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US 2004/0169505 A1Published application
Position sensor
AssigneeScientific Generics Limited
InventorsJames David Alun, Darran Kreit, Ross Peter Jones, David John Stocks
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AssigneeScientific Generics Limited
InventorsJames David Alun, Darran Kreit, Ross Peter Jones, David John Stocks
Estimating the term…
A Position Sensor comprises: one or more excitation windings; a signal generator adapted to apply excitation signals to the or each excitation winding; tag means displaceable relative to said excitation windings; one or more sensor windings electromagnetically coupled to said excitation windings such that in response to said excitation signals being applied to said excitation windings, there is generated sensed signal in the or each sensor winding; and a signal processor adapted to process said sensed signals to determine the position of said tag means in any location in the X, Y and Z planes essentially in accordance with phase values or in accordance with phase values and amplitude values.
A position sensor comprising:
A sensor according to any preceding claim, wherein the or each excitation winding comprises a plurality of essentially coplanar loops arranged so that current flowing through the excitation winding flows around at least one of the loops in an opposite direction to at least one other of the loops.
A sensor according to any preceding claim, wherein the excitation windings are essentially coplanar.
A sensor according to any preceding claim, wherein the or each tag means incorporates three sensor windings arranged essentially around orthogonal axes.
A sensor according to any preceding claim, wherein at least one of the sensor windings is a one-loop receiver winding which extends essentially in the plane of each or both sets of excitation windings X and Y and the or each tag means incorporates echoing means.
A sensor according to any preceding claim, wherein Helmholtz pairs of windings are employed to form excitation windings X and Y.
A sensor according to any preceding claim, wherein the or each excitation signal comprises a periodic carrier signal having a first frequency modulated by a periodic modulation signal having a second frequency, the first frequency being comprised within the range of 40-150 kHz and the second frequency being comprised within the range of 1-10 kHz.
A sensor according to any preceding claim, wherein the or each tag means incorporates means to modify the frequency of the sensed signals generated in the tag means' sensor windings and to transmit the modified signals.
A sensor substantially as hereinbefore described with reference to and/or illustrated in any appropriate combination of the accompanying text and drawings.
A matrix of sensors in accordance with any of the preceding claims.
Dependencies are inferred from the claim text.