"The woman is created for a man, not a man for a woman" - such a postulate ...
Those who have not yet acquired the welding machine (SA), I recommend to make it yourself on the basis of the resulting asynchronous electric motor. The cost is minimal, but the result ...
Experimenting with different sa, I made sure that the pursuit of a powerful apparatus (inherent, as a rule, beginners) is not always economically justified. For most work at home, the "welder" is performed on the basis of a 1-1.5 kW asynchronous electric motor stator with a magnetic pipe with a cross section of 40 cm2. To connect to a household network 220 V with an arc of the welding arc 40, 50 and 60 to the primary winding of such a CA should have 220 turns, and the secondary - 60, with the discreets from the 40th and 50th "tire" turns.
Fig.1. Welding machine from a stator of a faulty asynchronous electric motor:
1 - the base of electrical insulating; 2 - Terminal (6 pcs.); 3 - clamp; 4 - the winding of the secondary (60 turns of the thickened tire of the harness from 9-15 PEV2 wires with a total cross section of copper veins 30-35 mm2, wrapped with a tissue-based tape, taps from the 40th and 50th turns); 5 - Insulating interlayer (2 layers of linen or cotton fabric, followed by impregnating bakelitic varnish); 6 - the primary winding (220 turns of the tire - harness of 3-6 wires of PEV2 with a total cross section of copper veins 6-8 mm2, wrapped with a tissue-based tape); 7 - isolation reinforced (execution - as in paragraph 5, but the insulating layers are twice as much); 8 - torque magnetic circuit; 9 - pen.
After the stator turns out to be in your hands, do not rush to cut off or burn out the winding. After all, in most cases, it is quite suitable as the source material for "multi-chamber tires" required by the welding machine.
The stator winding in most asynchronous engines is somewhat overlapping each other sections. Laying each of them is made in the appropriate grooves of the magnetic pipeline. Carefully examined the stator, determine which sections was lathe was lathe. With it and start dismantling.
First of all, try to knock the wedges (usually wooden), which the winding turns are fixed in the grooves. If it is not possible to do with the help of girlfriend, "use the device in the form of a special configuration knife made from the Lobzik cloth.
Fig.2. Knife to remove wedges from the stator groove.
The technology is simple here. Moving the knife on yourself, remove the chip from the wedge, seeking to dismember it on the part. After removing the resulting fragments, start the coil behind the turn to extract the section itself from the grooves. Do it carefully and leisurely; In the sequence, inverse factory laying. With the release of the last section, unlock wires and rectate, getting a length of 20 to 30 m. Of these, and make the tires of the required section.
Thus, to obtain the primary (network) tire, the Ca winding must be folded together 3-6 blanks, so that the total cross-section of the copper veins was 6-8 mm2. The formed harness should be wrapped along the entire length of the tapenee on a tissue basis. It is quite acceptable and long insulating stripes, stitched (glued) from cropping linen or cotton fabric. Even paper tape, sliced, say, from postal or cement bags, will be used.
In order for the work on the manufacture of an isolated tire, the spores walked, the original beam of the wires tie out in several places with twine and roll into the bay with a diameter of 600-800 mm. The very same tape is imposed at an angle to the harness so that each subsequent coil overlap the half of the previous one, and the insulation was a two-layer. By applying fabric or paper, do not forget that these materials need to be subsequent impregnated by a bakelite varnish or any (excluding water-emulsion) paint.
Similarly, make a tire for the secondary winding of the welding transformer. Only here the wires in its composition should be so much that the total cross section of copper lives is 30-35 mm2.
Now about the refinement of the magnetic pipeline. Its essence is reduced to ensure that the base stator is to remove jumpers between sections with a hammer and chisel. And the sharp edges generated at the same time smooth the file. The finished magnetic core is covered with several layers of isolation according to the above technology.
To facilitate the winding, enter the wire into the core and rotate the entire ring until the last round is free to the core of the "welder". It will be as if two interrelated levels of heterogeneous (steel magnetic circuit and copper bay) chains.
