Unformatted text preview: g << w, x << 2w, so that fringing at the gap edges can be ignored. 3. Leakage flux is assumed negligible; that is, the only appreciable flux passes through the magnetic material except for gaps g and x. Needed to solve this problem are the quasi-static magnetic field equations (1.1.20) through (1.1.22) and (1.1.4). We first assume that the terminal current is i. Then by using (1.1.22) we establish that the current at each point along the winding is i. Next, we recognize that the specification of infinitely permeable magnetic material implies that we can write (1.1.4) as B = uH with u --+ o. Thus with finite flux density B the field intensity H is zero inside the magnetic Depth d perpendicular to page w Fig. 2.1.2 A magnetic field system. * A. E. Knowlton, ed., StandardHandbookfor ElectricalEngineers, 9th ed. McGraw-Hill, New York, 1957, Section 5-39 through 5-52. N A-PDF Split DEMO : Purchase from www.A-PDF.com to remove the watermark...
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- Fall '11
- Magnetism, Magnetic Field, permeable magnetic material, A. E. Knowlton