If you decide to assemble a semiautomatic welding machine with your own hands from an inverter, diagram and detailed instructions will become indispensable companions on the way to achieving your goal. The easiest way is to purchase factory semi-automatic devices such as Kedr 160, Kaiser Mig 300 with the required Ampere rating. But many people strive to do everything themselves. It's not that easy, but if you want to, you can achieve a positive result.

Mig, Mag, MMA welding requires the use of appropriate devices. Mig Mag is a semi-automatic welding that is performed in an inert argon gas environment. Sometimes Mig Mag is used for welding carbon dioxide. MMA welding is called manual arc processing with electrodes on which a special coating is applied. If you are working with stainless steel, then MMA welding is carried out only with direct current.

Since we are talking about how you can assemble a full-fledged semi-automatic machine based on an inverter with your own hands, you are not interested in MMA, but in Mig Mag welding.

To collect homemade apparatus, a worthy analogue for Kedr 160, Kaiser Mig 300, do it yourself, you will need a diagram, video instructions and necessary elements semi-automatic designs. These include:

• Inverter. Determine its welding ability by selecting the supplied current. Typically, craftsmen assemble devices capable of delivering 150 Amps, 170 Amps or 190 Amps. The higher the Amps, the higher the ability of your welding device;
• Feeding mechanism. We will tell you about it separately;
• Burner;
• Hose for supplying electrodes;
• A spool of special wire. This attachment is easily attached to the structure in any way convenient for you;
• Control unit for your welding unit.

Now regarding the feed mechanism for a semi-automatic machine and some important points.

1. It is responsible for supplying electrodes using flexible hose to the welding point.
2. The optimal feeding speed of the electrode wire corresponds to the speed of its melting during do-it-yourself welding.
3. The quality of the seam you make with your own hands depends on the wire feed speed.
4. It is recommended to make a semi-automatic machine with the ability to adjust the speed. This will allow you to adapt the semi-automatic device to different types of electrodes used.
5. The most popular electrode wires have a diameter from 0.8 to 1.6 mm. It must be wound on a coil and charged the inverter.
6. If you provide fully automated feeding, you will not have to do it yourself, and therefore the time spent on welding activities will be significantly reduced.
7. The control unit is equipped with a control channel, which is responsible for stabilizing the current.
8. The behavior of Amperes, that is, the current of a semi-automatic device, is regulated by a special microcontroller. It performs its work in pulse-width operating mode. The voltage created in the capacitor directly depends on its filling. This affects the parameters welding current.

Preparing a semi-automatic transformer

For a self-made semi-automatic to work no worse than welding machine type Kedr 160, Kaiser Mig 300, it is necessary to understand the features of transformer preparation.

• Wrap it with a copper strip. Its width should be 4 cm and thickness - 30;
• Before this, the strip is wrapped with thermal paper. The material used in cash registers is suitable. It is not difficult to purchase such paper;
• In this case, the circuit does not allow the use of ordinary thick wiring, otherwise it will begin to overheat;
• The secondary winding must be made by using three layers of tin at once;
• PTFE tape is used to isolate each layer of sheet metal from each other;
• At the output, you will need to solder the contact ends from the secondary winding with your own hands. This is necessary in order to increase current conductivity;
• Be sure to include a fan in the inverter housing. It will serve as a blowing mechanism that reduces equipment overheating.

Inverter setup

There are no problems with the operation of Kedr 160 and Kaiser Mig 300. Cedar 160 and Kaiser Mig 300 are factory equipment that have excellent technical specifications. These semi-automatic machines function perfectly and allow you to get required quantity Ampere - 160 Ampere, 170, 190 Ampere, etc. It all depends on how you configure the device.

But if you decide to remake the inverter and make it a semi-automatic device, then the idea of ​​​​buying Kedr 160, Kaiser Mig 300 should be thrown aside.

After completing work with the transformer, you should move on to the inverter. If you do correct settings the inverter itself, alteration will bring the desired result. And therefore homemade semi-automatic will function no worse than the finished device Kedr 160, Kaiser Mig 300.

