From the article you will learn what welding machines are. Making them with your own hands is quite simple if you have basic knowledge of electrical engineering and the necessary tools. As a basis for a welding machine, both a ready-made transformer and a home-made one can be taken.
Of course, such designs consume a lot of power, therefore, a strong voltage drop will be observed in the network. This may affect the operation of household electrical appliances. It is for this reason that designs based on semiconductor elements are much more effective. To put it simply, these are inverter welding machines.
The simplest welding machine
So, the first step is to consider the simplest designs that anyone can repeat. Of course, these are the devices based on transformers. The design discussed below allows you to work on voltages of 220 and 380 volts. The maximum diameter of the electrode used in welding is 4millimeter. The thickness of the welded metal elements ranges from 1 to 20 millimeters. You will now learn in full about how to make a welding machine with your own hands. Moreover, you can move from simple to complex.
Despite these excellent characteristics, the welding machine is made from readily available materials. You will need a three-phase step-down transformer for assembly. At the same time, its power should be about 2 kilowatts. It is also worth noting that you will not need all the windings. Therefore, in the event that one of them fails, there will be no problems with further construction.
Transformer conversion
The bottom line is that you only need to make changes in the secondary winding. To facilitate the task, the article below shows a diagram of the welding machine, its connection to the network is also described.
So, the primary winding does not need to be touched, it has all the characteristics necessary for operation from a 220 Volt AC mains. There is no need to disassemble the core, it is enough to disassemble the secondary winding directly on it, and wind a new one instead.
There are several windings on the transformer you have to choose. Three primary, the same number of secondary. But there are also medium windings. There are also three of them. It is instead of the middle one that it is necessary to wind the same wire that was used to make the primary one. Moreover, it is necessary to make taps from every thirtieth turn. Near300 turns in total should have each winding. By properly winding the wire, you can increase the power of the welding machine.
The secondary winding is wound on both extreme coils. It is difficult to specify the exact number of turns, since the more, the better. The wire is used with a cross section of 6-8 square millimeters. Together with it, a thin wire is wound at the same time. As a power cable, you need to use a stranded cable in reliable insulation. This is how do-it-yourself welding machines are made.
If we analyze all the structures made using this technology, it turns out that the approximate amount of wire is about 25 meters. If there is no wire with a large cross section, you can use a cable with an area of 3-4 square millimeters. But in this case, it must be folded in half when winding.
Transformer connection
The design has a simple welding machine. A semi-automatic device can be made on its basis if one more winding is made to power the electric drive for supplying electrodes. Please note that the output of the transformer will be a very large current. Therefore, all switching connectors must be made as strong as possible.
To make terminals for connecting to the secondary winding, you will need a copper tube. It should have a diameter of 10 millimeters and a length of 3-4 cm. It needs to be riveted from one end. You should get a plate in which you need to make a hole. Its diameter should be about one centimeter. Withwires are inserted at the other end. Regardless of whether the welding machine is DC or AC, switching is made as rigid and reliable as possible.
It is desirable to clean them perfectly, if necessary, treat them in acid and neutralize it. To improve contact, the second edge of the tube should be slightly flattened with a hammer. The conclusions of the primary winding are best attached to the textolite board. Its thickness should be about three millimeters, it can be more. It is rigidly attached to the transformer. In addition, 10 holes need to be made in this board, each with a diameter of about 6 millimeters. Look at the scheme of the welding machine, how it is connected to the 220 and 380 Volt network.
They need to install screws, nuts and washers. The conclusions of all primary windings are connected to them. In the event that welding is required to work from a 220-volt household network, the extreme windings of the transformer are connected in parallel. The middle winding is connected in series with them. Welding will work ideally when powered by 380 volts.
To connect the primary windings to the mains, you need to use a different scheme. Both extreme windings are connected in series. Only after that, the middle winding is switched on in series with them. The reason for this lies in the following: the middle winding is an additional inductive resistance, with its help, the voltage and current in the secondary circuit are reduced. Thanks to this, do-it-yourself welding machines work in normal mode.made by the above technology.
Production of the electrode holder
Of course, an integral part of any welding machine is the electrode holder. There is no need to buy ready-made, if you can make it from improvised materials. You need a three-quarter pipe, its total length should be about 25 centimeters. At both ends, it is necessary to make small notches, about 1/2 of the diameter. With such a holder, the welding machine will work normally. There is a separate requirement for plastic structural elements - they must be located as far as possible from the transformer and holder.
You need to make them three to four centimeters from the edge. Then take a piece of steel wire with a diameter of 6 millimeters, weld it to the pipe opposite the larger recess. On the other hand, you need to drill a hole, attach a wire to it, which will be connected to the secondary winding.
Getting online
It is worth noting that you need to connect the welding machine in accordance with all the rules. First, you need to use a knife switch, with which you can easily disconnect the device from the network. Please note that do-it-yourself welding machines, in terms of safety, should not be inferior to analogues manufactured by the industry. Secondly, the cross section of the wires for connecting to the network must be at least one and a half square millimeters. The current consumption of the primary winding is a maximum of 25 amperes. AtIn this case, the current in the secondary circuit can be changed in the range of 60..120 amperes. Please note that this design is relatively simple, so it is only suitable for domestic use.
Try to give a little break from time to time, regardless of whether the welding machine is semi-automatic or manual. Used a dozen electrodes - turn off welding, let it cool down a bit. But this is only if electrodes with a diameter greater than 3 millimeters are used. If you use smaller ones, for example 2 millimeters, then the temperature of the transformer windings does not rise more than 80 degrees. Therefore, it is possible to work without switching off the welding machine. When operating, be sure to observe safety precautions. Familiarize yourself with the fire safety rules when operating the welding machine. Do not be lazy and read about the rules of electrical safety.
