| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a toroidal coil or the like capable of coping with downsizing. <P>SOLUTION: The toroidal coil 10 includes: a gapless toroidal-shaped magnetic core member 11 formed to be a consecutive annular shape in a circumferential direction; and a conductor 12 wound on the magnetic core member 11, and the magnetic core member 11 comprises a ferrite sintered compact, as main constituents, containing 54.1 to 57.5 mol% Fe<SB>2</SB>O<SB>3</SB>, and the balance substantially MnO, and further containing, as additives, 60 to 800 ppm Si expressed in terms of SiO<SB>2</SB>, 600 to 4000 ppm Ca expressed in terms of CaCO<SB>3</SB>, and 1500 to 4000 ppm Co<SB>3</SB>O<SB>4</SB>. The ferrite sintered compact may furthermore contain Zn. The toroidal coil 10 as above has the inductance with excellent performance more than that of Ni group toroidal coils of prior arts, and the number of turns of the conductor 12 can be reduced more than that of the Ni group toroidal coils of prior arts. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
