Integral hall effect limit switch for control valve stem position sensor
First Claim
Patent Images
1. A position sensor assembly comprising:
- a magnetic circuit including a first pole piece and a second pole piece;
a primary sensor disposed between the first and second pole pieces, wherein said first and second pole pieces form a primary flux path through the primary sensor and permit a leakage flux path outside the primary sensor; and
a secondary sensor disposed in the leakage flux path, and being perpendicularly arranged to the primary sensor, wherein said leakage flux path provides a leakage flux through the secondary sensor to produce a voltage output from the secondary sensor proportional to a voltage output of the primary sensor produced by the primary flux of the primary flux path.
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Abstract
A non-contacting position sensor having primary and secondary sensors detects relative displacement between two objects. The secondary sensor may function as a limit switch detection element in a limit switch circuit, and is positioned to be in the path of magnetic flux not detected by the primary sensor. The primary sensor is positioned in a flux path between sections of a flux gathering pole. A secondary sensor is positioned in a leakage flux path outside the first sensor or may be positioned in a secondary flux path.
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Citations
25 Claims
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1. A position sensor assembly comprising:
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a magnetic circuit including a first pole piece and a second pole piece; a primary sensor disposed between the first and second pole pieces, wherein said first and second pole pieces form a primary flux path through the primary sensor and permit a leakage flux path outside the primary sensor; and a secondary sensor disposed in the leakage flux path, and being perpendicularly arranged to the primary sensor, wherein said leakage flux path provides a leakage flux through the secondary sensor to produce a voltage output from the secondary sensor proportional to a voltage output of the primary sensor produced by the primary flux of the primary flux path. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A position sensor assembly, comprising:
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a primary sensor including at least one Hall Effect sensing element being responsive to magnetic fields; a secondary sensor including at least one Hall Effect sensing element being responsive to magnetic fields; a U-shaped flux-gathering pole piece for collecting and directing magnetic flux at least to the primary sensor, the flux-gathering pole piece being constructed by the symmetric placement of a first and a second L-shaped section of magnetically permeable material forming a U-shape with a bifurcated base, the bifurcated base of the U-shaped pole piece having a gap separating the first and second L-shaped sections wherein the first L-shaped section further comprises a first asymmetric Y-shaped portion extending from the first L-shaped section, the first asymmetric Y-shaped portion having a head including first and second ends extending in a direction of the second L-shaped section and a second asymmetric Y-shaped portion having a head including first and second ends asymmetric Y-shaped portion having a head including first and second ends extending in a direction of the first L-shaped section, said primary sensor being arranged between the first ends of the first and second asymmetric Y-shaped portions and said secondary sensor being arranged between the second ends of the first and second asymmetric Y-shaped portions; and a magnetic flux source for generating a magnetic field that varies in a substantially linear manner. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A position sensor assembly comprising:
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a sensor housing; a U-shaped pole piece aligned by the sensor housing, said U-shaped pole piece including a first L-shaped section and a second L-shaped section, wherein the first L-shaped section terminates at an asymmetric Y-shaped portion and the second L-shaped section terminates at a second asymmetric Y-shaped portion; a primary sensor positioned between a first end of each of the first and second asymmetric Y-shaped portions, said first end of each of the first and second asymmetric Y-shaped portions being at a head of the respective asymmetric Y-shaped portion; and a secondary sensor positioned between a second end of each of the first and second asymmetric Y-shaped portions, said second end of each of the first and second asymmetric Y-shaped portions also being at the head of the respective asymmetric Y-shaped portion. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A position sensor assembly comprising:
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a first pole piece; a second pole piece; a primary sensor disposed between the first and second pole pieces, wherein said first and second pole pieces form a primary flux path through the primary sensor and permit a leakage flux path outside the primary sensor; and a secondary sensor disposed in the leakage flux path, wherein the secondary sensor is at least one of aligned immediately adjacent to the primary sensor and in contact with the primary sensor.
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24. A position sensor assembly comprising:
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a first pole piece; a second pole piece; a primary sensor disposed between the first and second pole pieces, wherein said first and second pole pieces form a primary flux path through the primary sensor and permit a leakage flux path outside the primary sensor; and a secondary sensor disposed in the leakage flux path, wherein the secondary sensor is arranged perpendicularly to the primary sensor.
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25. A position sensor assembly comprising:
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a first pole piece; a second pole piece; a primary sensor disposed between the first and second pole pieces, wherein said first and second pole pieces form a primary flux path through the primary sensor and permit a leakage flux path outside the primary sensor; a secondary sensor disposed in the leakage flux path; a voltage detector in electrical communication with the primary sensor and the secondary sensor;
a processor in communication with the voltage detector, said voltage detector being adapted to send a detected voltage output of the primary sensor and of the secondary sensor to the processor;
said processor including one or more predetermined voltages stored in an associated memory wherein said processor compares at least one of the voltage outputs of the primary sensor and the secondary sensor to said one or more predetermined voltages and said processor being adapted to generate a signal upon a selected proximity of the at least one voltage output to the one or more predetermined voltages.
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Specification