US2953752A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chopper-stabilized amplifier
Assignee: PORTRONICS Inc
•
Filing: 1957-03-14
•
Granted: 1960-09-20
•
Expires: 1977-03-14
Abstract
No abstract record available.
Inventors
- 👤 John H Porter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:10
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/30; H03F1/303
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2297543A
Cited
US2756286A
Cited
US2701309A
Cited
US2559245A
Cited
US2707752A
Cited
US2773946A
Cited
US2832848A
Cited
DK71982A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-09-20 | 1964-03-21 | 1964-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-09-20 | 1968-03-21 | 1968-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-09-20 | 1972-03-21 | 1972-09-20 | $7700.00 | Window Closed / Lapsed |