US4518941A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pulse transformer for switching power supplies
Assignee: Nihon Kohden Corp
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Filing: 1983-11-16
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Granted: 1985-05-21
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Expires: 2003-11-16
Abstract
Abstract A pulse transformer for use in a switching power supply having primary and secondary windings wound concentrically around a common core and two electrostatic shield foils interposed between the primary and secondary windings with an insulator disposed between the electrostatic shield foils.
Inventors
- 👤 Hajime Harada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:21
CPC Classifications
H; H01; H01F; H01F19/00; H01F19/04; H01F19/08; H01F27/00; H01F27/34; H01F27/36; H01F27/363
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
136 words
A pulse transformer for use in a switching power supply, comprising a common core, primary and secondary windings wound concentrically around said common core, one of said primary and secondary windings being disposed inwardly of the other, including another winding wound around the other winding and connected parallel to said one winding, a first pair of electrostatic shield foils interposed between said one winding and said other winding, a second pair of electrostatic shield foils interposed between said other winding and said another winding, and an insulator interposed between said electrostatic shield foils in each of said first and second pairs of foils, and connecting wires drawn from said electrostatic shield foils at points thereon where pulsed electromotive forces are induced which are of equal levels as seen from leading ends of the electrostatic shield foils.
Claim 2
Dependent Claim
136 words
A pulse transformer for use in a switching power supply, comprising a common core, primary and secondary windings wound concentrically around said common core, one of said primary and secondary windings being disposed inwardly of the other, including another winding wound around the other winding and connected parallel to said one winding, a first pair of electrostatic shield foils interposed between said one winding and said other winding, a second pair of electrostatic shield foils interposed between said other winding and said another winding, and an insulator interposed between said electrostatic shield foils in each of said first and second pairs of foils, and connecting wires drawn from said electrostatic shield foils at points thereon where pulsed electromotive forces are induced which are of equal levels as seen from leading ends of the electrostatic shield foils.
References Cited (Backward Citations)
US792248A
Cited
US2170048A
Cited
US2223737A
Cited
US3265998A
Cited
US3436704A
Cited
US3717834A
Cited
US3675175A
Cited
US3699488A
Cited
US3845436A
Cited
US4176334A
Cited
US4333900A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-05-20 | 1988-11-19 | 1989-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-20 | 1992-11-19 | 1993-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-20 | 1996-11-19 | 1997-05-21 | $7700.00 | Window Closed / Lapsed |