If you decide to assemble a semi-automatic welding machine with your own hands from an inverter, a 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 Cedar 160, Kaiser Mig 300 with the required Ampere rating. But many tend to do everything with their own hands. It is not so easy, but if you want to achieve a positive result, you will be able to.

Mig, Mag, MMA welding requires the use of appropriate devices. Mig Mag is a semi-automatic welding, which is performed in an inert argon gas environment. Sometimes carbon dioxide is used for Mig Mag welding. 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 inverter-based semi-automatic device with your own hands, you are not interested in MMA, but Mig Mag welding.

To collect homemade apparatus, a worthy analogue for Cedar 160, Kaiser Mig 300, with your own hands, you will need a diagram, video instruction 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 more Amperes, the higher the ability of your welding device;
feed mechanism. We will tell about it separately;
Burner;
Hose for supplying electrodes;
Spool with special wire. This prefix is easily attached to the structure in any way convenient for you;
Control unit for your welding machine.

Now with regard to the feed mechanism for the semi-automatic and some important points.

He is responsible for supplying the electrodes with a flexible hose to the welding point.
The optimum feed rate of the electrode wire corresponds to the rate of its melting during do-it-yourself welding.
The quality of the hand-made seam depends on the wire feed speed.
It is recommended to make a semi-automatic with the ability to adjust the speed. This will allow you to adapt the semiautomatic device to different type used electrodes.
The most popular electrode wires have a diameter of 0.8 to 1.6 mm. It must be wound on a coil and charged the inverter.
If you provide fully automated feeding, you do not have to do it yourself, and therefore the time spent on welding activities will be significantly reduced.
The control unit is equipped with an adjustment channel, which is responsible for stabilizing the current.
The behavior of Ampere, that is, the semiautomatic current, is regulated by a special microcontroller. It performs its work in the pulse-width mode of operation. The voltage created in the capacitor directly depends on its filling. This affects the parameters welding current.

Semiautomatic transformer preparation

So that a do-it-yourself semi-automatic device works no worse than welding machine such as Cedar 160, Kaiser Mig 300, it is necessary to understand the features of preparing the transformer.

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

Inverter setting

There are no problems with the work of Kedr 160, Kaiser Mig 300. Cedar 160 and Kaiser Mig 300 are factory equipment that have excellent technical characteristics. These semi-automatic machines function perfectly, allow you to receive required amount Amperes - 160 Amperes, 170, 190 Amperes, etc. It all depends on how you set up the device.

But if you decide to remake the inverter and make it a semi-automatic device, then the idea of \u200b\u200bbuying a Cedar 160, Kaiser Mig 300 should be thrown aside.

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

Be sure to include high efficiency heatsinks used for rectifiers (input and output) and power switches. Without them, the device will not work properly.
Inside the radiator case, which heats up the most, a temperature sensor should be installed to trigger it in case of overheating.
Connect the power unit to the control unit and plug it into the working network.
When the indicator is activated, you should connect an oscilloscope to the wires.
Look for bipolar impulses. Their frequency is in the range from 40 to 50 kHz.
The time parameters between pulses are adjusted by changing the input voltage. The time indicator should correspond to 1.5 µs.
Watch the inverter output square wave on the oscilloscope. Edges should not exceed 500 ns.
When the device has passed the test, connect it to the mains.
The indicator built into the semiautomatic device should give out 120 amperes. The parameters can reach up to 170, 190 amperes. But if the device does not show this value, you will have to go in search of the causes of low voltage in the wires.
Typically, this situation occurs when the voltage is less than 100 V.
Now we are testing the semi-automatic welding machine by starting the machine with variable current. In this case, constantly monitor the voltage across the capacitor.
We complete the test by checking the temperature indicators.
Check how the device behaves in the case of a loaded state. 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 that they are professionally suitable.
To test a homemade inverter or Kedr 160 with Kaiser Mig 300, you need to connect a 0.5 ohm load rheostat to the welding wires. Make sure that this element can withstand a load of more than 60 Amps. The voltmeter controls the current parameters.
If the test of the semiautomatic device showed that the set current value and the controlled value are different, it will be necessary to change the resistance. Do this until you get a positive result.

Assembling a device that will act as a full-fledged analogue for Kedr 160 and Kaiser Mig 300 is not so easy, but possible. You yourself determine whether the semiautomatic device will produce 120 or all 190 amperes. Make it easier to choose a factory model. But they are also priced accordingly. The price of the same Kedr 160 Mig semiautomatic device is from 27 thousand rubles. But the decision is up to you.

Technical data of our welding machine - semi-automatic:
Supply voltage: 220 V
Power consumption: no more than 3 kVA
Operating mode: intermittent
Operating voltage regulation: stepwise from 19 V to 26 V
Welding wire feed speed: 0-7 m/min
Wire diameter: 0.8mm
Welding current: PV 40% - 160 A, PV 100% - 80 A
Welding current regulation limit: 30 A - 160 A

In total, six such devices have been made since 2003. The device, shown below in the photo, has been working since 2003 in a car service and has never been repaired.

Appearance

Standard welding wire is used
5kg spool of wire with a diameter of 0.8mm

Welding torch 180 A with Euro plug
was bought in a store welding equipment.

Scheme and details

Due to the fact that the semi-automatic circuit was analyzed from such devices as PDG-125, PDG-160, PDG-201 and MIG-180, the circuit diagram differs from the circuit board, since the circuit loomed on the fly during the assembly process. Therefore, it is better to stick to the wiring diagram. On the printed circuit board, all points and parts are marked (open in Sprint and hover over the mouse).

Signet, see the drawing in the archive

As a power and protection switch, a single-phase automatic machine of the AE type for 16A is used. SA1 - welding mode switch type PKU-3-12-2037 for 5 positions.

