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US5846448A
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Ferrite and ferrite core for power supply
Assignee: TDK Corp
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Filing: 1994-04-27
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Granted: 1998-12-08
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Expires: 2014-04-27
Abstract
Abstract A ferrite having low power losses, high ΔB=Bm-Br at high frequency, and improved μa-B properties is provided as well as a core for a power supply using the same. The ferrite contains 30-41 mol % of MnO, 6-16 mol % of ZnO, and the balance of Fe 2 O 3 as main components and 50-250 ppm of SiO 2 , 200-1500 ppm of CaO, up to 4000 ppm of SnO 2 , up to 3000 ppm of TiO 2 , at least 300 ppm of SnO 2 +TiO 2 , from more than 0 to 500 ppm of Nb 2 O 5 , and from more than 0 to 400 ppm of ZrO 2 as subordinate components.
Inventors
- 👤 Katsushi Yasuhara
- 👤 Takashi Ito
- 👤 Osamu Takeda
- 👤 Shoji Inoue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:10
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/34; H01F1/342; H01F1/344; C; C01; C01G; C01G49/00; C01G49/009; C04; C04B; C04B35/00; C04B35/01; C04B35/26; C04B35/2658; C01P; C01P2002/00; C01P2002/30; C01P2002/32; C01P2002/50; C01P2002/52; C01P2004/00; C01P2004/01; C01P2004/02; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/42
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
198 words
A ferrite characterized by comprising manganese oxide, zinc oxide, and iron oxide as main components, and silicon oxide, calcium oxide, tin oxide and/or titanium oxide, niobium oxide, and zirconium oxide as subordinate components, wherein in the main components, the content of manganese oxide is 30 to 41 mol % calculated as MnO and the content of zinc oxide is 6 to 16 mol % calculated as ZnO, and the weight proportion of the subordinate components based on the main components is such that silicon oxide is 50 to 250 ppm calculated as SiO 2 , calcium oxide is 200 to 1,500 ppm calculated as CaO, tin oxide is up to 4,000 ppm calculated as SnO 2 , titanium oxide is up to 3,000 ppm calculated as TiO 2 , and the total of tin oxide and titanium oxide is at least 300 ppm, niobium oxide is from more than 0 to 550 ppm calculated as Nb 2 O 5 , and zirconium oxide is from more than 0 to 400 ppm calculated as ZrO 2 , P is present in a weight ratio of 5 to 35 ppm based on the main component, and the remainder iron oxide.
Claim 2
Dependent Claim
198 words
A ferrite characterized by comprising manganese oxide, zinc oxide, and iron oxide as main components, and silicon oxide, calcium oxide, tin oxide and/or titanium oxide, niobium oxide, and zirconium oxide as subordinate components, wherein in the main components, the content of manganese oxide is 30 to 41 mol % calculated as MnO and the content of zinc oxide is 6 to 16 mol % calculated as ZnO, and the weight proportion of the subordinate components based on the main components is such that silicon oxide is 50 to 250 ppm calculated as SiO 2 , calcium oxide is 200 to 1,500 ppm calculated as CaO, tin oxide is up to 4,000 ppm calculated as SnO 2 , titanium oxide is up to 3,000 ppm calculated as TiO 2 , and the total of tin oxide and titanium oxide is at least 300 ppm, niobium oxide is from more than 0 to 550 ppm calculated as Nb 2 O 5 , and zirconium oxide is from more than 0 to 400 ppm calculated as ZrO 2 , P is present in a weight ratio of 5 to 35 ppm based on the main component, and the remainder iron oxide.
Claim 3
Dependent Claim
48 words
The ferrite of claim 1 wherein the content of niobium oxide based on the main components is at least 50 ppm calculated as Nb 2 O 5 and the content of zirconium oxide based on the main components is at least 50 ppm calculated as ZrO 2 .
Claim 4
Dependent Claim
28 words
The ferrite of claim 1 wherein the content of niobium oxide based on the main components is 100 to 400 ppm calculated as Nb 2 O 5 .
Claim 5
Dependent Claim
21 words
The ferrite of claim 1 wherein the weight ratio of B based on the main components is 0 to 50 ppm.
Claim 6
Dependent Claim
35 words
The ferrite of claim 1 which has a power loss of up to 300 kW/m 3 at a temperature of 100° C. when an AC magnetic field of 100 kHz and 200 mT is applied.
Claim 7
Dependent Claim
36 words
The ferrite of claim 5 which has an eddy current loss of up to 200 kW/m 3 at a temperature of 100° C. when an AC magnetic field of 100 kHz and 200 mT is applied.
Claim 8
Dependent Claim
52 words
The ferrite of claim 1 wherein when an AC magnetic field of 100 kHz is applied at a temperature of 100° C., the resulting hysteresis curve has a ΔB value of at least 220 mT wherein ΔB=Bm-Br wherein Bm and Br are maximum magnetic flux density and residual magnetic flux density, respectively.
Claim 9
Dependent Claim
54 words
The ferrite of claim 1 wherein when an AC magnetic field of 100 kHz is applied at a temperature of 100° C., the resulting hysteresis curve has an effective magnetic permeability μa of at least 5,000 at magnetization B=200 mT and an effective magnetic permeability μa of at least 4,500 at magnetization B=300 mT.
Claim 10
Dependent Claim
71 words
The ferrite of claim 1 which has a residual magnetic flux density Br of up to 140 mT as measured in a DC magnetic field at a temperature of 25° C. or a ΔB value of at least 380 mT wherein ΔB=Bm-Br wherein Bm and Br are maximum magnetic flux density and a residual magnetic flux density, respectively, as measured in a DC magnetic field at a temperature of 25° C.
Claim 11
Dependent Claim
18 words
A ferrite core for use in an electric power supply, characterized by comprising the ferrite of claim 1.
References Cited (Backward Citations)
JPS60137830A
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JPH0254902A
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US5143638A
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JPH04322410A
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JPH05170527A
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JPH05226138A
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JPH05243034A
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JPH06140231A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2001-12-07 | 2002-06-08 | 2002-12-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-12-07 | 2006-06-08 | 2006-12-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-12-07 | 2010-06-08 | 2010-12-08 | $7700.00 | Window Closed / Lapsed |