Fig.3. Laying the turns of the tire, coated in the bay, on the torque with enhanced insulation.
The winding of the transformer tire is better to perform together. First, heal in the vice edge of the magnetic pipeline, then shake the end of the bus, rolled into the bay via the center of the Torah, and, gently turning the last, achieve, so that the chain link connected to each other is. Securing the beginning of the primary winding on the surface of the Torah with twine, continue to rotate the bus, tightly laying the coils on the isolated magnetic cure.
Behind the first layer of turns should be laying of lightweight isolation, the impregnation of the received "sandwich" discharged bakelite varnish or diluted paint. Then - a new layer of winding, distributed evenly throughout the entire surface of the torus followed by isolation. The coils are strictly radial.
Completes the primary (network) winding of the 220th round. Next comes secondary (welding). Place it before making reinforced multilayer isolation. In total, in this winding, as already noted, 60 (with loop outlets from the 40th and 50th) turns.
The general rule: if suddenly it turns out that the wire (tire) is shorter than required, the extension should be performed outside the winding, properly issued the corresponding conclusions.
The design of the self-made welding transformer depends on the capabilities of the author-performer. One of the most simple and acceptable options is the "lateral" consolidation of the "welder" on the insulating base as an uncomplicated clamp with a carrying handle.
Practical electronics
B. Andreev, 15 years old, Zainsk Tatarstan
Radio 2002, No. 7
In the manufacture of various amateur structures from the Radio log, the power transformer is often required. However, when selecting a suitable magnetic circuit, there may be problems. I use magnetic pipelines for old electric motors, on which you can wind the toroidal transformer with a capacity of 30 to 1000 W.
Paz S. inner Cylindrical stator electric motor 1 (see . picture ) I do not remove, but by wind and wind all the ring and every tooth separately. Then in the grooves, I lay the coil 2 of the primary winding I, pre-dividing total number turns on the number of grooves. If all the turns in the grooves do not fit together, then laying the additional layer of insulation on top of the filled grooves and keep the remaining turns of the primary winding.
Then I lay two or three layers of lackets 4 or cotton insulating tape and winding the secondary winding 3 as the toroidal transformers are usually wound. I soak each winding with an oil taken from a high-voltage paper capacitor (for example, 4 μF to 600 V from the daylight lamp) or molten paraffin from the candle.
Before winding the secondary winding, it is useful to specify the number of turns on the volt, because when winding the primary winding, errors are possible in the counting of the number of turns. For this, the trial secondary winding of 10 or 15 turns of any wire is wound and the voltage is measured on it. Then, expanding 10 (or, respectively, 15) on the measured voltage, calculate the number of turns to the volt, and then the number of turns of the secondary winding to the desired voltage. In the formula for calculating the number of turns onto the volt, which is written in a simplified form: n \u003d 45 / s, where S is the cross section of the magnetic pipeline in cm 2, I take the coefficient of not 45, and 65, while it almost disappears the need to increase the number of turns of the secondary winding 10 ... 20%, as is usually recommended, transformers do not heat, do not buzz and, in general, they work better. It is checked by me in practice.
From a stator of one electric motor, you can make magnetic pipelines of various thicknesses for several transformers of low power, if divided the stator to pieces between stamped plates. Thus, transformers for the laboratory power supply unit were made, charger And the musical call described in the "Radio".
From the editorial The author of the notes is intuitive and experimentally came to a completely correct conclusion about the need to increase the coefficient in the formula for calculating the number of turns to the volt. At the same time, induction in the magnetic circuit decreases, it ceases to go to saturation at the peaks of the sinusoidal voltage of the network, which is why idling current decreases sharply, the scattering field and the "buzz" of the transformer decreases. Article E. detailed description Our magazine has been taking place. Our magazine published another three years before the birth of the author (Polyakov V. "Reducing the transformer scattering field"
For the manufacture of a welding transformer, you can use a stator from an asynchronous engine. The size of the core is determined in this case The cross-sectional area of \u200b\u200bthe stator, which should be at least 20 cm 2. If, this condition is performed, then any stator is suitable. The cross-sectional area is defined as shown in the figure slightly lower.