Resistors R3, R4 - PEV-25, but you can not install them (I don’t have them). They are designed to quickly discharge inductor capacitors.

Now for the capacitor C7. Paired with a choke, it provides stabilization of combustion and maintenance of the arc. Its minimum capacity should be at least 20,000 microfarads, the optimal one is 30,000 microfarads. Several types of capacitors with smaller dimensions and greater capacity were tried, for example, CapXon, Misuda, but they did not show themselves reliably, they burned out.

As a result, Soviet capacitors were used, which work to this day, K50-18 for 10,000 microfarads x 50V, in the amount of three pieces in parallel.

Power thyristors for 200A are taken with a good margin. You can put it on 160 A, but they will work at the limit, application will be required good radiators and fans. The used B200s stand on a small aluminum plate.

Relay K1 type RP21 for 24V, variable resistor R10 wire type PPB.

Pressing the SB1 button on the burner energizes the control circuit. Relay K1 is activated, thereby, through contacts K1-1, voltage is supplied to the solenoid valve EM1 for supplying acid, and K1-2 to the power circuit of the wire pulling motor, and K1-3 to open power thyristors.

The SA1 switch sets the operating voltage in the range from 19 to 26 Volts (taking into account the addition of 3 turns per shoulder up to 30 Volts). Resistor R10 regulates the feed of the welding wire, changes the welding current from 30A to 160A.

When setting up, the resistor R12 is selected in such a way that when R10 is turned to a minimum speed, the engine still continues to rotate, and does not stop.

When the SB1 button on the burner is released, the relay releases, the motor stops and the thyristors close, the solenoid valve still remains open due to the charge of the capacitor C2, supplying acid to the welding zone.

When the thyristors are closed, the arc voltage disappears, but due to the inductor and capacitors C7, the voltage is removed smoothly, preventing the welding wire from sticking in the welding zone.

We wind the transformer

We take the OSM-1 transformer (1kW), disassemble it, put the iron aside, having previously marked it. We make a new coil frame from textolite 2 mm thick (the native frame is too weak). Cheek size 147x106mm. The size of the remaining parts: 2 pcs. 130x70mm and 2 pcs. 87x89mm. In the cheeks we cut out a window measuring 87x51.5 mm.
The coil frame is ready.
We are looking for a winding wire with a diameter of 1.8 mm, preferably in reinforced, fiberglass insulation. I took such a wire from the stator coils of a diesel generator). You can also use a conventional enameled wire such as PETV, PEV, etc.

Fiberglass - in my opinion, the most better insulation it turns out

We start winding - primary. The primary contains 164 + 15 + 15 + 15 + 15 turns. Between the layers we make insulation from thin fiberglass. Lay the wire as tightly as possible, otherwise it will not fit, but I usually had no problems with this. I took fiberglass from the remains of the same diesel generator. Everything, the primary is ready.

We continue to wind - the secondary. We take an aluminum tire in glass insulation measuring 2.8 x 4.75 mm, (you can buy it from wrappers). You need about 8m, but it is better to have a small margin. We start winding, laying as tightly as possible, we wind 19 turns, then we make a loop for the M6 bolt, and again 19 turns, We make the beginnings and ends 30 cm each, for further installation.
Here is a small digression, for me personally, for welding large parts at such a voltage, there was not enough current, during operation I rewound the secondary winding, adding 3 turns per shoulder, in total I got 22 + 22.
The winding fits back-to-back, so if you wind it carefully, everything should work out.
If you take enameled wire for the primary, then impregnation with varnish is mandatory, I kept the coil in varnish for 6 hours.

We assemble the transformer, plug it into the socket and measure the current idle move about 0.5 A, the voltage on the secondary is from 19 to 26 Volts. If so, then the transformer can be put aside, for now we no longer need it.

Instead of OSM-1 for a power transformer, you can take 4 pieces of TS-270, although there are slightly different sizes, and I only made 1 welding machine on it, I don’t remember the data for winding, but it can be calculated.

We will wind the throttle

We take an OSM-0.4 transformer (400W), we take an enamel wire with a diameter of at least 1.5 mm (I have 1.8). We wind 2 layers with insulation between the layers, lay them tightly. Next, we take an aluminum tire 2.8x4.75mm. and we wind 24 turns, we make the free ends of the tire 30 cm each. We collect the core with a gap of 1 mm (lay pieces of textolite).
The inductor can also be wound on iron from a color tube TV such as TS-270. It only has one coil.

We still have one more transformer to power the control circuit (I took it ready). It should give out 24 volts at a current of about 6A.

Hull and mechanics

With trances sorted out, proceed to the body. The drawings do not show flanges of 20 mm. We weld the corners, all the iron is 1.5 mm. The mechanism base is made of stainless steel.

See appendix for detailed housing drawings.

Motor M is used from the VAZ-2101 wiper.
Removed trailer return to the extreme position.

In the reel, to create a braking force, a spring is used, the first one that came to hand. The braking effect is increased by compressing the spring (i.e., tightening the nut).

Hull and mechanics drawings
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Scheme and printed circuit board
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Do-it-yourself welding semiautomatic device with a toroidal transformer

That's what happened. The Chinese semi-automatic device failed, which served me faithfully for a little over 5 years. Well, everything has its time. Now we need a new machine. For a long time I chose from what is on sale, but still I decided to make a homemade one. The fact is that sometimes there is a need to weld thicker metals (all sorts of household appliances), so I would like the device to be powerful, but also to easily weld metals of small thickness, and also not hurt the budget. I decided to build on the design popular on the Internet “from Sanych”. But still make some changes. I did not know then that there would be much more changes than I expected.
The first thing a welder needs is a transformer. At an online auction I bought transformer iron tor - a magnetic circuit with a cross section of 5.5 cm X 10 cm.

