Purchasing a welding machine (inverter) is always associated with a dilemma: quality or price. And, as often happens, the price wins. By purchasing an inexpensive welding inverter, its owner receives a slight reduction in the quality of work with the unit. More precisely: difficulty with igniting the electrode and the rigidity of the welding process. But a small modification (and inexpensive) makes it possible to change the characteristics of the device. The easiest option is to install a throttle. What is it and what is the throttle for?
Its main purpose is current stabilization. The thing is that in an alternating current device, the consumables must be ignited at a certain voltage, which must correspond to the sinusoid of the electric current. The welding choke included in the inverter circuit allows you to shift the phases between voltage and electric current. And this, in turn, affects the ease of ignition of the electrode, plus a more even burning of the electric arc. In the compartment, the final result is an even and high-quality weld. This is what is required to confirm the quality of the final result.
Chokes can be installed in welding transformers, inverters, and semi-automatic machines. When using the device in semi-automatic welding machines, one can note a decrease in metal spattering, the seam is welded deeper, and the welding process is smoother.
Methods for adjusting current using a choke
The advantages of the device are undoubted. Practice confirms this completely. But there are three transformer modes it can be in. At the same time, using the throttle in some of them you can adjust the force welding current. By the way, the inductor is connected to the secondary winding of the transformer, and the air gap in the core is adjusted.
- Idling. This is the mode when the device is turned on, but no work is performed on it. Voltage is applied to the transformer, electromotive force is present in the secondary winding, but there is no welding current at the output.
- Load. An arc is ignited, which closes the electrical input circuit. It includes the inductor winding and the secondary winding of the transformer. A current flows through the circuit, the value of which is determined by the resistances of the two windings. If a choke was not installed in the circuit, then the output would produce a current of maximum value. And this is a high probability of getting burnt through the metals being welded and sticking of the electrode. The degree of current adjustment will depend on the air gap in the rod on which the inductor winding is wound.
- Short circuit. A short circuit is formed at the moment when the tip of the electrode touches the welded metal blanks. In this case, a magnetic flux of an alternating type is formed on the transformer core, and an electromotive force is induced on the secondary winding. In this case, the current strength will depend on the total resistance of the inductor winding and the secondary winding of the transformer.
As for the air gap, its increase leads to the fact that the chain resistance increases. And this, in turn, leads to a decrease in the magnetic flux, and accordingly the inductive resistance of the transformer and inductor windings decreases. The resistance has decreased and the output current has increased. Everything is according to Ohm's law. Therefore, the arc current increases. This is how the current of the welding arc can be controlled using a choke.
There is one drawback to this throttle system. Any welding machine vibrates during operation. This negatively affects the passage of current through the inductor coil. Therefore, you can abandon smooth tuning and current regulation, and switch to step tuning. To do this, there is no need to install an air gap in the throttle core. To do this, the winding of the device is made with taps (through a certain number of turns), to which contacts are soldered. However, it is necessary to take into account the fact that a current of several hundred amperes will pass through these contacts. Therefore, you need to choose ones that can withstand such current.
And one more reason why the throttle for the welding machine needs to be turned on so that the welding process takes place under “soft” conditions. There is a characteristic of the dependence of the welding arc voltage on the current strength at the end of the electrode, which is called falling. This is a very useful relationship, especially in cases where it is difficult or difficult to maintain the distance between the electrode and the metal workpieces being welded.
It is almost impossible to provide a falling characteristic with one transformer, because the resistance of its windings is insufficient. The inductor winding almost doubles the total resistance of the electrical circuit, which allows for a decreasing dependence of voltage on current. That is, this is another plus for the throttle. Now it becomes clear why this device is needed.
How to make a throttle with your own hands
For the choke coil, it is better to use a UI series magnetic core. Winding wire onto a reel is a difficult and time-consuming process that requires patience and accuracy. There are several points in this matter that determine the quality of the final result.
- Be sure to insulate the yoke UI before starting winding.
- Copper or aluminum wire can only be wound in one direction.
- Each layer wound on the core must be insulated from the next one. For which fiberglass, special cotton insulation or cardboard can be used.
- The insulating layer must be treated with bakelite varnish.
- If stepwise current regulation is arranged, then the winding terminals must be marked. This will simplify the subsequent connection of the choke to the welding machine, that is, the desired output will be easy to find.
