Usually, spot welding machines use two electrodes to squeeze the workpiece during operation, creating a certain contact resistance between the two layers of metal under the pressure of the two electrodes. When welding current flows from one electrode to another, instantaneous thermal fusion is formed at two contact resistance points, forming a flow towards the electrodes along the two workpieces to ensure that the internal structure of the workpiece to be welded is not damaged.

Before purchasing a spot welding machine, it is essential to have a thorough understanding of it. Now I would like to share with you some essential precautions when purchasing an automatic spot welding machine:

1、 To confirm that the workpiece being welded is black metal, an AC automatic spot welding machine is generally used. Because AC spot welding machines use AC discharge welding, they are particularly suitable for materials with high resistance values. At the same time, AC spot welding machines can use single pulse, multi pulse signals, frequency, time, voltage, current, and program control methods to implement single point, double point continuous, automatic control, and manual control welding on the welded parts. Suitable for welding sheets, rods, and wires of various metals such as tungsten, molybdenum, iron, nickel, stainless steel, etc.

The advantages of automatic spot welding machines for communication are:

1. Good comprehensive benefits and high cost-effectiveness;

2. Wide range of welding conditions;

3. Small and lightweight welding circuit;

4. It can widely spot weld dissimilar metals.

The disadvantages of automatic spot welding machines for communication are:

1. It is greatly affected by voltage fluctuations in the power grid, that is, the current of the AC automatic spot welding machine during welding will fluctuate with the voltage fluctuations in the power grid, thereby affecting the consistency of welding.

2. The shortest discharge time for AC spot welding machines is usually 1/2 cycle or 0.01 seconds, which is not suitable for high standard welding of some special alloy materials.