Why Thor? Well, first of all, I liked that it was factory made in 1978, and the quality was then at its best. Secondly, the efficiency of the toroidal transformer is much higher, and the magnetic field dissipation is much less.
The only drawback of such a transformer is the inconvenience of winding. I will not delve into the calculation of the power of iron, I am not strong in it, but for those who wish, there is a sea of information on the Internet. I made the primary, as Sanych recommends, with copper wire 1.2, but since I purchased a 10-position switch, the number of turns I got was 180 + 12 + 12 + 12, and so on.

I made the secondary with an aluminum shank 16mm2 - 35 turns. Then, however, I had to wind it up, but winding it up (especially from toroidal iron) is always easier than winding it up.

I bought a diode bridge ready-made, mounted on radiators. Radiators cut in half to save space.

The circuit from Sanych for adjusting the wire feed speed in my assembly did not work stably, as a result, I replaced it simply with a 10OM 10W variable resistor. Perfectly keeps the feed rate and does not overheat.

The purchased contactor for 24 volts did not always work from 15 volts, so I had to wind a transformer with 15 and 24 volt outputs. And instead of a contactor, use a magnetic starter with a starting voltage of 24V.

The Sanych circuit uses a 30,000 microfarad capacitor, I also bought it, but in practice it turned out that it was superfluous. toroidal transformer, tightly wound, plus a diode bridge on four diodes, and it turned out that the inductor is quite enough to smooth the current. The machine cooks gently and without splashing.
Throttle, the only part of the Sanych circuit that has not been changed.

For the manufacture of the feeder, I used an electric motor from Volkswagen wipers. Why exactly from Volkswagen, well, firstly, Bosh, and secondly, they gave it to me cheaply. I advise you to look for everything on Internet auctions such as Hammer or AUKRO. It may take a long time, but sometimes you can get the right thing, well, very inexpensively.

The issue with cooling was solved very simply. IN back wall The device installed a fan, which is usually installed in the vents.

Gas valve of the times of the USSR for 12 volts.

For three months of work, the do-it-yourself welding semi-automatic device did not fail and did not overheat. I am not strong in circuit diagrams, here is Sanych's diagram with my changes.

How to make a semi-automatic device from an inverter with your own hands

A good owner must have a semi-automatic welding machine, especially for owners of cars and private property. With him you can always small works do it yourself. If you need to weld a part of the machine, make a greenhouse or create some kind of metal structure, then such a device will become indispensable assistant in personal business. Here the dilemma arises: buy or make yourself. If there is an inverter available, then it is easier to do it yourself. It will cost much less than buying in a retail network. True, you will need at least basic knowledge of the basics of electronics, the presence necessary tool and desire.

Creating a semiautomatic device from an inverter with your own hands

Convert the inverter into a semi-automatic welding machine for welding thin steel (low alloy and corrosion resistant) and aluminum alloys do it yourself is not difficult. It is only necessary to understand well the intricacies of the upcoming work and delve into the nuances of manufacturing. An inverter is a device for stepping down electrical voltage to the required level to power the welding arc.

The essence of the semi-automatic welding process in a protective gas environment is as follows. The electrode wire is fed at a constant speed into the arc burning zone. Shielding gas is supplied to the same area. Most often it is carbon dioxide. This ensures that a high-quality weld is obtained, which is not inferior in strength to the metal being joined, while there are no slags in the joint, since the weld pool is protected from negative impact air components (oxygen and nitrogen) with protective gas.

The kit of such a semi-automatic device should include the following elements:

current source;
welding process control unit;
wire feed mechanism;
shielding gas sleeve;
carbon dioxide cylinder;
torch gun:
wire spool.

Welding post device

Principle of operation

When connecting the device to network is being transformed alternating current into permanent. This requires a special electronic module, a high-frequency transformer and rectifiers.

For high-quality welding work, it is necessary that the future device has such parameters as voltage, current and welding wire feed speed in a certain balance. This is facilitated by the use of an arc power source having a rigid current-voltage characteristic. The length of the arc is determined by a fixed voltage. The wire feed speed controls the welding current. This must be remembered in order to achieve from the device best results welding.

Easiest to use circuit diagram from Sanych, who has long made such a semi-automatic device from an inverter and successfully uses it. It can be found on the Internet. Many home craftsmen not only made a semi-automatic welding machine with their own hands according to this scheme, but also improved it. Here is the original source:

Scheme of a semi-automatic welding machine from Sanych

Semiautomatic Sanych

For the manufacture of the transformer, Sanych used 4 cores from the TS-720. The primary winding was wound with copper wire Ø 1.2 mm (number of turns 180 + 25 + 25 + 25 + 25), for the secondary winding I used an 8 mm 2 bus (number of turns 35 + 35). The rectifier was assembled according to a full-wave circuit. For the switch, I chose a paired biscuit. I installed the diodes on the radiator so that they do not overheat during operation. The capacitor was placed in a device with a capacity of 30,000 microfarads. The filter inductor was made on the core from the TC-180. The power part is put into operation with the help of the TKD511-DOD contactor. The power transformer is installed TS-40, rewound to 15V. The roller of the broaching mechanism in this semi-automatic device has a diameter of 26 mm. It has a guide groove 1 mm deep and 0.5 mm wide. The regulator circuit operates on a voltage of 6V. It is sufficient to ensure optimum welding wire feed.

How other craftsmen improved it, you can read messages on various forums devoted to this issue and delve into the nuances of manufacturing.

Inverter setting

To ensure high-quality operation of the semiautomatic device with small dimensions, it is best to use toroidal type transformers. They have the highest efficiency.

