The U93/76/30-3C90 is a Transformer Core made with material grade of 3C90. U core with rectangular cross-sections and is easy to produce and are relatively inexpensive. For this reason it is very popular in many applications such as interference filters and output chokes in radio and TV equipment. There is no real optimization for transformer winding designs and the core is rather bulky. Large U core like U100 is suitable for very high throughput powers. It can be stacked to form transformers, capable of handling several kW in applications such as industrial HF welding.
