| 摘要 |
PROBLEM TO BE SOLVED: To provide magnetic cores which enables obtaining of a switching power source having a simple configuration, small-sized, high-efficiency, and is economical, and to obtain a coil component and a power circuit using them. SOLUTION: In the coil component to be used for an active filter circuit, a coil 12 is formed in the core portion of a pair of E-shaped magnetic cores 11A, 11B, having soft magnetic properties such as Mn-Zn ferrite, etc., so as to be interlinked with magnetic flux, and air gaps are formed in the joining parts of the outside legs out of the opposed surfaces of the pair of magnetic cores 11A, 11B, which are contraposed to each other. In the air gaps in the joining parts, film-like permanent magnets 13A, 13B are arranged into polarities reverse to the directions of magnetic fields formed in the magnetic cores by a coil current, which flows in from an input side in according conduction of a main transistor. |