1. Be sure to provide high-efficiency radiators used for rectifiers (input and output) and power switches. Without them, the device will not be able to work properly.
2. A temperature sensor should be installed inside the radiator housing, which heats up the most, to trigger it in case of overheating.
3. Connect the power part to the control unit and plug it into the working network.
4. When the indicator is activated, you should connect an oscilloscope to the wires.
5. Find bipolar impulses. Their frequency ranges from 40 to 50 kHz.
6. The time parameters between pulses are adjusted by changing the input voltage. The time indicator must correspond to 1.5 μs.
7. Make sure that the inverter produces square wave pulses on the oscilloscope. The edges should not exceed 500 ns.
8. When the device has passed the test, connect it to the power supply.
9. The indicator built into the semiautomatic device should produce 120 Amperes. Parameters can reach up to 170, 190 Amperes. But if the device does not show given value, you will have to go in search of the causes of low voltage in the wires.
10. Typically, this situation occurs when the voltage is less than 100 V.
11. Now we test the semi-automatic welding machine, starting the device with variable current. At the same time, constantly monitor the voltage on the capacitor.
12. We complete the testing by checking the temperature readings.
13. Check how the device behaves when loaded. Similar initial tests should be carried out with the Kedr 160 and Kaiser Mig 300. Although the Kedr 160 and Kaiser Mig 300 are factory semi-automatic machines from trusted manufacturers, it will never be superfluous to make sure of their professional suitability.
14. To check homemade inverter or Cedar 160 with Kaiser Mig 300, you need to connect a 0.5 Ohm load rheostat to the welding wires. Make sure this element can withstand a load greater than 60 Amps. The current parameters are monitored with a voltmeter.
15. If checking the semi-automatic device shows that the specified current value and the controlled value are different, the resistance will need to be changed. Do this until you achieve a positive result.

It is not so easy to assemble a device that will act as a full-fledged analogue for the Kedr 160 and Kaiser Mig 300, but it is possible. You yourself determine whether the semi-automatic device will produce 120 or all 190 Amperes. Make choosing a factory model easier. But their price is appropriate. The price of the same semi-automatic Kedr 160 Mig is from 27 thousand rubles. But the decision is yours to make.

Comments:

Any tool store can currently offer a fairly large assortment of various welding machines in various price categories. The majority of welding units, up to 70%, are occupied by welding inverters, and the rest of the “welders” are transformer-type devices. Not all people can purchase an industrial product for electric welding work, and some want to do it themselves.

A home welding machine will not be able to perform complex tasks, but for small jobs the power will be sufficient.

What is electric welding

Compound metal products between each other by heating the metal with an electric arc and then fusing it into a permanent seam is called electric welding. The main equipment in such a welding process is a welding machine, and the main tool for joining metal things is an electrode. The welding unit serves as a source of alternating or direct current, which, through an electrode, ignites an arc that melts the metal. The quality of the welded joint when welding with direct currents is much higher than the same joint made by alternating currents. The experience of an electric welder should not be discounted, although welding inverters that are popular today allow high-quality welding of metals almost the first time. That is why, for most of the various welding jobs, welding machines are used that use direct current in their work.

Return to contents

The simplest welding machine: instructions

For small home welding jobs, you can assemble a homemade compact device with low power. This is, of course, not an inverter, but a necessary thing. When solving the problem of creating a welding “assistant”, you can use various design features.

The simplest welding device is welding transformer with two windings: mains and working. The network voltage is calculated for the mains voltage, usually 220-240 volts, and the working one is calculated for a reduced voltage from 70 to 45 volts, and the change in current usually occurs by changing the number of turns of the working winding and its taps. You can use old ones as iron for transformers. asynchronous motors or industrial step-down three-phase transformers such as TOZ, etc.

The primary winding must be designed for a 25-amp current, the secondary or working winding must be designed for 160 A. This is reflected in the cross-section of the wires used. For a rough estimate of the current load per 1 sq. mm we allow 10 A, for aluminum - 4 A. We determine the cross-sectional area of ​​the transformer iron window in sq. cm, then we find the number of turns of the windings, if the required number for one volt is determined as 48, divided by the cross-sectional area of ​​the transformer iron window. Calculating the device is half the battle; the main thing is to assemble it.

The product created according to calculations is the simplest welding device AC, the design of the device depends on the materials used.

Return to contents

Let's make a DC welding machine with our own hands

In order for alternating current welding machines to turn into direct current “welders,” it is necessary to limit the rate of change of current with a choke and rectify the alternating current with diodes or a rectifier bridge.

The diodes must correspond to an output current of 200 A and have sufficiently good cooling so that the first welding does not damage them. This fully applies to the throttle. The use of these devices in conjunction with an alternating current welding unit turns it into a direct current apparatus. Welding with DC electrodes becomes possible, and the range of welded metals expands. Stainless steel and cast iron become available for welding. A welding machine can weld like an inverter, although the welder requires quite a lot of experience.

