with protective gases. This can be helium, argon, or carbon dioxide in the case of MAG or MIG systems. Household appliances work with carbon dioxide. Household argon is overpriced and needed for aluminum or stainless steel applications.
Semiautomatic device
Whichever semi-automatic welding machine you choose, they all consist of a source for creating an electric arc, a gearbox and a motor, a torch with a sleeve, a cable for connecting to a workpiece with a clamp. There is also a gas supply hose, a cylinder with a reducer, as well as a control system.
Equipment Pros
Such a semi-automatic welding machine allows you to work in various conditions - for this, the device hasfairly wide range of settings. With their help, you can very easily select the desired mode of operation at the moment.
The arc can be observed at any position of the torch. Plus specifically inverter models - the ability to operate in any position. This may be necessary to work in rather hard-to-reach places.
This equipment can operate with thin-sheet materials or with those that are difficult to weld. If there is a need to weld more massive parts, then you can work without gas at all. The gas is designed to remove oxygen to prevent oxidation of the metal. Reaction with oxygen during welding leads to weld slag, films, and other troubles that affect reliability.
A wide variety of wires can be used with the machines. The settings allow you to adjust the currents in a fairly wide range. So, using this type of semi-automatic welding machine, you can even perform body work. They need high welding accuracy - the inverter machine provides such accuracy.
Flaws
The first minus is the price. Next comes the price for consumables, in particular, the cost of gases is also quite high. To use this welding technology, either gas cylinders are needed, or it is necessary to connect the equipment to the gas network. It is also the almost complete lack of mobility. Also, a semi-automatic welding machine does not allow you to work with it on the street, and if you can work, it is very inconvenient - you need to protect the burner from blowing it out with the wind.
How to choose the right model
As in the case with any other equipment, here the devices are also conditionally divided into professional devices and amateur ones. But do not think that amateur devices have truncated functionality. No. In terms of functionality, household models are not much inferior to the professional group. Just an amateur inverter is designed for small loads. The work involves short-term approaches. The household model is not able to withstand an 8-hour work shift. Many appliances come with additional features that make them easier and better to use.
Many of the devices on the market can be purchased for the garage or for the home. The semi-automatic welding circuit can operate from a household electrical network. If there is a need to perform work away from sockets, then the equipment is equipped with the function of working from diesel generators.
You need to choose according to some important factors. Let's take a closer look at them.
Voltage
Semi-automatic devices are powered by a single-phase or three-phase network.
But for home use you need a 220V device.
Many products on the market today are very sensitive to unstable voltages. They regularly fail or simply do not cook. Repairing a semi-automatic welding machine is an expensive pleasure, so manufacturers equip their devices with surge protection. A household unit often has a range extended by 15%. And professional ones can work at voltages of 165-270 V. There are inverter models that work great at low rates.
Open circuit voltage
This is more true for conventional welding machines. This characteristic shows how this or that model can kindle, and then keep the arc burning. These parameters are limited by GOSTs at the level of 80 V in the case of alternating currents and 90 V for direct current. Practice shows that the device can ignite an arc even at 30 V. These are smart systems with electronic control. Among welders, it is believed that the higher the voltage at idle, the better the machine.
Power
The manual of the semi-automatic welding machine contains all the data about the device. The maximum power consumption for this type of work is also indicated there. This figure also corresponds to the level of peak loads on the network. This power is indicated either in kW or in kVA. The first option indicates the active power, while the second measures the apparent power. If you know how much a particular device consumes, you can accurately control the correct connection.
Even if the device can operate normally at low voltages, performance may drop. Knowing this, it is advisable to purchase a more powerful semi-automatic welding machine (which one to choose depends on the goals). Experts say that the power margin should be at least 30%. Also, do not use the device at the maximum of its capabilities.
Real power performance can only be determined by the strength of the current that it can deliver. It is from thischaracteristics depends on the thickness of the metal this or that model can work with. The maximum thickness of the electrode also depends on this.
For domestic purposes, a unit up to 250 A is enough. What can such a semi-automatic welding machine do? Owner reviews let you know what to expect. So, the maximum thickness of the metal is 6 mm, and the diameter of the electrode is 4 mm.
Working hours
This is the most useful and most important information for anyone looking for this equipment. This option allows you to evaluate performance. Engineers take a work cycle, which is limited in time, and divide it as a percentage - how much this or that model can work without interruptions, and how much the machine needs to rest so that it does not have to repair the semi-automatic welding machine later. For example, in European countries, they count for 10 minutes. In our country, they take 5 minutes as a basis. If the air defense is 30%, then the European model will turn off after 3 minutes of continuous operation, and it will be possible to start the device again only after 7 minutes. Of course, practice shows that no one works like this.
Generator capability and additional features
Generator power is a welcome option. However, not every device has it. Modern welding units are often equipped with other nice options. So, for example, "Hot start", "Forcing the arc", "Anti-stick" and others - all this is integral in the case of inverter systems. Don't pay attention to them - they are there by default.
If you need a semi-automatic welding machine, which one to choose?
The one that has a wide range of adjustments, an overload protection system. Also, the unit must be safe, maintainable, ergonomic.
Mechanics
Devices differ in equipment, level, cost. The mechanics also differ in type. So, for household appliances, a pushing mechanism is mainly used as a wire feeder. Here, the system simply pushes the filler wire into the sleeve, which can sometimes cause jams.
The pull mechanism is located in the handle of the torch and is fitted to mid-range models. The wire is pulled either from a spool located in the body, or from a small one that can be installed in the handle.
There is also a push-pull drive. They are equipped mainly with expensive, professional models. Here, two devices work synchronously.
As for the wire, most of both professional and amateur equipment can work with wire from 0.6 to 1 mm. Also emit a welding semiautomatic device without gas. This is a very convenient option due to the price of argon.
Feeders can be equipped with one or two pairs of rollers.
Single-pair movements are the most popular. They are used with burners with a sleeve up to 3.25 m long.
Each semiautomatic device is equipped with a wire feed speed control. There are both step adjustments and smooth ones. Some models feed the wire intovoltage.
Top Models
It is very difficult to recommend the best semi-automatic welding machine. This is the group of equipment where there is simply no universal model for everything. However, you can purchase some affordable devices that are suitable for both beginners and professionals. So, both those and others praise the models of the company Aurora. The brand offers a wide range of different semi-automatic machines.
