GB635704A - Improvements in and relating to magnetostriction oscillators - Google Patents

Abstract

635,704. Subaqueous signalling-apparatus. ROUND, H. J., and BUCKINGHAM, J. Feb. 1, 1947, No. 3118. [Class 118 (ii)] [Also in Group XXXIX] A magnetostrictive oscillator comprises a laminated nickel rod 1, Fig. 1, of square crosssection, with a square and radiating plate 2 of the metal known by the Registered Trade Mark " Monel Metal," which replaces, as far as natural period is concerned, approximately one quarter of the length of the rod and has a mass equal to approximately one-third of that of the rod. Alternatively, the end-plate and rod are formed by assembling laminations of the form shown in Fig. 4. With regard to partially closing the magnetic circuit, reference is made to Specification 572,500, [Group XXXIX]. In Fig. 5, two oscillator units are energized in opposite directions by windings 9 and polarized in opposite directions by magnets 10 and 11, and are provided with jumpers 12 of laminated low-loss iron alloy. Various arrays, Figs. 6 and 7, of oscillator units are described, in which the windings of individual units or groups may be of different numbers or turns or be in opposite senses or separately excited, so as to produce outputs of different amplitude or phase. In the array shown in Fig. 6, the rod 13 of a unit is attached to the back-plate by a wire 19 soldered at one end to the rod at a nodal point and bent over at the other end behind the back-plate. Loss of radiation from the back of the unit is reduced by cellular rubber blocks 20, 21, Fig. 5, as described in Specification 635,705.