We make a welding machine ourselves. Welding machine for welding small parts with your own hands The simplest home-made welding machine with your own hands

Nowadays it is difficult to imagine any work with metal without the use of a welding machine. With this device, you can easily connect or cut iron of various thicknesses and dimensions. Naturally, to perform high-quality work, you will need certain skills in this matter, but first of all, you need the welder himself. Nowadays, you can naturally buy it, as in principle, hire a welder, but in this article we will talk about how to make a welding machine with your own hands. Moreover, with all the wealth of various models, reliable ones are quite expensive, and cheap ones do not shine with quality and durability. But even if you decide to buy a welder in a store, familiarity with this article will help you choose the necessary device, since you will know the basics of their circuitry. There are several types of welders: DC, AC, three-phase and inverter. In order to determine which option you need, consider the design and device of the first two types, which can be assembled without specific skills with your own hands at home.

On 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 is quite easy to make at home, which confirms the photo below. To do this, you need to have a wire for the primary and secondary windings, as well as a core of transformer steel for winding the welder. In simple terms, an AC welding machine is a high power step-down transformer.

The optimal voltage during operation of a welding machine assembled at home is 60V. Optimum current 120-160A. Now it is easy to calculate what section the wire should have 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 the copper wire should be 3-4 square meters. mm, the optimal one is 7 sq. mm, because it is necessary to take into account the possible additional load, as well as the necessary margin of safety. 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 machine with your own hands, then the cross section for the copper wire must be multiplied by a factor of 1.6.

It is important that the wires are in a rag braid; conductors in PVC insulation cannot be used - when the wires are heated, it will melt and occur. If you do not have a wire of the required diameter, then you can use thinner cores by winding them in parallel. But then it should be borne in mind that the thickness of the winding will increase, and, accordingly, the dimensions of the apparatus itself. It must be borne in mind that the limiting factor may be a free window in the core and the wire may simply not fit there. For the secondary winding, you can use a thick stranded copper wire - the same as the core on the holder. Its cross section should be chosen based on the current in the secondary winding (recall that we focus on 120 - 160A) and the length of the wires.

The first step is to make the transformer core of a homemade welding machine. The best option would be a rod-type core as shown in Figure 1:

This core must be made from transformer steel plates. The thickness of the plates should be from 0.35 mm to 0.55 mm. This is necessary to reduce . Before assembling the core, you need to calculate its dimensions, this is done as follows:

First, the size of the window is calculated. Those. dimensions c and d in figure 1 must be chosen to accommodate all the windings of the transformer.
Secondly, the roll area, which is calculated by the formula: Sroll \u003d a * b, must be at least 35 square meters. see If there is more Sk, then the transformer will heat up less and, accordingly, work longer, and you will not need to be interrupted often in order for it to cool down. It is better that the screen is equal to 50 square meters. cm.

Next, we proceed to the assembly of the plates of a home-made welding machine. It is necessary to take the L-shaped plates and fold them, as shown in Figure 2, until you can make the core of the required thickness. Then we fasten it with bolts in the corners. At the end, it is necessary to process the surface of the plates with a file and insulate them by wrapping them with rag insulation in order to additionally protect the transformer from breakdown to the housing.

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

It is advisable to make a branch from 165 and 190 turns. We attach a thick textolite plate on top of the transformer. We fix the ends of the windings on it using a bolted connection, marking that the first bolt is a common wire, the second is a branch from the 165th turn, the 3rd is a branch from the 190th turn and the 4th is from the 215th. This will make it possible to subsequently adjust the current strength during welding by switching between different outputs of your welding device. This is a very important function, and the more branches you make, the more accurate your adjustment will be.

After we start winding 70 turns of the secondary winding, as shown in Figure 4.

A smaller number of turns are wound on the other 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, eddy currents will partially turn off the operation of the winding with a large number of turns, which will lead to a decrease in the welding current, and, accordingly, improve the quality of the seam. Thus, the arc will be easy to catch, but too much current will not interfere with high-quality cooking. We also fix the ends of the winding with bolts on the textolite plate. You can not attach them, but run the wires directly to the electrode holder and the crocodile to ground, this will remove connections where there could potentially be a voltage drop and heat. For better cooling, it is highly desirable to install a fan for blowing, for example, from a refrigerator or microwave.

