Inductive magnetic saturation displacement sensor
First Claim
1. A position sensor system comprising:
- first part comprising a coil and a core layer on a substrate, said core layer covering at least a portion of said coil; and
a second part comprising a magnet movable substantially parallel to said coil, said magnet operable to generate a field of greater magnitude than said core layer ovcr an area substantially equivalent to said core layer such that said field defines a relative position of said first part relative said second part.
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Accused Products
Abstract
A sensor system includes a coil positioned on a thin substrate sandwiched to a layer of mumeta, a high magnetic permeability material. The mumetal acts as an amplifier for the inductance L measured at the terminals of the coil. When a magnet passes in front a sheet of mumetal, its magnetic field locally saturates the mumetal whose magnetic permeability collapses on the saturated surface. The result is a reduction of the inductance factor (L) in proportion with that area of the coil covered by the saturated mumetal. This reduction in inductance is measured at the coil terminals to provide an estimation of that area of the coil that has been covered. By determining a particular layout of the coil, mumetal, and magnet, a predetermined electrical signal of inductance or coupling variations corresponding to movement of the magnet is provided.
45 Citations
18 Claims
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1. A position sensor system comprising:
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first part comprising a coil and a core layer on a substrate, said core layer covering at least a portion of said coil; and
a second part comprising a magnet movable substantially parallel to said coil, said magnet operable to generate a field of greater magnitude than said core layer ovcr an area substantially equivalent to said core layer such that said field defines a relative position of said first part relative said second part. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A position sensor system comprising:
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a first part comprising core layer having first and a second coil and a core Iayer on a substrate, said first and second coil having a coupling therebetween, said first coil and said second coil are located on opposite sides of said core layer, saturation of said core layer by said magnet creating said coupling between said first and second coil;
an alternating current source connected to said first coil;
a signal processing device connected to said second coil and;
second part comprising a magnet movable substantially parallel to said first part to alter said coupling said magnet operable to generate a field of greater magnitude than said core layer over an area substantially equivalent to said core layer such that said field defines a relative position of said first part relative said second part.
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18. A position sensor system comprising:
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first part comprising a core layer having a first and a second coil and a core layer on a substrate, said first and second coil having a coupling therebetween;
an alternating current source connected to said first coil;
a signal processing device connected in said second coil, layer includes a first and a second core layer located on opposite sides of said substrate such that movement of said magnet reduces said coupling between said first and said second coil; and
a second part comprising a magnet movable substantially parallel to said first part to altar said coupling said magnet operable to generate a field of greater magnitude than said core layer over an area substantially equivalent to said core layer such that said field defines a relative position of said first part relative said second part.
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Specification