Patent US513543A successfully refreshed from Google Patents.
Patent US1987976A successfully refreshed from Google Patents.
US1987976A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power supply circuit
Assignee: RCA Corp
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Filing: 1929-11-20
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Granted: 1935-01-15
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Expires: 1949-11-20
Abstract
No abstract record available.
Inventors
- 👤 Walter Van B Roberts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:40
CPC Classifications
H; H02; H02M; H02M1/00; H02M1/14; H02M1/15
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1938-01-14 | 1938-07-16 | 1939-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1942-01-14 | 1942-07-16 | 1943-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1946-01-14 | 1946-07-16 | 1947-01-15 | $7700.00 | Window Closed / Lapsed |