Patent · US Expired

Permanent magnet biased magnetostrictive transducer

US4703464A · kind A · utility

10Cited by
9References
21Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 10, 1985
Grant dateOct 27, 1987
Priority date
Expiry dateMay 10, 2005

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04R15/00
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A transducer which uses paramagnetic magnetostrictive rods or bars, e.g., compositions of the lanthanide series of elements such as Tb.sub.0.3 Dy.sub.0.7 Fe.sub.2, has the bars biased with a lengthwise flux by a permanent magnet, e.g. samarium-colbalt, of high resistance to demagnetization by the alternating field applied to the bars by alternating current in a coil surrounding the bar. The magnet is outside the coil to reduce the ac field to which it is subjected. Uniformity of flux density along the length of the bars is enhanced by having adjacent ends of the bars subjected to like-polarity poles of the permanent magnets associated with each bar.

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