Patent US5430424A successfully refreshed from Google Patents.
US5430424A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Planar transformer
Assignee: Toshiba Corp
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Filing: 1994-03-14
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Granted: 1995-07-04
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Expires: 2014-03-14
Abstract
Abstract Disclosed is a planar transformer comprising a planar primary spiral coil and a planar secondary spiral coil, which are mutually insulated and laminated, wherein, (1) when the winding width W 1 of the primary spiral coil and the winding width W 2 of the secondary spiral coil have the relationship of W 1 ≦W 2 , the inner size A i1 of the primary spiral coil and the inner size A i2 of the secondary spiral coil coincide with each other, and (2) when the winding width W 1 of the primary spiral coil and the winding width W 2 of the secondary spiral coil have the relationship of W 1 >W 2 , the central axes of the primary and secondary spiral coils coincide with each other, the outer size A o2 of the secondary spiral coil is equal to or smaller than the outer size A o1 of the primary spiral coil, and the secondary spiral coil is arranged corresponding to a position at which magnetic flux generated by a current flowing through the primary spiral coil is largest.
Inventors
- 👤 Toshiro Sato
- 👤 Tetsuhiko Mizoguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:27
CPC Classifications
H; H01; H01F; H01F27/00; H01F27/28; H01F27/2804; H01F17/00; H01F17/0006; H01F2017/0086
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
292 words
A planar transformer with increased coupling coefficient comprising: a primary spiral coil having a first cross-section of primary coil lines with center points lying in a first plane, said primary spiral coil including: an inner size A i1 of the primary spiral coil, A i1 being a distance between two inner-most primary coil lines in the first cross-section; an outer size A o1 of the primary spiral coil, A o1 being a distance between two outer-most primary coil lines in the first cross-section; a winding width W1 of the primary spiral coil which is half a difference between the outer size A o1 and the inner size A i1 ; a secondary spiral coil positioned adjacent to the primary coil and having a second cross-section with secondary coil lines with center points lying in a second plane, parallel to the first plane, said secondary spiral coil including: an inner size A i2 of the secondary spiral coil being a distance between two inner-most secondary coil lines in the second cross-section; an outer size A o2 of the secondary spiral coil being a distance between two outer-most secondary coil lines in the second cross-section; a winding width of the secondary spiral coil W2 which is less than the winding width of the primary spiral coil W1 (W1>W2), said winding width W2 being half of a difference between the outer size A o2 and the inner size A i2 ; wherein, the outer size A o2 of the secondary spiral coil is no greater than the outer size A o1 of the primary spiral coil; and wherein the primary and the secondary spiral coils are sandwiched between soft magnetic foils with insulating layers between the magnetic foils and primary and the secondary spiral coils.
Claim 2
Dependent Claim
292 words
A planar transformer with increased coupling coefficient comprising: a primary spiral coil having a first cross-section of primary coil lines with center points lying in a first plane, said primary spiral coil including: an inner size A i1 of the primary spiral coil, A i1 being a distance between two inner-most primary coil lines in the first cross-section; an outer size A o1 of the primary spiral coil, A o1 being a distance between two outer-most primary coil lines in the first cross-section; a winding width W1 of the primary spiral coil which is half a difference between the outer size A o1 and the inner size A i1 ; a secondary spiral coil positioned adjacent to the primary coil and having a second cross-section with secondary coil lines with center points lying in a second plane, parallel to the first plane, said secondary spiral coil including: an inner size A i2 of the secondary spiral coil being a distance between two inner-most secondary coil lines in the second cross-section; an outer size A o2 of the secondary spiral coil being a distance between two outer-most secondary coil lines in the second cross-section; a winding width of the secondary spiral coil W2 which is less than the winding width of the primary spiral coil W1 (W1>W2), said winding width W2 being half of a difference between the outer size A o2 and the inner size A i2 ; wherein, the outer size A o2 of the secondary spiral coil is no greater than the outer size A o1 of the primary spiral coil; and wherein the primary and the secondary spiral coils are sandwiched between soft magnetic foils with insulating layers between the magnetic foils and primary and the secondary spiral coils.
