GB900780A - A coincident-current switching core matrix - Google Patents

Abstract

900,780. Circuits employing bi-stable magnetic elements. TELEFUNKEN G.m.b.H. June 2, 1959 [July 3, 1958], No. 18795/59. Class 40 (9). Inductive output circuits, particularly the row and column wires of a storage matrix, are selectively energized by a positive, followed by a negative pulse which pulses are generated by switching a pair of cores associated with each output circuit, first and second cores of each pair being connected in first and second matrices, respectively, such that coincident energization of row and column wires of the first and second matrices produce the positive and negative pulse, respectively. The first and second matrices may have common row wires and their cores are biased into saturation. As shown in Fig. 3, two m X n matrices may be driven to selectively provide output in m X n output circuits. Corresponding cores in each matrix are linked by the windings such as W<SP>I</SP>, W<SP>II</SP>, connected in series with an inductive load L, as shown in Fig. 2a. By operation of one each of the row and column switches S z1 to S zm and S S1 to S Sn, and by selection of the first matrix by switch S<SP>I</SP>, the cores of the selected row and column are withdrawn from saturation under bias and the coincidently energized core at their intersection is turned over to provide a positive output pulse in winding W<SP>I</SP>. Disconnection of switch S<SP>I</SP> coincident with connection of switch S<SP>II</SP> to connect up the second matrix causes the corresponding core in the second matrix to be turned over to provide a negative output pulse in winding W<SP>II</SP>. To obtain equal value positive and negative pulses it is shown that the cores of the second matrix can be made smaller than those of the first. In the arrangement of Fig. 4a the matrices have common row wires and column wires threaded with both matrices such that energization of a column wire acts to switch one matrix but augments bias in the other matrix. Thus the equal and opposite shifts of flux in the saturation region suffered by each pair of cores of a column are additive in the output circuit and to cancel these unwanted pulses all the output circuits of each column are connected in parallel and placed in series with an inductor, Fig. 5, not shown, such that current through the selected energized load produces a voltage across the inductor to balance the unwanted voltages in the other load circuits. Unwanted pulses do not occur in the rows as energization of a row wire moves both cores of each pair from saturation to remanence in the same direction which induce opposite voltages in the load circuit.