Now your homemade welding machine is ready. Having connected the holder and the mass to the secondary winding, it is necessary to connect the network to the common wire and the wire extending from the 215th turn of the primary winding. If you need to increase the current, then you can make fewer turns of the primary winding by switching the second wire to a contact with fewer turns. You can reduce the current with the help of a resistance made of a piece of transformer steel bent in the form of a spring connected to the holder. It is always necessary to ensure that the welding machine does not overheat, for this, regularly check the temperature of the core and windings. For these purposes, you can even install an electronic thermometer.

This is how you can make a welding machine from a step-down transformer with your own hands. As you can see, the instructions are not too complicated and even an inexperienced electrician will be able to assemble the device on their own.

DC

Some types of welding require a DC welder. This tool can weld cast iron and stainless steel. You can make a DC welding machine with your own hands in no more than 15 minutes by redoing a homemade product with alternating current. To do this, a rectifier assembled on diodes must be connected to the secondary winding. As for the diodes, they must withstand a current of 200 A and have good cooling. Diodes D161 are suitable for this.

Capacitors C1 and C2 will help us equalize the current with the following characteristics: capacitance 15,000 microfarads and voltage 50V. Next, we assemble the circuit, which is indicated in the drawing below. Choke L1 is needed to regulate the current. Contacts x4 - plus for connecting the holder, and x5 - minus for supplying current to the part to be welded.

Three-phase welding machines are used for welding in production conditions, they are equipped with two-electrode holders, so we will not consider them in this article, and inverters are made on the basis of printed circuit boards and complex circuits with a large number of expensive radio components and a complex tuning process using special equipment. However, we still recommend that you familiarize yourself with the inverter design in the video below.

Visual master classes

So, if you decide to make a welding machine at home, we recommend that you watch the video tutorials provided below, which will clearly show how to assemble a simple welder from improvised materials yourself, and also explain to you some details and nuances of the work:

Now you know the basic principles of the design of welders and you can make a welding machine with your own hands, both on direct and alternating current, using the instructions from our article.

Also read:

Welding work at home has long been commonplace. The availability of devices and consumables, the ability to inexpensively study at welding courses, various manuals for obtaining independent skills. All these factors make it possible to save on the wages of a professional welder, and increase the efficiency of work.

However, if you carefully study the market for welding machines, unpleasant moments are revealed:

High-quality welders have a high cost, it is more profitable to hire a specialist several times (unless, of course, you do this work all the time).
Affordable units have a number of disadvantages: low reliability, poor quality of the seam, dependence on the supply voltage and type of consumables.

Hence the conclusion: if you need high quality equipment at an affordable price, you will have to make a welding machine from available materials with your own hands.

Before considering the options for homemade welders, we will analyze the principle of their work.

Ohm's law is at the heart of the operation of any unit. At constant power, there is an inverse relationship between current and voltage. For normal operation, a current of 60–150 A is required. Only in this case, the metal in the welding zone will melt. Imagine a welding machine that works directly with a voltage of 220 volts. To achieve the required current strength, a power of 15–30 kW is required. Firstly, for this it will be necessary to lay a separate power supply line: most inputs to residential premises are limited by technical conditions at the level of 5–10 kW. In addition, for such a current strength, wiring with a cross section of at least 30 mm² is required. You will have to cook in compliance with protective measures when working in electrical installations up to 1000 volts: rubber boots, gloves, workplace fencing, and so on.

Of course, it is impossible to provide such conditions in reality.

Therefore, any welding machine converts the voltage (downward): at the output we get the desired current while maintaining reasonable power.

The optimal voltage value is 60 volts. With a welding current of 100 A, this is quite acceptable 6 kW of power. How to convert voltage?

There are four main types of welding machines

Any of these devices can be assembled independently. Let's review manufacturing technologies by models:

Transformers (with or without rectifier)

The heart of a transformer is the core. It is recruited from transformer steel plates, which are quite problematic to make manually. By hook or by crook, the source material is mined in factories, in construction teams, at scrap metal collection points. The resulting structure (usually in the form of a rectangle) must have a cross section of at least 55 cm². This is a rather heavy construction, especially after laying the windings.

When assembling, it is imperative to provide an adjusting screw with which you can move the secondary winding relative to the stationary primary.

In order not to go into the complexity of calculating the cross section of wires, we take typical parameters:

current strength on the secondary 100–150 A;
open circuit voltage 60–65 volts;
operating voltage when welding 18–25 volts;
current strength on the primary winding up to 25 A.

