DIY welding inverter from scrap materials: Instruction + Video diagram

DIY welding inverter from scrap materials: Instruction + Video diagram Welding works are in great demand in any assembly and repair work. High-quality metal welding is highly valued and paid for. In order to carry out all the welding work yourself, you need a personal machine. And you don't have to buy it. You can assemble a do-it-yourself inverter welding installation.

Which will not be inferior to the conveyor representatives by a gram.

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General information about the welding inverter

Every real owner should have in his household a machine for welding.

This device is indispensable in agricultural subsidies, and in construction and home improvement , and in car maintenance and many other places.

In addition, it is quite possible to do inverter welding with your own hands, even if you are not a professional electrician.

Technical indicators

Indicators of the welding inverter assembled independently will be as follows:

  1. DIY welding inverter from scrap materials: Instruction + Video diagram Voltage 220V.

  2. Current at the input to the device - 32 A, and at the output - 250A.
  3. A similar installation will be able to perform welding work with the electrode 5th with a long arc up to 1 cm.
  4. Efficiency it will not be lower than purchased.

Elements of the assembled structure

  1. power supply unit,
  2. power key drivers,
  3. power unit.

Tools required for assembly

  1. knife, set of screwdrivers, hacksaw for metal,
  2. soldering iron for working with electrical circuit,
  3. threaded fasteners,
  4. a thin sheet of metal,
  5. elements for a microcircuit, copper wires and strips,
  6. cash register thermal paper, fiberglass, textolite, mica.

DIY inverter welding

Assembling the power supply

The most important component for this inverter unit will be the transformer ... It provides a stable voltage supply.

It is made of four windings:

  1. DIY welding inverter from scrap materials: Instruction + Video diagram primary - 100 turns made of wire PEV 0.

    3 mm in diameter;

  2. first secondary - 15 turns made of wire PEV 1mm in diameter;
  3. second secondary - 15 turns made of wire PEV 0.2 mm in diameter;
  4. third secondary - 20 turns made of wire PEV 0.3 mm in diameter.

After finishing the winding of the primary winding, the resulting surface should be insulated with fiberglass. And then wind a layer of shielding wire.

Moreover, its turns should cover the entire first layer.

Important! It is better to wind the transformer evenly over the entire width of the frame. This will minimize the impact of voltage surges.

The shielding wire must be taken of the same diameter as the primary winding and wound in the same direction. This condition applies to all other windings.

Each layer of the winding is insulated from each other with fiberglass or masking tape.

Correctly selected resistors to the electronic circuit will ensure the strength of the voltage transmitted from the power supply to the relay in the range of 20-25V. The diodes in the circuit must be assembled according to the "oblique bridge" method.

During the operation of the device, the diodes will heat up significantly, so it is imperative to attach radiators to them. Sometimes, for this purpose, cooling elements are borrowed from an old computer.

The diode bridge installation must have two radiators. The top of the bridge is attached through a mica gasket to one radiator, the bottom - through thermal paste to the second.

The leads of the diodes must be directed in the same direction with the leads of the transistors, which ensure the transformation of direct current into alternating current.

The length of the wires for connecting the leads must be less than 15 cm. The power supply unit and the inverter unit are separated by a sheet of metal welded to the unit body.

Assembling the power unit

The main unit of the power unit is a transformer. It lowers the voltage of the high-frequency current and increases the strength.

The day of such a transformer requires two cores Ш20х208 2000 nm. It is better to provide a gap between them with newsprint.

The transformer winding should be made of a copper strip 40mm wide and 0.

25mm thick.

All layers must be additionally wrapped with cash register tape for thermal insulation.

Secondary winding is made with three layers of copper strips with PTFE tape between each of them.

Total transformer winding should consist of 12 turns x 4 turns, 10 sq. mm x 30 sq.


Thermal insulation can be done with plain paper, but tape from the cash register will be more durable.

It should be borne in mind that during the operation of the device the made transformer will overheat significantly, therefore, it is necessary to provide a cooling cooler. For example, from an old computer.

Composition of the inverter unit

This unit of the device converts direct current into alternating high-frequency.

The best option would be to collect such a block from two medium and lower power transistors. Then the frequency of the current will be stabilized, and the noise, during operation, will be minimal.

DIY welding inverter from scrap materials: Instruction + Video diagram

In a homemade welding inverter, you must install at least six cooling low-power fans from the computer, or one powerful, directing it to blowing a step-down power transformer. If multiple fans are used, at least three of them should be located near the power transformer.

For greater protection against overheating of the device, a thermal sensor is installed to the hottest radiator.

Its function when reaching the maximum allowable temperature is to turn off the power to the entire device.

An approximate diagram of a home-made welding inverter

The completed transformer winding is attached to the base of the unit with several brackets.

Boards are made using 1mm thick foil-coated PCB.To reduce the load, several small slots are formed in the boards.

As the base of the unit, a 0.

5 cm thick getinax plate with a round slot in the center for the fan is used.

Important! All wires should be located so that there is e space between them.

The resistor knobs and toggle switches, clamps and LEDs are brought out to the base surface. The top of the device is covered with a vinyl or textolite casing with a minimum thickness of 4 mm.

Description of the main malfunctions of the welding inverter and its repair

Determining the causes of the breakdown should begin with an external examination.

If areas with poor contact are found, they are disconnected, cleaned and connected again.

The following malfunctions are quite common:

  1. Excessive current consumption with no load at all .
    In this case, most likely, the loops are closed. You just need to rewind and improve the insulation of the layer.
  2. DIY welding inverter from scrap materials: Instruction + Video diagram Frequent drop in the welding arc.

    Winding breakdown is most likely, as a result of which an overvoltage is supplied to the circuit.

  3. Incorrect welding current setting.
    Possible shorts in terminals or choke coil, failure of the current regulating screw.
  4. The current is insufficient .
    This indicates that the mains voltage has dropped.

    In this case, check the serviceability of the regulator.

  5. Increased noise level of the transformer .
    Increased noise is often accompanied by overheating of the machine. In such cases, it is necessary to check the fastenings of the tightening parts of the magnetic circuit, fastenings of the movement mechanisms, the coil core. Most likely there is a short in the welding leads.

  6. Automatic shutdown of the device .
    It should be assumed that there is a short circuit in the electrical circuit that caused the auto shutdown.

In addition, the weakest point of the inverter will always be block terminal for connecting the welding cable.

( 2 marks, average 2 of 5 )