US4939459A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High sensitivity magnetic sensor
Assignee: TDK Corp
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Filing: 1988-12-21
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Granted: 1990-07-03
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Expires: 2008-12-21
Abstract
Abstract A magnetic sensor is provided for use in detecting an external magnetic field, typically geomagnetism. Pulse or alternating current is applied across a wire or strip-shaped electrically conductive, magnetic body in its longitudinal direction to create an internal magnetic field in the magnetic body. A pick-up winding is wound around the magnetic body. The sensor detects an electric signal developed in the winding as a result of interaction of the internal and external magnetic fields.
Inventors
- 👤 Yoshiaki Akachi
- 👤 Mutumi Kinosita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 04:49
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/02; G01R33/04
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
108 words
A magnetic sensor for use in the detection of an external magnetic field, comprising an elongated, electrically conductive, magnetic body, means for applying pulse or alternating current i d across the magnetic body in its longitudinal direction to create a non-saturating internal magnetic field in a circumferential direction of the magnetic body such that a pulse output v o is obtained during the rise or fall time of said current i d , and detecting means including a winding wound around the magnetic body for detecting an electric signal developed in the winding as a result of interaction of the internal magnetic field and the external magnetic field.
Claim 2
Dependent Claim
108 words
A magnetic sensor for use in the detection of an external magnetic field, comprising an elongated, electrically conductive, magnetic body, means for applying pulse or alternating current i d across the magnetic body in its longitudinal direction to create a non-saturating internal magnetic field in a circumferential direction of the magnetic body such that a pulse output v o is obtained during the rise or fall time of said current i d , and detecting means including a winding wound around the magnetic body for detecting an electric signal developed in the winding as a result of interaction of the internal magnetic field and the external magnetic field.
Claim 3
Dependent Claim
14 words
The magnetic sensor of claim 1 wherein the magnetic body is of wire shape.
Claim 4
Dependent Claim
16 words
The magnetic sensor of claim 2 wherein the magnetic body is a bundle of magnetic wires.
Claim 5
Dependent Claim
14 words
The magnetic sensor of claim 1 wherein the magnetic body is of strip shape.
Claim 6
Dependent Claim
16 words
The magnetic sensor of claim 1 wherein the magnetic body is of substantially magnetostriction-free magnetic material.
Claim 7
Dependent Claim
17 words
The magnetic sensor of claim 5 wherein the magnetic body is formed from an amorphous cobalt-base alloy.
Claim 8
Dependent Claim
28 words
The magnetic sensor of claim 1 wherein the conducting means includes a power supply and a pair of leads extending therefrom to opposite ends of the magnetic body.
Claim 9
Dependent Claim
22 words
The magnetic sensor of claim 1 wherein the detecting means includes a detecting circuit electrically connected to output terminals of the winding.
Claim 10
Dependent Claim
17 words
The magnetic field sensor of claim 1 for detecting geomagnetism or a magnetic field of similar strength.
Claim 11
Dependent Claim
21 words
The magnetic field sensor of claim 9 wherein the magnetic body has a length of about 10 to about 130 mm.
Claim 12
Dependent Claim
25 words
The magnetic field sensor of claim 9 wherein the magnetic body has a cross sectional area of about 0.01 to about 0.28 mm 2 .
Claim 13
Dependent Claim
114 words
A magnetic sensor for use in the detection of an external magnetic field, comprising an elongated magnetic body, an elongated electric conductor disposed adjacent the magnetic body, means for applying pulse or alternating current i d across the conductor in its longitudinal direction to create a non-saturating internal magnetic field in a circumferential direction of the magnetic body such that a pulse output v o is obtained during the rise or fall time of said current i d , and detecting means including a winding wound around the magnetic body for detecting an electric signal developed in the winding as a result of interaction of the internal magnetic field and the external magnetic field.
Claim 14
Dependent Claim
114 words
A magnetic sensor for use in the detection of an external magnetic field, comprising an elongated magnetic body, an elongated electric conductor disposed adjacent the magnetic body, means for applying pulse or alternating current i d across the conductor in its longitudinal direction to create a non-saturating internal magnetic field in a circumferential direction of the magnetic body such that a pulse output v o is obtained during the rise or fall time of said current i d , and detecting means including a winding wound around the magnetic body for detecting an electric signal developed in the winding as a result of interaction of the internal magnetic field and the external magnetic field.