Based on this, the cross section of the primary wire should be at least 5 mm², if done with a margin, you can take a wire of 6–7 mm². The insulation must be heat-resistant, of a material that does not support combustion.

The secondary winding is recruited from a wire (or preferably a copper bus), with a cross section of 30 mm². Rag insulation. Don't let the thickness scare you, the number of turns on the secondary is small.

The number of turns of the primary winding is determined by a factor of 0.9–1 turns per volt (for our parameters).

The formula looks like this:

W(number of turns) = U(voltage) / factor.

That is, with a network voltage of 200–210 volts, it will be about 230–250 turns.

Accordingly, at a secondary voltage of 60–65 volts, the number of its turns will be 67–70.

From a technical point of view, the transformer is ready. For ease of use, it is recommended to make a small margin for the secondary winding, with several branches (at 65, 70, 80 turns). This will allow you to work confidently in places with low mains voltage.

Hiding the unit in the case, or leaving it open is a matter of safe use. A typical manufactured do-it-yourself welding transformer looks like this:

The optimal material for the case is textolite 10–15 mm.

Adding a rectifier

A home-made powerful welding transformer from the point of view of circuitry is a conventional power supply. Accordingly, the rectifier is arranged as simply as in a mains charger for a mobile phone. Only the element base will look several orders of magnitude more massive.

As a rule, a couple of capacitors are added to a simple diode bridge circuit to dampen the rectified current pulses.

You can assemble a rectifier without them, but the smoother the current, the better the welding seam is obtained. To assemble the bridge itself, powerful diodes of the D161–250 (320) type are used. Since a lot of heat is generated on the elements under load, it must be dissipated using heatsinks. Diodes are attached to them with a bolted connection and thermal paste.

Of course, the radiator fins must either be blown by a fan or protrude above the case. Otherwise, instead of cooling, they will heat the transformer.

mini welding transformer

If you do not need to weld rails or channels from 4–5 mm steel, you can assemble a compact welder for soldering steel wire (making frames for homemade products) or welding thin sheet metal. To do this, you can take a ready-made transformer from a powerful household appliance (ideally, a microwave oven), and rewind the secondary winding. Wire cross section 15–20 mm², power consumption no more than 2–3 kW.

The scheme is calculated in the same way as for more powerful units. When assembling the rectifier, you can use less powerful diodes.

micro welder

If the scope is limited to soldering copper wires (for example, when installing junction boxes), you can limit yourself to a design the size of a couple of matchboxes.

It is performed on the transistor KT835 (837). The transformer is made independently. In fact, this is a high-frequency boost converter.

Unlike traditional welders, this circuit uses high voltage, up to 30 kV. Therefore, care must be taken when working.

We wind the transformer on a ferrite rod. Two primary windings: collector (20 turns 1 mm), base (5 turns 0.5 mm). Secondary (step-up) winding - 500 turns of 0.15 wire.

We assemble the circuit, solder the resistor piping according to the circuit (so that the transformer does not overheat at idle), the device is ready. Powered from 12 to 24 volts, with the help of such a device you can weld wire harnesses, cut thin steel, connect metals up to 1 mm thick.

A thick sewing needle can be used as welding electrodes.

Inverter (switching power supply for welding)

A homemade inverter welding machine cannot be made simply “on the knee”. This will require a modern element base and experience with the repair and creation of electronic devices. However, the scheme is not as terrible as it is painted. There are a great many such devices, and they all work no worse than factory counterparts. In addition, in order to create a pulse welding machine with your own hands, it is not necessary to purchase dozens of expensive radio components and ready-made assemblies. Most of them, especially high-frequency elements for the power supply, can be borrowed from old TVs or a PSU from a computer. The cost is close to zero.

The considered inverter has the following characteristics:

Load current on electrodes: up to 100 A.
Power consumption from a 220 volt network - no more than 3.5 kW (current about 15 A).
Used electrodes up to 2.5 mm.

The illustration shows a finished scheme, which has been repeatedly tested by many home craftsmen.

