Determine the workpiece is welded black metal, the general election AC automatic spot welding. Because the AC spot welder adopts AC discharge welding, it is especially suitable for the material with larger resistance value. At the same time, AC spot welder can control all kinds of control methods by using single pulse, multi-pulse signal, cycle, time, voltage, current, Was the implementation of single-point workpiece, two-point continuous, automatic control, artificial control of welding. For tungsten, molybdenum, iron, nickel, stainless steel and other metal pieces, rods, silk materials welding.

Its advantages are:

1. Comprehensive benefits better cost-effective

2. Welding conditions range

3. Welding circuit small and lightweight

4. Can be widely spot welding dissimilar metals.

The disadvantage is:

1. Affected by the grid voltage fluctuations, AC automatic spot welding welding current fluctuations with the grid voltage fluctuations, thus affecting the consistency of welding.

2. AC welding spot welding discharge time is shortest is usually 1/2 or 0.01 seconds, not suitable for some high alloy special alloy welding.