Stepwise current regulation can also be achieved using a load ohmic resistance. Essentially, this is an ordinary spiral of nichrome wire that connects to the output of the inductor. However, it should be noted that this option is not the best. Nichrome wire gets very hot, sometimes even red hot, so this is a great danger.
In welding transformers, smooth current regulation is ensured by displacement of the primary winding relative to the secondary. By decreasing the distance between them, the magnetic field decreases. And, accordingly, a decrease in resistance in the circuit. Typically, transformer devices are equipped with a handle, which is located on top of the unit. By rotating the knob in one direction or the other, the arc current decreases or increases.
But for an inverter welding machine that is used in everyday life, it is better to use a choke to improve operation. Simpler, more convenient, inexpensive. Moreover, making it yourself is not a problem.
Choke is the industrial name for an electrical element such as an inductor. This device has a wide range of applications, in particular, a powerful choke can be used to improve the performance of a semi-automatic machine or inverter for welding.
The main property of an inductor, which is a magnetic circuit wound under certain conditions around a ferromagnetic core, is the stabilization of current strength over time.
Simply put, voltage applied to the coil causes a smooth increase in current output. Changing the polarity leads to the same smooth decrease in current.
The main factor is the condition that the current passing through the inductor cannot sharply increase or decrease. This is precisely what determines the value of using a choke for welding - resistance compensation allows you to avoid sudden jumps in amperage.
This allows you to protect against accidental burning of the workpieces being welded, reduce spattering of the melting metal and accurately select the current parameters for welding for a given metal thickness. Chances of getting good seam with the use of a choke for welding is much higher.
The parameter that determines the coefficient of change in current is inductance. It is measured in H (henry) - in 1 second at a voltage of 1 V, only 1 A can pass through a choke with an inductance of 1 H.
The number of turns on the coil directly affects the amount of inductance. It is directly proportional to the number of turns squared. But if you need to make a welding choke with your own hands, then it is not necessary to calculate the exact number of turns.
Since the parameters of welding machines for household use are mostly standard and well-known, a welder will only need to use the instructions below to make a choke with his own hands.
Purpose
In an inverter for welding, a choke is needed to create an electric arc on the electrode. Ignition occurs when a certain voltage level is reached.
The welding choke increases the resistance, which shifts the phases between current and voltage and allows for smoother ignition. This fact in itself often allows one to avoid burning through the workpiece, especially if parts made of thin sheet metal are welded.
A smooth change in current makes it possible to avoid damaging the workpiece by abruptly applying too much power, to optimally set the arc temperature and, accordingly, to prevent metal spattering while maintaining the required processing depth.
Another valuable property of it is partial protection from unstable voltage in the network.
Throttle for welding inverter significantly facilitates the ignition of the electrode, which should light up at a higher voltage than the inverter produces.
An example is the MP-3 electrode, which must have a voltage of 70 V to ignite. An output choke for welding can greatly facilitate the work with this one, which produces only 48 V in mode idle move.
This occurs due to the phenomenon of self-induction. The device induces EMF (electromotive force), which causes air breakdown and flashing of the welding arc, as soon as you bring the additive a few millimeters from the metal surface.
The choke for welding is connected to the secondary winding of the transformer in the machine. It can be used in devices of any type - both home-made and factory-made, operating on any principle - inverter, with a step-down transformer, and the like.
Materials for manufacturing
The choke for retrofitting a semi-automatic device or inverter can be assembled with your own hands using structural elements from old equipment - tube TVs, street lamps old design and other devices that contain a transformer.
Structurally, it consists of a core made of a material that conducts a magnetic field, but does not conduct electricity or reliably insulated, and three layers of windings separated by a dielectric.
As a basis for the core, either a special material - ferrite, which has these properties, or a yoke (horseshoe) from an old transformer is suitable. Winding of the device for welding is done with aluminum or copper wire with a cross-section of 20-40 mm.
If aluminum is used, the wire cross-section must be at least 36 mm; copper wire can be thinner. A flat copper busbar with a cross-section of 8 mm is suitable.
The dimensions of the core should allow the winding of approximately 30 turns of a busbar of a given section, taking into account the dielectric spacers. A core from the step-up transformer of the Soviet TV TCA 270-1 is recommended.
