Super high initial permeability and high permeability, super low coercivity and low saturation magnetic induction. Fe-Ni Soft Magnetic Alloy (Permalloy) Core 1. Material Grade: 1J50,1J79 ... , precision current transformer, magnetic amplifier, power transformer, choke, pulse transformer, change polarity pulse transformer, DC voltage converter, magnetic modulator, constant inductance element, unipolar ...