Structurally, the inverter consists of three elements:

Power supply for the converter and control circuit. Made on an affordable element base, using an optocoupler from an old computer power supply. With the independent manufacture of the transformer, the cost is almost zero: the parts are cheap. Denominations and names of radioelements in the illustration.
Capacitor charge delay unit (for the starting arc). Made on the basis of KT972 transistors (absolutely not a shortage). Of course, transistors are mounted on radiators. For switching, an ordinary automobile relay with a current load on the contacts of up to 40 A is sufficient. For manual control, conventional circuit breakers (bags) of 25 A are installed. Output 300 volts - idle. When loaded, the voltage is 50 volts.
The current transformer is the most critical node. When assembling, special attention should be paid to the accuracy of the inductors. Some tuning can be done using a variable resistor (highlighted in red in the diagram). However, if the parameters are not consistent, the required arc power cannot be achieved. PWM is implemented on the US3845 chip (one of the few parts that you have to buy). Power transistors - all the same KT972 (973). Some elements in the diagram are imported, but they can be easily replaced with available domestic ones by looking for analogues on the datasheet website. The high-frequency unit is made from parts of a horizontal transformer from a TV.

Working wires no more than 2 meters long are connected to the output of the welding inverter. The cross section is at least 10 squares. When working with electrodes up to 2.5 mm, the current drop is minimal, the seam is smooth and even. The arc is continuous, not worse than the factory analogue.

In the presence of active cooling (fans from the same computer power supply), the design can be compactly packed into a small case. Considering high frequency transducers, it is better to use metal.

Outcome

The more complex the homemade welding machine, the greater the savings. It is simple transformers that are more expensive due to the use of expensive copper in the windings or transformer iron. Switching power supplies, especially if there are old parts from typical electrical appliances in stock, are almost free.

AC Welder

This is the most common type of apparatus for welding metals. It is easy to make at home, and it is unpretentious in operation. But the main disadvantage of the apparatus is large mass of step-down transformer, which is the basis of the aggregate.

For home use, it is enough that the device produces a voltage of 60 V and can provide a current of 120-160 A. Therefore, for primary, to which a 220 V household network is connected, a wire with a cross section of 3 mm 2 to 4 mm 2 is required. But the ideal option is a conductor with a cross section of 7 mm 2. With such a cross section, voltage drops and possible additional loads will not be terrible for the device. From this it follows that for the secondary you need a conductor having a diameter of 3 mm. If we take an aluminum conductor, then the calculated cross section of the copper is multiplied by a factor of 1.6. For resale a copper bus with a cross section of at least 25 mm 2 is required

It is very important that the winding conductor is covered with rag insulation, since the traditional PVC sheath will melt when heated, which can cause an interturn short circuit.

If you did not find a wire with the required cross section, then it can be make your own from several thinner conductors. But at the same time, the thickness of the wire and, accordingly, the dimensions of the unit will increase significantly.

First thing, the basis of the transformer is made - the core. It is made of metal plates (transformer steel). These plates should have a thickness of 0.35-0.55 mm. The studs connecting the plates must be well insulated from them. Before assembling the core, its dimensions are calculated, that is, the dimensions of the “window” and the cross-sectional area of the core, the so-called “core”. To calculate the area, use the formula: S cm 2 \u003d a x b (see figure below).

But it is known from practice that if a core is made with an area of less than 30 cm 2, then it will be difficult to obtain a high-quality seam with such an apparatus due to a lack of power reserve. Yes, and it will heat up very quickly. Therefore, the cross section of the core must be at least 50 cm 2 . Despite the fact that the mass of the unit will increase, it will become more reliable.

To assemble the core, it is better to use L-shaped plates and place them as shown in the following figure until the thickness of the part reaches the required value.

At the end of the assembly, the plates must be fastened (at the corners) with bolts, then cleaned with a file and insulated with fabric insulation.

Now we can start transformer winding.

One caveat should be taken into account: the ratio of turns on the core should be 40% to 60%. This means that on the side where the primary is located, there should be fewer turns of the secondary. Due to this, at the start of welding, the winding with more turns will be partially switched off due to the occurrence of eddy currents. This will increase the current strength, which will positively affect the quality of the seam.

When the winding of the transformer is completed, the network cable is connected to the common wire and to the 215 turn branch. Welding cables are connected to the secondary winding. After that, the contact welding machine is ready for operation.

DC device

To cook cast iron or stainless steel, a DC apparatus is required. It can be made from a conventional transformer unit, if its secondary winding connect rectifier. Below is a diagram of a welding machine with a diode bridge.

Scheme of a welding machine with a diode bridge

The rectifier is assembled on D161 diodes, capable of withstanding 200A. They must be installed on radiators. Also, to equalize the current ripple, you will need 2 capacitors (C1 and C2) for 50 V and 1500 uF. This circuit also has a current regulator, the role of which is performed by the inductor L1. Welding cables are connected to contacts X5 and X4 (direct or reverse polarity), depending on the thickness of the metal to be joined.

