Svaris 220 DIY repair

In detail: do-it-yourself weld 220 repair from a real master for the site my.housecope.com.

The RESANTA SAI 220 welding machine is well suited for home use. The equipment works on the principle of converting electricity with a frequency of 50 Hz into a voltage of 400 V, modulation is used for regulation. The inverter circuit is not very complicated, the design consumes up to 6.5 kW. High stroke voltage - 80 V, allows the use of different types of electrodes.

Features of RESANTA SAI 220:

The diagram of the RESANT SAI 220 apparatus is based on the UC3842BN microcircuit. Powerful FQP4N90C transistors are used, the gate of which is insulated.

Voltage - 220 V.
The diameter of the electrode is 5 mm.
Arc voltage - 80 V.
The consumed current is 30 A.
Weight - 5 kg.
Protection class - IP21.

Welding inverter.
Shoulder strap.
Grounding terminals.
Electrode holder.

The main malfunctions that users face when operating the RESANTA SAI 220 inverter:

The RESANTA SAI 220 welding machine is a good choice for a small workshop or home use. Everything you need to work in the device is present. The design flaws are offset by the low price - 9930r.

As already mentioned, the filling of the welding inverter is designed for high power. This can be seen from the power section of the device.

The input rectifier has two powerful diode bridges on the radiator, and four electrolytic capacitors in the filter. The output rectifier is also complete with: 6 dual diodes, a massive choke at the output of the rectifier.

three ( ! ) soft start relay. Their contacts are connected in parallel to withstand the large current surge when welding starts.

If we compare this Resanta (Resanta SAI-250PN) and TELWIN Force 165, then Resanta will give him a dashing head start.

But, even this monster has an Achilles heel.

Video (click to play).
- The device does not turn on;
- The cooling cooler does not work;
- There is no indication on the control panel.
After a cursory inspection, it turned out that the input rectifier (diode bridges) turned out to be in good order, the output was about 310 volts. Therefore, the problem is not in the power section, but in the control circuits.

External examination revealed three burned out SMD resistors. One in the gate circuit of the 47 Ohm field-effect transistor 4N90C (marking - 470 ), and two at 2.4 ohms (2R4 ) - connected in parallel - in the source circuit of the same transistor.

4N90C bipolar transistor (FQP4N90C ) is controlled by a microcircuit UC3842BN... This microcircuit is the heart of the switching power supply, which powers the soft-start relay and the integrated stabilizer at + 15V. He, in turn, feeds the entire circuit, which controls the key transistors in the inverter. Here is a piece of the RESant SAI-250PN diagram.

It was also found that there is also a resistor in the power circuit of the UC3842BN (U1) ShI controller in the open circuit. In the diagram, it is designated as R010 (22 ohm. 2W ). It has the reference designation R041 on the printed circuit board. I will warn you right away that it is quite difficult to detect a break in this resistor during an external examination. A crack and characteristic burns can be on the side of the resistor that faces the board. This was the case in my case.

Apparently, the cause of the malfunction was the failure of the UC3842BN (U1) ShI controller. This, in turn, led to an increase in the consumed current, and the resistor R010 burned out from a sharp overload. SMD resistors in the FQP4N90C MOSFET circuits played the role of a fuse and, most likely, thanks to them, the transistor remained intact.

As you can see, the whole switching power supply unit on the UC3842BN (U1) has failed. And it feeds all the main units of the welding inverter. Including soft start relay. Therefore, welding did not show any "signs of life."

As a result, we have a bunch of "little things9quot;" that need to be replaced in order to revive the unit.

After replacing the indicated elements, the welding inverter turned on, the display showed the value of the set current, the cooling cooler clinked.

For those who want to independently study the device of the welding inverter - the complete schematic diagram of "Resant SAI-250PN".

The Resant SAI 220 inverter welding machine arrived.
Power t-ry burnt down (HGTG30N60A4D) There are four of them there.
The replacement of transistors and the subsequent inclusion in the network led to their repeated departure to the short circuit. I put such t-ry MGW20N60D.
The problem turned out to be absurdly funny)))
The board is two-layer, it turned out that either during operation, or in some other way, I don't know, the metallization of the holes, into which the self-tapping screws fixing the radiator of the transistors are screwed, was broken.
In short, the protective diode of the return of one of the transistors just hung in the "air". Because of this, a return (trance inductance) jumped out from the main transformer directly to the transyuk, which were not protected by a diode.
Such is the story)))

Resanta 220 A. When turned on, it does not work at all, no smell, no overheating. Where to start? Help.

