US3555448A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transducer controlled variable frequency wien-bridge oscillator
Assignee: DATA RESEARCH CORP
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Filing: 1969-06-03
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Granted: 1971-01-12
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Expires: 1989-06-03
Abstract
Abstract THE FREQUENCY SELECTIVE BRIDGE OF A STANDARD WIENBRIDGE OSCILLATOR IS PROVIDED WITH AN ADDITIONAL PHASE SHIFTING NETWORK COMPRISING A CAPACITOR AND A LINEARIZED TRANSDUCER. THE TRANSDUCER EXHIBITS IMPEDANCE CHANGES RESPONSIVE TO PHYSICAL VARIATIONS OF A FUNCTION BEING MEASURED, AND THE OVERALL CIRCUIT DIRECTLY CONVERTS SUCH TRANSDUCER IMPEDANCE VARIATIONS INTO A LINEAR DIGITAL FUNCTION IN A COMPUTER COMPATIBLE FORMAT WITHOUT THE USE OF A VOLTAGE DRIVEN ANALOG-TO-DIGITAL CONVERTER MODULE.
Inventors
- 👤 James W Clarke Jr
- 👤 Worley C Wilson Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:44
CPC Classifications
H; H03; H03B; H03B5/00; H03B5/20; H03B5/26
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) | 1974-01-11 | 1974-07-13 | 1975-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-11 | 1978-07-13 | 1979-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-11 | 1982-07-13 | 1983-01-12 | $7700.00 | Window Closed / Lapsed |