Claim 3
Dependent Claim
292 words
A planar transformer according to claim 1, further comprising: a magnetic layer sandwiching the primary spiral coil and the secondary spiral coil, wherein a center point of the winding width W2 of the secondary spiral coil is positioned along an x-axis X with respect to the primary spiral coil at a point where the magnetic flux Φ(x) is at a maximum, the point where the maximum exists determined according to formulas (1) to (4): ##EQU3## wherein V i (x) indicates a function relating to a magnetic flux component at the region according to the width of each line of coil conductor; W 1 (x) indicates a function relating to a magnetic flux component at a left side region of each line of coil conductor placed at the left side to a central axis; W.sub. '(x) indicates function relating to a magnetic flux component at the left side of each line of coil conductor placed at a right side to the central axis; and U i (x) indicates a function relating to a magnetic flux component at the right side of each line of coil conductor placed at the left side to the central axis; wherein: ##EQU4## wherein W m is a total length of the magnetic layer, t m is a thickness of the magnetic layer, μs is a relative magnetic permeability, g is an inner width of the magnetic layer, δ indicates a width of an individual coil conductor along the x-axis, s is a distance between individual coil conductors, and (X 1 , X 2 , . . . , X N-1 , X N ) are the points along the x-axis where the individual coil conductors begin, X N corresponding to a last individual coil conductor along the x-axis.
Claim 4
Dependent Claim
21 words
The planar transformer according to claim 1, further comprising a magnetic layer laminated on the primary and the secondary spiral coils.
Claim 5
Dependent Claim
21 words
The planar transformer according to claim 1, further comprising: an insulating layer interposed between the primary and the secondary spiral coils.
Claim 6
Dependent Claim
13 words
The planar transformer according to claim 4, wherein said insulating layer is polyimide.
Claim 7
Dependent Claim
15 words
The planar transformer according to claim 4, wherein each said insulating layer is silicon oxide.
Claim 8
Dependent Claim
11 words
The planar transformer according to claim 1 is a dc-to-dc converter.
Claim 9
Dependent Claim
90 words
A planar transformer according to claim 1, further comprising: a first central axis of the primary spiral coil aligned at a center point of the primary spiral coil and perpindicular to the first and the second planes; and a second central axis of the secondary coil aligned at a center point of the secondary spiral coil and perpindicular to the first and the second planes, wherein, the first central axis is aligned with the second central axis to obtain a maximum amount of magnetic flux through the secondary spiral coil.
Claim 10
Dependent Claim
264 words
A planar transformer with increased coupling coefficient comprising: a primary spiral coil having a first cross-section of primary coil lines with center points lying in a first plane, said primary spiral coil including: an inner size A i1 of the primary spiral coil, A i1 being a distance between two inner-most primary coil lines in the first cross-section; an outer size A o1 of the primary spiral coil, A o1 being a distance between two outer-most primary coil lines in the first cross-section; a winding width W1 of the primary spiral coil which is half a difference between the outer size A o1 and the inner size A i1 ; a secondary spiral coil positioned adjacent to the primary coil and having a second cross-section with secondary coil lines with center points lying in a second plane, parallel to the first plane, said secondary spiral coil including: an inner size A i2 of the secondary spiral coil being a distance between two inner-most secondary coil lines in the second cross-section; an outer size A o2 of the secondary spiral coil being a distance between two outer-most secondary coil lines in the second cross-section; a winding width of the secondary spiral coil W2 which is greater than the winding width of the primary spiral coil W1 (W1<W2), said winding width W2 being half of a difference between the outer size A o2 and the inner size A i2 ; and wherein, the inner size A i1 of the primary spiral coil and the inner size of the secondary spiral coil A i2 are set equal.
Claim 11
Dependent Claim
264 words
A planar transformer with increased coupling coefficient comprising: a primary spiral coil having a first cross-section of primary coil lines with center points lying in a first plane, said primary spiral coil including: an inner size A i1 of the primary spiral coil, A i1 being a distance between two inner-most primary coil lines in the first cross-section; an outer size A o1 of the primary spiral coil, A o1 being a distance between two outer-most primary coil lines in the first cross-section; a winding width W1 of the primary spiral coil which is half a difference between the outer size A o1 and the inner size A i1 ; a secondary spiral coil positioned adjacent to the primary coil and having a second cross-section with secondary coil lines with center points lying in a second plane, parallel to the first plane, said secondary spiral coil including: an inner size A i2 of the secondary spiral coil being a distance between two inner-most secondary coil lines in the second cross-section; an outer size A o2 of the secondary spiral coil being a distance between two outer-most secondary coil lines in the second cross-section; a winding width of the secondary spiral coil W2 which is greater than the winding width of the primary spiral coil W1 (W1<W2), said winding width W2 being half of a difference between the outer size A o2 and the inner size A i2 ; and wherein, the inner size A i1 of the primary spiral coil and the inner size of the secondary spiral coil A i2 are set equal.
Claim 12
Dependent Claim
35 words
A planar transformer according to claim 2, wherein: said center point of the winding width of the primary spiral coil is not equal to the center point of the secondary spiral coil on the x-axis.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-07-03 | 1999-01-02 | 1999-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-07-03 | 2003-01-02 | 2003-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-07-03 | 2007-01-02 | 2007-07-04 | $7700.00 | Window Closed / Lapsed |