Patent US2929918A successfully refreshed from Google Patents.
Patent US4290018A successfully refreshed from Google Patents.
US4290018A
Expired / Lapsed
US
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Magnetic field strength measuring apparatus with triangular waveform drive means
Assignee: Boeing North American Inc
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Filing: 1979-08-22
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Granted: 1981-09-15
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Expires: 1999-08-22
Abstract
Abstract A magnetic field directional magnetic sensor wherein the magnetic material has a large length-to-diameter ratio and comprises two coils wound around the magnetic material which also have a small diameter compared to the length. A first coil is driven with a triangular waveform signal. After each occurrence of saturation, a voltage will be produced by the output coil. The voltage amplitude of the drive signal can be measured upon the occurrence of each of the output pulses from the second coil with the measuring or detection of the drive signal being used in a sample and hold circuit which averages the detected values for a determination of magnetic field being sensed in the longitudinal or long direction of the magnetic sensor.
Inventors
- 👤 Melvin H. Rhodes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:35
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/02; G01R33/04
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
127 words
Apparatus for measuring magnetic field comprising in combination: magnetic rod sensing means having a large length-to-diameter ratio and including drive and output windings; triangular waveform drive means, including logic output means, connected to said drive winding for cyclically altering the magnetic field in a linear manner as a function of time between first and second magnetic field values, said logic output means providing output signals indicative of times at which the magnetic field reaches said first and second values; and sample and hold means, connected to said output winding and to said logic output means, for outputting a signal indicative of sensed magnetic field as obtained by taking the average voltage appearing on said drive winding at times determined by signals received from said logic output means.
Claim 2
Dependent Claim
127 words
Apparatus for measuring magnetic field comprising in combination: magnetic rod sensing means having a large length-to-diameter ratio and including drive and output windings; triangular waveform drive means, including logic output means, connected to said drive winding for cyclically altering the magnetic field in a linear manner as a function of time between first and second magnetic field values, said logic output means providing output signals indicative of times at which the magnetic field reaches said first and second values; and sample and hold means, connected to said output winding and to said logic output means, for outputting a signal indicative of sensed magnetic field as obtained by taking the average voltage appearing on said drive winding at times determined by signals received from said logic output means.
Claim 3
Independent Claim
80 words
The method of measuring an external magnetic field comprising the steps of: driving a multiple winding magnetic sensor having a large length-to-diameter ratio with a drive signal such that the magnetic field strength in the sensor cyclically varies in the manner of a triangular waveform; sensing the voltage output by said sensor at times coincident with the peaks of said triangular waveform; and averaging the sensed voltages to provide a signal indicative of an external field affecting said magnetic sensor.
Claim 4
Independent Claim
80 words
The method of measuring an external magnetic field comprising the steps of: driving a multiple winding magnetic sensor having a large length-to-diameter ratio with a drive signal such that the magnetic field strength in the sensor cyclically varies in the manner of a triangular waveform; sensing the voltage output by said sensor at times coincident with the peaks of said triangular waveform; and averaging the sensed voltages to provide a signal indicative of an external field affecting said magnetic sensor.
Claim 5
Independent Claim
66 words
The method of external magnetic field intensity detection comprising the steps of: periodically and bidirectionally driving a magnetic field direction sensitive magnetic material to saturation using a bipolar drive signal; detecting flux magnitudes at opposing drive field intensities; outputting signals indicative of magnitudes of drive signals at times of detected flux magnitudes; and averaging the outputted signals to provide an indication of external magnetic field intensity.
Claim 6
Independent Claim
66 words
The method of external magnetic field intensity detection comprising the steps of: periodically and bidirectionally driving a magnetic field direction sensitive magnetic material to saturation using a bipolar drive signal; detecting flux magnitudes at opposing drive field intensities; outputting signals indicative of magnitudes of drive signals at times of detected flux magnitudes; and averaging the outputted signals to provide an indication of external magnetic field intensity.
Claim 7
Dependent Claim
106 words
Apparatus for measuring an external magnetic field comprising in combination: multiple winding magnetic sensor means wherein the magnetic portion thereof has a large length-to-diameter ratio; first means for driving said sensor means with a drive signal, such that the magnitude of the magnetic field in the vicinity of said sensor means varies in the manner of a triangular waveform; second means for sensing the magnitude of the drive signal to said sensor means at times coincident with saturation of said sensor means; and third means for averaging the sensed drive signal magnitudes to provide an output signal indicative of an external field affecting said magnetic sensor.
Claim 8
Dependent Claim
106 words
Apparatus for measuring an external magnetic field comprising in combination: multiple winding magnetic sensor means wherein the magnetic portion thereof has a large length-to-diameter ratio; first means for driving said sensor means with a drive signal, such that the magnitude of the magnetic field in the vicinity of said sensor means varies in the manner of a triangular waveform; second means for sensing the magnitude of the drive signal to said sensor means at times coincident with saturation of said sensor means; and third means for averaging the sensed drive signal magnitudes to provide an output signal indicative of an external field affecting said magnetic sensor.
References Cited (Backward Citations)
GB1207313A
Cited
GB1248567A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-09-14 | 1985-03-16 | 1985-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-14 | 1989-03-16 | 1989-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-14 | 1993-03-16 | 1993-09-15 | $7700.00 | Window Closed / Lapsed |