Abstract: 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.

Abstract: An inductive detector for measuring the position of a first body relative to a second body along a measurement path comprises: a first body which comprises a substantially planar surface and a passive electromagnetic target; a second body which comprises a substantially planar surface facing the planar surface of the first body and an arrangement of laminar windings; said first and second body being configured such that the electromagnetic influence of the first body on the second body varies according to the position of the first body relative to the second body along the measurement path; wherein said passive electro-magnetic target comprises a first portion incorporating said planar surface and a second portion with a lower thickness than said first portion; whereby the second portion incorporates an insulating aperture.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An inductive detector operable to measure displacement along a path comprises: a first inductive arrangement; a second inductive arrangement; said second inductive arrangement being spaced from said first inductive arrangement and extending along at least part of the measurement path; at least one of said inductive arrangements comprises a winding which extends along at least part of the measurement path; and said winding comprising at least four loops in electrical series; wherein adjacent loops have opposite magnetic polarity; and the pitch distance of said winding varies at least once along the measurement path.

Abstract: An inductive detector for measuring the position of a first body relative to a second body along a measurement path comprises: a first body which comprises a substantially planar surface and a passive electromagnetic target; a second body which comprises a substantially planar surface facing the planar surface of the first body and an arrangement of laminar windings; said first and second body being configured such that the electromagnetic influence of the first body on the second body varies according to the position of the first body relative to the second body along the measurement path; wherein said passive electro-magnetic target comprises a first portion incorporating said planar surface and a second portion with a lower thickness than said first portion; whereby the second portion incorporates an insulating aperture.

Abstract: An apparatus for user interfaces is described to measure inductively the deformation of a body (1) comprising at least two laminar conductive elements (3, 4), at least one of which is an AC energized inductor (4), wherein deformation causes relative axial movement between the at least two laminar elements (3, 4) and the maximum deformation distance is limited to prevent damage.

Abstract: An inductive detector operable to measure displacement along a path comprises: a first inductive arrangement; a second inductive arrangement; said second inductive arrangement being spaced from said first inductive arrangement and extending along at least part of the measurement path; at least one of said inductive arrangements comprises a winding which extends along at least part of the measurement path; and said winding comprising at least four loops in electrical series; wherein adjacent loops have opposite magnetic polarity; and the pitch distance of said winding varies at least once along the measurement path.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A detector for measuring relative position along a measurement path comprising: a passive, laminar electrical intermediate device extending along the measurement path wherein the extent of the said electrical intermediate device in an axis normal to the measurement path varies along the measurement axis; at least one laminar transmit winding and at least two laminar receive windings wherein the said at least two laminar receive windings are displaced from each other along the measurement path wherein each laminar receive winding is substantially electrically balanced with respect to the at least one laminar transmit winding; arranged such that the mutual inductance between at least one laminar transmit winding and at least two laminar receive windings indicates the relative position of the electrical intermediate device.

Abstract: 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.

Abstract: 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.

Abstract: A low cost, high performance method and apparatus for identifying electrical intermediate devices and measuring their position relative to an antenna is provided. The technique preferably uses electrical intermediate devices co-operating with AC energized antennae. The resulting electrical data can be used in a wide variety of user interfaces, identification systems and sensors to measure, for example, rotary position, linear position, weight, level, torque, vibration, turbidity and flow. The invention includes means for the contactless transmission of data and power to general instrumentation.