GB896714A - Electromechanical signal translating devices - Google Patents

Abstract

896,714. Magnetostrictive data-storage devices. WESTERN ELECTRIC CO. Inc. Feb. 23, 1959 [March 19, 1958], No. 6102/59. Class 106 (1). [Also in Group XL (b)] An information storage device comprises a magnetostrictive member 40, positioning means 51 for determining the spacing and/or polarity of a plurality of movable magnets 42-49 and thus setting up a pattern of bifurcated longitudinal magnetic fields in the member 40 in accordance with signals from a data source 50, and a read-out signal source 41. If the member 40 is sufficiently retentive the magnets need be placed only momentarily in contact with or close proximity to the member to establish a pattern of remanent magnetic induction. The read-out source 41 supplies a single current pulse which produces a circumferential magnetic field throughout the length of member 40, thus producing a torsional strain impulse in each portion of member 40 conditioned by the presence of a longitudinal field. The torsional impulses propagate in member 40 and on arrival sequentially under an output winding 12 distort the remanent circumferential magnetization to produce a sequence of longitudinal field variations which link the winding and induce voltage pulses which are passed to a utilization circuit 13. Destructive or non- destructive read-out is obtainable depending on the amplitude of the pulse supplied by source 41. In an alternative embodiment (Fig. 5, not shown), suitable for use if the member 40 has no retentive properties, the circumferential field in the region of the winding 12 is produced by a biasing source, and the data source is arranged to selectively energize a plurality of electromagnets.