The most rational amount of the secting of the core is in the range of 20 cm 2 - 50 cm 2. You can use a core with an area less than 20 cm 2, but it is necessary to reduce the cross section of the wire in the windings, and this will behave to a noticeable reduction of the power of the machine and narrows its parameters. Use cores with a cross-section area more than 50 cm 2 also flies, as the device will be too heavy and bulky.
Welding transformer schematic scheme inclination
As can be seen from the circuit, the welding current is adjusted using SA1. To do this, several conventional network sockets are fixed on the device panel by the number of outputs of additional winding. The circuitager is a network plug, in which the legs of the connector are twisted with each other with a single-core wire, the diameter of which is 1/4 diameter of the wire of the primary winding. This makes it possible to use a wire in the role of a fuse, which burns with possible overloads.
Remember that use in the rectifier of powerful diodes with direct from 200 A makes it possible to weld the part of the DC arc it provides better ignition of arcs and more accurate seam.
Welding transformer If properly assembled, it does not require any configuration and is immediately ready for operation.
remember, that welding work It should be carried out in a special mask and in overalls, eliminating splashes of the molten metal and the light spectrum on the open areas of the human body.
Welding transformer on the magnetic lines from the logs |
Common material for the manufacture of homemade st are burnt latries. Those who had the case with them know well what it is. As a rule, all Latters have about the same appearance: a well ventilated tin body round shape With a tin or ebonite facial cover with a scale from 0 to 250 V and a rotating handle.
Inside the case there is a toroidal autotra-torus built on a large cross section magnetic core. It is this core that will be needed from the latra for the manufacture of a new art. Usually 2 identical magnetic rings from large logs are used.
When developing the design and manufacture of its devices, "says O. Lavrov," I used the former publications of different magazines. He began with the manufacture of a welding "baby" from the autotransformer Latr on 9a, using its winding and the quality of the network. I did not find the secondary winding of a special winding wire in cotton or fiberglass insulation, so I had to use a flexible stranded wire in vinyl insulation with a total cross section of copper lived 6 mm 2. Made by me "Baby" made it possible to obtain a welding current up to 140a, but very strongly overheated even when using only one electrode ∅3 mm.
In this regard, in experiments on the further improvement of the welding machine for the manufacture of magnetic pipelines, asynchronous three-phase electric motors were used. As a result, it was possible to make a device that allows you to keep welding with electrodes with a diameter of 2 to 5 mm and even up to 6 mm, providing a magnitude welding current Up to 200 and at idle voltage 56 V, it has a small size - 350x350x200 mm and weigh no more than 20 ... 25 kg. In addition, it is easy to design, and the proposed manufacturing technology allows you to perform all the work in a home workshop.
For the manufacture of the magnetic pipeline, it is convenient to use a stator of an asynchronous three-phase electric motor with a capacity of 4 to 6 kW. The stator must be released from the housing, cast from aluminum alloywhich is easily split by several blows of heavy hammer. Next you need to remove stator windings from the internal grooves. To do this, it is enough to cut the protruding parts of the windings from one of the ends of the metal with a metal, and then from the opposite end, the remaining parts of the windings are simply pulled out of the slots or in parts.
The combined T-shaped teeth from the inside of the stator should be removed with the help of a chisel and clean the irregularity of the abrasive circle. It is unacceptable to apply gas or electric welding to the teeth.
In fig. 1 shows the size of the core harvesting, which should turn out after the execution of the transactions listed. These sizes must be considered when choosing a stator. The cross-sectional area of \u200b\u200bthe toroidal core S ab \u003d a · in (cm 2), equal to the height of the core in centimeters on its thickness A (in centimeters), is the value that defines all the main characteristics of the future welding machine. The optimal value of S AB \u003d 20 ... 25 cm 2. When using states recommended above engines, the billet height is usually equal to 150 ... 200 mm, from such a workpiece it is possible to get magnetic pipelines for two devices.