Computer power supply inverter

It is impossible to make a welding machine from a computer power supply. But using its case and some parts, as well as the fan, is quite realistic. So, if you make an inverter with your own hands, then it can be easily placed in the PSU case from the computer. All transistors (IRG4PC50U) and diodes (KD2997A) must be installed on radiators without the use of gaskets. For cooling parts, it is desirable use a powerful fan, such as Thermaltake A2016. Despite its small size (80 x 80 mm), the cooler is capable of 4800 rpm. The fan also has a built-in speed controller. The latter are regulated using a thermocouple, which must be mounted on a radiator with installed diodes.

Advice! It is recommended to drill several additional holes in the PSU case for better ventilation and heat dissipation. The overheating protection installed on the radiators of the transistors is set to operate at a temperature of 70-72 degrees.

Below is a circuit diagram of a welding inverter (in high resolution), according to which you can make a device that fits in the PSU case.

The following photos show what components a homemade inverter welding machine consists of, and how it looks after assembly.

electric motor welder

To make a simple welding machine from the stator of an electric motor, it is necessary to select the motor itself that meets certain requirements, namely, that its power is from 7 to 15 kW.

Advice! It is best to use a 2A series motor, as it will have a large magnetic circuit window.

You can get the right stator in places where scrap metal is accepted. As a rule, it will be cleaned of wires and after a couple of blows with a sledgehammer it will split. But if the body is made of aluminum, then in order to remove the magnetic circuit from it, stator needs to be annealed.

Preparation for work

Place the stator with the hole up and place bricks under the part. Next, stack the wood inside and set it on fire. After a couple of hours of roasting, the magnetic core will easily separate from the body. If there are wires in the housing, they can also be removed from the grooves after heat treatment. As a result, you will receive a magnetic circuit cleaned of unnecessary elements.

This blank should be well saturate with oil varnish and let it dry. You can use a heat gun to speed up the process. Impregnation with varnish is done so that after removing the screeds, the package does not spill.

When the blank is completely dry, using the grinder, remove the ties located on it. If the ties are not removed, they will act as short-circuited turns and take power from the transformer, as well as cause it to heat up.

After cleaning the magnetic circuit from unnecessary parts, you will need to make two end caps(see picture below).

The material for their manufacture can be either cardboard or pressboard. You also need to make two sleeves from these materials. One will be internal, and the second - external. Next, you need:

install both end plates on the blank;
then insert (dress) the cylinders;
wrap all this structure with keeper or glass tape;
impregnate the resulting part with varnish and dry.

Transformer manufacturing

After carrying out the above steps, it will be possible to make a welding transformer from the magnetic circuit. For these purposes, you will need a wire covered with fabric or glass-enamel insulation. To wind the primary winding, you need a wire with a diameter of 2-2.5 mm. The secondary winding will require about 60 meters of copper bus (8 x 4 mm).

So, the calculations are done as follows.

20 turns of wire with a diameter of at least 1.5 mm should be wound on the core, after which 12 V must be applied to it.
Measure the current flowing in this winding. The value should be about 2 A. If the value is greater than the required, then the number of turns must be increased, if the value is less than 2A, then reduced.
Count the number of turns you get and divide it by 12. As a result, you will get a value that indicates how many turns you need per 1 V of voltage.

For primary winding a conductor with a diameter of 2.36 mm is suitable, which needs to be folded in half. In principle, you can take any wire with a diameter of 1.5-2.5 mm. But first you need to calculate the cross section of the conductors in the coil. First you need to wind the primary winding (at 220 V), and then the secondary. Its wire must be insulated along its entire length.

If you make a tap in the secondary winding in the area where 13 V is obtained and put a diode bridge, then this transformer can be used instead of the battery if you want to start the car. For welding, the voltage on the secondary winding should be in the range of 60-70 V, which will allow the use of electrodes with a diameter of 3 to 5 mm.

If you have laid both windings, and there is free space left in this design, then you can add 4 turns of a copper bus bar (40 x 5 mm). In this case, you will receive a winding for spot welding, which will allow you to connect sheet metal up to 1.5 mm thick.

For case manufacturing metal is not recommended. It is better to make it from textolite or plastic. In places where the coil is attached to the body, rubber gaskets should be laid to reduce vibration and better insulation from conductive materials.