The transformer for the operation of the inverter is prepared as follows: it must be wrapped with a copper strip (40 mm wide, 30 mm thick), protected by thermal paper, of the required length. The secondary winding is made of 3 layers of sheet metal, isolated from each other. To do this, you can use fluoroplastic tape. The ends of the secondary winding at the output must be soldered. In order for such a transformer to work smoothly and at the same time not overheat, it is necessary to install a fan.

Transformer winding diagram

Work on setting up the inverter begins with a de-energization of the power unit. Rectifiers (input and output) and power switches must have heatsinks for cooling. Where the radiator is located, which heats up the most during operation, it is necessary to provide a temperature sensor (its readings during operation should not exceed 75 0 C). After these changes, the power section is connected to the control unit. When included in the email the network indicator should light up. Using an oscilloscope, you need to check the pulses. They must be rectangular.

Their repetition rate should be in the range of 40 ÷ 50 kHz, and they should have a time interval of 1.5 µs (the time is corrected by changing the input voltage). The indicator should show at least 120A. It will not be superfluous to check the device under load. This is done by including a 0.5 ohm load rheostat in the welding leads. It must withstand a current of 60A. This is checked with a voltmeter.

A correctly assembled inverter when performing welding operations makes it possible to regulate the current in a wide range: from 20 to 160A, and the choice of the operating current strength depends on the metal to be welded.

For making an inverter with my own hands you can take computer block which must be in working order. The body needs to be reinforced by adding stiffeners. An electronic part is mounted in it, made according to the Sanych scheme.

Wire feed

Most often, in such home-made semi-automatic devices, it is possible to feed a welding wire Ø 0.8; 1.0; 1.2 and 1.6 mm. The feed rate must be adjustable. The feeder together with the welding torch can be purchased from the distribution network. Upon request and availability necessary details it is quite possible to do it yourself. Savvy innovators for this use an electric motor from car wipers, 2 bearings, 2 plates and a Ø 25 mm roller. The roller is mounted on the motor shaft. Bearings are fixed on the plates. They stick to the roller. Compression is carried out using a spring. The wire, passing along special guides between the bearings and the roller, is pulled.

All components of the mechanism are installed on a plate with a thickness of at least 8-10 mm, made of textolite, while the wire should come out at the place where the connector connecting to the welding sleeve is installed. A coil with the necessary Ø and brand of wire is also installed here.

Broaching mechanism assy

A homemade burner can also be made with your own hands, using the figure below, where its components are shown clearly in disassembled form. Its purpose is to close the circuit, to provide the supply of shielding gas and welding wire.

Homemade burner device

However, those who want to make a semi-automatic device faster can buy a ready-made gun in the distribution network, along with sleeves for supplying shielding gas and welding wire.

To supply shielding gas to the welding arc, it is best to purchase a cylinder standard type. If you use carbon dioxide as a protective gas, you can use a fire extinguisher cylinder by removing the mouthpiece from it. It must be remembered that it requires a special adapter, which is needed to install the reducer, since the thread on the cylinder does not match the thread on the fire extinguisher neck.

Semiautomatic do-it-yourself. Video

You can learn about the layout, assembly, testing of a home-made semiautomatic device from this video.

Do-it-yourself inverter welding semiautomatic device has undoubted advantages:

cheaper than store counterparts;
compact dimensions;
the ability to cook thin metal even in hard-to-reach places;
will become the pride of the person who created it with his own hands.

Work on a semi-automatic homemade welding machine: manufacturing technology

Those craftsmen who are fond of welding have repeatedly thought about how to build an installation for pairing elements and parts. The self-made semi-automatic welding machine described below will have the following technical characteristics: mains voltage equal to 220 V; power consumption level not exceeding 3 kVA; works in intermittent mode; correctable
operating voltage is stepped and varies between 19-26 V. The welding wire is fed at a speed ranging from 0 to 7 m/min, while its diameter is 0.8 mm. Welding current level: 40% duty cycle - 160 A, 100% duty cycle - 80 A.
Practice shows that such a semi-automatic welding machine is able to demonstrate excellent performance and long term vital activity.

Semi-automatic device for welding.

Preparation of elements before starting work

As a welding wire, you should use the usual one, the one that has a diameter within 0.8 mm, it is sold in a coil of 5 kg. Such a semi-automatic welding machine cannot be manufactured without a 180 A welding torch, which has a Euro connector. You can buy it in the department specializing in the sale of welding equipment. On fig. 1 you can see a diagram of a semi-automatic welding machine. For installation, you will need a power and protection switch, you can use a single-phase AE (16A) circuit breaker for it. During the operation of the device, it will be necessary to switch between modes, for this you can use PKU-3-12-2037.

Scheme of power supply of a semi-automatic welding machine.

Resistors can be omitted. Their purpose is to quickly discharge the inductor capacitors.
As for the capacitor C7, in tandem with a choke, it is able to stabilize combustion and maintain an arc. Its smallest capacitance can be 20,000 microfarads, while the most suitable level is 30,000 microfarads. If you try to introduce other types of capacitors that are not so impressive in size and have a larger capacity, then they will not be reliable enough, as they will burn out pretty soon. For the manufacture of a semi-automatic welding machine, it is preferable to use old-type capacitors; you need to arrange them in the amount of 3 pieces in parallel.
Power thyristors for 200 A have a sufficient margin, it is permissible to install at 160 A, however, they will function at the limit, in the latter case it will be necessary to use quite powerful fans at work. The B200s used should be mounted on the surface of an oversized aluminum base.

winding transformer

When making a semi-automatic welding machine with your own hands, the process must begin with the winding of the OSM-1 transformer (1 kW).

