US3743884A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Overvoltage protector
Assignee: ABB Inc USA
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Filing: 1972-02-02
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Granted: 1973-07-03
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Expires: 1992-02-02
Abstract
Abstract Protection apparatus for a capacitive means which is effectively connected in series with a power transformer. A first spark gap and a resistance are serially interconnected and the combination is connected in parallel with the capacitive means. A second spark gap is connected in parallel with the resistance. The first spark gap is constructed to arc at a lower voltage than the second spark gap. With this apparatus, ferroresonance is dampened without an overvoltage surge on the capacitive means.
Inventors
- 👤 J Wafer
- 👤 J Borst
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:31
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/16
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
145 words
Protective means for limiting the voltage across a capacitive means, said protective means comprising a first switching means, an impedance means connected in series circuit relationship with said first switching means, the series combination of said impedance means and said first switching means being connected in parallel circuit relationship with the capacitive means, a second switching means connected in parallel circuit relationship with said impedance means, said first switching means having a first predetermined voltage rating, said second switching means having a second predetermined voltage rating, said first and second switching means each having switching characteristics dependent upon the voltage across said switching means, each of said switching means becoming substantially conductive when the voltage across the particular switching means is equal to its predetermined voltage rating and remaining substantially conductive until the magnitude of the current flowing through the switching means is substantially zero.
Claim 2
Dependent Claim
145 words
Protective means for limiting the voltage across a capacitive means, said protective means comprising a first switching means, an impedance means connected in series circuit relationship with said first switching means, the series combination of said impedance means and said first switching means being connected in parallel circuit relationship with the capacitive means, a second switching means connected in parallel circuit relationship with said impedance means, said first switching means having a first predetermined voltage rating, said second switching means having a second predetermined voltage rating, said first and second switching means each having switching characteristics dependent upon the voltage across said switching means, each of said switching means becoming substantially conductive when the voltage across the particular switching means is equal to its predetermined voltage rating and remaining substantially conductive until the magnitude of the current flowing through the switching means is substantially zero.
Claim 3
Dependent Claim
20 words
The protective means of claim 1 wherein the first predetermined voltage rating is lower than the second predetermined voltage rating.
Claim 4
Dependent Claim
35 words
The protective means of claim 1 wherein the impedance means comprises a resistance means having a value of resistance which is substantially within the range of the value of the impedance of the capacitive means.
Claim 5
Dependent Claim
14 words
The protective means of claim 1 wherein each switching means comprises spark gap means.
Claim 6
Dependent Claim
49 words
The protective means of claim 4 wherein the spark gap means comprises first, second and third electrodes, said second electrode being positioned between said first and third electrodes, the gap distance between said first and second electrodes being smaller than the gap distance between said second and third electrodes.
Claim 7
Dependent Claim
35 words
The protective means of claim 5 wherein the electrodes are shaped to permit the movement of arcs which strike across the gaps between the electrodes for the purpose of extending the life of the electrodes.
Claim 8
Dependent Claim
23 words
The protective means of claim 5 wherein the electrodes have arc resistant material disposed adjacent to the gap surfaces of the spark gaps.
Claim 9
Dependent Claim
16 words
The protective means of claim 5 including means which produce a magnetic field across the gaps.
Claim 10
Dependent Claim
99 words
Protective means for limiting the voltage between primary windings of a transformer wound with a plurality of capacitively coupled primary windings, said protective means comprising first spark gap means, resistance means connected in series circuit relationship with said first spark gap means, the series combination of said first spark gap means and said resistance means being connected between the primary windings of the transformer, second spark gap means connected in parallel circuit relationship with said resistance means, said first spark gap means having a breakdown voltage which is lower than the breakdown voltage of said second spark gap means.
Claim 11
Dependent Claim
99 words
Protective means for limiting the voltage between primary windings of a transformer wound with a plurality of capacitively coupled primary windings, said protective means comprising first spark gap means, resistance means connected in series circuit relationship with said first spark gap means, the series combination of said first spark gap means and said resistance means being connected between the primary windings of the transformer, second spark gap means connected in parallel circuit relationship with said resistance means, said first spark gap means having a breakdown voltage which is lower than the breakdown voltage of said second spark gap means.
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) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |