The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 14, 1998
Filed:
Mar. 21, 1997
Shoji Inoue, Chiba, JP;
TDK Corporation, Tokyo, JP;
Abstract
A ferrite core for line filters according to the invention comprises, as main components, manganese oxide in an amount of 13.5 to 16% by weight, calculated as MnO and zinc oxide in an amount of 14 to 16% by weight calculated as ZnO with the rest being iron oxide, and as subordinate components, silicon oxide in an amount of 50 to 200 ppm calculated as SiO.sub.2, calcium oxide in an amount of 100 to 350 ppm calculated as CaO, niobium oxide in an amount of 30 to 150 ppm calculated as Nb.sub.2 O.sub.5, molybdenum oxide in an amount of 20 to 300 ppm calculated as MoO.sub.3, and bismuth oxide in an amount of 100 to 800 ppm calculated as Bi.sub.2 O.sub.3. Such a core has high inductance at about 1 kHz and high impedance at about 500 kHz, and shows a high noise reduction coefficient over a wide frequency band.