Other

Tt Electronics Technology Limited

Zettlex (uk) Limited

Sensopad Limited

Kreit, Darran

Howard, Mark Anthony

Darran Kreit

Mark Anthony Howard

Colin Stuart Sills

David Alun James

Ross Jones

Richard Allen Doyle

An inductive detector is provided for measuring the relative position of bodies along a measurement path comprising: an inductive target arranged along the measurement path; a laminar antenna arranged facing a portion of the target; an electronics circuit arranged along the measurement path; wherein, the inductance of at least one winding in the antenna varies continuously in proportion to the relative position of target and antenna.

Inductive position detector

An inductive position detector with a first and second body, at least one of said bodies being displaceable relative to the other along a measurement path wherein said first body comprises one or more antenna windings forming a first arrangement of windings and said second body comprises a passive resonant circuit incorporating one or more target windings in series with a capacitor; said circuit covering at least in part said first arrangement; characterized in that said first body comprises an additional winding arrangement disposed along at least part of said measurement path; said additional winding arrangement being spaced from said first arrangement of windings; and said second body comprises an additional winding arrangement covering at least in part said additional winding arrangement of said first body.

A detector to measure the displacement of relatively moveable bodies along an axis comprising: a resonant electrical intermediate device further comprising an inductor, whose width varies along the displacement axis, and a capacitor in electrical series which co-operates with an antenna comprising transmit and receive windings whose mutual inductance varies according to the position of the electrical intermediate device relative to the antenna.

Inductive position sensor

An inductive detector operable to measure displacement along a path comprises:

Detector

An apparatus for user interfaces is described to measure inductively the deformation of a body () comprising at least two laminar conductive elements (), at least one of which is an AC energized inductor (), wherein deformation causes relative axial movement between the at least two laminar elements () and the maximum deformation distance is limited to prevent damage.

Pressure sensitive inductive detector for use in user interfaces

An inductive detector arranged to measure position along a axis comprising: a transmit winding; a receive winding; a passive circuit comprising a winding in electrical series with a capacitor; wherein: the mutual inductance between the transmit winding and the receive winding is a function of the relative displacement of the passive circuit along the measurement axis; a first portion of one of the windings is wound on a first pitch and a second portion of the same winding is wound on a second pitch whose extent is greater than the first pitch.

A system to measure the displacement of relatively moveable bodies along an axis comprising: a resonant electrical intermediate device further comprising an inductor, whose width varies along the displacement axis, and a capacitor in electrical series which co-operates with an antenna comprising transmit and receive windings whose mutual inductance varies according to the position of the electrical intermediate device relative to the antenna.

A device for measuring the position of a first body relative to a second body comprising: a first body which further comprises an electrical intermediate device; a second body which further comprises at least two inductors energised with an alternating current and at least one of which is formed by a planar spiral winding on a printed circuit board normal to the measurement axis and attached to the second body; arranged such that displacement of the electrical intermediate device causes a change in inductance of the planar spiral winding and whereby measurement of the ratio of the inductances indicates the position of the first body relative to the second.

An inductive detector operable to measure relative displacement along a measurement path of a first body including an electrical intermediate device and a second body including at least three windings. At least one winding is a transmit winding and at least one other is a receive winding. The windings are arranged such that relative displacement of the two bodies causes a change in inductive coupling between at least one transmit winding and at least one receive winding. At least two windings are formed by a convoluted conductor with a first portion extending along the measurement path on a first surface of the substrate and a second portion returning back along the measurement path on an opposite second surface of the substrate. The first and second portions are connected via a connection extending between the first and second surfaces. Each convoluted conductor forms a series of loops defined between the portions on the first and second surfaces, the width of each loop varying along the measurement path and adjacent loops having opposite electromagnetic polarity. At least two windings are spaced in an axis normal to the measurement path.

Inductive detector with variable width loops on first and second surfaces of substrate

A sensor for sensing a parameter such as position, comprises: (i) an excitation winding for example coils () in quadrature; (ii) a signal generator () operable to generate an excitation signals and arranged to apply the generated excitation signal to the excitation winding; (iii) a sense coil () that can be electromagnetically coupled to the excitation winding such that, in response to the excitation signal being applied to the excitation winding by the signal generator, a periodic electric signal is generated in the sense coil that is indicative of the value of the parameter to be measured by the sensor; and (iv) a signal processor () operable to process the periodic electric signal generated in the sensor winding to determine a value representative of the parameter being measured. The signal processor may be arranged to generate a second signal (f) at a frequency slightly different from that of the excitation signal, and to mix the second signal with the signal received from the sense coil to generate a third signal having a frequency component (f&#x2212;f) equal to the difference between the frequency of the excitation signal and that of the second signal. The processing unit then determines the parameter from the phase of the third signal.

Sensing apparatus and method

There is described a sensing apparatus comprising first and second members which are supported relative to each other by a support means. The first member comprises a magnetic field generator for generating a magnetic field and the second member comprises an aerial for monitoring the magnetic field generated by the magnetic field generator. At least one of the first and second members is locally deformable relative to the other of the first and second members in order to vary at least one of the magnetic field generated by the magnetic field generator and the electromagnetic coupling between the magnetic field generator and the receive aerial so that, in response to a local deformation, a signal is induced in the receive aerial indicative of the position of the local deformation.

There is described a sensor comprising an excitation winding, a signal generator operable to generate an excitation signal and arranged to apply the generated excitation signal to the excitation winding, a sensor winding electromagnetically coupled to the excitation winding and a signal processor operable to process a periodic electric signal generated in the sensor winding when the excitation signal is applied to the excitation winding by the signal generator to determine a value of a sensed parameter. The 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 greater than the second frequency. In this way, the sensor is well suited to using digital processing techniques both to generate the excitation signal and to process the signal induced in the sensor windings. In an embodiment, the sensor is used to detect the relative position of two members. In other embodiments, the sensor is used to detect environmental factors such as temperature and humidity.

There is described an inductive position sensor in which a signal generator applies a excitation signal to an excitation winding formed on a first member, the excitation winding being electromagnetically coupled to at least two resonant circuits formed on a second member which are spaced from each other along a measurement path. The excitation windings are shaped so that the electromagnetic coupling between the exciting winding and each of the resonators varies along the measurement path. In this way, by applying an excitation signal to the excitation winding, respective different signals are induced in the resonators which depend upon the relative position of the first and second members.

Position sensing apparatus and method

There is described an inductive sensor for sensing a parameter such as position. The inductive sensor includes: receive aerial which is electro-magnetically coupled to a magnetic field generator via a resonant circuit with the electromagnetic coupling varying in dependence upon the sensed parameter so that a sense signal induced in the receive aerial is representative of the sensed parameter. The magnetic field generator generates a magnetic field including a first magnetic field component at a first frequency which is operable to induce resonance in the resonant circuit and a second magnetic field component at a second frequency which is not operable to induce resonance in the resonant circuit. The signal processor processes the sense signal to generate a signal component corresponding to a first component of the sense signal at the first frequency adjusted using a second component of the sense signal at the second frequency so that a noise component of the first component of the sense signal is reduced, and determines a value representative of the sensed parameter using the signal component.

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Foxton, United Kingdom

Darran Kreit