Forum fan
Posts: 3817

Rezyuk softstart look

Guys, help me find the diagram of the RESANT SAI 220 apparatus. Not GP where there are 6 high-speed diodes but 4. And there are 2 optocouplers on the overload protection circuit

Resanta 220 A. When turned on, it does not work at all, no smell, no overheating. Where to start? Help.

option number one - take it to the master
option number two (if the master himself) - the sense of smell and touch are not assistants in creating a topic or post on a forum where they are engaged in professional repairs.
Where or what was checked, what kind of food is there (if any)?

Forum fan
Posts: 4937

wow, with an annual difference, the device must have been made by someone else, it burned out again, again after repairs and now it's already in the trash heap for a year, at most two they live,

You you can not start threads
You you can not reply to messages
You you can not edit your posts
You you can not delete your posts
You you can not vote in polls
You you can not add files
You can you download files

decided to pile the oscillator to the inverter, saw the video and ended up in the pantry
such a transformer from neon advertising.
piled, for sequential inclusion. a spark gap of 2 x auto-spark plugs, everything works, but after 1 turn on the copper bus (secondary) of the transformer, ferrite 2x Ш 65 2000 nm, the voltage is not transformed.
I wound another transformer with wire (purely for experiment) but the high voltage is not transformed to the secondary.
I put different capacitors, from a tube TV, from an electric knife, I changed the gap in the spark gap (I made it on the thread there)
but there is no spark on 9 turns of a copper bus even with a gap of its ends of 0.2 mm
can the people tell me?

Good day everyone!
I got my hands on an inverter with 12V - 220V (300W max) model DCI-305C.

Duck, I decided to take it up in a couple of months. The owner wanted to throw him out. But he gave it to me. He said that it does not turn on and that's it. Well, I gave it up for two months. And today I stumbled upon it by accident. I took it, I think, let me see what's wrong with it.
I connected it to a computer power supply unit, but the power supply unit did not turn on itself.
I suspect that two field workers or one of them are faulty. (P60NF06)
Further, according to the diagram, there are two assemblies based on ka7500b PWM controllers (analogue of TL494) and four planar UF730L power modules are installed at the output. As I understand it, two of them work on one half-wave, the other two on the other half-wave (like a swing) of the output voltage of 220V.

Do I understand correctly - if the poliviks fail, the input voltage and current will not go further than these transducers? Just why I think so. I have a car VCL and there on the board there are also installed power transyuks irfz 34 n (they were. Replaced with irfz 44 n). It also did not turn on, after replacing transyuk everything worked. So I'm thinking of replacing the voles with an inverter.
Actually, why did you come here?
I would like to know the reason (s) for the failure of the field workers in general. And is it possible to install a diode in the circuit against polarity reversal?
The device itself.

Good day! Please help me figure out what happened to my Patriot DC-200C. When the power was turned on, a popping occurred and stopped working. It all happened in the spring when I took it out of the cold garage into the street. The resistor on the board burned out, it says R3, I can't find out the value, there is a possibility that the Toshiba K3878 transistor has failed. I found only the Patriot DC-180 circuit, I thought to find the resistance rating in it and re-solder it by analogy. I ask for help to suggest what could have happened and what else could fail.

Hello.
I decided to try to make an inverter 12-220. By this time, I had already made 2 inverters, but this was a repetition of ready-made circuits (one from the power supply, the second on the finished metal magnetic circuit). And so I decided to try winding my first pulse transformer. Rummaging through the junk at home, I found an old card from a CRT monitor taken from nowhere. There was such a transformer.

He began to cook it in water, since he easily figured it out. I rewound all the windings. There are two halves and a coil left. And now the question arose. I want to calculate this whole thing in the ExcellentIT program, but I cannot decide on a few questions:
1) What type of ER or ETD core?

2) The closest analogue in size, as I understand it, is ETD 49/25/16 (ER 49/27/17). But the dimensions of my core are different from the standard sizes of this core.

How to be? Add my core to the program database. And if so then
3) Where to get the effective permeability?
4) My core has a gap in the middle. Can such a core be used to wind a transformer for an inverter?

5) in the program, where the core is selected, is only one half of the core indicated or should it be selected taking into account the dimensions of both halves?
And maybe someone has a datasheet for this transformer? Unfortunately, I did not find anything on the network.
Thank you in advance.

Good afternoon members of the forum!
To test solar inverters after repair, you need
solar panel string emulator
Output voltage of the emulator 450V current 3-4 A
Stabilized server power supply HP 12V 2250Wt is available
a variant of the DC / DC step-up pulse preprocessor suggests itself
I ask for help tk not a radio amateur

If you know how to repair welding inverters with your own hands, then you can fix most of the problems yourself. Possession of information about other faults will prevent unreasonable costs for service maintenance.