Claim 15
Dependent Claim
21 words
The magnetic sensor of claim 12 wherein the conductor is disposed in parallel with and in contact with the magnetic body.
Claim 16
Dependent Claim
14 words
The magnetic sensor of claim 12 wherein the magnetic body is of wire shape.
Claim 17
Dependent Claim
16 words
The magnetic sensor of claim 14 wherein the magnetic body is a bundle of magnetic wires.
Claim 18
Dependent Claim
14 words
The magnetic sensor of claim 12 wherein the magnetic body is of strip shape.
Claim 19
Dependent Claim
23 words
The magnetic sensor of claim 12 wherein the conductor is an elongated rod and the magnetic body is a sheath enclosing the rod.
Claim 20
Dependent Claim
16 words
The magnetic sensor of claim 12 wherein the magnetic body is of substantially magnetostriction-free magnetic material.
Claim 21
Dependent Claim
17 words
The magnetic sensor of claim 18 wherein the magnetic body is formed from an amorphous cobalt-base alloy.
Claim 22
Dependent Claim
27 words
The magnetic sensor of claim 12 wherein the conducting means includes a power supply and a pair of leads extending therefrom to opposite ends of the conductor.
Claim 23
Dependent Claim
22 words
The magnetic sensor of claim 12 wherein the detecting means includes a detecting circuit electrically connected to output terminals of the winding.
Claim 24
Dependent Claim
17 words
The magnetic field sensor of claim 12 for detecting geomagnetism or a magnetic field of similar strength.
Claim 25
Dependent Claim
21 words
The magnetic field sensor of claim 22 wherein the magnetic body has a length of about 10 to about 130 mm.
Claim 26
Dependent Claim
24 words
The magnetic field sensor of claim 22 wherein the magnetic body has a cross sectional of about 0.01 to about 0.28 mm 2 .
Claim 27
Dependent Claim
92 words
A magnetic sensor for use in the detection of an external magnetic field, comprising an elongated, electrically conductive, magnetic body, means for applying pulse or alternating current i d across the magnetic body in its longitudinal direction to create a non-saturating internal magnetic field in the magnetic body such that a pulse output v o is obtained during the rise or fall time of said current i d , and detecting means associated with the magnetic body for detecting the interaction of the internal and external magnetic fields as an electric signal.
Claim 28
Dependent Claim
92 words
A magnetic sensor for use in the detection of an external magnetic field, comprising an elongated, electrically conductive, magnetic body, means for applying pulse or alternating current i d across the magnetic body in its longitudinal direction to create a non-saturating internal magnetic field in the magnetic body such that a pulse output v o is obtained during the rise or fall time of said current i d , and detecting means associated with the magnetic body for detecting the interaction of the internal and external magnetic fields as an electric signal.
Claim 29
Dependent Claim
99 words
A magnetic sensor for use in the detection of an external magnetic field, comprising an elongated magnetic body, an elongated electric conductor disposed adjacent to the magnetic body, means for applying pulse or alternating current i d across the conductor in its axial direction to create a non-saturating internal magnetic field in the magnetic body such that a pulse output v o is obtained during the rise or fall time of said current i d , and detecting means associated with the magnetic body for detecting the interaction of the internal and external magnetic field as an electric signal.
Claim 30
Dependent Claim
99 words
A magnetic sensor for use in the detection of an external magnetic field, comprising an elongated magnetic body, an elongated electric conductor disposed adjacent to the magnetic body, means for applying pulse or alternating current i d across the conductor in its axial direction to create a non-saturating internal magnetic field in the magnetic body such that a pulse output v o is obtained during the rise or fall time of said current i d , and detecting means associated with the magnetic body for detecting the interaction of the internal and external magnetic field as an electric signal.
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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) | 1993-07-02 | 1994-01-01 | 1994-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-02 | 1998-01-01 | 1998-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-02 | 2002-01-01 | 2002-07-03 | $7700.00 | Window Closed / Lapsed |