ferrite transformer core
https://k1ttqkw518.doodlekit.com/blog/entry/9142136/a-look-into-the-future-what-will-the-transformer-core-industry-look-like-in-10-years
Most transformers are made of either copper or an iron Main. Even so, the technology of currently offers you a lot of transformer possibilities in the form of magnetic Main products and the most well-liked of all