Common mode filter

• US 6,373,366 B1
• Filed: 09/19/2000
• Issued: 04/16/2002
• Est. Priority Date: 09/20/1999
• Status: Expired due to Term

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Kuroshima, Toshihiro, Suzuki, Hiroshi, Saito, Katsumi, Sato, Kouki
• Primary Examiner(s): Donovan, Lincoln
• Assistant Examiner(s): NGUYEN, TUYEN T
• Application Number:
  US09/664,831
• Time in Patent Office: 574 Days
• Field of Search: 336/83, 336/192, 336/198, 336/200, 336/205, 336/96, 336/65, 296/021
• US Class Current: 336/192
• CPC Class Codes: H01F 17/045 with core of cylindric geometry and coil wound along its longitudinal axis, i.e. rod or drum core
• CPC Class Codes: H01F 27/292 Surface mounted devices

Abstract

A common mode filter includes a drum-shaped core 1 with a winding 2 and a plate-like core fixed to flanges 1b to form a closed magnetic path. Concave portions 4a are formed in at least one of facing potions of both cores to provide gaps between the flanges 1b of the drum-shaped core and the plate-like core 4. A plurality of electrodes 3 each of which is successive over a upper surface, end face and lower surface of each flange are provided at portions corresponding to the gaps in each flange 1b. A plurality of windings 2 are wound around the winding core 1a so that both ends of each of the plurality of windings are electrically connected and secured to the portions of the electrodes on the upper surface of each of the flanges, respectively, by conductive fixing agent. The drum-shaped core 1 and the plate-like core 4 are fixed to each other by an adhesive 5.

Claims

1. A common mode filter comprising:

a drum-shaped core having flanges at both ends of a winding core around which a winding is wound; and

a plate-like core, opposite ends of which fixed to said flanges by an adhesive to form a closed magnetic path between said plate-like core and said drum-shaped core wherein a plurality

gaps between the flanges of said drum-shaped core and said plate-like core are formed by concave portions located on at least said plate-like core

a plurality of electrodes, each of which is successive over an upper surface, end surface and lower surface of each of said flanges, said electrodes being provided at portions corresponding to said gaps in each of said flanges; and

a plurality of windings wound around said winding core, opposite ends of each of said plurality of windings being connected and secured to portions of said electrodes on the upper surface of each of the flanges, respectively.

2. A common mode filter according to claim 1, wherein said gaps are filled with said adhesive.

3. A common mode filter according to claim 1, wherein said concave portions are formed on both said drum-shaped core and said plate-like core, and the concave portions of the drum-shaped core are located opposite the concave portions of the plate-like core.

4. A common mode filter according to claim 1, wherein said winding core includes a plurality of winding portions which are spaced from each other.

5. A common mode filter according to claim 1, wherein said concave portions are formed on facing portions of both said drum shaped core and said plate-like core.

6. A common mode filter according to claim 1, wherein said concave portions are formed on both said drum shaped core and said plate-like core.