Transformer shielding cover, what is the role of shielding cover in toroidal transformer +15 years the manufacturer tells you

Technicians who produce hardware for transformer shields said that shields are also called magnetic shields. They are generally made of magnetically permeable materials. The better ones belong to Permalloy, but they are expensive. They usually use magnetically conductive silicon steel strips or It is made of iron, so what role does the shielding cover play in the toroidal transformer? Xiaoshuo will come to understand with you: The toroidal transformer with shielding cover has small magnetic leakage and low interference. For power amplifier transformers, electromagnetic interference can be largely eliminated. The sound quality is quite pure and noise-free. It is mainly used for magnetic shielding, effectively reducing the interference of magnetic field on circuits and electronic components. Hardware, 15 years of focus on transformer shielding, 20,000+ sets of mold custom processing and production experience, monthly 100+ sets of mold processing capacity, daily production capacity of 3 million strokes, stamping accuracy up to 0.01mm, and 16 quality inspections strictly. It can quickly solve time-critical problems for you, solve stamping accuracy problems, and solve mass production quality problems. Choose, choose to rest assured!