Patent ID: 6583615
Filing Date: 2003-06-24
Classification: G01D

Abstract:
A magnetostrictive sensor device comprising:a delay line; a pulse generator coupled to the delay line for periodically generating electrical current pulses in the delay line from an initial starting time; a magnet located proximate the delay line for converting the current pulses propagating in the delay line into acoustic pulses propagating in the delay line; a mode converter coupled to the delay line for detecting the acoustic pulses and converting the acoustic pulses into corresponding mode converter signals, each having an electrical voltage indicative of the corresponding acoustic pulse; a reference voltage signal generator for generating a reference voltage signal having an electrical voltage which increases in accordance with a known function over time from the initial starting time; a comparator coupled to the mode converter and the reference voltage signal generator for comparing each mode converter signal to the reference voltage signal, wherein the comparator switches when the voltage of a mode converter signal at a given time after the initial starting time becomes equal to the voltage of the reference voltage signal, wherein the comparator switches a second time when the voltage of the next mode converter signal occurring after the given time is equal to the voltage of the reference voltage signal; and a logic component coupled to the comparator and the reference voltage generator, wherein the logic component causes the reference voltage generator to maintain the voltage of the reference voltage signal upon the comparator switching at the given time, the logic component being operable for, upon the comparator switching the second time, outputting an output signal indicative of the given time and the time period between the mode converter signal at the given time and the next succeeding mode converter signal occurring after the given time; wherein the voltage of the mode converter signal at the given time is determined using the known function and the given time indication provided by the output signal.