Patent US3908157A successfully refreshed from Google Patents.
US3908157A
Expired / Lapsed
US
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Electrolytic capacitor construction and system
Assignee: Sprague Electric Co
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Filing: 1974-11-08
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Granted: 1975-09-23
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Expires: 1994-11-08
Abstract
Abstract In an electrolytic capacitor the electrodes are separated by spacer material made of porous polypropylene film having an electrical porosity which results in lower equivalent series resistance, particularly at low temperatures. The electrolytes associated with the porous polypropylene are those having as a solvent, 2-methoxy-proprionitride, tri-n-butylphosphate, Nmethylpyrrolidone, hexamethylphosphortriamide, butylcellosolve, and N,N,-dimethylformamide.
Inventors
- 👤 Sidney D Ross
- 👤 Franz S Dunkl
- 👤 Clinton E Hutchins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:22
CPC Classifications
H; H01; H01G; H01G9/00; H01G9/004; H01G9/022
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
36 words
IN AN ELECTROLTIC CAPACITOR HAVING A FIRST AND SECOND ELECTRODE AND A COMBINATION SEPARATING THE ELECTRODES OF A SPACER OF PORUS POLYPROPYLENE AND AN ELECTROLYTE IMPREGNATED IN THE SPACER HAVING AN ELECTROLYTE SOLVENT OF THE CLASS
Claim 2
Dependent Claim
36 words
IN AN ELECTROLTIC CAPACITOR HAVING A FIRST AND SECOND ELECTRODE AND A COMBINATION SEPARATING THE ELECTRODES OF A SPACER OF PORUS POLYPROPYLENE AND AN ELECTROLYTE IMPREGNATED IN THE SPACER HAVING AN ELECTROLYTE SOLVENT OF THE CLASS
Claim 3
Dependent Claim
64 words
In an electrolytic capacitor having a first and second electrode and a combination separating the electrodes of a spacer of porous polypropylene and an electrolyte impregnated in the spacer having an electrolyte solvent of the class consisting of tri-n-butylphosphate, N-methylpyrrolidone, hexamethylphosphortriamide, butylcellosolve, N,N-dimethylformamide, and 2-methoxypropionitrile, said combination having an electrical porosity above 14 and thereby providing to said capacitor a stable ESR-to-temperature change characteristic.
Claim 4
Dependent Claim
64 words
In an electrolytic capacitor having a first and second electrode and a combination separating the electrodes of a spacer of porous polypropylene and an electrolyte impregnated in the spacer having an electrolyte solvent of the class consisting of tri-n-butylphosphate, N-methylpyrrolidone, hexamethylphosphortriamide, butylcellosolve, N,N-dimethylformamide, and 2-methoxypropionitrile, said combination having an electrical porosity above 14 and thereby providing to said capacitor a stable ESR-to-temperature change characteristic.
Claim 5
Dependent Claim
17 words
An electrolytic capacitor as claimed in claim 2 wherein the porous polypropylene is a microporous polypropylene film.
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) | 1978-09-22 | 1979-03-24 | 1979-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-22 | 1983-03-24 | 1983-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-22 | 1987-03-24 | 1987-09-23 | $7700.00 | Window Closed / Lapsed |