Sequencing
When necessary tools and the materials are prepared, you can begin to manufacture the throttle for welding. The algorithm of actions is as follows:
- disassemble the transformer, clean the coils from traces of old windings;
- make gaskets from fiberglass, cardboard impregnated with bakelite varnish, or other suitable dielectrics, which will subsequently play the role of an inductive (air) gap. They can simply be glued to the corresponding surfaces of the coils. The thickness of the gasket should be 0.8-1.0 mm;
- wind a thick copper or aluminum wire onto each coil. You should focus on a round wire made of aluminum with a cross-section of 36 mm or copper with a similar ohmic resistance. Each “horseshoe” is covered with 3 layers of 24 turns each;
- lay a dielectric material between the layers - fiberglass, cardboard impregnated with bakelite varnish or another dielectric. The gaskets must be reliable, since a choke of this design is prone to self-breakdown between windings. If the resistance between the windings is lower than the air resistance between the electrode and the additive, then a breakdown will occur between the windings, and the welding device will be irreversibly damaged.
Winding must be done evenly, without overlaps, strictly in the same direction, so that the “bridge” between the coils is on one side of the future inductor, and the input and output contacts are on the other.
In case of an error, the jumper can also be installed askew. It is important that its installation turns coils with different winding directions into coils with the same direction in fact.
Power on and check
The choke for welding is connected to the system between the diode bridge and ground - a contact that connects to the material being welded. The output of the diode bridge is connected to the input of the inductor, to the output of the assembled inductor - respectively, the ground contact.
The entire assembly for welding must be tested on a piece of metal of the same chemical composition and thickness, with which in the future it is planned to conduct most of welding work. Quality indicators are:
- easy electric ignition;
- arc stability;
- relatively weak crackling sound;
- smooth combustion without strong splashes of melt.
Please note that the introduction of this element into the design of the welding machine leads not only to stabilization of operation, but also to a slight drop in current strength. If the inverter or semi-automatic device begins to cook worse, it means that the current strength has dropped.
The choke needs to be disconnected and a few turns removed from each coil. The exact number of turns in each specific case is selected empirically.
Comments:
A step-down transformer is the basis of a simple welding machine. More difficult is welding machine, which has a rectifier at the output that converts alternating voltage to direct voltage. Such welding machines are called rectifiers.
There are three types of transformers: toroidal, rod and armored, the differences between them can be seen in the figure above.
The most complex is the welding machine, which first converts the input power frequency of 50 Hz into a direct voltage, like rectifiers, and then converts it into an alternating voltage, the frequency of which is measured in kilohertz. This is an inverter.
Only someone who is well versed in radio electronics and the element base used there can make an inverter with their own hands. For this specialist, there is no need to explain why the inductor is needed and where its place is in the circuit. It would be advisable to explain to an unprepared person what a transformer and a rectifier for it are.
Calculation of the cross-section of the wires of the primary winding of the transformer
The theory of transformers is complex in that it is based on the laws of electromagnetic induction and other phenomena of magnetism. However, without using complex mathematical apparatus, it is possible to explain how a transformer works and whether it can be assembled independently.
The transformer can be manually wound on a metal core assembled from transformer steel plates. It is easier to wind on a rod or armored core than on a toroidal one. You should immediately note that the difference in the thickness of the wires is clearly visible in the image: thin wire located directly on the core, and it is clearly visible large quantity turns. This is the primary winding. The thicker wire with fewer turns is the secondary winding.
Without taking into account the power losses inside the transformer, let's calculate what the current I 1 should be in its primary winding. The ideal network voltage is U=220 V. Knowing the power consumption, for example, P=5 kW, we have:
I 1 = P:U= 5000:220=22.7 A.
Based on the current in the primary winding of the transformer, we determine the diameter of the wire. The current density for a household welding transformer should be no more than 5 A/mm2 wire cross-section. Therefore, for the primary winding you will need a wire with a cross section of S 1 = 22.7: 5 = 4.54 mm 2.
Using the cross-section of the wire, we determine the square, its diameter d without taking into account the insulation:
d 2 =4S/π=4×4.54/3.14=5.78.
Taking the square root, we get d=2.4 mm. These calculations were performed for copper wire cores. When winding wires with an aluminum core, the obtained result must be increased by 1.6-1.7 times.
For the primary winding, copper wire is used, the insulation of which must withstand well high temperatures. This is fiberglass or cotton insulation. Rubber and rubber-fabric insulation is suitable. Wires with PVC insulation should not be used.
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Calculation of the cross-section of the wires of the secondary winding of the transformer
The voltage at the output of the welding machine transformer in the absence of a welding arc (idle mode) is usually 60-80 V. The higher the idle voltage, the more reliably the arc is ignited. The welding arc voltage is usually 1.8-2.5 times less than the no-load voltage.
Attention. It is necessary to constantly remember that in the absence of an arc the voltage at the transformer output is life-threatening.
For welding in everyday life, an electrode with a diameter of 3 mm is usually used, which is sufficient to provide an arc current of approximately 150 A. With an open circuit voltage of 70 V, the arc voltage will be approximately 25 V, and the power consumption P of the welding machine must be at least
Р=25×150=3750 W =3.75 kW.
It is advisable to design the transformer for higher power, that is, higher welding arc current. For example, with an arc current of 200 A, the power consumption will be approximately 5 kW. This is the power the transformer should be designed for.
The single-phase voltage in the house should be 220 V, but it can vary by ±22 V. This is one of the reasons why the arc current may change and will need to be adjusted.
The cross-section of the wire in the secondary winding of the transformer is determined based on the current density equal to 5 A/mm 2. For a current of 200 A, the wire cross-section is 40 mm 2, that is, it can only be a bus that is wound with layer-by-layer insulation. According to existing standard sizes You can select the required tire both in length and cross-section.
Typical sizes of copper busbars produced by industry:
- length from 0.5 to 4 m with intervals of 0.5 m;
- width from 2 to 60 cm with intervals of 1 cm (with widths from 4 to 10 cm) and with intervals of 5 cm (with widths from 10 to 60 cm);
- thickness from 3 to 10 mm.
You can also use a stranded wire, the cross-section of which corresponds to the calculated value. To increase the cross-section, the wire can be folded in half or three. For aluminum wire, the cross-section must be increased by 1.6-1.7 times.
For a choke that is connected at the output of the transformer, the cross-section of the wire must be the same as in the secondary winding of the transformer.
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Rectifier for welding machine
For welding on DC An AC-to-DC converter must be connected to the output winding of the transformer. Such a device is called a rectifier, which is why a welding machine with this device is called a rectifier.
The top graph represents the sinusoidal voltage at the output of the transformer secondary winding. The horizontal t-axis is the time axis. The time interval between zero voltage values is determined by the oscillation period. It consists of positive and negative half-cycles.
It can be seen that the current is not constant, but pulsating. The only way to reduce ripple is by increasing the capacitance of the capacitor.
To regulate the arc current, the choke must be connected between the transformer output and point 3 of the rectifier.
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Methods for regulating welding arc current
Let's consider one of the methods of regulating the welding arc current, based on the use of a choke in the secondary winding of the transformer. The arc current is regulated by changing the air gap provided in the core on which the busbar is wound.
Let's consider three modes in which a transformer can be.
- Idle mode. Alternating voltage is supplied to the input of the transformer. An emf is induced in the secondary winding, but there is no current in the output circuit.
- Load mode. As a result of ignition of the arc, it closes the output circuit, consisting of the secondary winding of the transformer and the inductor winding. A current flows, the magnitude of which is determined by the inductive reactance of these windings. If there were no choke, the current would be maximum. The degree of impact depends on the size of the air gap in the rod on which the winding is wound.
- Mode short circuit. This is the moment the electrode touches the parts of the workpiece being welded. An alternating magnetic flux is created in the transformer core, and an emf is induced in the secondary winding. The current in the circuit is determined by the inductive reactance of the inductor and the secondary winding of the transformer.
As the gap increases, the resistance increases. This leads to a decrease in the magnetic flux and, accordingly, to a decrease in the inductive resistance of the choke coil and the total resistance of the circuit. The arc current increases. This method allows you to smoothly regulate the current.
However, the moving system has the disadvantage that as a result of the vibration of the metal when passing alternating current through the coil, it becomes not very reliable.
You can, sacrificing the smoothness of the adjustment, make it stepwise. To do this, it is necessary to make the choke so that there is no air gap in the magnetic core. During the winding process, taps must be made through a certain number of turns. In this option, the current can be adjusted in steps, through contacts that must be made powerful in order to carry a current of hundreds of amperes.
There is another reason why the throttle must be turned on to create normal manual welding conditions.
