US4403515A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Position sensor
Assignee: Aisin Corp
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Filing: 1982-04-26
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Granted: 1983-09-13
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Expires: 2002-04-26
Abstract
Abstract A position sensor for detecting a displacement of an object, comprising a movable member coupled to the object, a permanent magnet connected to the movable member, and a magnetically soft member surrounded by an electrical coil secured adjacent to a range of movement of the magnet. Voltage pulses are applied to one end of the electrical coil, the other end of which is connected in series with the resistor. For each pulse applied to the coil, a voltage drop across the resistor is detected and a time lag between the leading edge of the applied pulse and the corresponding voltage drop across the resistor is measured by a processing circuit which produces an analog voltage or a digital code indicative of the time lag. A displacement of the object produces a change in magnetic field at the magnetically soft member which results in a corresponding variation in the above-noted time lag, which is therefore indicative of the displacement of the object.
Inventors
- 👤 Shinichiro Iwasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:47
CPC Classifications
G; G01; G01B; G01B7/00; G01B7/003
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
169 words
A position sensor for detecting a displacement of an object, comprising: a movable member coupled to said object; permanent magnet means connected to said movable member for producing a magnetic field which varies in a predetermined region in dependence on the displacement of said movable member; core means made of a magnetically soft material and disposed in said predetermined region for forming a magnetic circuit with said magnet means; electric coil means including at least one coil wound around said core means for detecting a change in magnetic flux in said magnetically soft member; and means for detecting the displacement of said object, comprising, means for applying a pulse voltage to a first terminal of said coil to saturate magnetically said core means, and means coupled to a second terminal of said coil for producing a displacement output signal indicative of the displacement of said magnet means and therefore of said movable body based on the time between application of said pulse voltage and saturation of said core means.
Claim 2
Dependent Claim
169 words
A position sensor for detecting a displacement of an object, comprising: a movable member coupled to said object; permanent magnet means connected to said movable member for producing a magnetic field which varies in a predetermined region in dependence on the displacement of said movable member; core means made of a magnetically soft material and disposed in said predetermined region for forming a magnetic circuit with said magnet means; electric coil means including at least one coil wound around said core means for detecting a change in magnetic flux in said magnetically soft member; and means for detecting the displacement of said object, comprising, means for applying a pulse voltage to a first terminal of said coil to saturate magnetically said core means, and means coupled to a second terminal of said coil for producing a displacement output signal indicative of the displacement of said magnet means and therefore of said movable body based on the time between application of said pulse voltage and saturation of said core means.
Claim 3
Dependent Claim
17 words
A position sensor according to claim 1, wherein said core means consists of: an amorphous magnetic material.
Claim 4
Dependent Claim
20 words
A position sensor according to claim 2, further comprising: a synthetic resin board to which said core means is secured.
Claim 5
Dependent Claim
28 words
A position sensor according to claim 3, further comprising: a connecting member secured to one end of said movable member and acting to displace said permanent magnet means.
Claim 6
Dependent Claim
25 words
A position sensor according to claim 4, further comprising: a spring for applying a biasing force to said permanent magnet means at its other end.
Claim 7
Dependent Claim
66 words
A position sensor according to claim 1, further comprising: said permanent magnet means magnetized in a longitudinal direction thereof and fixed to said movable member; said core means comprising opposed core members each of which comprises a magnetically soft material positioned on opposite sides of said magnet means; said movable member undergoing displacement in a direction perpendicular to the longitudinal axis of the permanent magnet means.
Claim 8
Dependent Claim
30 words
A position sensor according to claim 1, further comprising: said core means having a longitudinal direction; and said movable member means movable in the longitudinal direction of said core means.
Claim 9
Dependent Claim
34 words
A position sensor according to claim 1, further comprising: said core means having a longitudinal axis; and said movable member means movable in a direction perpendicular to the longitudinal axis of said core means.
Claim 10
Dependent Claim
37 words
A position sensor device according to claim 1, wherein said detecting means comprises: constant current means for producing a constant current through said coil upon application of said pulse voltage to said first terminal of said coil.
Claim 11
Dependent Claim
28 words
A rotational angle sensor according to claim 9, wherein said constant current means comprises: at least one field effect transistor connected to said second terminal of said coil.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-09-12 | 1987-03-14 | 1987-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-12 | 1991-03-14 | 1991-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-12 | 1995-03-14 | 1995-09-13 | $7700.00 | Window Closed / Lapsed |