Modern manufacturers produce large number welding inverters with a wide range of functions. These include semi-automatic devices operating in MIG/MAG mode, which means the supply of inert or active gas and welding wire to the junction of the workpieces. Unfortunately, the cost of such units exceeds the financial capabilities of many people. Therefore, the desire to convert welding inverters into semi-automatic machines is finding more and more followers, since it is possible to save significant amounts. We will consider the possibility of such a modification and the necessary details for this.

Often, the master is faced with the question of choosing between an inverter or a semi-automatic welding machine, the difference between which lies in the quality of the seam and the types of metals being welded. If a conventional inverter allows welding in AC/DC mode, with piece electrodes of different thicknesses, then semi-automatic welding machines carry out the connection of parts. It is fed into the melting zone at a controlled speed and has different thicknesses, and to ensure best result, the process takes place in an inert or active gas environment (MIG/MAG).

Semi-automatic machines allow you to weld all kinds of metals of various thicknesses, while the size of the electrode does not change and work area always at the same distance from the person. It contains an inverter, but also an adjustable wire feed unit and a special hose with a torch and a cylinder. This equipment can weld aluminum alloys, carbon and stainless steel, cast iron and titanium, and with special wire - brass and galvanized metal. When assembling a semi-automatic machine from an inverter with your own hands, you will need the following factory or home-made components:

1. welding machine with AC/DC modes, outputting adjustable currents from 10 to 200A, with variable pulse voltage;
2. a torch with the ability to supply welding wire and the corresponding gas to the place of welding work;
3. a hose reinforced with a spring to ensure uninterrupted supply of wire and gas;
4. gas cylinder with gearbox and pressure gauge;
5. reverse welding cable with clamp;
6. control unit;
7. reliable, adjustable unit for feeding welding wire of various thicknesses.

These elements can be purchased factory-made, and some of them can be made by hand. The inverter, burner and gas cylinder must be purchased from the manufacturer, since technical requirements These components require a quality certificate.

Of course, your own semi-automatic machine will cost much less, but it is important that home-made elements meet safety requirements when performing electric welding work.

Construction of a torch and hose for a semi-automatic welding machine

Using a semi-automatic welding machine, we can increase the speed of work by more than two and a half or three times, since there is no need for multiple passes of the seam, its cleaning and replacement of piece electrodes. To increase productivity, it is necessary to ensure an uninterrupted supply of inert gas, voltage and wire to the weld pool. For this purpose, use a device consisting of the following components:

• a cylinder with a reducer, adjusted to a flow rate of 6-10 liters per minute and equipped with a gas supply hose;
• Euro-sleeve, hose-cable 3 m long, through which current, wire and gas are supplied, as well as a control signal;
• a torch with a tip, a power button and a nozzle for different wire diameters, equipped with a nozzle for inert or active gas.

Creating a Euro-sleeve yourself is quite difficult; you need to take into account that the diameter of the wire used ranges from 0.8 to 1.6 mm, and it must pass through the welding hose without any hindrance. For this purpose, the channel is equipped with a spring, using a Teflon coating; in addition, a gas supply passes through the same hose. The control signal from the burner button also passes through the cable, and at the end there is usually a multi-pin Euro connector, through which all components are turned on and supplied.

The complex design of the burner and its operation in conditions high temperatures, implies the presence of refractory nozzles with holes for different diameters welding wire. Gas is supplied through the torch, as well as the wire feeding mechanism to the weld pool is turned on. It consists of the following elements:

• handle with control button;
• burner;
• gas nozzle;
• calibrated current-carrying tip.

It is important to ensure the reliability of electrical contacts and tight connections of gas hoses.

Feeder design

The process of assembling a semi-automatic welding machine with your own hands can occur either using a factory feeder or its homemade version. In order to make it yourself, you need to understand what the factory product consists of, namely:

• on the front panel there is a Euro connector for connecting a welding sleeve;
• on the back of the case there is a toggle switch for turning on the power supply and connectors for connecting to the inverter and gas supply system;
• inside the case there is a power supply unit for the feeding device;
• feed unit with a fixed, freely rotating spool of wire;
• Next there is a clamping, adjustable feeding device connected through a gearbox to the electric motor shaft;
• circuit for adjusting the speed of the electric motor, ensuring the forward movement of the welding wire at a given speed;

• a solenoid that provides or shuts off the gas supply to the burner through the valve;
• gas supply tubes to the solenoid and Euro connector;
• power cable supplying welding current to the wire feed unit;
• a scheme for coordinating gas supply and wire movement with a delay of 1-2 seconds, preventing burnout or sticking of the wire when working in an aggressive oxygen environment;
• cables connecting the inverter and the feeder.

It is important that the feed system be mounted on electrically insulating material, since the welding wire is energized and acts as an electrode, and electrical contact with the equipment frame must be prevented.

It is necessary to ensure effective adjustable pressure on the feed roller, since the wire has different section, depending on the thickness of the workpieces being welded. It is important to ensure the ratio of all nodes involved in ensuring the translational movement of the wire in order to avoid kinks that impede smooth feeding at the required speed. The material of the gas supply hose must be heat-resistant, and the connections must be provided with reliable clamps. It won’t be difficult to choose a power supply with suitable parameters that will ensure the operation of the electric motor and electronic circuits of the feeder.

Step-by-step assembly of a semi-automatic device

When converting inverters into semi-automatic machines, it is necessary to take into account some circumstances. When purchasing an inverter, it is desirable that it supports MMA+MIG/MAG mode. The device will not cost much more, but when switching to the MIG mode, it will provide a stable current-voltage characteristic at the output, which will ensure smooth operation of the semiautomatic device at a current below 40 A. Otherwise, you will have to make changes to electronic circuit inverter and use PWM to stabilize the voltage parameters. This can be done provided that you understand electronics and are good at using a soldering iron.

It is important to match the reference and output voltages by installing a divider and selecting the component values ​​for supplying a signal to the controller inputs.

Further steps for assembling a semi-automatic machine from a welding inverter, a feeder and a Euro-sleeve with a torch are as follows:

• switch the inverter to MIG mode and connect it to the feeder with a power and control cable;
• connect a gas cylinder through a reducer and a pressure gauge to the supply device, and also adjust the flow of 6-10 liters per minute depending on the gas composition and welding conditions;
• install and secure the wire reel into the feed unit;
• using the speed control circuit, set the required feed speed of the welding wire and make sure that it moves unhindered;
• connect the burner to the euro-sleeve, which, in turn, connects to the feeder;
• turn on the inverter and feeding equipment and make sure there is a delay of 1-2 seconds between the arrival of gas and the movement of the wire.

Correct selection of wire thickness, composition of inert or active gas, as well as correct operation of radio-electronic components will ensure high speed and quality of welding work.

If difficulties arise, it is necessary to seek advice from specialists so as not to cause failure of expensive equipment, and also to avoid risk to life.

Let's sum it up

We looked at some ways to convert welding inverters into semi-automatic machines with our own hands. It's pretty difficult task, when studied closely, is not particularly difficult. It is only important to ensure reliable operation of the elements and electrical safety. The main thing is that these efforts and temporary losses will provide very significant savings.

Among beginners and professional welders, an inverter-type semi-automatic welding machine is the most popular device. For the former, it provides ease in acquiring welding skills; for the latter, it provides productivity and a large range of additional settings.

Semi-automatic welding equipment can be useful for almost any welder, but has a fairly high cost. If available manual arc welding you can convert it into a semi-automatic inverter type.

The semi-automatic welding machine is initially designed to work with filler wire in a protective gas environment (inert or active). Its difference from a conventional manual arc welding machine is the presence of a wire feed mechanism, a gas cylinder, a special torch and a gas and additive control unit.

The power source itself in the form of an inverter is no different. If the feed mechanism is built into the inverter housing, there is an additional wire connector.

Therefore, many owners of manual arc welding machines eventually have a desire to expand their capabilities and make a homemade semi-automatic machine. It can be implemented very easily. There are several implementation options; which one to choose depends on the availability of funds, time and desire.

Multifunction devices

Some manufacturers of manual arc welding inverters, taking into account the wishes of customers, have provided the required additional connectors. They help convert the device into a semi-automatic device as quickly as possible.

Some models of “Source” type inverter devices on the rear panel have a key for switching the operating mode from MMA to MIG and a connector for controlling on/off the inverter. usually equipped with a 3 m long Euro hose with a burner at one end and a connector at the other.

The connector allows you to supply welding wire and shielding gas; in addition, a cable passes through it to supply control signals to the electric motor for drawing the additive and connecting the gas.

There is a special cable for connection to the inverter device. It must be connected to the connector through which the welding current from the inverter was supplied to the electric holder. Now, in a semi-automatic mode, it will go to the MIG torch.

The second cable powers the feed mechanism from the inverter, if it has an appropriate connector, or from another low-power 12 V DC source.