After removing the teeth and the rounding of sharp edges with an abrasive circle, a self-shaped core must be wrapped in a cotton-based insulating tape. To exclude damage and closure of the network winding, the insulating tape must strive to apply tightly and evenly without passes so that neighboring turns overlap each other.
The welding machine must have two independent and isolated windings from each other. Principal electrical circuit shown in Fig. 2. The primary winding is calculated on the connection to the 220 V network. The electrode holder and the welded part are connected to the secondary winding. This winding must be calculated on a voltage of 56 V, and in order to be able to adjust the power of the welding current, it is necessary to provide additional tensions with a voltage of 50, 44, 38 and 32 V.
The number of turns of the primary winding p, It is possible to determine by the formula:
S AB (see Fig. 1) must be expressed in cm 2. The obtained value of N 1, one can boldly round up to an integer number of tens of turns. From its experience in the construction of welding machines according to the proposed technology, I can add that if necessary, the calculated number of turns for the network winding can be reduced, but not more than 6%. L 1 wire length in meters required to perform the primary winding:
L turn - the length of the turn of the first layer in meters (the measurement method is shown in Fig. 1).
To perform the primary winding, it is best to use a special copper winding wire in fiberglass insulation with a cross-sectional area of \u200b\u200b2 ... 3 mm 2. Such wires can be found, breaking old electric motors. But you can use aluminum wires with a cross-section 1.65 times more than copper. For example, I successfully used for the network winding a two-housing aluminum wire in vinyl insulation with a cross section 2 ... 2.5 mm 2.
It is necessary to increase isolation on the first layer of the primary winding, laying under the ribs of the magnetic pipeline of the cardboard strips with cuts.
The primary winding with a shuttle is uniformly, the coil to the turn is laid along the length of the circumference of the toroidal magnetic pipeline and is isolated by one to two layers of cotton insulating tape. The secondary winding is stacked directly on this layer of insulation.
The number of turns of the secondary winding can be calculated by the formula:
For the secondary winding, you should use the copper winding wire of the rectangular section in fiberglass insulation, but you can wind the winding and a flexible stranded wire with a cross-sectional area of \u200b\u200b10 ... 30 mm 2. Also, as for the primary winding, it is permissible to use aluminum wires with a cross section of 1.65 times more.
The body of the welding machine is made of two square shields of 10 millimeter plywood (Fig. 3). The length of the sides of the square should be at 20 ... 30 mm exceed the largest diameter of the toroidal core with windings. Shields are tightened with six pins with M8 thread. The same studs are used as terminals to connect the outlook outlook. The central hole with a diameter of 30 mm is necessary for ventilation. The connection between the heels and conclusters of the transformer should be performed by a flexible stranded wire with a cross section of at least 10 mm2 two sections of the same wire with a length of 10 m can be used to connect the electrode holder and the part welded to the machine. For network conclusions, any flexible wires with a cross section of 1.5 ... 4.0 mm 2 are suitable.
The presence of secondary winding taps with increments of 6 V allows you to connect to the device any load designed for voltage 6, 12, 18, 24, 32, 38, 44, 50 or 56 V and consumes tookdo 200 A. so, for example, by connecting to Conclusions 44 and 56 Rectifier, designed for current 200 A, we obtain a constant current with a voltage of 12 V to run the engine of the motor of a passenger car on the output of the rectifier.
From the editorial Descriptions of welding machines, methods of their manufacture and used for this material has already been published quite a few. But we decided to continue the conversation on this exciting, apparently the topic of our readers. Choosing a material for this brought to the editor of Muscovite O. Lavrov, we hope that interested readers will see in it and interesting finds, and new ideas.
I would like to make only the most general comments, but ... about the most important thing: about electrical safety!
The welding machine is simple, but, like any other device with a network. alternating currentmust meet certain requirements. One of the mains is that all elements of the design of the device, which, when turned on, turn out to be under voltage of more than 12 V, should be either insulated or closed with an insulating or metal (but grounded) case. Following this requirement, the conclusions of the secondary winding of the transformer should be connected to the simplest terminal assembly, for example, from bolts M8 with nuts and close with a lid, and all switching can be performed only after disconnecting the device from the network.
