Linear position sensor

摘要

In a linear position encoder, a support is provided upon which a pair of phase quadrature windings are mounted. The windings are arranged to have a sinusoidal magnetic sensitivity characteristic along the length of the support. Mounted on a movable element there is a resonant circuit including a coil and capacitor that can magnetically couple with the windings. When the circuit is excited, it induces currents in the windings that are dependent upon the position of the circuit within a period T_s of the windings. An excitation and processing unit is provided to energize the circuit and to process the signals induced in the windings. The excitation and processing unit is operably coupled to an external high permeability rod extending along the measurement path in a first plane having the windings but removed therefrom. The rod has first and second excitation coils connected in series and wound around the rod and disposed at opposite ends defining a length of the rod.