GB803300A - Improvements in or relating to intelligence storage equipment - Google Patents

Abstract

803,300. Controlled non-linear inductors. STANDARD TELEPHONES & CABLES, Ltd. July 13, 1956, No. 21804/56. Class 40 (9). A magnetic switching arrangement which sequentially applies full amplitude read and half amplitude write pulses to each row lead of a magnetic information storage matrix comprises cores 1A-9A, 1B-9B having substantially rectangular hysteresis characteristics which are positioned in columns and rows with a pair of cores such as 1A, 1B located at each intersection, a selected core being driven from a normally saturated condition into the unsaturated region by triple coincidence of pulses applied to a column winding W4, a row winding W3 and a " pair " winding W2 whereby the core provides an effective electromagnetic coupling to an output winding W1. Two sets of "pair" windings are provided, one being associated. with the A cores and the other with the B cores, and the windings are alternately energized over leads T1, T2 by pulses t1, t2, each having a duration corresponding to the read and half-write pulse period. The column and row windings are also energized over leads C1-C3 and R1-R3 respectively by pulses c1-c3 and r1-r3 having durations and time positions as shown in Fig. 2, the pattern of pulse energization establishing cycles in which each core of the switch is desaturated in turn in the order 1A, 1B, 2A, 2B ... 9A, 9B by triple coincidence of pulses in the C, R and T leads. These pulses act in opposition in the leads to continuous biasing currents which normally maintain the cores in the saturated state. A single lead which threads all the cores of the switch and is not shown in Fig. 1, is energized by read and half-write pulses which are transferred to the output winding W1 of an unsaturated core, each output winding being connected to an individual row lead of the storage matrix which are arranged in two separate groups U and L. The storage cores are constituted by separate holes in a common ferrite block or plate and are arranged such that certain cores are associated with a single row and a single column lead, such as those cores threaded by column leads CW1, CWN, whereas two row leads are associated with other cores such as those threaded by column lead CW2.