Scheme homemade device for winding transformers.

It will initially have to be completely dismantled, the iron should be put aside for a while. It is necessary to make a coil frame, using a textolite with a thickness of 2 mm for this, such a need arises for the reason that its frame does not have an adequate margin of safety. The dimensions of the cheek should be equal to 147x106 mm. In the cheeks, you need to prepare a window, the dimensions of which are 87x51.5 mm. On this we can assume that the frame is completely ready.
Now you need to find a winding wire Ø1.8 mm, it is preferable to use one that has reinforced fiberglass protection.

When making a semi-automatic welding machine with your own hands, you need to create the following number of turns on the primary winding: 164 + 15 + 15 + 15 + 15. In the gap between the layers, you need to lay insulation using thin fiberglass. The wire must be wound with maximum density, otherwise it may not fit.

Scheme of winding a welding transformer.

To prepare the secondary winding, you need to use an aluminum bus, which has glass insulation with dimensions equal to 2.8x4.75 mm, you can purchase it from the winders. It will take about 8 m, but you need to purchase material with some margin. Winding should begin with the formation of 19 turns, after which it is necessary to provide a loop directed under the M6 bolt, then another 19 turns must be made. The ends should be 30 cm long, which will be needed for further work.
In the manufacture of a semi-automatic welding machine, it should be noted that if you may not have enough current at a similar voltage to work with dimensional elements, then at the installation stage or already in the process further use device, you can redo the secondary winding, adding it with three more turns per shoulder, in the end result this will allow you to get 22 + 22.

A semi-automatic welding machine must have a winding that fits back to back, for this reason it should be wound very carefully, this will allow everything to be positioned correctly.
When used to form the primary winding of the enameled wire, then it is mandatory to process it with varnish, the minimum time the coil is held in it is limited to 6 hours.

Scheme of primary and secondary windings.

Now you can mount the transformer and connect it to the mains, which will allow you to determine the no-load current, which should be approximately 0.5 A, the voltage level on the secondary winding should be equivalent to 19-26 V. If the conditions match, you can temporarily postpone the transformer and proceed to the next step.

When making a semi-automatic welding machine with your own hands, instead of OSM-1 for a power transformer, it is permissible to use 4 units of TS-270, however, they have slightly different dimensions, if necessary, for this case, you can independently calculate the data for winding.

Choke winding

Making a case from an old power supply.

To carry out the winding of the inductor, a 400 W transformer should be used, enameled wire Ø1.5 mm or more. The winding must be done in 2 layers, laying the insulation between the layers, while observing the requirement that the wire be laid as tightly as possible. Now you have to use an aluminum tire with dimensions of 2.8x4.75 mm, when winding you need to make 24 turns, the rest of the tire should be 30 cm.
At self-manufacturing It is permissible to wind the throttle on a semi-automatic welding machine on iron borrowed from an old tube TV.
To power the circuit, you can use a ready-made transformer. Its output should be 24 V at 6 A.

Case assembly

At the next stage, you can start assembling the installation case. To do this, you can use iron, the thickness of which is 1.5 mm, the corners will have to be connected by welding. It is recommended to use stainless steel as the base of the mechanism.

The model that is used in the windshield wiper of a VAZ-2101 car can act as a motor. It is necessary to get rid of the limit switch, which works to return to the extreme position.
In the reel, a spring is used to obtain the braking force, you can use absolutely any that is available for this. The braking effect will be more impressive if the effect of a compressed spring begins to influence this, for this you have to tighten the nut.

In order to make a semiautomatic device with your own hands, you need to prepare the following materials and tools:

enamel wire;
wire;
single-phase machine;
transformer;
welding torch;
iron;
textolite.

The manufacture of such an installation will be a feasible task for the master, who has familiarized himself with the recommendations presented above in advance. This machine will turn out to be much more profitable in terms of cost compared to the model that was produced in the factory, and its quality will not be lower.

Do-it-yourself semi-automatic welding inverter: diagram, photo, video

A semi-automatic welding machine is a functional device that can be purchased ready-made or made from an inverter with your own hands. It should be noted that the manufacture of a semi-automatic device from an inverter device is not an easy task, but if desired, it can be solved. Those who set themselves such a goal should study the principle of operation of a semiautomatic device well, watch thematic photos and videos, and prepare everything necessary equipment and accessories.

Scheme of semi-automatic welding in shielding gas

What is required to convert the inverter into a semi-automatic

To remake the inverter, making it a functional semi-automatic welding machine, you must find the following equipment and additional components:

inverter machine capable of generating a welding current of 150 A;
a mechanism that will be responsible for feeding the welding wire;
the main working element is a burner;
a hose through which the welding wire will be fed;
hose for supplying shielding gas to the welding area;
a coil with welding wire (such a coil will need to be subjected to some alterations);
an electronic unit that controls the operation of your homemade semi-automatic device.

Electric circuit of a homemade semiautomatic device

Special attention should be devoted to the alteration of the feeder, due to which the welding wire is fed into the welding zone, moving along a flexible hose. In order for the weld to be of high quality, reliable and accurate, the speed of wire feed through the flexible hose must match the speed of its melting.

Since when welding using a semiautomatic device, wire from different materials and different diameters, its feed rate must be regulated. It is this function - the regulation of the welding wire feed speed - that the feed mechanism of the semiautomatic device should perform.

Appearance of a homemade semi-automatic welder

Internal layout Wire spool Wire feeder (view 1)
Wire feeder (view 2) Attaching the welding sleeve to the feeder Construction of a homemade torch

The most common wire diameters used in semi-automatic welding are 0.8; 1; 1.2 and 1.6 mm. Before welding, the wire is wound on special coils, which are prefixes of semi-automatic devices, fixed on them with the help of simple structural elements. During the welding process, the wire is fed automatically, which significantly reduces the time spent on such a technological operation, simplifies it and makes it more efficient.

