Structure and working principle of electronic welding machine

An electronic welding machine is a device that uses electricity to create an electric arc, which melts the metal at the welded site, creating a sustainable weld. Electronic welding machines are increasingly commonly used in mechanical construction, construction, and repair industries due to their outstanding advantages over traditional welding machines such as high efficiency, good weld quality, safety and convenience. In the article below, join RX Tradex to learn about the structure and working principle of electronic welding machines, as well as the general characteristics of this type of machine.

1. Structure of electronic welding machine

Based on the operation function, the electric welding machine is divided into many types such as rod welding machine, Tig welding machine, Mig welding machine. Although the construction and operating principle of these machines are different, they still have some common basic parts as follows:

• Power input: Industrial welding machines typically use a voltage of 380V, while residential welding machines use a voltage of 220V.
• Welding torch and mass clamp: These are the important parts that help connect the electricity and create the weld.
• Inverter Current Transformer: This unit optimizes energy usage, which helps to save and use electricity more efficiently.
• Gas cylinders and pressurized valves: Usually present in Mig and Tig welding machines, where the protective gas is stored and regulated.
• Other parts: Includes cooling system, controls, and wires.

These parts work together to ensure the welding machine works stably and efficiently during the welding of various materials.

2. Working Principle of Electronic Welding Machine

The working principle of each type of electronic welding machine is different, but in general, inverter welding machines today work according to the following basic steps:

Power filter diodes and capacitors

Rectify and filter alternating current into direct current. Depending on the input voltage, there are two rectifier circuits:

• 3-phase 380V outputs 620V DC.
• 1 phase 220V outputs 310V DC.

Motivational Circuit

Pulse hashing to control transformers, using IGBT or Mosfet semiconductor components. Oscillating Operating Frequency:

• IGBT: 20 – 40 KHz.
• Mosfet: Above 100 KHz.

Post-transformer rectifier and filtration circuits

Receives AC pulses, rectifiers, and filtering to provide welding voltage, typically around 60 – 70V DC.

Retrograde Block

Ensure a stable power supply by returning the voltage to the control circuit.

Welding Line Installation Block

Designed to make it easy for the worker to adjust the welding parameters as required.

Control Boards

Generate control pulse with variable width, adjust the output power via push button or resistor.

These components work closely together to ensure the welding machine works efficiently and stably throughout the welding process.

3. General characteristics of electric welding machine

Electronic welding machines, also known as low-voltage transformers, have the following general characteristics:

• Low secondary voltage: The  secondary voltage is less than 100V, usually from 40V to 80V, ensuring the safety of users.
• Large secondary current: Provides enough heat to melt the metal quickly when welded.
• Transformer Structure: The  number of secondary winding turns is less than that of the primary winding, the cross-section of the secondary winding wire is larger, and the number of secondary winding winding turns can be changed to adjust the current intensity.

Some general notes to note:

• Limit short-circuit current to avoid damage to the machine.
• Hand arc welding machines need their own inductors or portable magnetic cores to characterize the steep outer curve.
• Individual power supply systems when using multiple welding machines at the same time, it is recommended to equip a separate system and check the power supply regularly.

4. Conclusion

Electronic welding machines are not only an important tool in industries, but they also offer many benefits in terms of weld efficiency and quality. Understanding the structure and working principle of electronic welding machines helps businesses optimize the use of equipment, ensure safety and improve work quality. In addition, this year, businesses wishing to learn more about the latest manufacturing machinery can immediately participate in the Vietnam Manufacturing Expo organized by RX Tradex Vietnam. At the same time, also in 2024, RX Tradex will also organize leading exhibition events in the region such as:  NEPCON Vietnam, METALEX Vietnam and Waste and Recycling Vietnam.