The features of BXI-400 AC arc welding machine include novel structure, static iron core is stacked with inclined joints, low no-load current, low noise, small volume, light weight, convenient adjustment, easy maintenance, etc. In addition, the welding machine adopts the full oblique joint core form, compared with the usual direct seam core form. no-load loss can be reduced by aboue 1/3, under the same output power, input power can be reduced by 200w