The main element of the electronic circuit of the semi-automatic control unit is a microcontroller, which is responsible for regulating and stabilizing the welding current. It is from this element of the electronic circuit of the semi-automatic welding machine that the operating current parameters and the possibility of their regulation depend.

How to remake an inverter transformer

In order for the inverter to be used for a homemade semiautomatic device, its transformer must be subjected to some alterations. It is not difficult to do such an alteration with your own hands, you just need to follow certain rules.

In order to bring the characteristics of the inverter transformer in line with those required for a semiautomatic device, it should be wrapped with a copper strip, on which a thermal paper winding is applied. It must be borne in mind that for these purposes it is impossible to use an ordinary thick wire, which will be very hot.

Converted inverter transformer

The secondary winding of the inverter transformer also needs to be redone. To do this, do the following: wind a winding consisting of three layers of tin, each of which must be insulated with a fluoroplastic tape; solder the ends of the existing winding and do-it-yourself winding to each other, which will increase the conductivity of the currents.

Structural diagram of the inverter. used for its inclusion in the semi-automatic welding machine, must necessarily provide for the presence of a fan, which is necessary for effective cooling of the device.

Setting the inverter used for semi-automatic welding

If you decide to make a semi-automatic welding machine with your own hands, using an inverter for this, you must first de-energize this equipment. To prevent such a device from overheating, its rectifiers (input and output) and power switches should be placed on radiators.

Power diodes on additional heatsinks

In addition, in that part of the inverter housing where the radiator is located, which heats up more, it is best to mount a temperature sensor, which will be responsible for turning off the device if it overheats.

After all the above procedures are completed, you can connect the power part of the device to its control unit and connect it to electrical network. When the mains indicator lights up, connect an oscilloscope to the outputs of the inverter. Using this device, it is necessary to find electrical impulses with a frequency of 40–50 kHz. The time between the formation of such pulses should be 1.5 μs, which is regulated by changing the voltage value supplied to the input of the device.

Oscillogram of welding voltage and current: on the left on the reverse polarity, on the right - on the straight line

It is also necessary to check that the pulses reflected on the oscilloscope screen have a rectangular shape, and their front is no more than 500 ns. If all checked parameters correspond to the required values, then the inverter can be connected to the electrical network. The current coming from the output of the semiautomatic device must have a strength of at least 120 A. If the current strength is less, this may mean that a voltage is supplied to the equipment wires, the value of which does not exceed 100 V. In the event of such a situation, the following must be done: test the equipment by changing the current (in this case, it is necessary to constantly monitor the voltage on the capacitor). In addition, the temperature inside the device should be constantly monitored.

After the semi-automatic has been tested, it is necessary to check it under load. To make such a check, a rheostat is connected to the welding wires, the resistance of which is at least 0.5 ohms. Such a rheostat must withstand a current of 60 A. The current supplied to the welding torch in this situation is controlled using an ammeter. If the current strength when using a load rheostat does not meet the required parameters, then the resistance value this device selected empirically.

How to use a welding inverter

After starting the semi-automatic machine that you assembled with your own hands, the inverter indicator should show a current value of 120 A. If everything is done correctly, then it will happen. However, the inverter display may show eights. The reason for this is most often insufficient voltage in the welding wires. It is better to immediately find the cause of such a malfunction and promptly eliminate it.

If everything is done correctly, then the indicator will correctly show the strength of the welding current, which is regulated using special buttons. Operating current adjustment interval, which provide welding inverters. is in the range of 20–160 A.

Approximate modes of semi-automatic welding of butt welds

How to control the correct operation of the equipment

So that the semi-automatic welding machine that you assembled with your own hands serves you long time, it is better to constantly monitor temperature regime inverter operation. To implement such control, it is necessary to press two buttons simultaneously, after which the temperature of the hottest radiator of the inverter will be displayed on the indicator. Normal operating temperature the one whose value does not exceed 75 degrees Celsius is considered.

If this value is exceeded, then, in addition to the information displayed on the indicator, the inverter will emit an intermittent sound signal, which should be immediately paid attention to. In this case (as well as in the event of a breakdown or short circuit of the temperature sensor), the electronic circuit of the device will automatically reduce the operating current to a value of 20A, and an audible signal will be emitted until the equipment returns to normal. In addition, a malfunction of DIY equipment may be indicated by an error code (Err) displayed on the inverter indicator.

Setting the welding mode on the Resanta inverter

In what cases is a semi-automatic welding machine used?

Practice shows that it is better to use a semiautomatic device in cases where it is required to obtain accurate and accurate connections of parts made of steels. With the help of such equipment, which, if desired, can be made by hand, welded joints are made thin metal, which is very important when repairing the body of a vehicle.

Learning how to work on such a device is also not difficult: lessons taken from qualified specialists or a training video will help with this.

Attention, only TODAY!

Do-it-yourself semiautomatic welding machine is made from improvised means. The semi-automatic welding machine can be used to repair vehicles, build a greenhouse frame, and manufacture metal products.

The semi-automatic welding machine is used in various fields: in construction, in mechanical engineering, in the manufacture of metal structures and in installation work.

Selection rules

Preliminary it is recommended to choose a gun and a cylinder of carbon dioxide. Shielding gas can be used if desired. Experts recommend considering the features of the functioning of the mechanism that feeds the wire. Before deciding how to make a semi-automatic welding machine, you should find out its components. A gun and a cylinder are essential elements of a welding machine. Experts advise to carefully approach the choice of a gas cylinder. Initially, you can use a carbon dioxide fire extinguisher, but such a replacement is short-lived.

