US3829894A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Parametric magnetic sensor
Assignee: KDDI Corp
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Filing: 1972-10-18
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Granted: 1974-08-13
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Expires: 1992-10-18
Abstract
Abstract A parametrically excited magnetic sensor, in which an inductance element is formed with a magnetic substance and a winding wound on the magnetic substance, in which a capacitor is connected in parallel to the winding to form a resonance circuit, in which an AC exciting current magnetic field is applied to the magnetic substance to generate a second harmonic oscillation wave having a frequency twice the frequency of the AC exciting current in the resonance circuit, so that a minute magnetic field is detected by utilizing a change in the phase of the second harmonic oscillation wave caused in accordance with the polarity of the minute magnetic field. The magnetic substance forms a part of magnetic circuit having a narrow gap so that the gap portion issued as a magnetic detecting head.
Inventors
- 👤 T Watanabe
- 👤 T Fukui
- 👤 S Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:52
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/02; G01R33/04; G01R33/05; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/335
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
192 words
A parametric magnetic sensor comprising, sensing means receptive in operation of an oscillating excitation signal having a frequency f for sensing an external magnetic field, said sensing means comprising means for developing in operation an output signal having a substantially constant amplitude, a frequency 2f, and having one of two phases differing by pi radians and determined by said external magnetic field being sensed, said sensing means comprising a conductor having a straight portion having a longitudinal axis and comprising input means for receiving said excitation signals, magnetic circuit means having a portion disposed on said straight portion of said conductor and being provided with a gap in a portion remote from said straight portion of said conductor, an inductor wound around said portion of said magnetic circuit means disposed on said straight portion of said conductor and having a longitudinal axis of symmetry parallel to said longitudinal axis of said straight portion of said conductor, a capacitor connected in parallel with said inductor to form a resonant output circuit therewith having a resonance frequency 2f, and said output circuit comprising output means for providing said output signal having a frequency 2f.
Claim 2
Dependent Claim
192 words
A parametric magnetic sensor comprising, sensing means receptive in operation of an oscillating excitation signal having a frequency f for sensing an external magnetic field, said sensing means comprising means for developing in operation an output signal having a substantially constant amplitude, a frequency 2f, and having one of two phases differing by pi radians and determined by said external magnetic field being sensed, said sensing means comprising a conductor having a straight portion having a longitudinal axis and comprising input means for receiving said excitation signals, magnetic circuit means having a portion disposed on said straight portion of said conductor and being provided with a gap in a portion remote from said straight portion of said conductor, an inductor wound around said portion of said magnetic circuit means disposed on said straight portion of said conductor and having a longitudinal axis of symmetry parallel to said longitudinal axis of said straight portion of said conductor, a capacitor connected in parallel with said inductor to form a resonant output circuit therewith having a resonance frequency 2f, and said output circuit comprising output means for providing said output signal having a frequency 2f.
Claim 3
Dependent Claim
41 words
A parametric magnetic sensor according to claim 1, in which the magnetic circuit is entirely formed by a magnetic wire having the narrow gap, the magnetic wire being formed by a conductor and a ferromagnetic thin film coated on the conductor.
Claim 4
Dependent Claim
47 words
A parametric magnetic sensor according to claim 1, in which the magnetic circuit is formed by a magnetic wire of U-letter configuration and a magnetic yoke, the magnetic wire being formed by a conductor and a ferromagnetic thin film coated on the conductor except the narrow gap.
Claim 5
Dependent Claim
70 words
A parametric magnetic sensor according to claim 1, in which the magnetic circuit is formed by a magnetic wire and a pair of yokes having the narrow gap, the pair of yokes being magnetically connected to the ends of the magnetic wire at respective ends of the yokes opposite to the narrow gap, the magnetic wire being formed by a conductor and a ferromagnetic thin film coated on the conductor.
Claim 6
Dependent Claim
36 words
A parametric magnetic sensor according to claim 1, in which the magnetic circuit is formed by a ferrite yoke having the narrow gap and at least one bore, an exciting conductor being inserted in the bore.
Claim 7
Dependent Claim
29 words
A parametric magnetic sensor according to claim 1, in which the magnetic circuit is formed by a ferromagnetic thin film having the narrow gap and deposited on a substrate.
Claim 8
Dependent Claim
40 words
A parametric magnetic sensor according to claim 1, in which the magnetic circuit is formed by a magnetic sheet having the narrow gap and a rolled-up to provide a substantially straight bore, an exciting conductor being inserted in the bore.
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US3189880A
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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) | 1977-08-12 | 1978-02-11 | 1978-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-12 | 1982-02-11 | 1982-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-12 | 1986-02-11 | 1986-08-13 | $7700.00 | Window Closed / Lapsed |