Diagram of the fubag ir 200 welding inverter DIY repair

help to define the PWM controller in the Fubag IR200 welding inverter! package DIP8. (the part burst after a power surge) thanks in advance

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Sergeyb3 15 Aug 2015

help determine the shim controller

Judging by the legs, it is UC38xx. But what kind of xx, 42-43-44 or 45, it is impossible without a diagram or drawing.

Thanks! I rested on them. but how is the plot? strapping? or will the photo help?

would anyone have a diagram?

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tehsvar 15 Aug 2015

They put it on the master city. Now I don't remember which section.

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copich 18 Aug 2015

They put it on the master city. Now I don't remember which section.

On the Internet there is it (a diagram), but it does not look like reality.

If the DIP package is usually UC3842, I don't remember anything else. There have been others for SMD editing.

It's easier to run along the legs, i.e. take 3842 as a basis, download the datasheet and check what is where and what are approximately denominations. And if the mikruhu is torn apart, then there is no point in storing it and you need to check the same power supply (sequential switching on of resistors after the primary rectifier). Otherwise, immediately burn a new one.

Thank you for that clarification! there is just 3842-I will check everything and put it on. and unsubscribe.

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NW51 12 Feb 2018

A lot of time has passed since the start of this topic, but maybe someone will come in handy.

I ran into a similar problem, according to my carelessness, don't ask how, snow got into the device, there was a cotton and it stopped working. An autopsy showed that the PC817 optotron exploded and the PWM failed. I, like the topikstarter, did not find the scheme, but found a similar duty room scheme, I altered it a little and set the denominations and designations in accordance with the original that was in front of my eyes. Shim, in the original UC3843B and only with such a device I got started, I tried the UC3843A with it, the device showed signs of life in the form of weakly spinning fans and a flickering display.

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copich 12 Feb 2018

tried UC3843A read datasheet on chip. There are differences! And there may be differences in different versions.

On the FUBAG IR 220 welding inverter, the PWM controller burned out and the inscription on it is not visible. From various sources in the net they advised to put the UC3843 PWM in place of the burned one. I found and put the UC3843B PWM at my own risk. ... The device turned on the thread of the lamp burns in full heat, the fans started up and the relay worked. There is no smoke or light anywhere. I measured the output voltage at all. The RJH60F7 transistors rang all intact. Powerful ohm resistors are also intact. There are no circuits for this device, therefore It is difficult to figure out why there is no voltage at the output, when everything seems to be intact, so I am asking for help in this matter.

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      Here are my photos, I will immediately apologize for the quality, not a professional. And my question remains valid, why is there no +60 volt voltage at the output of the inverter?

      
      
      
      
      
      
      

      Edited by Andryzel (27.06.2016 16:51:22)

      The fans are spinning, the relay is triggered, everything starts smoothly, the lamp is on, the network is on, but there is no output. The power keys are all whole voltages on the conductors of almost 400 volts. It feels like there is a breakage somewhere at the output, but without a circuit I can't eat this beast. Maybe the second shim is dead. After all, I replaced UC3846 first with UC3843. Also, the zener diode burned out without a circuit, I don't know the name, it is in the base circuit of the K3878 transistor. We need a Russian analogue of a zener diode.

      • I agree. It's difficult without a diagram, but it's worth trying.

        Maybe the second shim is dead UC3846 because the first one I replaced UC3843. The zener diode also burned out without a circuit, I do not know the name, it is in the base circuit of the K3878 transistor. We need a Russian analogue of a zener diode.

        Zener diode for 18V. 1N4746A Russian analogue of КС218Ж.

        Let's figure it out. Fortunately, I have the same apparatus.Tell us with what malfunction it came to you, how did this malfunction occur, what have you already done?

        Edited by Andryzel (06/29/2016 06:42:12 PM)

        • a on L7815 +11.8 volts. It seemed a little understated

          It is not normal. Strongly underestimated. You are looking in the right direction and close to the answer.

          Today I changed the voltage regulator L7815 to an analogue of K142EN8, the voltage remained 11.8 volts. The direction seems to have chosen the wrong one. Power to the voltage regulator L7815 comes from the secondary winding of the transformer Tr2 through diodes. Power is also supplied to the fans from here. So where the fans are powered, it says +24 volts. Measure there +15.6. A big request to you, if you have the same welding worker, please measure how much voltage goes to the fans, where it is + 24V.