With the help of a gun, the wire wound from the reel is fed to the welding zone. Attached to this device is a hose that supplies gas. The substance is fed to the nozzle of the gun with the help of solenoid valve, triggered by the short circuit of the wire in contact with the surface of the gun.

A gun for a homemade welding machine is chosen based on personal preferences. Experts do not recommend purchasing cheap devices that have low-quality gas hose. Semi-automatic welding machines can be equipped with a CO2 gas system. In the operation of this equipment, the use of gas is necessary in order to obtain high-quality seams. Carbon dioxide is supplied to the welding area, which protects it from the effects of nitrogen and oxygen. The seams made by the apparatus with gas contain little slag.

Gas welding can be replaced with flux-cored wire. The advantages of this system are the absence of the need for gas and the speed of the work process, but the quality of the seams is low. Gas protection necessary if high demands are placed on products.

The apparatus that feeds the wire can be assembled using the windshield wiper motor in cars. A roller is put on the shaft. It can be prevented from sliding along the drive roller if the structure is additionally pressed with a firmly fixed satellite roller.

Welding, for which semi-automatic welding is used, requires the use of a rectifier. It is chosen depending on the method of winding the corresponding transformer. The manufacture of a welding machine with 2 windings will require the use of 2 diodes "DL161-200". A bridge rectifier circuit will require 4 diodes. A capacitor (30000x63V) helps smooth out voltage ripples.

In a DC circuit, in order to enhance the stability of the arc after the rectifier diodes, it is necessary to install a choke wound on the transformer core with about 20 turns of wire. The core section is 35x35 mm. The diameter of the wire must not be less than that used for the secondary winding in the transformer. The power supply of the electric motor, which is used in the wire feeder, comes from a power supply in which the current is 5 A and the output voltage reaches 12-15 V.

Welding semiautomatic devices are additionally equipped with:

electromagnetic start for inclusion;
electrovalve for gas;
wire feed sleeve.

Additional work

Do-it-yourself semi-automatic machines can be of high quality and reliable if all the nuances are thought out. You can adjust the wire feed speed during the operation of the welding machine using a variable resistor. The gas supply valve will open synchronously with the switching on of the transformer of the apparatus after pressing the "Start" button.

The scheme according to which the semiautomatic device will be made by hand can be changed taking into account the available parts.

The rectifier block contains:

throttle;
bridge rectifier (200 A);
an electrolytic capacitor with a capacity of 22,000 microfarads or more (63 V).

The inductor is necessary to filter the variable component of the device. When using the transformer "TC - 270", 60 turns of the winding are sufficient. To one end of the throttle of the welding machine, it is necessary to connect the “+” of the rectifier, and to the other end of the “+” of the capacitor and a cable that will supply the “+” of the rectifier, which is equipped with a semi-automatic welding machine, to the wire. The gun must be wired to one of the valve contacts. The minus of the rectifier and the 2nd contact of the valve must be connected to the product.

Make a semi-automatic welding machine yourself without extra costs it is possible using the solenoid valve from the Zhiguli car. By pressing the button, the master will be able to turn on the MPP, the wire will be fed to the gun head, closing the circuit of the electrovalve, which is responsible for the gas supply. The supply of the substance supply valve and the MPP motor is carried out using an additional transformer (200 V). It is recommended to close access to the “stuffing” of the device in order to welding work were safe.

Many welders working in production have no idea what it looks like circuit diagram welding semiautomatic device. They have never opened or repaired the machine they are working on. And if you don’t understand the device yourself, then you won’t need to pay a “round” sum for restoring the circuit.

additional information

To facilitate the welding process and obtain a high-quality even seam, devices with partial automation of work are used. Execution of welding semiautomatic devices on their own will help answer two questions at once:

Figure 1. The main parts of the semi-automatic welding mechanism.

Finance. Such a device will cost significantly less.
Repair. When manufacturing, you will have to look at various schemes of semi-automatic devices, and then choose and assemble one that suits you.

Schemes of welding machines, the operation of which is based on the occurrence electric arc, their design and setup process are now publicly available. This will help to find and manufacture a unique, reliable device.

A semi-automatic or automatic welding machine is a device in which the principle of connecting parts is applied by heating them to the melting point with an electric arc. The process involves an electrode and a rapidly crystallizing seed, which, when heated, fills the seam, firmly fastening the parts as it cools.

Automation (partial) is solved like this:

Figure 2. The design of the semi-automatic welding torch.

instead of an electrode, welding wire is used (on a reel or in segments);
by using special device(mechanical or electromagnetic) continuously feed the wire to the welding site;
the speed of the process of approaching the electrode to the objects to be welded is regulated by gear shifting in the mechanical version or by applying the appropriate current (voltage) in the electromechanical version.

The welder only has to lead the wire along the seam.

To ensure protection working area from impact external factors devices are divided into devices for cooking:

A wire with a flux located inside it. DIYers almost never use this option because of the high cost.
Cored wire in a gas environment. The option is ubiquitous.

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Basic designs of mechanisms

The device that supplies the electrode to the work area can be of two types:

Pulling - pulls the wire to the place of welding through a special channel in the torch itself.
Pushing - the flexible electrode is pushed through the guide sleeve to the place of the future seam.

Figure 3. The electrical part of the semi-automatic welding machine.

Each of the devices can be made on the basis of the windshield wiper of any car. The design of both mechanisms is almost the same and represents something reminiscent of a device for wringing out clothes on old (shovel) washing machines. Picture 1.

The wire (1) is drawn through the rotation of the rollers (2), which are rigidly fixed on the axles (3). One of the axles (upper) is pressed into the bearing (4) mounted on the frame (6). The second axis is the motor shaft. The lower bearing is required if a gearbox or transfer roller is installed instead of the motor.

