Title |
The Magnetic Shield Effect of a Close-Ended Shield Can |
DOI |
http://dx.doi.org/10.5207/JIEIE.2018.32.10.039 |
Keywords |
Magnetic Shield ; Shield Can ; Flat Cap ; Demagnetization ; Permalloy ; Permeability ; FEM |
Abstract |
Permeabilities of 3,000 and 50,000 were experimentally obtained through inductance measurement for a butt-welded and a filltet-welded permalloy ring cores. And the value range of 3,000-50,000 was assigned as a material constant to calculate the inside axial magnetic fields in the FEM analysis of 4-layered magnetic shield cans. While open-ended shield can had the optimum length according to the assigned permeabilities, flat cap-ended shield can did not show the dependence on the length of the inside layers of shield can. And flat cap-ended shield can exhibited a good advantage as compared with open-ended shield can because demagnetization could be sufficiently weakened by using flat-caps. As permeability was high, the axial magnetic field was small in the flat cap-ended shield can. And flat cap-ended shield can could be easily designed without considering the optimum length and permeability variety of inside layers. |