The characteristic of the dependence of arc voltage on its current is called falling. An inexperienced welder will have to believe that such a relationship is useful when welding if it is difficult to maintain a constant distance between the electrode and the parts being welded. To provide such a characteristic, the inductive reactance of the secondary winding of the transformer alone is not enough. The immediate task of a choke for a welding machine is to add the missing resistance.
How to install a choke for a welding machine with your own hands is of interest to many who have started assembling it with their own hands or purchased an inexpensive model. After all, with a little modification, you can get good technique, not inferior to expensive samples. You can buy a ready-made throttle or make it yourself with minimal financial investment.
Diagram of an AC welding machine with a separate choke: 1 - primary winding, 2 - core, 3 - secondary winding, 4 - choke winding, 5 - fixed part of the choke core, 6 - moving part of the choke core, 7 - screw pair, Др - current regulator.
Advantages of a choke for a welding machine
The function of the choke in a welding machine is to regulate the current used for welding. It compensates for the missing resistance during operation. The inductor should be connected to the secondary winding of the transformer.
This way you can achieve a phase shift between current and voltage and thereby facilitate the ignition of the electric arc at the very beginning of work. This will allow you to obtain a uniform burning of the weld and, accordingly, a uniform, high-quality weld. The current strength in the absence of a choke always has maximum values, which can cause unpleasant moments during the welding process.
The choke can be installed in a conventional welding machine that works with electrodes, and in a semi-automatic device. A semi-automatic machine equipped with a choke allows you to make a higher quality and deeper weld with minimal metal spattering. The optimal solution the inductor will be used in conjunction with a current rectifier. Then you can use almost all types of electrodes for welding work, and the welding will be soft.
The choke can also be installed on a welding machine equipped with a step-down transformer. It must be connected to the secondary circuit of the transformer. So, from a homemade welding machine you can get a semi-automatic machine, similar in design to expensive factory models.
As you can see, this part has great advantages. You can install the choke not only on a homemade welding machine, but also on a factory model. This part, installed on an inexpensive model of a welding machine that is prone to various problems, can make working with it easier and perform it efficiently.
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Materials for self-assembly of the throttle
By choosing the right material, you can easily assemble the welding choke yourself. It is a regular core with a wound wire. Many faulty electrical appliances can be used for this purpose. Very often, transformers from old tube TVs are used to make it, from which you can remove the old winding and wind a new one with the required cross-section.
Another device that can remove the throttle is an old street light. The old winding that has become unusable must be removed from this part, leaving only cardboard spacers to provide a gap between the main core element and the closing element. During the process of winding the wire, these elements should be installed in their original place.
To make a choke, any magnetically conductive core with a cross-section of 10 -15 cm is suitable. Between its parts you need to make a non-magnetic section by inserting an insulating gasket 0.5 -1 mm thick.
Copper or aluminum wire is used to wind the inductor.
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Winding and installing the choke
To wind an aluminum wire, you need to choose a cross-section of 35-40 mm, for copper - 25 mm is enough. You can also replace the wire with a copper (4 by 6 mm) or aluminum busbar with a large cross-section. So, when using regular wire, you need to make 25-40 turns, and the bus needs to be wound in 3 layers. If you have selected a part from street lamp, then the wire should be wound along the entire length of one of its sides until the window is filled.
Before winding the wire, the yoke should be insulated. When winding the wire, do not change direction. The next layer of winding is insulated from the previous one with cotton cloth, fiberglass or cardboard for insulation, and insulating impregnation with bakelite varnish is applied. When winding, the terminals must be marked.
Stepwise adjustment of the welding arc current is achieved by turning on a load ohmic resistance at the output, which is a nichrome spiral, through an equal number of turns of which taps are made with good contacts, withstanding heavy loads. There is no air gap in the throttle core. But this method has a drawback: the filament heats up a lot, sometimes red hot.
Smooth current regulation is achieved by installing movable transformer windings.
By changing the distance between the primary and secondary windings of the transformer, the magnitude of the magnetic flux and resistance in the secondary winding changes.
Particular attention should be paid to throttle settings.
You can configure it like this:
- adding or unwinding the number of turns of wire;
- by changing the dimensions of the air gap in the core.
A properly manufactured and configured choke will allow you to work with a homemade welding machine no worse than with an expensive imported model.
