The welding inverter is actively used today not only in production needs, but also at home. This is due to the excellent functional and production advantages.
If you are well versed in electronics, then having a scheme and instructions for manufacturing, you can do an inverter welding machine with your own hands, while spending money only on consumables. This option is suitable for people who like to buy good quality equipment. Inverter devices of well-known companies are very expensive, and cheap - only will bring disappointment from use.
In order to begin to design a homemade welding inverter, you must carefully to work on his scheme: examine the whole structure, deal with electronics, arrange the sequence performance of work.
- 1 The structure of the homemade inverter
- 2 DIY welding machine diagram
- 3 Preparatory work before assembling the device
- 4 We collect the welding invertor device
- 5 We adjust the welding inverter for work
- 6 Welding service and repair rules
- 7 DIY welding inverters
The structure of the homemade inverter
Virtually all self-made welding inverters have such basic elements:
- Power Supply;
- Power key drivers;
- Power unit
When designing a welding inverter is important to be guided in its characteristics:
- The maximum value of current consumption - 32 A;
- During operation, a current of not more than 250 A is used;
- To perform welding work sufficient mains voltage of 220 V;
- For work, electrodes with a diameter of 3-5 mm and a length of 10 mm are used.
- The received device will have indicators of efficiency not less than the professional version of the device.
DIY welding machine diagram
When you have decided that the inverter unit will be built independently, the first thing will be charting.
You need to think over and provide for ventilation of the mechanisms of the device, since it is extremely important to avoid overheating of the parts inside. The simplest and most optimal solution would be to use radiators from the Pentium 4, Athlon 64 system units. These components are commercially available and have a low price.
The scheme must provide for the presence and location of brackets that will fix the transformer.
Preparatory work before assembling the device
When the scheme of the device is made, it is necessary to proceed to the preparation of components and parts. To assemble the inverter with your own hands, you will the following materials are needed:
- Copper wires;
- Cotton fabric;
- Electrical steel;
In order to avoid problems with voltage drops, it is necessary to wind across the entire width of the frame. In the specifically proposed version of the apparatus there will be 4 windings:
- Primary. It will include 100 turns, a PEV of 0.3 mm;
- Secondary first - 15 turns, sew 1 mm;
- Secondary second - 15 turns, PEV 0.2 mm;
- Secondary third - 20 turns, sew 0.3 mm.
The board and the power supply unit are installed separately from each other, between them there is a sheet of metal. To fasten it to the body of the welding inverter, it is necessary to use welding seams.
To produce shutter control, you must install conductors. Their length should be no more than 15 cm; no special requirements are imposed on the cross section. During the assembly processes of the apparatus, it is necessary to study in detail the scheme for it, to understand all the important points of connecting the parts together.
Power supply is required after the primary winding covered with screening winding. Its made from a similar wire. All coils of the covering should have the same direction as the primary ones and completely overlap them. Between each winding must be isolation. You can use varnished cloth or masking tape for it.
When commissioning the power supply, it is necessary to work on the selection of the necessary resistance. It must be balanced so that the power supplied to the relay is in the range of 20-25 V.
Carefully approach the selection of radiator elements for input rectifiers. They must be powerful and reliable. Excellently proved used parts from computers. They are available for sale on the radio market.
For welding inverter availability of 1 thermal sensor. It is installed inside the radiator. To regulate the current in the arc, a PWM controller is purchased and installed on the control unit. The capacitor will produce the PWM voltage, the parameters of the welding current strength will depend on it.
We collect the welding invertor device
Having bought all the necessary parts for the welding inverter, we proceed to its assembly. Before starting the installation of parts, check their health. Find a ready choke and start winding it. For this you need use wire sew-2. Required number of turns - 175. The selected capacitor must have a voltage of at least 1000 V. If you cannot buy a single capacitor with such a voltage, you can set up several, so that their total capacity is 1000 V.
Try not to use one powerful transistor in the installation, it is better to replace it with a few, less powerful ones. These indicators affect the operating frequency, which leads to the formation of large noise effects during welding. If you incorrectly calculate the required power of the apparatus, this will entail its quick breakdown and repair work.
When the welding inverter assembly begins, it is imperative that keep distance between the winding and the magnetic circuit. Between the layers of the winding must be laid plate of the PCB. This will help to increase the electrical safety of the device, and to achieve rapid and sufficient cooling.
Next, go to the fastening of the transformer to the very base of a homemade inverter. For this, 2-3 brackets are used. They can be made of copper wire with a diameter of 3 mm. For boards, you can use foil textolite with a thickness of 0.5-1 mm. Be sure to make narrow cuts in the plates, they will help to freely output the diodes so that overloads do not occur.
When all the basic elements of the apparatus are assembled, you can proceed to fastening it to the base. The base itself can be made of getinaks plates. For normal operation suitable plate thickness of 0.5 cm. Be sure to cut a round window in the center of the plate, there will be fixed the fan, which must be protected by a protective grid. Do not forget, when installing magnetic cores, leave gaps for free air flow.
On the front side you need to install a knob toggle switch and LEDs, clips for cables and a variable resistor knob. This will be the design of a practically finished welding machine. It is placed in a 4 mm thick casing. The button is installed on the holder of the electric wire. The cable that is connected to it and the wires thoroughly isolate.
We adjust the welding inverter for work
Having collected the whole mechanism, it is necessary correctly and correctly configure it and put into operation. There are such situations that it is difficult to solve the problem on your own, you have to resort to the help of a specialist.
- The first step is to connect the device to the 15V power supply to the PWM, and one of the convectors is connected in parallel. This will help to avoid overheating of the device, and the noise level will be much lower.
- In order for a resistor to close, a relay must be connected. It is put into operation after charging the capacitors. This will help avoid large voltage fluctuations when connected to a 220V network. If the connection of the resistor is neglected directly, an explosion may occur.
- Further, careful control over the operation of the resistor short-circuit relay when it is connected to the current on the PWM board is required. Be sure to diagnose the presence of pulses on the board, after the relay is triggered.
- Then we feed 15V to the bridge. It helps to check its normal and proper operation, correct installation. The device should not exceed 100A current. In this case, the course must be idle.
- Verification of the installation of transformer phases is required. You can use a 2-beam oscilloscope for this. For it, it is necessary to apply 220V power to the bridge from the capacitors through the lamp, setting the PWM frequency to 55 kHz. Having installed the oscilloscope, look at the signal form, and observe, the voltage should not exceed 330V. Calculate the frequency of oscillation transformer is easy. It is necessary to gradually remove the PWM frequency until the lower key IGBT gives a small turn. This indicator should be divided by 2, and the resulting quotient should be added with the value of the supersaturation frequency. The parameters of current consumption by the bridge should not be higher than 150 ma. Watch the light from the light bulb. Strongly bright indicates problems with the winding, possible breakdown in it. No sound effects should come from the transformer. If there is any noise, pay attention to the correct polarity connection. In the form of a test control on the bridge, you can use a 220V electric kettle. All conductors from the PWM, you must be bored, and located away from sources of interference.
- Using resistors, it is necessary to gradually increase the current. At the same time listen to extraneous noise and sounds, watch the oscilloscope readings. Indications of the lower key is not more than 500V. The norm is 240V.
- Start welding work from 10 seconds. Then, the radiators are checked. If they are cold, then work lasts another 20 seconds. Further, the time increases to 1 minute.
Welding service and repair rules
For proper and long-term operation of the device, it is necessary to periodically check and control each structural element. This will facilitate your repairs and reduce them to a minimum. If the unit breaks down, find the cause of the malfunction and carry out repair work.
To perform these works it is necessary have these tools:
- Soldering iron;
- A vacuum cleaner;
The first and main cause of failure may be a rectifier. Through it converts the AC to DC voltage. The surge protector makes it possible to smooth out voltage drops. The transistor circuit is responsible for the formation of a single-phase high-frequency voltage. The block regulates the operation of the keys by means of feedback signals, so it can change the mode of operation of the inverter. The brewing transformer is responsible for reducing the voltage, then the valve blocks straighten it and feed it to the electrode.
DIY welding inverters
If the welding machine breaks, remove the housing cover and blow with a regular vacuum cleaner. Places that are difficult to clean in this way should be treated with a brush or cloth. Begin diagnosis of the input circuit. Check if the inverter is receiving voltage. If not, then repair the power supply. The fuses may have burned out. It’s easy to create a welding inverter with your own hands, but repairs, if misdiagnosed, can take a long time.
Next, start the temperature sensor diagnostics. Compare the nominal values with those available. This item is not repairable, it must be replaced with a new one. Then, the study of the basic elements of the apparatus. If you, at one of them, see a darkening, it means that the spike was poorly assembled during assembly. Use the tester to check connection chains.
If the contacts are made poorly, then it causes overheating, breakage and costly repair of the inverter. Check the connectors, if they are loose - pull up, poor connection - solder. If during welding work metal sprays, electrode sticking, arc burning, then it is necessary to adjust the current flow or replace the electrodes.
Watch for cable serviceability; in the event of a break, immediately replace it with a new one. Only in this case the inverter welding machine, created by own hands, will work efficiently and reliably.