Homemade spot welding machine

The finished spot welding machine has a rather high price, which does not justify its internal “stuffing”. It is arranged very simply, and it will not be difficult to make it yourself.

To make a spot welding machine yourself, you need one transformer from a microwave oven with a power of 700-800 watts. It is necessary to remove the secondary winding from it in the manner described above, in the section where the manufacture of a microwave welding machine was considered.

The spot welding machine is made in the following way.

Make 2-3 turns inside the manitoduct with a cable with a conductor diameter of at least 1 cm. This will be the secondary winding, which allows you to get a current of 1000 A.
It is recommended to install copper lugs at the ends of the cable.
If you connect 220 V to the primary winding, then on the secondary winding we will get a voltage of 2 V with a current strength of about 800 A. This will be enough to melt an ordinary nail in a few seconds.
Followed by make a case for the device. For the base, a wooden board is well suited, from which several elements should be made, as shown in the following figure. The dimensions of all parts can be arbitrary and depend on the dimensions of the transformer.
To give the case a more aesthetic appearance, sharp corners can be removed using a hand router with an edge moulder mounted on it.
On one part of the welding tongs, it is necessary cut a small wedge. Thanks to him, ticks will be able to rise higher.
Cut holes on the back wall of the case for the switch and the mains cable.
When all the details are ready and sanded, they can be painted with black paint or varnished.
From an unnecessary microwave, you will need to disconnect the mains cable and limit switch. You will also need a metal door handle.
If you do not have a switch and a copper rod lying around at home, as well as copper clips, then these parts must be purchased.
From the copper wire, cut 2 small rods that will act as electrodes, and fix them in the clamps.
Screw the switch to the rear wall of the device.
Screw the back wall and 2 posts to the base, as shown in the following photos.
Attach the transformer to the base.
Next, one mains wire is connected to the primary winding of the transformer. The second network wire is connected to the first terminal of the switch. Then you need to attach the wire to the second terminal of the switch and connect it to another output of the primary. But on this wire you should make a gap and install in it microwave interrupter. It will act as a welding start button. These wires must be long enough to accommodate a breaker at the end of the clamp.
Fasten the cover of the device with the handle installed on the racks and the rear wall.
Fasten the side walls of the case.
Now you can install the welding tongs. First, drill a hole at their ends into which the screws will be screwed.
Next, attach the switch to the end.
Insert the pliers into the housing, after placing a square bar between them for alignment. Drill holes in the pliers through the side walls and insert long nails into them to serve as axes.
Attach copper electrodes to the ends of the clamps and align them so that the ends of the rods are opposite each other.
To make the top electrode rise automatically, screw in 2 screws and fix the elastic band on them, as shown in the following photos.
Turn on the unit, connect the electrodes and press the start button. You should see an electrical discharge between the copper bars.
To check the operation of the unit, you can take metal washers and weld them.

In this case, the result was positive. Therefore, the creation of a spot welding machine can be considered completed.

Now it is difficult to see any work with metal without the use of a welding machine. This device freely cuts or connects iron parts, regardless of its thickness and dimensions. To engage in welding, you need to have some skills, and, in fact, the device itself. You can buy it, you can hire a welder to carry out the necessary work, or you can make the unit yourself.

Standard scheme of the welding machine and its types

Before you start creating a welding machine at home, you should understand its structure.

The main element of the welder, of which it consists, is a transformer that feeds the arc of the apparatus, controls the alternating voltage and controls the quality and magnitude of the current.

The designs of standard welding machines are very diverse, but the following main types can be distinguished:

AC apparatus;
Working with direct current;
Three-phase;
Inverter.

Welding with direct current is usually used for working with thin sheet material, automotive and roofing steel.

DC and AC welding devices are reliable, unpretentious in operation, heavy in weight and very sensitive to voltage drops. If it falls below 200 volts, it will be difficult to work, there will be problems with ignition and arc support.

These welding machines are very similar in design, and if we have AC welding, then by modifying it a little, we will get a device for working with direct current.

As for inverters, thanks to the use of electronic parts, their weight has become much lighter. They are not afraid of voltage drops, but at the same time they are very sensitive to overheating. These devices must be handled with care, otherwise they may break.

Homemade AC welding machine

The AC welding unit is one of the most common models. It is the easiest to use and easy to assemble at home compared to other types of welders.

What is needed for this:

Wires for secondary and primary winding;
winding core;
Step-down transformer (you can take "LATRA").

