GB868549A - Improvements in or relating to magnetic core storage elements - Google Patents

Abstract

868,549. Circuits employing bi-stable magnetic elements. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. July 7, 1959 [July 21, 1958], No. 23401/58. Class 40 (9). [Also in Group XXXV] In order to reduce the flux switching time of a square loop ferrite core 1 (Fig. 4), it is tightly coupled by a winding 3 to an auxiliary core 2. The dimensions of cores 1 and 2, the materials of which they are made and the numbers of turns of the coupling winding 3 which link with each core are so related that while switching of the core 1 from saturation in one direction to saturation in the other direction produces in core 2 only a fraction of the maximum change of flux density of which it is capable, the flux change produced in core 2 requires a substantially greater coercive current to produce it than is required for the switching of core 1. The ratio of the changes of flux density in core 2, to the maximum change possible in that core may be the same as the ratio of the coercive current needed by core 1 to that needed by core 2. The main core 1<SP>1</SP> (Fig. 6), may be arranged within the auxiliary core 2<SP>1</SP> for use in a matrix store, a smaller drive current being then required. The output conductor 5<SP>1</SP> may be linked with both cores or only with the auxiliary core 2<SP>1</SP> and may carry inhibit or partial drive currents for storing information in a coincident current matrix store. The coupling loop 3<SP>11</SP> (Fig. 7), may form part of the input winding 411 so that in a matrix store, the input conductors of storage elements mounted in parallel can be connected in series, each loop 3<SP>11</SP> being a metallic band which abuts against the bands of the two corresponding elements in the adjacent planes. The invention can be applied to multi-dimensional matrix stores, magnetic shift and scaling circuits and logical circuits. Long thin bar cores may be used instead of ring cores.