Welding inverter machines provide high quality welding with minimum professional skills and maximum welder comfort. They have a more complex design than welding rectifiers and transformers and, accordingly, less reliable. Unlike the aforementioned predecessors, which are mostly electrical products, inverter devices are a rather complex electronic device.

Therefore, in the event of a failure of any component of this equipment, an integral part of diagnostics and repair will be checking the performance of diodes, transistors, zener diodes, resistors, and other elements of the inverter's electronic circuit. It is possible that you will need to be able to work not only with a voltmeter, digital multimeter, and other ordinary measuring equipment, but also with an oscilloscope.

The repair of inverter welding machines also differs in the following feature: there are often cases when it is impossible or difficult to determine the faulty element by the nature of the malfunction and you have to consistently check all the components of the circuit. From all of the above, it follows that for a successful self-repair, knowledge in electronics (at least at the initial, basic level) and little skills in working with electrical circuits are required. In the absence of these, do-it-yourself repairs can result in a waste of energy, time and even lead to additional malfunctions.

An instruction is included with each unit, which contains a complete list of possible malfunctions and the corresponding solutions to the problems that have arisen. Therefore, before doing anything, you should familiarize yourself with the recommendations of the manufacturer of the inverter.

All malfunctions of welding inverters of any type (household, professional, industrial) can be divided into the following groups:
- caused by the wrong choice of the welding operating mode;
- associated with the failure or malfunction of the electronic components of the device.
In any case, the welding process is difficult or impossible. Several factors can cause a problem with the machine. They should be identified sequentially, moving from a simple action (operation) to a more complex one. If all the recommended checks have been completed, but normal operation of the welding machine has not been restored, then there is a high probability of a malfunction in the electrical circuit of the inverter module. The main reasons for the failure of an electronic circuit are:
- Ingress of moisture into the device - most often occurs due to precipitation (snow, rain).
- Dust accumulated inside the housing interferes with the normal cooling of the electronic components. As a rule, most of the dust gets into the machine when it is used on construction sites. To prevent this from causing damage to the inverter, it must be cleaned periodically.
- Failure to comply with the manufacturer's mode of continuity of welding work can also lead to failure of the inverter electronics as a result of its overheating.
The inverter is on, its indicators are on, but no welding. Most often this occurs due to overheating of the device, when the glow of the control indicator or lamp (if available) is hardly noticeable, and the inverter does not have a sound signal. The second reason is spontaneous disconnection of welding cables or their breakage (damage).
Turning off the mains voltage during welding - an incorrectly selected circuit breaker is installed in the electrical panel. This device must be rated for currents up to 25 A.
The inverter does not turn on - low voltage in the network, insufficient for the operation of the device.
Stopping the operation of the inverter during prolonged welding - most likely the temperature protection has tripped, which is not a malfunction. After a pause of 20-30 minutes, welding can be resumed.

Serious damage to the inverter module may be indicated by the smell of burning or smoke coming from the casing. In this case, it is better to seek help from service specialists. Do-it-yourself repair of welding inverters requires certain skills and knowledge.To identify and eliminate the cause of the malfunction, the body of the device is opened and its filling is visually inspected. Sometimes the whole point is only in poor-quality soldering of parts, wires, other contacts on the circuit boards, and it is enough to re-solder them to make the device work. At first, they try to identify damaged parts visually - they may be cracked, have a darkened case or pins burned out on the board, electrolytic capacitors will be swollen at the top. All identified faulty elements are soldered and replaced with the same or similar ones with suitable characteristics. The selection is made according to the markings on the case or according to tables. When soldering parts, the use of a soldering iron with suction will provide maximum speed and convenience of work. Image - Svaris 220 DIY repair

If the visual inspection did not bring any result, then proceed to ringing (testing) the parts using an ohmmeter or multimeter. The most vulnerable elements of inverter modules are transistors. Therefore, the repair of the apparatus usually begins with their inspection and verification. Power transistors rarely fail by themselves - as a rule, this is preceded by a failure of the elements of the "swinging" circuit (driver), the details of which are checked first. In the same way, by means of the tester, they call the rest of the board elements.

On the board, it is necessary to check the condition of all printed conductors for the absence of breaks and burns. The burnt areas are removed and the jumpers are soldered, as in the case of breaks, with a PEL wire (with a cross section corresponding to the board conductor). You should also check and, if necessary, clean (with a white eraser) the contacts of all connectors in the device.

