US2807677A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stable direct-current amplifier
Assignee: Dow Chemical Co
•
Filing: 1951-03-01
•
Granted: 1957-09-24
•
Expires: 1971-03-01
Abstract
No abstract record available.
Inventors
- 👤 Victor J Caldecourt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 09:55
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/34; H03F3/36
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2375283A
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US2210390A
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US2210997A
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US2300133A
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US2354718A
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US2459730A
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US2462190A
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GB620140A
Cited
US2559515A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-09-23 | 1961-03-25 | 1961-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-09-23 | 1965-03-25 | 1965-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-09-23 | 1969-03-25 | 1969-09-24 | $7700.00 | Window Closed / Lapsed |