The AC welding machine is a welding machine whose output power type is AC power. It essentially uses a special step-down transformer to convert 220v and 380v AC power into low-voltage AC power. The advantage of AC welding machine is that it is cheap. Generally it is not easy to fail, but the disadvantages are energy consumption, large volume, and inconvenient handling, and inconvenient current regulation (you must shake the handle hard), so you can only weld acid welding electrodes. In addition, the single-phase power supply of the AC welding machine is likely to cause an imbalance in the power grid and affect the work of other equipment.