Rectifiers (input and output), which are conventional diode bridges mounted on a heatsink, are considered to be quite reliable components of inverters. But sometimes they fail. It is most convenient to check the diode bridge after unsoldering the wires from it and removing it from the board. If the entire group of diodes rings for a short time, then you should look for a broken (faulty) diode.

The key management board is checked last. In the inverter module, this is the most complex element and the operation of all other components of the apparatus depends on its functioning. The final stage in the repair of the inverter welding device should be to check the presence of control signals coming to the busbars of the gates of the key block. Diagnose this signal using an oscilloscope.

In cases that are unclear and more complex than those described above, the intervention of specialists will be required. Trying to fix the malfunction yourself is not worth it, especially when the inverter device is under warranty.

Repair of welding inverters, despite its complexity, in most cases can be done independently. And if you are well versed in the design of such devices and have an idea of what is more likely to fail in them, you can successfully optimize the costs of professional service.Replacement of radio components in the process of repairing a welding inverterThe main purpose of any inverter is to generate a constant welding current, which is obtained by rectifying a high-frequency alternating current. The use of a high-frequency alternating current, converted by means of a special inverter module from a rectified mains supply, is due to the fact that the strength of such a current can be effectively increased to the required value using a compact transformer. It is this principle underlying the operation of the inverter that allows such equipment to be compact in size with high efficiency.Functional diagram of the welding inverterThe welding inverter circuit, which determines its technical characteristics, includes the following main elements:

a primary rectifier unit, the basis of which is a diode bridge (the task of such a unit is to rectify an alternating current coming from a standard electrical network);

an inverter unit, the main element of which is a transistor assembly (it is with the help of this unit that the direct current supplied to its input is converted into an alternating current, the frequency of which is 50–100 kHz);

a high-frequency step-down transformer, on which, due to a decrease in the input voltage, the output current is significantly increased (due to the principle of high-frequency transformation, a current can be generated at the output of such a device, the strength of which reaches 200–250 A);

output rectifier, assembled on the basis of power diodes (the task of this block of the inverter includes rectifying an alternating high-frequency current, which is necessary for performing welding).

The welding inverter circuit contains a number of other elements that improve its operation and functionality, but the main ones are the above.

The UPS key is made on a transistor, field 4N90C. In my case, the transistor remained intact, but the microcircuit required replacement. There was also an open circuit resistor R 010 - 22 Om / 1Wt. After that, the power supply unit started working.

However, it was too early to rejoice, having measured the voltage at the output of the welder, it turned out that it was not there, and in idle mode it should be about 85 volts. I tried to move the board, remember from the words of the owner it affected, but nothing.

Further searches revealed the absence of one of the voltages of 25 volts at points V2-, V2 +. The reason is an open circuit in the winding transformer 1-2. Had to drink a trance, used a medical needle to release the conclusions.

In the transformer, one of the ends of the winding was cut off from the terminal.

We carefully restore the connection using a suitable wiring, the restored connection will not be superfluous to fix it with a drop of glue or sealant. I had polyurethane glue at my fingertips and used it, we revise other conclusions, if necessary, we solder.

Before installing the transformer, you should prepare the board so that it fits into its place without effort. To do this, you need to clean the holes from the remnants of solder; this can also be done with a needle from a syringe of a suitable diameter.

After installing the transformer, the welding inverter started working.

How to check the microcircuit without unsoldering it from the board and what else to pay attention to.

You can partially check the microcircuit if you have a voltmeter and an adjustable stabilized constant voltage source. A signal generator and oscilloscope are required for a complete test.

Let's talk about what is easier. Be sure to turn off the power to the inverter before checking. Further - from the external regulated power supply to pin 7 of the microcircuit, we apply a voltage of 16 - 17 volts, this is the starting voltage of the MS. In this case, at pin 8 there should be 5 V. this is the reference voltage from the internal stabilizer of the microcircuit.

It should remain stable when the voltage at pin 7 changes. If not, the MS is faulty.

When changing the voltage on the microcircuit, keep in mind that below 10 V, the microcircuit turns off, and turns on at 15-17 volts. You should not increase the supply voltage of the MS above 34 V There is a protective zener diode inside the microcircuit and if the voltage is too high, it will simply break through.

Below is a block diagram of the UC3842.

Addendum to this article: After a while, another apparatus was brought. Out of order due to falling on its side. This happened because during the operation the screws holding the case loosened, and some were simply lost, so when the board fell, it played and touched the case with the mounting side.As a result of the short circuit, all 4 output transistors K 30N60HS failed. Analogs G30N60A4D, G40N60UFD. After the replacement, everything worked.

Video (click to play).

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