Inductive joystick and signal processing circuit therefor
First Claim
1. An inductive joystick, comprising a movable actuator which is provided with an element of electrically conductive material of low magnetic permeability, a pair of secondary coils for respective axes of deflection of said actuator, and a primary induction coil for inducing signals in said secondary coils, said primary induction coil being positioned to encircle said secondary coils and said actuator being arranged so that its said electrically conductive element is positioned within the magnetic field of the primary induction coil and is deflected relative to said secondary coils upon movement of said actuator.
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Accused Products
Abstract
An inductive joystick includes a movable actuator which carries an element of electrically conductive low magnetic permeability material (e.g., copper or aluminum), such that movement of the actuator differentially affects the coupling between a primary coil and a pair of secondary coils which are encircled by the primary coil. The arrangement provides a desirable output characteristic, in which the minimum output of each secondary coil is preferably greater than the maximum difference between the outputs of the two secondary coils, useful for detecting component failure. The secondary coils are preferably connected in a processing circuit which rectifies the outputs of the two coils before combining them to form a resultant "difference" output.
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Citations
17 Claims
- 1. An inductive joystick, comprising a movable actuator which is provided with an element of electrically conductive material of low magnetic permeability, a pair of secondary coils for respective axes of deflection of said actuator, and a primary induction coil for inducing signals in said secondary coils, said primary induction coil being positioned to encircle said secondary coils and said actuator being arranged so that its said electrically conductive element is positioned within the magnetic field of the primary induction coil and is deflected relative to said secondary coils upon movement of said actuator.
- 8. An electronic circuit for an inductive joystick, comprising a primary induction coil and at least one secondary circuit, said secondary circuit including a first coil and a second coil, said first coil having a first output and said second coil having a second output, a first rectifying means connected to said first output and providing a first rectified signal, a second rectifying means connected to said second output and providing a second rectified signal, and combining means connected to said first and second rectifying means for receiving said first and second signals and providing a resultant signal according to the difference between said first and second rectified signals and representing the deflection of an actuator of said joystick, each of said first and second rectified signals being greater than the maximum differences between said first and second rectified signals in the absence of a fault in said at least one secondary circuit.
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16. An electronic circuit as claimed in 8, wherein:
in the absence of a fault in said at least one secondary circuit, each of said first and second rectified signals is at least 1.5 times the maximum difference between said first and second rectified signals.
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17. An inductive joystick, comprising:
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a movable actuator which is provided with an element of electrically conductive material of low magnetic permeability, a pair of secondary coils for respective axes of deflection of said actuator, and a primary induction coil for inducing signals in said secondary coils, said primary induction coil being positioned to encircle said secondary coils, and said actuator being arranged so that said element is positioned within a magnetic field of said primary induction coil and is deflected relative to said secondary coils upon movement of said actuator, said pair of secondary coils being included in an electronic circuit having a combining means and a pair of rectifying means connecting the outputs of the respective secondary coils to said combining means, said combining means providing a resultant signal according to the difference between the outputs of said pair of secondary coils and representing the deflection of said actuator.
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Specification