Patent US3305638A successfully refreshed from Google Patents.
US3305638A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Condenser microphone circuit with solid electrolyte battery polarizing source
Assignee: Individual
•
Filing: 1964-02-17
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Granted: 1967-02-21
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Expires: 1984-02-17
Abstract
No abstract record available.
Inventors
- 👤 Steven D Teachout
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:33
CPC Classifications
H; H04; H04R; H04R19/00; H04R19/04
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
63 words
A CONDENSER TRANSDUCER SYSTEM COMPRISING, A SOUND SENSITIVE CONDENSER TRANSDUCER, A DIRECT CURRENT POLARIZING SOURCE COMPRISING A SOLID ELECTROLYTE BATTERY IMPOSING ON SAID TRANSDUCER A SUBSTANTIALLY CONSTANT POLARIZING CHARGE, AND IN WHICH SAID TRANSDUCER AND SAID SOLID ELECTROLYTE BATTERY ARE CONTAINED WITHIN A MICROPHONE STRUCTURE OF CYLINDRICAL SHAPE, LIGHTWEIGHT AND CAPABLE OF BEING HELD IN THE HAND, AND AMPLIFYING MEANS FOR AMPLIFYING THE
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US3207848A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-02-20 | 1970-08-22 | 1971-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-02-20 | 1974-08-22 | 1975-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-02-20 | 1978-08-22 | 1979-02-21 | $7700.00 | Window Closed / Lapsed |