A water-cooled DC welding transformer (抵抗溶接トランス, SCHWEIßTRANSFORMATOREN, transformateur de soudage, transformador de soldadura, transformador de soldagem, trasformatore di saldatura, kaynak transformatörü, lastransformator, محول اللحام) is a crucial part in DC welding machines. It produces low-voltages, high-amperage current suitable for welding. Compared to AC welding transformers, DC welding transformers offer reduced output losses and improved energy efficiency.