          Edited by Andryzel (07/03/2016 10:55:14 PM)

          • • • Thank you for the hint. So I did, I turned on the device without a light bulb. The device started up and the output really became more + 77 volts. But my joy was not long. After driving the device for about 20 minutes at idle without load, I turned it off with a button from the mains. In general, I was 100% sure that it was possible to give the device to the owner. The device stood at work at night and in the morning I came to work and decided to check the welder again. Plugging it into the network, the device started up and soon stopped working. Having disassembled it, I began to measure the power on the UC3843B with a multimeter. The power supply showed + 7.9 volts. I think very little again, the microcircuit is out of order. I soldered the mikruhu from the board and began to check with a multimeter between the 5th and 6th legs, There is no short. Then I also measured between 5 and 7, there is also no short, then 6 and 7. In general, there is no short anywhere. Only this is not an indicator for microcircuits. But how do you know that it is intact? Then I turned on the device without a microcircuit in the network and again I measured the supply voltage of the microcircuit and was very surprised at the + 80volt reading. I measured it on the C75 encoder (47mkfX63v), which is parallel to the microcircuit power buses. In general, I'm in a slight shock. Either the device showed it without load. Or again there is a malfunction in the microcircuit power circuit. In general, I don’t know how much + 80v should come without load. or maybe + 12V.

                • Thank you again for helping me. I read in the net about the UC3843B about all its functions. A smart thing is this mikruha.
                  In short, if, what is wrong with the diodes in the secondary circuit of the TP2 transformer, the microcircuit simply stops working and goes into protection. All the intricacies of electronics. I found the cause of all the troubles with the launch of the UC3843B was a leakage diode D25. I replaced it and everything returned to normal. The device whispered and again the joy visited me that it was not in vain.

                  • Good luck!

                    Edited by Andryzel (06/29/2016 11:42:12 PM)

                    And what is the real capacity of the C75 condenser?

                    The device is half restored, it starts up, but the current is not regulated, only five amperes. Can anyone have a diagram or have encountered such a problem, tell me. Thank you.

                    the circuit should be in the topics about these devices of the IR series
                    ” >
                    ” >
                    and here is the diagram

                    If a resistor heats up that charges the capacitors of 22-57 Ohm during operation, then look most likely there is a zener diode next to the relay and it is broken. There was something like it works, the current is small, but the problem is not in the control, namely in the relay circuit (the current goes through the poorly pressed relay contacts and through the resistor (it does not burn out at the same time). Or the contacts in the relay burned out, or it happens before laughter - the contacts of the power switch are burnt and does not give out power, although it seems to turn on and there is xx.

                    Hello everyone. The other day, a welding inverter was brought to the repair, perhaps my note about this repair will be useful to someone.

                    This is not the first welding machine that had to be done, but if in one case the malfunction manifested itself like this: He switched on the inverter to the network ... and broads, knocked out the circuit breakers in the electrical panel. As the autopsy in the welder showed, the output transistors broke through, after the replacement everything worked.

                    But in this case, everything was somewhat different, according to the owner, the device at times stopped cooking, although the power-on indicator was on. These guys themselves opened the case - they tried to determine the malfunction and noticed that the inverter reacted to the bending of the board, i.e. when it was bent, it could work. But when the welding inverter came to me, it did not turn on at all, even the on indicator did not light up.

                    "Titan - BIS - 2300" - it was this model of the inverter that was repaired, the circuitry repeats the welding machine of the same power of "Resant" and, as I suppose, many other inverters. You can view and download the diagram here.

                    In this welding machine, a pulsed power supply is used to power low-voltage circuits, and it was just it that was faulty. The UPS is based on the UC 3842BN PWM controller. Analogues - domestic 1114EU7, Imported UC3842AN differs from BN only in lower current consumption, and КА3842BN (AN). See UPS diagram below. (Click on it to enlarge) The voltages that were already supplied by the working UPS are marked in red. Please note that you need to measure the 25V voltage not relative to the common minus, namely from the points V1 +, V1- and also V2 +, V2- they are not connected to the common bus.

                    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 changes at pin 7. 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.

                    That's all! If you found this article useful, leave your comments, share with your friends by clicking on the social media buttons.

                    The design of a welding inverter is rather complex, therefore, the least safe to operate. The great advantage is the high quality of the work performed by the device. At the same time, any structure wears out and breaks down over time. Therefore, there are two solutions to this problem. In the first case, the apparatus is repaired by hand, and the second case is associated with contacting specialists for the repair of welding inverters.