Another requirement that should not be neglected in the manufacture of a welding machine is the mandatory presence of a fuse in the network winding circuit. It can be either an industrial fuse of any design at a current of 25 ... 50 A or the simplest homemade.
And one more note, which refers not only to the design described above. The desire of our authors to the creation of light and compact welding machines leads to a high tension of the thermal operation of the transformer winding. At the same time, the inaccessibility of the winding wires of a large cross section with special heat-resistant insulation forces the use of wires intended for laying electrical networks. The choice here is very limited. Only wires in rubber or rubber-tissue isolation have satisfactory heat resistance. And completely unsuitable for work when increased temperature In the windings of the transformer of the wire in polyvinyl chloride (PVC) isolation. This insulating material with increasing temperature loses mechanical strength, melted and, in the end, flows out of the winding, leaving the naked wire tightly laid down to the turn. The consequences are obvious - short circuit. Therefore, PVC isolation from the wires is better to remove and wrap them along the entire length of the cotton insulating tape.
The design of the proposed welding machine "Dry" - made on the basis of a stator from the electric motor. Make sure: it is best to use the corresponding magnetic conduit from an asynchronous three-phase machine with a capacity of 4-5 kW. The release of such a stator from the cabinet shell is easiest to be a sledgehammer or a sweaty hammer, hitting the weakest places.
Next, the winding is deleted. And in two receptions. First, remove it from some one side, using the metal hacksaw. Although it is quite applied for the same purpose a hammer with a chisel, directing the strength of the strike on the diameter of the stator. And then, by going with opposite side, Start passatages to pull out the segments "half-splashable" wires from the grooves. The magnetic circuit released from the winding and will become a toroidal core of the welding transformer.
Fig.1. Welding transformer with magnetic core from the stator of the burnt electric motor (Isolation between windings, their layers, and the magnetic circuit is not conditionally shown):
1 - shock absorber leg (from bottles with household chemicals, Rubber, 6 pcs.), 2 - wall-housing (10 mm heat-resistant sheet insulator, 2 pcs.), 3 - terminal screed (bolt M8 from copper or brass, 6 pcs.), 4 - Nut M8 (from copper or brass, 18 pcs.), 5 - Copper washer (28 pcs.), 6 - cable power single-core cross section 20 mm2 (2 pcs.), 7 - nut-lamb M8 (2 pcs.), 8 - removal (segment The wires of the electric multiple cross section of 20 mm2 in cotton insulation, 4 pcs.), 9 is a magnetic pipe with a cross section of AXB (from the stator of the burnt electric motor), 10 - a second-tier cable, 11 - output of the secondary transformer winding (2 pcs.).
As practice shows, when choosing a "iron pack" for it, it is necessary to strive for it to ensure that the size of the "A" of the stator-blank would be within 30 ... 40 mm. Then, to obtain the optimal section of 20 ... 25 cm2, we will have to define our source torus for 2-3 parts so that the size of "B" turned out to be 50 ... 80 mm. It is better to make it with a metal hacksaw, peeling the outdoor cast screeds in the grooves (usually 8). Then, removing "abandoned" 3 ... 4 sheets of "stator iron", spread the screeds, thereby bonding each of the future toroidal cores. But the arc sharp-welding here should not be carried away, since the vortex currents of Foucault arising in these places lead to the heating of the magnetic pipeline and significantly reduce the efficiency of the transformer.
Fig.2. Sharpening chisel-crutzmere.
The internal teeth - the pole of the stator - are chosen by chisel-cruitsee with a special sharpening (see Fig.). Naturally, it should not be neglecting the safety regulations. Be sure to use glasses and mittens. The chisel is best to keep the passatizes, and not by hand.
In no case can not cut the teeth with electric or gas welding. After all, in the magnetic circuit, when the transformer is working, the currents of Foucault will arise. Therefore, it is best to take advantage of the "Dedovsky method" here with a chisel and a hammer mass in 1 kg. And remaining after cutting the teeth of irregularity, it is advisable to remove grinding with the help of an abrasive circle. The finished magnetic pipeline is wrapped with a mold or other insulating tape on a tissue basis.