Spot welding machine
A spot-type welding machine will also be useful. The designs of such devices are no less simple than the previous ones. However, the output current is very large. But it is possible to produce resistance welding of metals up to three millimeters thick. In most designs there is no adjustment of the output current. But you can do it if you wish. True, the whole homemade work becomes more complicated. The need to regulate the output current is eliminated, since the welding process can be controlled visually. Of course, inverter welding machines will be much more efficient. But point ones can do whatdoes not allow to make any other design.
For the manufacture you will need a transformer with a power of about 1 kilowatt. The primary winding remains unchanged. Only the secondary will need to be redone. And if a transformer from a household microwave oven is used, then you need to knock out the secondary winding, instead winding several turns of large-section wire. If possible, it is better to use a copper bus. The output should be about five volts, but this will be enough for the full operation of the device.
Design of the electrode holder
Here it is slightly different from the one discussed above. For the manufacture you will need small duralumin blanks. Suitable rods with a diameter of 3 centimeters. The lower one must be motionless, completely isolated from the contacts. As an insulating material, you can use textolite washers, as well as varnished cloth. Any, even the simplest spot welding machine needs a reliable electrode holder, so pay maximum attention to its design.
Electrodes are made of copper, their diameter is 10-12 millimeters. They are firmly fixed in the holder with rectangular brass inserts. The initial position of the electrode holder - its halves are divorced. Springs can be used to give elasticity. Perfect for old cots.
Resistance welding work
It is necessary to connect such welding toelectrical network using a circuit breaker. It must have a rated current of 20 amps. Pay attention to the fact that at the input (where you have the counter) the machine must be either the same in terms of parameters or larger. To turn on the transformer, a simple magnetic starter is used. The operation of a contact-type welding machine is somewhat different from the one discussed above. And you will now learn these features.
To turn on the magnetic starter, you must provide a special pedal that you will press with your foot to generate current in the secondary circuit. Please note that resistance welding is switched on and off only if the electrodes are fully brought together. If you neglect this rule, then a lot of sparks will appear, as a result, this will lead to burning of the electrodes, their failure. Try to pay attention to the temperature of the welding machine as often as possible. Take small breaks from time to time. Do not allow the unit to overheat.
Inverter welding machine
It is the most modern, but more difficult to design. It uses a pulse transformer and high power semiconductor transistors. Perhaps these are the most expensive and scarce parts. First of all, the power supply is made. It is pulsed, so it is necessary to make a special transformer. And now in more detail about what such a welding machine consists of. See the characteristics of its componentsnext.
Of course, the transformer used in the inverter is much smaller than those discussed above. You will also need to make a throttle. So, you should get a ferrite core, a frame for making a transformer, copper tires, special brackets to fix the two halves of the ferrite core, electrical tape. The latter must be chosen based on the data of its thermal stability. Follow these tips when making inverter welders.
Transformer winding
The transformer is wound over the entire width of the frame. Only under this condition will it be able to withstand any voltage drop. For winding, either a copper bus or wires assembled in a bundle is used. Please note that aluminum wire cannot be used! It cannot withstand such a large electric current density, which is available in the inverter. Such a welding machine for giving is able to help you out, and its weight is extremely small. The coils are wound as tightly as possible. The secondary winding is two wires with a thickness of about two millimeters, twisted together.
They should be isolated from each other as much as possible. If you have large stocks of horizontal transformers from old TVs, you can use them in the design. It takes 5 pieces, and you need to make one common magnetic circuit out of them. In order for the device to work with maximum efficiency, you need to pay attention to every little thing. In particular, the wire thickness of the output windingtransformer affects its continuity.
Inverter design
To make a welding machine 200, you need to pay maximum attention to all the little things. In particular, power transistors must be mounted on a heatsink. Moreover, the use of thermal paste is welcomed to transfer heat from the transistor to the radiator. And it is recommended to change it from time to time, as it tends to dry out. In this case, heat transfer worsens, there is a possibility that semiconductors will fail. In addition, you need to do forced cooling. For this purpose, exhaust coolers are used. Diodes used to rectify alternating current must be mounted on an aluminum plate. Its thickness should be 6 millimeters.
The connection of the terminals is carried out using an uninsulated wire. Its cross section should be 4 mm. Please note that there is a maximum distance between the connection wires. They should not touch each other, no matter what impact the body of the welding machine experiences. The throttle must be fixed to the base of the welding machine with a metal plate.
Moreover, the latter should completely repeat the shape of the throttle itself. To reduce vibration, it is necessary to install a rubber seal between the housing and the throttle. Power wires inside the device are bred in different directions. Otherwise, there is a possibility that a shortclosure. It is necessary to install the fan in such a way that it blows all the radiators at the same time. Otherwise, if you cannot use one fan, you will have to install several.
But it is better to fully calculate in advance the installation location of all elements of the system. Please note that the secondary winding must be cooled as efficiently as possible. As you can see, not only radiators need effective airflow. On this basis, it is possible to make an argon welding machine at no cost. But its construction will require the use of other materials.
Conclusion
Now you know how to make several types of welding machines. If you have skills in the design of electronic equipment, then it is better, of course, to stop at an inverter welding machine. You will spend time, but at the end you will get an excellent device that is not inferior even to expensive Japanese counterparts. Moreover, its production will cost mere pennies.
But if there is a need to make a welding machine, as they say, in haste, it will be easier to connect two transformers from microwave ovens with modified secondary windings. Subsequently, the entire unit can be improved by adding an electric drive for supplying electrodes to it. You can also install a cylinder filled with carbon dioxide in order to weld metals in its environment.
