Patent US3381235A successfully refreshed from Google Patents.
US3381235A
Expired / Lapsed
US
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Amplifier having feedback bias control circuit
Assignee: Webster Electric Co Inc
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Filing: 1965-03-22
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Granted: 1968-04-30
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Expires: 1985-03-22
Abstract
No abstract record available.
Inventors
- 👤 Richard H Campbell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:53
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/02; H03F1/0205; H03F1/0261; H03F3/00; H03F3/26
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2777057A
Cited
US3015075A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-04-30 | 1971-10-30 | 1972-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-04-30 | 1975-10-30 | 1976-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-04-30 | 1979-10-30 | 1980-04-30 | $7700.00 | Window Closed / Lapsed |