Before work, the required gas flow rate is set on the gas cylinder, and the feed rate of the additive is set on the feed mechanism. The inverter sets the welding current, the value of which depends on the thickness of the metal being welded.

Then start welding. As you can see, turning manual arc welding into semi-automatic does not require any modifications; it is enough to purchase the missing equipment. The only drawback is that the inverter will come with a pulling device attachment.

Pulling device

In more difficult case The manufacture of a semi-automatic machine consists of altering the arc welding inverter and creating a broaching device from scrap materials. If you had to repair an inverter device, then you can safely implement the second option.

A system unit is ideal as a housing for a drawing device for an inverter-type semi-automatic machine. It is quite easy to open, yet spacious and durable.

This will allow you to simply adjust the pressure of the rollers and install the spool of wire. Another advantage of the system unit is that it is easy to make holes in it in the right places, and there is a built-in 12 Volt power supply. It is needed to power the additive broach drive and the gas valve.

For the necessary fasteners, it is necessary to make mock-ups of the built-in components from scrap materials and try them on inside the box. After making sure that the selected layouts are correct, you can begin manufacturing the fasteners.

You can buy a reel for a semi-automatic machine ready-made or make it yourself. It is very simple to produce. The diameter of the cheeks should be 200 mm, and the cylinder on which the wire will be wound should have a diameter of 50 mm, so that it can be used as an axis plastic pipe with the same denomination.

The feed mechanism will require two pressure rollers and one guide roller and a spring. An electric motor from the wipers can be used as a broaching motor. As a base on which the parts will be attached, you need to use a three-millimeter metal sheet.

Holes are drilled in the plate in the right places for fastening the rollers and the electric motor shaft of the future semi-automatic device. Since one roller is a pressure roller, the hole for it is drilled in an oblong shape.

A pressure spring will press on it from above, the force of which is adjusted through a screw. The roller and bearings are mounted on one side of the plate, and the motor on the other. A feed roller is mounted on the motor shaft.

The resulting device is installed inside the system unit so that the alignment of the rollers and the axis of the MIG torch connector are in the same plane. This will prevent the wire from creasing when pulling. To straighten the additive during unwinding, a tube is installed in front of the rollers.

Control node

To supply gas and additives to the semi-automatic welding machine you will need:

• 2 relays;
• diode;
• PWM regulator;
• capacitance with transistor and resistance;
• solenoid valve;
• wires.

The valve is required to allow gas to enter the welding zone. All components can be purchased at the used parts sale.

The control circuits in an inverter-type semiautomatic device may be different, but their essence is simple and is as follows.

When you press the button on the burner, both relays switch. The first supplies voltage to the valve that opens the gas supply.

The second relay supplies power to the wire feed motor. But its activation occurs a little later due to the low-pass filter in the form of an RC chain formed by a capacitor and a resistor.

Sometimes it is necessary to draw wire without gas supply. For this case it is provided additional button, which provides broaching bypassing the gas relay.

Self-inductance from the valve is removed if a diode is connected. To power the MIG torch from the inverter, you need to install an additional one next to the Euro connector, through which the current will flow.

When you turn on the button on the burner, gas begins to flow, after a while the additive is supplied. The delay time is regulated by selected capacitance and resistor values. A pause in an inverter-type semi-automatic machine is necessary to protect the weld pool from exposure to atmospheric air with gas.

When the button is turned on, voltage is supplied to the capacitor. It gradually charges, and when a certain value is reached, the transistor opens, which causes the relay to turn on.

Burner

You can also make a torch for an inverter-type semi-automatic welding machine yourself, but it is easier to purchase an inexpensive model with sufficient welding current.

If you manufacture it yourself, you will still need a Euro connector and a supply cable if you want to end up with an aesthetically pleasing semi-automatic welding machine. In addition to the welding current, you need to consider the length and flexibility of the hose.

Excessive softness of the hose leads to bending and, accordingly, braking of the wire. A good addition is a spring or a powerful rubber seal at the junction of the hose with the burner and connector. This will prevent it from breaking in these places.

Inverter

The manual arc welding inverter also needs to be rebuilt. Although it can be used without modifications, the quality of welding will then be lower than that of factory semi-automatic welding machines. It's all about the current-voltage characteristics. The difference is minor, but it has an impact.

To eliminate these differences, you will need a toggle switch, three resistances, one of which is variable.

To adjust the characteristic, it is necessary to install a divider in front of the shunt, which controls the current. By changing the parameters of the divider, an adjustment will occur. The toggle switch is needed to switch the inverter operating mode from manual arc to MIG.

