Patent US3671810A successfully refreshed from Google Patents.
US3671810A
Expired / Lapsed
US
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Saturated core transient current limiter
Assignee: Singer Co
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Filing: 1969-09-18
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Granted: 1972-06-20
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Expires: 1989-09-18
Abstract
Abstract A transient current limiting device which includes a saturated core reactor having its windings in circuit with a power supply and a load. The magnetic core is biased into saturation for normal load currents and driven out of saturation by abnormally high transient load currents, such as currents caused by semiconductor loads which have been irradiated by high energy electromagnetic radiation. In one embodiment, the reactor comprises a magnetic core in the form of a wound toroid which exhibits a square loop hysteresis curve and includes a permanent magnet for biasing the core into saturation. A number of configurations are disclosed for placement of the permanent magnet relative to the core to saturate the magnetic element. The invention also permits automatic resetting of the magnetic flux density in the core to saturation when the abnormal load current is removed.
Inventors
- 👤 Lell E Barnes
- 👤 David Morris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:08
CPC Classifications
H; H02; H02H; H02H9/00; H02H9/02; H02H9/021; H01; H01F; H01F29/00; H01F29/14; H01F29/146; H01F3/00; H01F3/10; H01F2003/103
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
179 words
An electrical circuit including: a. a direct current source of power, b. a load, and c. magnetic means in circuit with said source and said load for limiting the current between said source and load in the event of a transient short circuit, wherein said magnetic means comprises an elongate discontinuous magnetic core ring member having a longitudinal axis and having a center portion and having a pair of axially spaced opposite end portions defining an air gap therebetween, a permanent magnet disposed adjacent to both said end portions of said core and arranged to provide an elongate flux path coaxially therewith and having sufficient strength for biasing said magnetic core into saturation for normal load currents, and a winding wound on said core center portion and connected between said source and said load and arranged to provide a second elongate flux path coaxially therewith, said second flux path being directed opposite to said first flux path and having sufficient strength so that said core is driven out of saturation by abnormally high load currents flowing through said winding.
Claim 2
Dependent Claim
179 words
An electrical circuit including: a. a direct current source of power, b. a load, and c. magnetic means in circuit with said source and said load for limiting the current between said source and load in the event of a transient short circuit, wherein said magnetic means comprises an elongate discontinuous magnetic core ring member having a longitudinal axis and having a center portion and having a pair of axially spaced opposite end portions defining an air gap therebetween, a permanent magnet disposed adjacent to both said end portions of said core and arranged to provide an elongate flux path coaxially therewith and having sufficient strength for biasing said magnetic core into saturation for normal load currents, and a winding wound on said core center portion and connected between said source and said load and arranged to provide a second elongate flux path coaxially therewith, said second flux path being directed opposite to said first flux path and having sufficient strength so that said core is driven out of saturation by abnormally high load currents flowing through said winding.
Claim 3
Dependent Claim
38 words
The circuit as defined in claim 1 wherein said core is a toroidal element and said permanent magnet is disposed in said air gap in such a manner that said magnet is geometrically coextensive with said toroidal element.
Claim 4
Dependent Claim
35 words
The circuit as defined in claim 1 wherein said core is a toroidal element and said permanent magnet is positioned adjacent to the outer cylindrical wall of said toroidal element and bridges said air gap.
Claim 5
Dependent Claim
34 words
A circuit as defined in claim 1 wherein said core is a toroidal element and said permanent magnet is positioned adjaCent to a radial wall of said toroidal element and bridges said air gap.
Claim 6
Dependent Claim
82 words
A circuit as defined in claim 1 wherein said core ring member is a portion of an assembly, said assembly including an I section element and a generally E-shaped magnetic element, said E-shaped element having an outer pair of legs and a middle leg, said winding being disposed about at least one of said legs, said E-shaped element and said I section element being spaced to define said air gap therebetween, and wherein said permanent magnet is located in said air gap.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-20 | 1975-12-20 | 1976-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-20 | 1979-12-20 | 1980-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-20 | 1983-12-20 | 1984-06-20 | $7700.00 | Window Closed / Lapsed |