Patent JPS6296969A successfully refreshed from Google Patents.
US3859569A
Expired / Lapsed
US
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Overvoltage surge arrester with improved voltage grading circuit
Assignee: General Electric Co
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Filing: 1974-01-16
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Granted: 1975-01-07
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Expires: 1994-01-16
Abstract
Abstract An overvoltage surge arrester for relatively high voltage applications is provided with a voltage grading circuit comprising a relatively low exponent resistor in parallel with a relatively high exponent resistor, for preventing spurious operation of the arrester under conditions in which the outside surface of the porcelain housing becomes contaminated with a conductive film. A linear resistor is additionally connected in series with the high exponent non-linear resistor of the above circuit to prevent excessively high current in the high exponent resistor near the sparkover voltage of the arrester.
Inventors
- 👤 James S Kresge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 18:06
CPC Classifications
H; H01; H01T; H01T4/00; H01T4/16; H01T4/20; H01C; H01C7/00; H01C7/10; H01C7/12
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
184 words
An electrical overvoltage surge arrester of the type including: a housing comprising at least two conductive terminal members spaced apart by a hollow insulating member; a spark gap section disposed inside said housing, said spark gap section comprising at least one spark gap assembly electrically connected in series with said terminal members; a first grading resistor of a first nonlinear resistance material electrically connected in parallel with said spark gap section, the degree of nonlinearity of said first material being indicated by a first numerical exponent for the voltage in an equation describing the general current-voltage characteristics of said first material, and a second grading resistor of a second nonlinear resistance material electrically connected in parallel with said spark gap section and with said first grading resistor, the degree of nonlinearity of said second material being indicated by a second numerical exponent for the voltage in an equation describing the general current-voltage characteristics of said second material, said first exponent being substantially greater than said second exponent, wherein the improvement comprises; a substantially linear resistor electrically connected in series with said first grading resistor.
Claim 2
Dependent Claim
184 words
An electrical overvoltage surge arrester of the type including: a housing comprising at least two conductive terminal members spaced apart by a hollow insulating member; a spark gap section disposed inside said housing, said spark gap section comprising at least one spark gap assembly electrically connected in series with said terminal members; a first grading resistor of a first nonlinear resistance material electrically connected in parallel with said spark gap section, the degree of nonlinearity of said first material being indicated by a first numerical exponent for the voltage in an equation describing the general current-voltage characteristics of said first material, and a second grading resistor of a second nonlinear resistance material electrically connected in parallel with said spark gap section and with said first grading resistor, the degree of nonlinearity of said second material being indicated by a second numerical exponent for the voltage in an equation describing the general current-voltage characteristics of said second material, said first exponent being substantially greater than said second exponent, wherein the improvement comprises; a substantially linear resistor electrically connected in series with said first grading resistor.
Claim 3
Dependent Claim
21 words
The arrester defined in claim 1 and wherein said first exponent is at least twice the magnitude of said second exponent.
Claim 4
Dependent Claim
46 words
The arrester defined in claim 2 wherein said first exponent is about ten times as great as said second exponent and said linear resistor has a resistance value on the order of at least several hundred ohms and a current-voltage characteristic exponent of less than two.
Claim 5
Dependent Claim
15 words
The arrester defined in claim 3 wherein said first material is substantially a metal oxide.
Claim 6
Dependent Claim
26 words
The arrester defined in claim 4 wherein said first material is substantially zinc oxide and said linear resistor has a resistance value of about 1,000 ohms.
Claim 7
Dependent Claim
14 words
The arrester defined in claim 5 wherein said second material is substantially silicon carbide.
Claim 8
Dependent Claim
29 words
The arrester defined in claim 6 comprising at least one nonlinear resistance valve block element electrically connected in series between said spark gap and one of said terminal members.
Claim 9
Dependent Claim
27 words
The arrester defined in claim 7 wherein said spark gap section comprises a plurality of said spark gap assemblies electrically connected in series between said terminal members.
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) | 1978-01-06 | 1978-07-08 | 1979-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-06 | 1982-07-08 | 1983-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-06 | 1986-07-08 | 1987-01-07 | $7700.00 | Window Closed / Lapsed |