Patent ID: 7932715

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