Patent GB-1105513-A (GB)
Title: Improvements in or relating to magnetic core devices
Inventor: RICKARD BRYAN WILLIAM
IPC: G11C11/08
Filed: 1965-01-15
Abstract: 1,105,513. Circuits employing bi-stable magnetic elements. GENERAL ELECTRIC CO. Ltd. 17 Jan., 1966 [15 Jan., 1965], No. 2023/65. Heading H3B. [Also in Division H1] In a two-aperture transfluxor the state of the device is interrogated by an interrogate conductor extending through one of the apertures and a reset conductor extending through both apertures in opposite directions, both conductors being arranged to, carry unidirectional current and the setting conductor constitutes the sense conductor. The basic device is as shown in Fig. 1 and in operation the core is first placed in a blocked state indicative of a binary " 0 " and having a flux pattern as shown by current through winding 7. The core is then placed in a set state, Fig. 2 (not shown), indicative of a binary " " by simultaneously applying half set pulses to windings 8, 9 which pulses partially reverse flux round aperture 2 so that the flux relative to aperture 3 is in opposite directions. A subsequent pulse on reset conductor 13 reverses the flux around aperture 3, Fig. 3 (not shown), and produces a kidney-shaped flux pattern around aperture 2. This reversal of flux produces an output signal in select conductor 9. The next pulse on interrogate conductor 12 re-establishes the " set " flux pattern of Fig. 2. If the core is in its blocked state pulses applied to conductors 12, 13 have no effect on the flux pattern and no output signal is induced in winding 9. By using correctly polarized unidirectional pulses for the interrogate function the possibility of excessive currents through the read aperture 3 unblocking the core are obviated. In order to remove the possibility of reset pulses disturbing the blocked state the reset winding 13 is wound as shown. Matrix.-Fig. 4 shows one plane of a matrix comprising a plurality of transfluxors, the transfluxors being arranged on edge and at 45 degrees to the edge of the matrix plane. The columns are arranged in groups 14 of eight every transfluxor having the same wiring arrangement as shown in Fig. 1. The block winding 7 and reset winding 13 thread the write apertures of all the transfluxors of a group 14. The windings 9 thread all the 64 transfluxors in a row and by means of edge connections all the corresponding rows in the 16 planes, Fig. 6 (not shown). Any element is selected to store a digit by applying set pulses only to the two set conductors 8, 9 which intersect at that element. Since each column includes 4 words of 20 digits each word and parallel read out is employed only 20 outputs are required the necessary selection is effected in the input stage of each read amplifier. Fig. 5 (not shown) illustrates the vertical connections of the interrogate conductors 12. The read amplifier, Fig. 7, comprises four input stages 25 and each read amplifier corresponds to a particular one of twenty digits and has to select one of four simultaneous signals, one from each word. Each group of four adjacent H. H. S/sense conductors 9 are connected together at one end and to a common input lead 33 of the four stages and the other ends are connected to respective inputs 34 of the four input stages. Both transistors 26, 27 are normally non-conducting and in operation negativegoing strobe pulses are applied sequentially to the four input stages on leads 31 of all twenty read amplifiers in parallel. At the end of the strobe pulse period the change of collector potentials of transistors 26, 27 and their difference on leads 44 indicates the flux switched during interrogation and is produced as a square output pulse on lead 54.