| 摘要 |
PROBLEM TO BE SOLVED: To provide a closed magnetic circuit inductor which is increased in magnetoresistance so as to have a desired inductance and direct current superimposition characteristics and generates no irritating sound. SOLUTION: An upper E-type core 1 and a lower I-type core 2 are combined into a closed magnetic circuit core. The permeability of the I-type core 2 is set lower than that of the E-type core 1 so as to be increased in magnetoresistance to set the closed magnetic circuit core at the desired inductance. The center leg 1a and outer legs 1b and 1b of the E-type core 1 are set equal to each other in length, no gap is produced between the center leg 1a and the outer legs 1b and 1b, and even when a load variation is produced in an audio frequency range to generate magnetostriction, the cores are hardly deflected in a vertical direction to set up vibrations, and non irritating sound is produced. COPYRIGHT: (C)2004,JPO
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