← Back to Patent Explorer
US3859568A Expired / Lapsed US ⏱️ 0.0 years remaining

Overvoltage surge arrester with improved voltage grading circuit

Assignee: General Electric Co
•
Filing: 1974-01-16
•
Granted: 1975-01-07
•
Expires: 1994-01-16
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

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. Also disclosed is a grading circuit in which a linear resistor is additionally connected in series with the high exponent non-linear resistor of the above circuit.

Inventors

  • 👤 Eugene C Sakshaug

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 06:31
CPC Classifications
H; H01; H01T; H01T4/00; H01T4/16; H01T4/20

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 168 words
An electrical overvoltage surge arrester, comprising: 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 with a gap electrically connected in series with said terminal members; a first grading resistor of a first non-linear resistance material electrically connected in parallel with the gap of said spark gap assembly, the degree of non-linearity of said first material being indicated by a first numerical exponent for the voltage in an equation describing the general currentvoltage characteristics of said first material, and a second grading resistor of a second non-linear resistance material electrically connected in parallel with said gap and with said first grading resistor, the degree of non-linearity 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.
Claim 2
Dependent Claim 168 words
An electrical overvoltage surge arrester, comprising: 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 with a gap electrically connected in series with said terminal members; a first grading resistor of a first non-linear resistance material electrically connected in parallel with the gap of said spark gap assembly, the degree of non-linearity of said first material being indicated by a first numerical exponent for the voltage in an equation describing the general currentvoltage characteristics of said first material, and a second grading resistor of a second non-linear resistance material electrically connected in parallel with said gap and with said first grading resistor, the degree of non-linearity 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.
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 20 words
The arrester defined in claim 2 wherein said first exponent is about ten times as great as said second exponent.
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 14 words
The arrester defined in claim 4 wherein said first material is substantially zinc oxide.
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 non-linear 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)

US3091721A Cited
US3313978A Cited
US3611044A Cited

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

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag