US3539931A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Current-frequency converter wherein output frequency is proportional to the square root of the input current
Assignee: Societe Nationale des Petroles dAquitaine SA
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Filing: 1968-02-13
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Granted: 1970-11-10
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Expires: 1988-02-13
Abstract
No abstract record available.
Inventors
- 👤 Philippe Jouve
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:47
CPC Classifications
H; H03; H03M; H03M1/00; G; G06; G06G; G06G7/00; G06G7/12; G06G7/20; H03K; H03K4/00; H03K4/04; H03K7/00; H03K7/06; H03M1/12; H03M1/50
Claims Analysis
Total Claims: 0
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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) | 1973-11-09 | 1974-05-11 | 1974-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-11-09 | 1978-05-11 | 1978-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-11-09 | 1982-05-11 | 1982-11-10 | $7700.00 | Window Closed / Lapsed |