How to make a welding inverter with your own hands

To make a welding inverter with your own hands, you need to study the scheme of the unit. Fee designs are made independently. It is separated from the power unit by a metal sheet, which is attached to the welding body. To make welding machines with your own hands, you need a wire of any cross section, a thermal sensor, masking tape, tape measure, indicator, PWM controller TL494. The length of the conductor must be no more than 15 cm.

Invertor welding machine

The invertor welding machine is supplied with double insulation, therefore it is absolutely safe during electric welding works.


Inverter welding machines are equipped with radiators, the size of which depends on the constant operation time of the entire device. Welding inverter is made by hand with the help of a thermal sensor that is placed inside the body of the previous element. The control unit is equipped with a TL494 PWM controller. The last device has a control channel, which is necessary to stabilize the current in the arc.

The welding inverter is made by hand using transistors (for switches). Inverter welding is presented in the form of such components:

  • Power Supply;
  • drivers;
  • power element.
The circuit elements of the inverter welding machine

Diagram of the elements of the inverter welding machine.

Experts recommend making welding inverters with a current of 250 A. Winding is performed across the entire width of the structure. The power supply is presented in the form of a classic flyback. On the primary winding stack shielding winding of the same wire. Between coils settling isolation. This will require masking tape or varnished cloth. The power supply set up after the selection of resistance. It should be equal to 20-25 V. Input rectifiers can be taken from PC processors like Alton 64 or Pentium 4. They can be bought in computer stores and on radio markets.

The next stage involves setting up the resulting design. Pre-check the power supply. Then it is connected to the control unit. Welding inverter connected to the network. Bipolar pulses should have frequencies of 40-50 kHz. The magnitude of the dead time is adjusted by changing the voltage. The last indicator is checked using an oscilloscope. If the complete circuit of the welding inverter is assembled, then eights are displayed on the display. Then turn on the relay. The indicator should be 120 A.

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Repair and adjustment

Holding one button helps to automatically change the current. In order to switch to the temperature display mode, you will need to simultaneously press two buttons. After 1 minute of welding (current 120 A), the home-made welding inverter is turned off.

Inverter welding machine power supply circuit

Inverter welding machine power supply circuit.

If during operation of the unit the temperature of the radiator exceeds 75 °, then the sound signal is activated. In this case, the welding machine continues to work, but the current strength automatically drops to 20 A. If the temperature is below 65 °, then the sound signal will disappear. Repair of homemade welding inverter begins with inspection of the unit. The weak point of the homemade device is the terminal block. The temperature in the wires increases with a large value of current.

Self-made welding inverters quickly fail for various reasons. In the absence of the network load and the simultaneous consumption of a large amount of current on the coils there is a closure of coils. This fault is eliminated by rewinding or overlay insulating layer. The frequent disappearance of the welding arc may be accompanied by minor sparks. This is due to the breakdown of the winding and the supply of high voltage.

The efficient operation of inverter welds depends on the correct adjustment of the welding current.

A similar procedure is performed using the scheme. If the homemade welding inverter is excessively heated, then the value of the welding current is set above the permissible rate. Otherwise, the unit worked for a long time without interruption, and for welding, thick electrodes were used, which were not designed to work with the device in question. If the unit is hot, the insulation provided on the coils may burn out. In this case, you will need to restore insulation or rewind the coil.

The buzz of the device is observed at the weakened fastenings tightening the elements of the magnetic circuit. In some cases it will be necessary to replace the fastening of the core coils. The buzz can increase when the circuit between the wires, then you need to tighten the bolts, restore fasteners and insulation. Spontaneous disconnection of the inverter is associated with a circuit in the circuit and the start of protection mechanisms. Experts recommend independently ringing the electrical circuit, finding the damaged area. It will need to recover.

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