In a power transformer the coils are on an iron core made of ferromagnetic material in order to confine the flux so that almost all of the flux linking any one coil links all the others.

• 在电源变压器卷在铁芯由铁磁物质制成为了限制涨潮，以便几乎连接所有一卷的所有涨潮连接所有其他。