Patent GB-1026064-A (GB)
Title: Multi-aperture magnetic core
IPC: H03K3/51
Filed: 1964-07-15
Abstract: 1,026,064. Magnetic storage apparatus. AMP Inc. July 15, 1964 [July 16, 1963], No. 29035/64. Heading H3B. [Also in Divisions G4 and H1] At least three of the minor apertures of a rectangular loop multi-aperture magnetic storage core are of different dimensions so that the magnetic circuits around them have different remanent flux storage capacities. The crosssectional area of the core material at the largest aperture 5 (Figs. 2 and 2A) is the smallest cross-sectional area of the core so that, after the core flux has been rendered clockwise by a pulse in clearing winding 39 (the " O " state) the application of an input pulse in winding 48 (Fig. 2A) reverses only the flux around the major aperture 12 inside the minor apertures. The "1" output pulse then produced in winding 28 by a clearing pulse in winding 39 following a priming pulse in winding 38 is of a minimum value (A in Fig. 3a, not shown) which is not dependent on the value of the original input pulse in 48 but is high in relation to the spurious output pulse obtainable at aperture 5 from winding 28 on clearing when a "O" is recorded in the core, this giving a high discrimination ratio. In the case of the smallest aperture 4 the input pulse switches flux about aperture 4 as well as around the major aperture 12 (" flux clipping ") so that on clearing for read-out appreciably more flux is switched at aperture 4 than was the case at aperture 5 and a much larger output is obtained on clearing but the discrimination ratio is lower (Fig. 3f, not shown). At the aperture 1 and the two equal apertures 2, 3, which are smaller than 5 but larger than 4 some " flux dipping " is obtainable through less than at 4. Shift registers.-In a shift register as described in Specification 899,367, comprising two coaxial sets of cores 10, shown end on in Fig. 4, the input aperture 3 is chosen to give an intermediate amount of flux clipping to compensate for variations in the power supply to the shift register. The output aperture 5- providing no flux clipping gives the highest obtainable discrimination ratio to reduce the tendency for spurious signals to be transmitted on "O" read-out to the right-hand core 10. The effect of any such spurious signals is reduced by connecting the transfer winding 54 to an aperture 2 in the right-hand core 10 providing substantial flux clipping. The aperture 5 of the right-hand core 10 is connected by the transfer winding 58 to aperture 2 of the succeeding core 10 behind the left-hand core 10 shown in Fig. 4 and the remaining cores of the shift register are coupled in a similar manner. The cores may be similarly oriented in relation to the insulating panel in which they are held and may have output windings for actuating signal lamps with radio frequency signals (Fig. 5, not shown). The two sets of cores may be arranged with selected minor aperture in axial alignment for the passage of transfer windings and may have a common priming winding through the aligned minor apertures (Figs. 6 and 7, not shown), data being transferable in either direction as described in Specification 939,673. Data treatment apparatus is described (Fig. 8, not shown), in which input device 80 may be the outlet of a telemetry receiver and input device 82 a message address source having a "O" to "1" discrimination ration greater than than that of 80; the latter is therefore coupled to aperture 1 which has a higher discrimination ratio than aperture 4 to which 82 is coupled. Data from 80, 82 is stored in core 10 from which it is fed selectively to shift registers 90, 92, each having cores identical with core 10. Signal lamp 84 shows the instantaneous state of the core. Advance windings 100, 101 are energized alternately. Priming source 88 is energized for transfer of data from core 10 to shift register 92 for transmission to heavy duty relay 96 which is coupled, e.g. with the aid of an audio-frequency read-out winding, through an aperture 4 of the last core in register 92 since it needs high " 1 " signals to actuate it. For transfer to a voltage sensitive device 94, source 86 is activated, coupling being through an aperture 5 in the last core of 90 since 94 requires a high discrimination ratio.