Current regulator, transformer of welding machine and welding machine

The utility model provides a current regulator. The current regulator comprises a fixing support, an adjusting screw rod installed on the fixing support and movable iron cores located on the two sides of the adjusting screw rod, and is characterized in that the fixing support is bent to form a cavity, the end portion of each movable iron core extends outwards to form a fixing boss which is inserted into the cavity, and the movable iron cores are connected to the fixing support in a riveted mode. The current regulator has the advantages that the fixing bosses are formed in the mode that multiple steel discs located in the middles of the movable iron cores formed by the multiple steel discs in a stacked mode extend outwards, on the basis of guaranteeing that the movable iron cores are firmly connected with the fixing support, a few materials are used, and cost is reduced.