Patent · US Expired

Magnetostrictive torque sensor air gap compensator

US5495774A · kind A · utility

16Cited by
11References
14Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 5, 1994
Grant dateMar 5, 1996
Priority date
Expiry dateApr 5, 2014

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB60G2800/802
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

Disclosed are a method and apparatus for minimizing or eliminating the effect of air gap variation on the output signal of a magnetostrictive stress/torque signal. An RLC drive circuit is utilized by choosing appropriate circuit parameters and drive frequency such that the flux reducing effect from increasing air gap due to increase in magnetic reluctance is offset by a flux increasing effect from a concomitant reduction in eddy currents. The invention is particularly suited to cross design magnetostrictive sensors and to automotive engine diagnostics applications such as misfire, knock, and roughness detection.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.