US3397358A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotating coil magnetometer with means to compensate for variations in rotational speed
Assignee: Associated Electrical Industries Ltd
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Filing: 1965-04-22
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Granted: 1968-08-13
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Expires: 1985-04-22
Abstract
No abstract record available.
Inventors
- 👤 Allenden Dennis
- 👤 Harrison Terence Trevor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:45
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/02; G01R33/028; G01R33/0283
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
154 words
CIRCUIT MEANS FOR THE PURPOSE OF PROVIDING A SIGNAL REPRESENTATIVE OF THE MAGNETIC FLUX DENSITY IN A MAGNETIC FIELD COMPRISING (A) AN ELECTRICAL PICK-UP COIL ARRANGED IN THE MAGNETIC FIELD; (B) DRIVING MEANS BY WHICH THE COIL IS CONTINUOUSLY ROTATED IN USE AT A SUBSTANTIALLY UNIFORM SPEED; (C) AN AMPLIFIER TO WHICH THE E.M.F. FROM THE COIL IS APPLIED AS INPUT AND HAVING CAPACITIVE NEGATIVE FEEDBACK AND ARRANGED TO YIELD AN OUTPUT WITH A GAIN WHICH DECREASES INVERSELY IN MAGNITUDE WITH AN INCREASE IN THE FREQUENCY OF THE INPUT TO THE AMPLIFIER; (D) A SYNCHRONOUS DETECTOR TO WHICH THE OUTPUT FROM THE AMPLIFIER IS APPLIED AS INPUT AND WHICH SERVES TO BLOCK SUBSTANTIALLY ALL FREQUENCIES WHICH ARE HARMONICS OF THE BASIC FREQUENCY OF ROTATION OF THE COIL; AND (E) OUTPUT MEANS ARRANGED TO RECEIVE THE OUTPUT FROM THE SYNCHRONOUS DETECTOR AND TO PROVIDE THE SAID SIGNAL REPRESENTATIVE OF THE MAGNITUDE OF THE MAGNETIC FIELD.
Claim 2
Dependent Claim
154 words
CIRCUIT MEANS FOR THE PURPOSE OF PROVIDING A SIGNAL REPRESENTATIVE OF THE MAGNETIC FLUX DENSITY IN A MAGNETIC FIELD COMPRISING (A) AN ELECTRICAL PICK-UP COIL ARRANGED IN THE MAGNETIC FIELD; (B) DRIVING MEANS BY WHICH THE COIL IS CONTINUOUSLY ROTATED IN USE AT A SUBSTANTIALLY UNIFORM SPEED; (C) AN AMPLIFIER TO WHICH THE E.M.F. FROM THE COIL IS APPLIED AS INPUT AND HAVING CAPACITIVE NEGATIVE FEEDBACK AND ARRANGED TO YIELD AN OUTPUT WITH A GAIN WHICH DECREASES INVERSELY IN MAGNITUDE WITH AN INCREASE IN THE FREQUENCY OF THE INPUT TO THE AMPLIFIER; (D) A SYNCHRONOUS DETECTOR TO WHICH THE OUTPUT FROM THE AMPLIFIER IS APPLIED AS INPUT AND WHICH SERVES TO BLOCK SUBSTANTIALLY ALL FREQUENCIES WHICH ARE HARMONICS OF THE BASIC FREQUENCY OF ROTATION OF THE COIL; AND (E) OUTPUT MEANS ARRANGED TO RECEIVE THE OUTPUT FROM THE SYNCHRONOUS DETECTOR AND TO PROVIDE THE SAID SIGNAL REPRESENTATIVE OF THE MAGNITUDE OF THE MAGNETIC FIELD.
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) | 1971-08-13 | 1972-02-12 | 1972-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-08-13 | 1976-02-12 | 1976-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-08-13 | 1980-02-12 | 1980-08-13 | $7700.00 | Window Closed / Lapsed |