On the rollers, for better meshing of the wire, it is desirable to make corrugations or notches. All this device must be carefully isolated, because the electrode in contact with the rollers and the frame is supplied with current. The mechanism must be placed on the burner through an insulating gasket or in close proximity to it.

The design of the burner is conventional. The only difference is the presence of a valve, which, when gas is supplied, closes the contacts of the wires going to the relay of the feed mechanism. The relay turns on the motor that guides the wire to the welding spot. Figure 2.

The cost of units for semi-automatic welding is currently rather big. Not every private master, owner of a car or a private house can afford to buy it. But most home craftsmen can assemble such a semi-automatic welding machine with their own hands from quite affordable and relatively inexpensive components. Subject to the following recommendations, you can achieve an excellent result - to assemble a home-made welding machine suitable for almost all household needs.

Today on the Internet there are several variations of semi-automatic welding circuits that differ slightly. There are many videos, drawings that allow you to assemble a semi-automatic device based on a conventional inverter household purpose. As a basis for the manufacture of a semi-automatic welder, any inexpensive factory model welding inverter, capable of producing D.C. value from 150A. In addition, to assemble a workable device circuit, you will need the following equipment, assemblies and materials:

feeder for semi-automatic;
an element characteristic of the design of a semi-automatic unit - a gas gun-burner;
a cylinder with an inert gas (carbon dioxide);
modified coil with consumable- wire;
two sleeves - for supplying welding wire and shielding gas to the burner;
electronic control module.

The assembly sequence of a homemade semi-automatic

Feeder

According to the information from the craftsmen, one of the most difficult tasks in the independent manufacture of a semi-automatic welding machine is the creation of a reliable and efficient wire feed mechanism. IN general case it is a coil connected to the shaft of a low-power electric drive by means of a pressure roller device. It may be sufficient to use an electric motor mounted on the windshield wipers of a car. When choosing a drive, one-way rotation motors should be preferred.

All elements of the feed mechanism are mounted on a thick-walled textolite plate (at least 8-10 mm thick). The coil is fixed by means of one or two ball bearings on a shaft of the corresponding diameter, fixed in the housing. A roller is mounted on the motor shaft, which is fixed on both sides with ball bearings. At the outlet of the assembly, it is necessary to install a guide with a hole diameter slightly larger than the size of the wire used.

The operation of the wire feed controller is as follows:

The wire from a loosely fixed spool is pulled through the guide element and pressed with optimal force by one of the rollers. The force must be such that the welding wire is pulled through without slippage, but not excessive, which can lead to an increase in the mechanical load on the electric drive, which can easily damage it. For this effect, use a spring on an adjustable threaded connection.

The wire feed control scheme is best implemented using a classic thyristor unit with a diode bridge, designed for current exceeding 10A. Under other conditions, this node is able to supply welding wire most standard sizes used in household welding (from 0.8 to 1.6 mm), and the broach speed can be adjusted by yourself (depending on the diameter of the consumable material).

Refinement of the factory inverter

Alteration of the semi-automatic welding circuit from an inverter-type unit consists in finalizing its transformer. To do this, it is necessary to wind its primary coil with a strip of thin copper in a thermally insulating winding. Ordinary copper wire cannot be used for this purpose due to high temperatures that can damage the PVC insulation.

The transformer secondary circuit coil should also be adapted to new tasks by winding three layers of the same wire over the existing winding, insulated with fluoroplastic tape. To increase the conductivity of currents, it is necessary to solder together the standard coil leads with additional windings.

Burner

This element for semi-automatic welding can be done independently. But it is better to use the ready-made factory solutions of the manufacturers of this equipment by installing a standard torch equipped with welding sleeves (for inert gas and wire) in a home-made welding machine, since this unit is one of the most responsible for the quality of the welding processes.

Balloon

Of course, it is better to use a standard inert gas cylinder, since only such a product is able to meet all safety requirements. However, such containers are overly bulky and quite expensive, so many home craftsmen have found a way out: for the infrequent operation of a semi-automatic welder as a cylinder (only for carbon dioxide), a fire extinguisher is used, connected to the gearbox using a special threaded adapter.

How to set up a homemade semi-automatic welding unit

To ensure safety and full functionality, the semi-automatic welding circuit should provide for cooling means - passive (radiators) installed in the areas of greatest heating (on power switches and rectifiers) and active - one or two fans mounted in the device case. In case of overheating during operation, a temperature sensor should be installed near the hottest radiator, configured to turn off the power when the temperature reaches 75 degrees. And for ease of use, you can mount an indicator light in the power circuit, signaling the presence of incoming voltage.

A self-made semi-automatic welding machine must be subjected to diagnostics. For this, two types of electrical measuring instruments are used. With the help of an oscilloscope and a multimeter, the shape, amplitude of the pulses, their repetition rate and some other characteristics are controlled. Ideally, instruments should show the following values: frequency - within 40 ... 50 kHz (with a temporary interpulse distance of 1.5 μs), current value - not lower than 120A (better - 150A). The signal shown on the oscilloscope screen should be as close to a rectangular shape as possible.

When switched on in operating mode (under load with calibrated parameters - an active resistance of 0.5 Ohm), a current of at least 60A must be provided, which can be checked with a multimeter. If this value is less, in this case it is necessary to independently select the resistance for the normal operation of the unit empirically.

As can be seen from the above material, an independent conversion of an inverter welder into a semi-automatic one is a feasible task for any person who has a certain level of knowledge and experience in the field of mechanics and electrical engineering. Having the necessary components, materials and, most importantly, desire, you can quickly and easily assemble a machine for semi-automatic welding at home.