What wires are needed? The optimal voltage during the operation of the device, created independently, is 60V with the optimal current - 120 -160A. Based on this, we understand that the minimum cross-section of copper wires to wind the primary should be 3-4 square meters. mm. Optimal - 7 square meters. mm, which takes into account possible additional load and power surges.

Do not use wires in PVC or rubber insulation, as they can overheat and cause a short circuit.

If there is no wire of the desired cross section, you can use thin wires wound together. True, the thickness of the winding will increase, which will entail an increase in the dimensions of the apparatus itself. To make the secondary winding, you can take a thick copper wire, consisting of many strands.

The core for homemade is made from a transformer steel plate, the thickness of which should be from 0.35 mm to 0.55 mm. They must be folded so that a core of the required thickness is obtained, and then the device is bolted to the corners. At the end of the work, the surface of the plates should be treated with a file and insulation should be made.

Then the winding starts. First, primary (about 240 turns can be done). In order to be able to regulate the passing current, you need to make several taps with an approximate step of 20-25 turns.

How much copper is needed for the secondary winding? Usually the number of turns is 65-70. The cross section of the wire is 30 - 35 sq. mm. As with the primary winding, taps must be made to regulate the current. Wire insulation must be reliable and resistant to heat.

Winding is done in one direction and each layer is isolated. The ends of the winding are bolted to the plate and we can assume that the homemade welder is ready.

If you need to increase the current strength, a voltage boost can help in this matter, or you can do it manually by reducing the number of turns of the primary winding and switching the wire to a contact with a smaller number of turns.

When creating a welding machine, you must not forget to ground it, according to safety precautions. And also always make sure that the welding machine does not overheat!

Simple DC Welding Machine

For welding cast iron and stainless steel, you will need a machine with direct current. You can create it in 15 minutes if you already have an AC machine. In this case, the existing device will be upgraded.

Alteration of the change will consist in connecting a rectifier to the secondary winding, which is assembled on diodes. Diodes, in turn, must withstand a current of 200 A and be well cooled.

The rectifier will do its job better if you use 50V capacitors and a special choke to regulate the current.

What you need to know when connecting the device to the network permanently:

Be sure to use a knife switch, which at any time can disconnect the device from the network;
The cross section of the wire for connection must be greater than or equal to 1.5 square meters. mm, and the current consumption in the primary winding is a maximum of 25 A.

The scheme of work of the welder is such that from time to time he needs to be given a rest. It doesn't matter if it's a semi-auto or a handbrake. However, if the device works on electrodes with a diameter of less than 3 mm, then you can not interrupt.

Inverter: how to make a welding machine with your own hands

The inverter itself can be assembled from small parts and wiring from a Soviet TV or vacuum cleaner.

Features of the inverter:

The device works with direct current and its smooth adjustment from 40 to 130 A;
The largest current for the primary winding is 20A, the electrodes used should be no more than 3 mm;
The electric holder must have a button, by pressing which voltage will go into the device.

All elements of the inverter are located on a special printed circuit board, and for better heat removal from the diodes, they are fixed on a special heat sink, which is screwed to the board. The board itself is usually made of fiberglass, with an approximate thickness of 1.5 mm.

For additional cooling of the circuit, you can use a fan fixed directly to the case in which the inverter is located.

With the help of such an apparatus, you can safely cook non-ferrous and ferrous metals, blanks from a thin sheet.

Three-phase welding machines are usually used for welding in production conditions, so it does not make sense to make them at home.

Timval, Budyonny and thyristor welders are especially popular.

Tips on how to make a welding machine at home: spot welding

One of the most convenient and economical mini-welding has recently become spot welding, which takes place by contact. In everyday life, such a thing is used for repairing household appliances and welding batteries.

Heating occurs with the help of an impulse, and the impulse moment does not exceed one tenth of a second, that is, everything happens very quickly.

Such a mini-welding is created using a transformer from an old microwave oven, which will be finalized in the process of creating the apparatus. The goal is to be able to get a short-term pulse of at least 1000A at the output.

The processing goes like this:

Everything is removed from the transformer except the core and primary winding;
A wire with a cross section of at least 100 square meters is wound in place of the secondary winding. mm;
The main thing here is to wind the wire very tightly around the core.

As a result, the output should be about 5 volts, but if the power is too low, you can take another transformer. Then you need to check the voltage again. If it is not more than 2000 A, the micro welding machine is ready for use.

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