2 options for assembling a simple welding machine

It is difficult to imagine, in our time, any work with metal without the use of a welding machine. With this device, you can easily connect or cut iron of different thickness or dimensions. Naturally, for performing high-quality work you will need certain skills, but first of all you need a welder. Nowadays it can naturally be bought, as in principle and hire a welder, but in this article we will talk about how to make a welding machine with our own hands. Moreover, with all the richness of the choice of models, reliable ones are quite expensive, and cheap ones do not shine with the quality of the work performed. But even if you decide to buy a welding machine - getting acquainted with this article will help you choose the device you need. Welders are of several types: direct current, alternating, three-phase and inverter. In order to determine which option is necessary for you, we will consider the design and construction of the first two, which you can build without your own specific skills at home.

Contents:

AC alternating current
DC direct current
Visible master classes

AC alternating current

This type of welding machine is one of the most common options both in industry and in private households. It is easy to operate, compared to the rest it can be easily done at home, which is confirmed by the photo below. For this you need to have a wire for the primary and secondary winding, as well as a core of transformer steel for winding the welder. In simple words, an AC welding machine is a step-down transformer. An example of a self-made welding machine

The optimum voltage for the welding machine assembled at home is 60V.The optimum current is 120-160A.Now it is easy to calculate which section should be at the wire in order to make the primary winding of the transformer( the one that will be connected to the 220 V network).The minimum cross-sectional area of a copper wire should be 3-4 kV.mm, the optimal is 7 square meters.mm, in fact it is necessary to take into account voltage drops and possible additional load. We get that the optimal diameter of the copper core for the primary winding of the step-down transformer should be 3 mm. If you decide to take an aluminum wire in order to make a welding with your own hands, then the cross section of a copper wire should be multiplied by a factor of 1.6.It is important that the wires are in a rag sheath, you can not use conductors in PVC insulation - it will melt when the wires heat up and a short circuit occurs. If you do not have a wire of the required diameter, you can use thinner wires, winding them in pairs. But then it should be taken into account that the thickness of the winding will increase, and accordingly the overall dimensions of the apparatus. For a secondary winding, you can use a thick stranded copper wire - the same as the core on the holder.

The first thing to do is to fabricate a transformer core of a homemade welding machine. The optimum option is the core type as shown in Figure 1:

Core layout

This core must be made of transformer steel plates. The thickness of the plates should be from 0.35 mm to 0.55 mm. Before assembling the core, it is necessary to calculate its dimensions, in the following way: first, the size of the window, i.e., the dimensions of c and d in Figure 1, must be chosen so as to place all the windings of the transformer, and secondly, the roll area thatis calculated by the formula Skrena = a * b, should be at least 35 square meters.see If the screen is longer - then the transformer will be heated less and consequently work longer. It is better that the street is equal to 50 square meters.see Next we proceed to assemble the plates of a self-made welding machine. It is necessary to take the L-shaped plates and fold them, as shown in Figure 2, until you can make a core of the required thickness. Then fasten it with bolts in the corners. At the end it is necessary to process the surface of the plates with insets and insulate them by wrapping them with rags. Correct laying of plates

Then proceed to winding the welding machine from the step-down transformer. At the beginning, we wind the primary winding, which will consist of 215 turns, as shown in Figure 3. Primary winding of a mini welding machine

It is advisable to make a branch from 165 and 190 turns. At the top of the transformer we attach a thick textolite plate. The ends of the windings are fixed on it by means of a bolted connection, marking that the first bolt is a common wire, the second is a branch from 165 turns, the third - a branch from 190 turns and the fourth - from 215th. This will enable later to regulate the current during welding, the greater the number of turns in the primary winding - the higher the current strength of your welding device. After proceeding to winding 70 turns of the secondary winding, as shown in Figure 4.

A smaller number of turns are wound on the side of the core - where the primary winding is wound. The ratio of turns should be made approximately 60% to 40%.This contributes to the fact that after you catch the arc and start welding, the eddy currents partially disconnect the work of the winding with a large number of turns, which will lead to an increase in the welding current, and consequently improve the quality of the seam. The ends of the winding are also fixed with bolts on the textolite plate. Now your homemade welding machine is ready. Having connected the holder and mass to the secondary winding, it is necessary to connect the network to the common wire and the wire departing from the 215th turn of the primary winding. If you need to increase the amperage, you can make fewer turns of the primary winding by switching the second wire to a contact with fewer turns. Reduce the characteristics can be with the help of a resistance made of a curved in the form of a spring piece of transformer steel connected to the holder. Always ensure that the welding machine does not overheat.

That's how you can make a welding machine from a step-down transformer yourself. As you can see, the instruction is not too complicated and even an inexperienced electrician will be able to assemble the device on his own.

Direct current

For some types of welding a DC welding welder is required. This tool can be cast iron and stainless steel. Make a DC welding machine with your own hands can be no more than 15 minutes, transforming the self-made on an alternating current. To do this, a rectifier must be connected to the secondary winding assembled on the diodes. As for the diodes, they must withstand a current of 200 A and have good cooling. Diodes D161 are suitable for this. Align current to us help capacitors C1 and C2 with the following characteristics 15000 uF and voltage 50V.Next, we compile the scheme that is shown in the figure below. A choke L1 is required for current regulation. Contacts x4 for connecting the holder, and x5 for supplying current to the welded part of the part.

Visual diagram with rectifier

Three-phase welding machines are used for welding in production conditions, they use two-electrode holders, so in this article we will not consider them, and inverters are manufactured on the basis of printed circuit boards, for the manufacture of which you need special equipment. Now you know the basic principles of welding machine design and can use them, make a welding machine with your own hands, both a constant and alternating current. We also recommend viewing the video lessons provided below, which will help you to see clearly how to assemble a simple welder from improvised materials.