                    

                    Diagram of a welding inverter semiautomatic device.

                    A complex device requires appropriate knowledge and the correct approach to repair. It is important to understand electronics here, that is, diodes, transistors, resistors and stabilizers.

                    What devices will be needed for this:

                    

                    Multimeter connection diagram.

                    Other special instruments will be required to measure various indicators. It can be too difficult to detect a malfunction, therefore, it will be necessary to check all the elements more than once, their certain sequence, in which they should be contained in the general scheme.

                    The operation of the inverter is based on a scheme associated with a step-by-step signal conversion. Initially, the current is rectified due to the input rectifier, after which it begins to be converted into variable frequency current due to the inverter module. Then, a power transformer is involved in the conversion process, therefore, the frequency current is converted into a welding one. After the transformer, the variable frequency current is converted into a welding form due to the output rectifier. Before inspecting the inverter, refer to its microcircuit and drawings.

                    It is necessary to emphasize that the main features of welding inverters is the accuracy of work. If even the highest quality inverter is out of order, then among the main reasons for this are the following:

                    1. Incorrect use of the device.
                    2. Lack of accurate connection of the device.
                    3. Changes in mains voltage.
                    4. Changes in current strength.

                    

                    Figure 1. List of possible malfunctions of the welding inverter.

                    The causes of breakdowns can also be bad weather conditions, if they are observed during the operation of the device on the street. These may be too dirty rooms, high levels of humidity, rain, snow, etc. The most vulnerable point of the inverter is the terminal block, the cable is connected to it. The lack of normal contact and at the same time a significant indicator of the current strength will be a prerequisite associated with overheating of all elements and connections.

                    Melting of the insulation is also a malfunction, which can cause a short circuit. The list of possible malfunctions is presented in the table (Fig. 1). At the same time, do-it-yourself repair of the welding inverter is carried out by stripping the contacts and tightly joining the connection, which heats up during operation.

                    There are the following main stages associated with the diagnosis of inverter malfunctions:

                    1. The equipment does not turn on.
                    2. The inverter shuts down by itself.
                    3. The appliance makes a lot of noise.
                    4. Strong overheating of the structure occurs.
                    5. An interruption of the electric arc is observed during welding.
                    6. Poor current regulation.
                    7. Electricity consumption is over-limit.

                    If the device does not turn on, then the main reason for this is:

                    1. Lack of mains voltage.
                    2. Operation of the machine on the dashboard.
                    3. The equipment stops working.

                    Before starting the repair of the inverter for welding with their own hands, they check the transistors, which often fail in the first place.

                    

                    Diagram of an electronic oscilloscope device.

                    A thorough inspection will be required here. The appearance of the faulty part speaks for itself, featuring a warped body. If a burned-out transistor is found, it must be replaced with a new one. If there are no external defects, then with the help of a multimeter it is necessary to ring the transistor, after which you should select a new element and make it a high-quality installation in place of the previous transistor.

                    Power transistors have driver elements that should be checked second.This type of parts is more resistant to damage, since this can happen to the elements that power the drivers themselves. An ohmmeter allows you to check the performance of the power transistors, after which the part can be evaporated and replaced with an analog.

                    If there are difficulties in detecting defects, then it is very important to check the rectifiers connected by diode bridges mounted on the basis of a radiator. These elements of the inverter have significant durability, as breakdown inside the mechanism can occur. Diagnostics of the diode bridge requires first to release it from any wires with a soldering iron, removing it from the control board, respectively. The work with the inverter is greatly facilitated by the lack of dependence of the circuit on a short circuit. A soldering iron equipped with a suction helps to evaporate the faulty diode.

                    Finishing the diagnostics, they inspect the board that allows you to manage the keys. This detail is a complex and important element of the apparatus. Finishing the repair of the inverter, they check the operation of the control signals, which should go to the busbars of the gates of the key module.

                    

                    Diagram of the front panel of the inverter.

                    Monitoring this control signal is not difficult as an oscilloscope can be used. If the case is unclear, expert intervention will be required.