Now it's a primary winding. The number of turns in it with an accuracy acceptable to practice can be found by multiplying the voltage value in the network for a private division "40" on the cross-sectional area (in cm2) of the transformer core. In our case, this coefficient characterizing the estimated number of turns by 1 V is two.
Thus, for the network (primary) winding of the "welder" offered by me, only 440 turns will be required. And it's best to use here copper wire section 2 ... 3 mm2 (with a diameter of 1.6 ... 2 mm) in fiberglass isolation. The layers of the primary winding are carefully isolated from each other. As, however, the layers of the secondary, the number of turns in which, based on the required voltage (56 V) and the above coefficient (2), should be 112, and the cross section is 10 ... 30 mm2. Winding wires can be taken from old electric motors with a phase rotor capacity of 3 ... 6 kW. For example, I used it from them a wire with fiberglass insulation (section - 3 mm2) for the primary winding. By the way, from the same electric motors can be borrowed and the busbar of the 18 mm cross section for the secondary winding of the welding transformer. Especially since all this is from the purest copper.
Naturally, for the winding of the "welder" can be content with aluminum. But then the size of the cross section of each of the windings increases 1.65 times. For example, the primary will require a wire for at least 3.3 ... 5 mm2. Remembering this, in one of the options for welding transformers, was forced to use the two-housing aluminum wire - "noodles" with a cross section of 2x2.5 mm2 (the diameter of one vein is almost 1.9 mm).
How much do you need to take wires for a particular winding? Determine this, as they say, is easier than simple. Having measured the wire consumption for 1 turn of the winding (see Fig.), It is necessary to multiply this value to the estimated number of turns of the winding. But take (considering the thickness of insulation, etc.) with a three-percent reserve (for primary) or six percent (for the secondary winding).
In their "welders" providing 5 steps of adjustment (up to a maximum of 56 V), making taps in the secondary winding, designed for voltages 32 V, 38 V, 44 V and 50 V. When switching to the turns, it is, respectively, will be 64, 76 , 88 and 100. Taps prefer to perform by winding the segments of the flexible wire with a cross section of at least 10 mm2.
Find accurate findings in the secondary winding is the easiest way experimentally, the "trial and error" method. Especially if her winding "loose", and also conducted flexible wire. Then boldly include a transformer on the network and conditionally, adopting the first output of the secondary winding for the "common", pour insulation with a probe-needle in one, then elsewhere. And finding the voltage of 32 V, 38 V, 44 V, 50 V, marked them. If the secondary winding is wound by busbar, then you have to limit ourselves to the "calculated" method. That is, it is in advance to determine on which twist one or another will be performed, multiplying the above-mentioned coefficient (2) to the desired volt number.
The finished transformer gives a convenient and reliable form from the point of view of users. For this, there are two squares of 10-mm plywood. And even better - from a fiberglass or another heat-resistant insulator. In the middle drill a 30-mm circle for ventilation (see Fig.), And it is symmetrically in the corners - seven 8 mm holes for the passage of the terminals and the network wire.
The housing is essentially ready. Well, the rest, I think, clearly from the illustrations that are given here. Convinced: make yourself a good welding transformer According to the above method, anyone can.
In the proposed welding in the secondary winding, conclusions were made in increments of 6 V. Using the principle of the autotransformer, it is possible to have a whole "gamma" of stresses: from 6 to 56 V. In particular, using conclusions 56 V and 50 V, it is easy to get a difference voltage 6 V. Conclusions 44 V and 56 B allow you to have 12 V. in exit, by connecting, for example, to such a transformer rectifier for 200 A, you can safely run the engine starter.
Yes, "Welder" really gives up to 200 A in the secondary winding. And this means that you can already use electrodes with a diameter of 2 ... 5 mm! Being made according to the proposed technology, the welding transformer has small dimensions (within 350x350x200 mm) and truly minimal mass (up to 25 kg).
