Use of a conductor screen to magnetize NdFeB magnets

The magnetizer presented in this paper consists of a magnetic core made with silicon iron sheets with a large airgap in which the permanent magnets to be magnetized are located, This magnetic structure is energized by two symmetrical coils placed on the central leg above and below the airgap. The cross section of the airgap is four times the area of the permanent magnet, so with a copper plate that surrounds the magnet (not completely), effective concentration of the flux density lines is obtained. The copper plate was called “electromagnetic conductor screen”. The capacitor-discharge-bank was rated 1080 μF, 2000 V and 3.5 tesla were obtained in the central airgap. The paper presents the experimental results and theoretical analysis used to evaluate the conductor screen time-constant of the proposed magnetizing system