A powder magnetic core is provided for operating at high frequencies that is obtained by pressure forming an iron-based magnetic powder covered with an insulation film, which has a specific resistance more than 1000, preferably more than 2000, and most preferably more than 3000 Î¼Î©m, and a saturation magnetic flux density B above 1.5, preferably above 1.7, and most preferably above 1.9 (T). A method for the preparation of such cores as well as a powder which is suitable for the preparation also are provided.

Claims

19 · 2 independent · depth 4

19 granted claims

›1.independentAn iron powder consisting of electrically insulated, iron base powder particles, which have a particle size less than 100 Î¼m, wherein the iron base p…+9

›2.↳ 1Iron powder according to claim 1, wherein D90 is below 75 μm and D50 is between 10 μm and 50 μm.d2+3

›3.↳ 1Iron powder according to claim 1, wherein Ptot is equal to, or higher than 0.05%.d2+1

›8.↳ 1Method of preparing an iron core comprising the steps of mixing an insulated powder as defined in claim 1 with a lubricant in an amount less than 1% o…d2+1

›10.↳ 1A method of producing the iron powder according to claim 1 comprising the steps of:na) treating an iron base powder at least once with phosphoric acid…d2

›4.independentA powder magnetic core for operating at frequencies between 2 and 100 kHz obtained by compaction moulding of an iron powder, the particles of which ar…+8

›5.↳ 4A powder magnetic core according to claim 4, wherein the electrically insulated particles have a D90 of 75 μm or less and a D50 between 10 μm and 50 μ…d2+2

›6.↳ 4A powder magnetic core according to claim 4, wherein the electrically insulating coating comprises phosphorus.d2+1

›7.↳ 4A powder magnetic core according to claim 4 having a core loss of at most 30 W/kg at 0.1 T and 10 kHz.d2

›12.↳ 4A powder magnetic core according to claim 4 for operating at frequencies of between 5 and 100 kHz having a specific resistance Ï above 2000 Î¼Î©m, and…d2

›13.↳ 4A powder magnetic core according to claim 4 for operating at frequencies between 5 and 100 kHz having a specific resistance Ï above 3000 Î¼Î©m, and a …d2

Classifications

4 codes

IPC · International Patent Classification

Section H — Electricity

H01F1/147

USPC · US Patent Classification

148/306428/403148/104

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Pendency

3.9 y

1,433 days filing → grant

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non-final + final

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1 RCE

Examiner

John Sheehan

art unit 1736 · TC 1700

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1 priority documents

›Priority documents — 1

Type	Document	Date
related publication	US 20100038580 A1	18 Feb 2010

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