Most craftsmen involved in private repairs of equipment sooner or later begin to think about how to assemble. Nowadays, equipment manufacturers offer a considerable number of such devices for use in small-scale production. It can be a device operating on alternating or direct current, semi-automatic welding or a device using electrodes. However, any good branded device costs big money, and there are more cheap analogue, as a rule, is unreliable and quickly begins to fail. To assemble a welding machine, you first need to select or manufacture necessary details, this also applies to such a device as a throttle.
When creating a welding machine with your own hands, you need to pay attention to Special attention on the throttles.
The benefits of a choke for a welding machine
The welding choke is a regulator of the current used for welding. Its immediate task is to compensate for the missing resistance. It can be connected to the secondary winding of the transformer. This allows a phase shift between the passing current and its voltage, which makes it easier to ignite the electric arc at the beginning of the process. At the same time, it burns much more evenly, and this allows you to achieve sufficient High Quality weld seam. Without a choke, the current will always be at its maximum, which can create problems during the welding process.
Semi-automatic welding circuit diagram.
The choke can be included in the design of both a welding machine, which uses electrodes during the welding process, and as part of a semi-automatic device. A semi-automatic welding machine that has it splashes much less metal during operation, the welding process itself is much smoother than without it, and the weld seam is welded to a greater depth. So the advantages of using such a part are beyond doubt, and it can be installed not only on, but also on a similar factory-made device. This is especially true for inexpensive models that are prone to malfunctions. This will greatly facilitate the work on it and improve the quality of welding.
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Options for using scrap materials
To make a welding choke yourself, you first need to find suitable material. Many electrical devices that have reached the end of their service life and are discarded as unnecessary are quite suitable for this purpose. Since it is simply a core with a wire wound around it, there is quite a wide choice here. A transformer that was once part of the design of a device such as a tube TV may well be suitable for this purpose. The entire winding will have to be removed from it, and the freed core will be used to wind a new wire, the length and cross-section of which must be calculated in advance.
To create a choke, already used electrical devices are used.
You can also, if possible, use chokes that were on burnt-out street lamps. In this case, the old windings will have to be removed, since they have become unusable, but leave the cardboard spacers that created a gap between the main part of the core and the closing part. When winding a new wire, they will need to be put in their original place. In general, it should be noted that to wind the inductor, you can use any magnetically conductive core having a cross-section from 10 to 15 cm. In this case, it is necessary to create a non-magnetic gap between its parts, for which you insert an insulating gasket with a thickness of 0.5 to 1 mm.
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Manufacturing technology and installation
Aluminum or copper wire is involved in creating the inductor.
Aluminum or copper wire is used to wind the inductor. In the first case, its cross-section should be 35-40 mm, in the second, 25 mm will be sufficient. You can also use a busbar as a replacement for the wire, in particular a copper one, 4 by 6 mm, or a thicker aluminum one. In this case, the wire is wound in an amount of 25 to 40 turns, and the bus will need to be wound in 3 layers. If the above-mentioned part from a street lamp acts as the core, then winding is done only on one of the sides along the entire length until the window is completely filled. In this case, the winding direction cannot be changed. Each layer must be insulated from the previous one by laying cotton fabric, fiberglass or special insulating cardboard, which should also preferably be impregnated with bakelite varnish.
If the device is provided with not a smooth, but a step adjustment, then no air gap is made in the magnetically conductive core of the choke, and when winding through an equal number of turns, taps must be made. The contacts on them need to be strong enough, since they will bear a large load. In general, it must be recognized that installing a throttle has a positive effect on the operation of any welding machine, be it a semi-automatic welding machine or a primitive homemade one. For a device operating on alternating current, it will be optimal to use it together with a current rectifier, which will allow it to use almost the entire range of electrodes, and it will work much smoother.
You can also install a choke on the device together with a step-down transformer. It connects to secondary circuit welding transformer. This replicates the design of a proprietary Japanese semi-automatic, which costs a lot of money. In this case, the throttle must be very accurately calculated according to the formula that is published in specialized literature, and this will give a considerable advantage. Such a device will have a transformer with good dissipation, and its characteristics will be clear.
It is worth immediately warning that before assembling a welding machine assembled on your own, the throttle must be correctly configured. This can be done in two main ways: by adding or unwinding the number of turns of wire, or by changing the size of the air gap in the core.
After the throttles have been successfully configured, homemade apparatus It may well work no worse than an expensive branded semi-automatic machine.
It will meet exactly the requirements that the owner needs.
