Patent GB-956111-A (GB)
Title: Load selecting apparatus
IPC: G11C19/06
Filed: 1962-11-22
Abstract: 956,111. Circuits employing magnetic storage elements. AMP Inc. Nov. 22, 1962 [Dec. 1, 1961], No. 44140/62. Heading H3B. [Also in Division G4] An arrangement for selectively energizing one of a number of loads comprises groups of cores each consisting of at least two cores in cascade, each core having a plurality of apertures and three states of magnetic remanence to which it is switched in turn by respective driving sources, the cycle of three stable states being passed from core to core in a group in response to sequential energization by the driving sources, the order of driving energization being different for each group of cores. An arrangement of one group of cores is shown in Fig. 2 in which toroidal cores 13-15 are coupled by transfer windings 22, 23 wound through respective transmit minor apertures 18 and major apertures 16. Each core has an initial clear state in which the flux is unidirectional around the major aperture, a set state in which the flux is unidirectional about the transmit aperture, a priming state in which the direction of flux about the transmit minor aperture is reversed and a reset condition in which the flux is restored to the set state. Setting of the first core 13 is effected by driving source A<SP>11</SP> energizing set winding 19, priming of all the cores is carried out by driving sources B<SP>11</SP>, D<SP>11</SP>, F<SP>11</SP> energizing respective priming windings 20, and resetting of the cores is effected by current from driving sources C<SP>11</SP>, E<SP>11</SP>, G<SP>11</SP> in resetting windings 21. If the driving sources are sequentially energized in the order A<SP>11</SP> to G<SP>11</SP>, the first core 13 is set, primed and reset, and similar conditions are obtained in sequence in the cores 14 and 15 so as to eventually apply an output pulse to a load 26. The operating cycle may be repeated when the cores are reestablished in the clear state by a pulse in a common clear winding (not shown). Other groups of cores have the drive sources A<SP>11</SP> to G<SP>11</SP> connected to the windings 19-21 in different orders so that a unique order code from the combination A<SP>11</SP> to G<SP>11</SP> applies to each core group. In a modification, Fig. 4, the priming phase is not used and cores 47, 48, 49 produce an output pulse in load 55 when the cores are first cleared by a common winding (not shown), core 47 is set by a driving source A2, cores 48 and 49 are set by respective driving sources B2 and C2, and the three pulse sources are then energized simultaneously. Fig. 3 shows the basis of an arrangement in which an order code of 5 out of 6 driving sources is used. Two loads 24L, 25L are shown, and the wiring is arranged in conjunction with cores 27-30 having four minor apertures only two, 31, 32, of which are used. Driving sources A1-F1 are connected to windings 35, 37 and 42 to 46 which are arranged so that source A1 resets core 29, B1 resets cores 28 and 30, C1 resets core 27, D1 primes cores 28 and 29, E1 sets core 27 and primes 30, and source F1 primes 27 and sets core 29. With the winding arrangement load 24L is energized if the sources are operated in the order E1, F1, C1, D1, B], and load 25L is energized if the order is F1. D1, A1, El, B1. A common clearing winding is used (not shown). A further embodiment is shown in Fig. 5 in which three out of four sources A, B, C, D are selectively energized in turn to switch a load core 83, the order code being indicated against each core. Thus to switch load core BDA, source B is first energized to set a core 62 in a first stage comprising cores 61-64. When source D is subsequently energized, core 64 is set and at the same time core 72C in the second stage of cores 70A-73C is set from core 62, the drive current from D passing through conductor 88 to a transfer winding on each of the first stage cores. Energization of source A sets core 61, and the driving pulse passes through conductor 85 to a transfer winding linking core 72C to the load core DA, so causing the load core to be switched. A common clearing winding (not shown) is used. The sources may be controlled from a keyboard. Specification 899,366 is referred to.