As a result of modification of the inverter and self-made devices for drawing filler wire, resulting in semi-automatic welding equipment with good parameters. At the same time, you save money and get a lot of pleasure from the fact that you did everything yourself.

If you have to do professional welding, then it is better to purchase a ready-made semi-automatic machine. Today, the choice of these devices is wide, and it is quite possible to choose a budget model of acceptable quality.

Selection of household welding machines for modern market huge - from transformer and inverter to devices plasma cutting. The main area of ​​use of this electrical equipment for domestic purposes is the repair of automobiles and motorcycles, welding work on small construction sites ( country house construction). In this article, I propose to consider some points on the modernization of household transformer welding machines using the example of BlueWeld welding model Gamma 4.185.

Let's consider schematic diagram The device - as you can see, is nothing complicated - an ordinary power transformer, with a primary winding of 220/400V, with thermal protection and a cooling fan.

The operating current of the device (from 25 to 160A) is regulated by the retractable part of the transformer core. The device is designed to work with coated electrodes from 1.5 to 4 mm in diameter. What was the prerequisite for the modernization of this device? First of all, the instability of the supply voltage in the area where it was planned to use this device - on other days it barely reached 170V (by the way, some inverter devices They just don’t start at that supply voltage). In addition, the device is not initially designed for making welds with high aesthetic characteristics (for example, when using electric arc welding in the process of artistic cold forging metal or when welding thin-walled profile pipes) - in general, the main purpose of the device was to “solder” two iron blanks together. Among other things, it was very difficult to “light” the arc with this welding even at the rated supply voltage - there is no need to talk about reduced voltage at all. As a result, it was decided first of all to transfer the device to direct current (for stability electric arc and as a consequence of increasing the quality of the welded joint) as well as increasing the output voltage for more stable and easier ignition of the electrode. For these purposes, the rectifier/multiplier circuit designed by A. Trifonov was ideal - fundamental electrical diagram(a) and current-voltage characteristics (b) are shown in the figure.

A special role in this technical solution seemingly ordinary rectifier, the jumper X1X3 plays - by inserting it, a rectifier device is obtained from a conventional diode bridge VD1-VD4 with a low-frequency filter C1C2L1, at the output of which in idle mode we have double the voltage (compared to the version of the device without a jumper). Let's take a closer look at the operation of the circuit. A positive half-wave of voltage is supplied to the semiconductor valve VD1 and, having charged capacitor C1 to the maximum, returns to the beginning of the transformer winding. In the other half-cycle, the charge passes to the capacitor C2, and from it to the valve VD2 and further to the winding. Capacitors C1 and C2 are connected in such a way that the resulting voltage is equal to the total (double) voltage, which is supplied through the inductor to the electrode holder and thus contributes to stable ignition of the arc. When the X2X3 jumper is closed and there is no welding arc, valves VD3 and VD4 do not participate in the operation of the circuit. The main advantage of the circuit is that when using a conventional bridge circuit, there is a sharp decrease in the rectified voltage with an increase in the load current at the moment of ignition of the arc; it is necessary to install electrolytic capacitors of huge capacity - 15000 microfarads, and all this despite the fact that at the moment the electrode touches the welded surfaces and instantaneous discharge of a large capacitor, a plasma micro-explosion occurs with destruction of the electrode coating, and this impairs ignition. Now a little about the design details.

Semiconductor diodes D161 or B200 with standard radiators for them are used as diode bridge valves.

If you have 2 D161 diodes and 2 B200 diodes, you can make the bridge more compact - the diodes are made with different conductivities and the radiators can be fastened with studs directly to each other without using gaskets. As capacitors, to play it safe, I used a set of non-polar capacitors MBGO (you can use MBGCh, MBGP).

The capacity of each was 400 microfarads, which was quite enough for stable operation of the device. The current inductor L1 is wound on the core from the TS-270 transformer with a wire with a cross-section of 10 mm square.

We wind until the window is completely filled. When assembling, we place 0.5mm thick textolite plates between the halves of the transformer core. Since it was planned to use the apparatus for welding thin-walled profile pipes, the negative terminal of the rectifier was connected to the electrode holder, and the positive terminal to the “crocodile” of the mass. The tests carried out showed the following results: stable arc ignition; reliable maintenance of the arc; excellent thermal conditions for long-term operation (10 electrodes in a row); good quality weld seams (compared to using a device without a rectifier). Conclusion - modernization of a welding machine using a Trifonov rectifier significantly improves its performance in all respects.