Magnetostrictive waveguide position measurement apparatus with piezoceramic element

Abstract

A magnetostrictive waveguide position measuring apparatus includes a waveguide extending between opposed anchored ends. A magnet is displaceable along the waveguide and generates torsional strain in the waveguide in response to an electrical excitation signal transmitted along the waveguide. A piezoceramic element sensor is coupled to the waveguide to sense the torsional strain signal on the waveguide. A signal processor determines the relative elapsed time between the excitation signal and the output signal of the piezoceramic element to determine the position of the magnet along the waveguide. The sensor is coupled to the waveguide by a low resonance coupling medium. A differential piezoceramic element is formed of two piezoceramic elements, each coupled to the waveguide by individual coupling media, with the two elements connected in a differential parallel configuration and mechanically stressed out of phase to double the output current of the piezoceramic element or connected in a differential series configuration and mechanically stressed out of places to double the output voltage of the piezoceramic element.

Dependencies are inferred from the claim text.