                    Long and trouble-free operation of the inverter can be ensured by observing special rules:

                    1. Carrying out a technical inspection of the welding inverter before starting work with it and preparing the workplace.
                    2. Installation of the device in a horizontal position, which will prepare the workplace.
                    3. Connecting welding cables to the power connectors of the device: to the electrode holder with a "+" sign, and to ground - with a "-" sign.
                    4. Checking the fixation of the cable glands in the soldering sockets by turning them clockwise.
                    5. Connect the appliance to the power supply by plugging it into a power outlet.
                    6. Switch the switch to the "ON" position to turn on the fan.
                    7. Trial arc ignition.
                    8. The current regulator knob sets the required mode for welding.

                    If you follow the recommendations related to the correct maintenance of the device, then it will serve for a long time:

                    

                    Block diagram of a digital voltmeter with a time-to-pulse converter.

                    1. It is strictly forbidden to use the device with the cover removed for a long time.
                    2. Inspection of the internal components of the device should be carried out more often, which is determined by the frequency of use of the device and the degree of contamination of the working space.
                    3. The dust accumulated in the device must be removed by using compressed air at low pressure, i.e. less than 10 bar.
                    4. Cleaning of electronic boards is not done with a jet of compressed air, but only with a small brush.
                    5. Before carrying out work, a safety check should be carried out when fixing the power connectors in the corresponding sockets of the device, check the power plug, socket and the insulation of the electronic cable.
                    6. Transport and storage of the device must be suitable for weather conditions.
                    7. When transporting the device by transport, it can also be placed in an upright position.
                    8. Store the device only in a dry room where the relative humidity is 80%.
                    9. The inverter is kept disconnected from the mains.

                    Welding inverter circuit.

                    To repair a faulty inverter, you should find out all the principles of its operation. At the first stage of work with the welding inverter, the mains voltage is rectified by the devices, and then it is converted into a variable frequency voltage.After that, it is reduced to a level that allows safe welding. The last stage is associated with the presence of constant welding voltage.

                    The listed processes are regulated by the control unit, which has a rather complex design. Starting the repair of the welding inverter, it must be visually inspected in order to clean out all the places that do not have normal contact.

                    These zones are traditionally rectifier diodes. It is possible to mount the diodes using threaded connections, and all special tools are not needed.

                    Pre-check the diodes, examining their "throughput" or "breakdown", which is associated with the possibility of free passage of current through the diode in the same direction. This is done with a multimeter. With a constant resistance, in the case of measurements from plus to minus, the diode should be replaced.

                    

                    Even a faulty diode will allow welding with an inverter, and the ability to turn on the device is not associated with ensuring normal operation. If the device cannot be turned on or off normally, an urgent repair will be required. Any inverter model has a fuse on the control board. If you dismantle it, then you can get to this device.

                    Removing the control board requires marking all connectors, of which there can be more than three, and they themselves are similar to each other. If the fuse is defective, then it is not difficult to assemble and install it, only patience and accuracy are required.

                    

                    Welding inverter power circuit.

                    Often the reason for the failure of the transistors of welding inverters is insufficient cooling. The element contact must have thermal grease and a heat sink plate. It is not difficult to unsolder and install the part, but it is imperative to control the possibility of its overheating, since a sufficiently hard-melting solder is used for soldering.

                    If the power transistor fails, then this leads to breakdown of the drivers adjacent to this part. Diodes and zener diodes can often fail. The transistors are first inspected from the outside and then replaced.

                    If the transistors have already been inspected and checked, followed by replacement, since the cause of their breakdown has been found, then the presence of a "swinging" driver is considered as a prerequisite. Similarly, using the tester, you can call any elements of the board, replacing them with serviceable ones.

                    It is imperative to check the printed conductors of the board, which will reveal the presence of burn. Existing burnt-on areas can be removed and the other jumpers can be re-soldered. All soldering points are covered with a special varnish. First, check and clean each pin of the connectors with a white drawing eraser.

                    

                    Diagram of the internal device of the welding inverter.

                    Rectifiers are output and input full-wave diode bridges that are equipped with silicon valves. They are considered reliable parts, but they can also wear out. Controlling them is not a difficult task. Soldering bridges from electronic circuits is associated with dismantling the brackets. If the bridge is ringing only in one of the directions, then it is serviceable, and if in both directions at once, then this bridge is broken. The check is carried out when the bridge is already assembled and in place.

                    Checking the board that allows the control of the device is associated with a continuity tester, which allows you to control the gate control signal using the key module. You can check it using an instrument called an oscilloscope. In a normal test, all signals will be correct, otherwise it will turn out that something has been missed.