Inductor
AssigneesHitachi Metals, Ltd., Hitachi, Ltd.
InventorsMasahiko Fukui, Yasuji Kamata
Life of this patent
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Abstract
An inductor having a coil member commonly wound on a couple of closed magnetic circuits made of a soft magnetic material. A magnetic gap is provided at a part of the soft magnetic material of at least one of the two closed magnetic circuits, and a permanent magnet providing a magnetic bias is inserted in the magnetic gap. This inductor is used in series between a DC power source providing a superimposed current of a DC current and an AC current and a load. The inductance of the inductor is very large with respect to a small DC current, while it reduces sharply when the applied DC current increases to be a certain value to show a substantially constant low value with respect to a DC current value beyond the certain value.
Claims13
An inductor comprising:
- a first magnetic circuit which includes at least one magnetic core formed from a soft magnetic material, at least one airgap formed in a portion thereof, and a permanent magnetic member disposed in said one airgap to produce magnetic flux flowing through said first magnetic circuit;
- a second magnetic circuit including at least one magnetic core formed from a soft magnetic material;
- the magnetic core of said second magnetic circuit being disposed face to face with the magnetic core of said first magnetic circuit;
- and
- coil means wound around adjacent portions of said magnetic cores in common to produce a magnetic flux therein.
Dependencies are inferred from the claim text.