Many transformers are manufactured with a core made by stacking sheets of magnetic permeable steal. This is common for large machine press welder transformers. This type of transformers can be manufactured into large transformers for a large application like 500 KVA.
Typical Stacked and Wound Core Steel Transformer Components
Wound cores are used for robotic weld gun transformers. They allow for higher outputs with smaller weight and sizes.
The actual core material used for the transformers in these applications can vary by the transformer manufacturer and design. Contact the manufacturer for information on the material used in the core.
Machine Type Transformer
Reference: RWMA Resistacne Welding Manual, Chapter 19
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