Patent GB-1040142-A (GB)
IPC: G11C11/06
Abstract: 1,040,142. Magnetic storage devices. WESTERN ELECTRIC CO, Inc. March 14, 1963 [March 15, 1962], No. 10094/63. Heading H3B. In a magnetic storage matrix in which the distributed capacitance between adjacent and parallel inhibit and sense conductors I, S, Fig. 1, causes noise signals of different configurations to be coupled to various sections of the sense conductor when the inhibit conductor is pulsed, a pattern of direct and reversed couplings is provided between the various sections of the two conductors to minimize the coupled noise. The matrix comprises a stack of multi-apertured ferrite plates 21 which is wired in three planes by inhibit and sense conductors I, S, select conductors x, and select conductors y, respectively. Switching of the flux about any aperture in a y plane is effected by coincidently applying half-select pulses to the appropriate x and y conductors. If the flux is not to be switched about any aperture in the plane the associated inhibit winding I is pulsed simultaneously. The inhibit pulses are applied from a source 26 through a transformer 32, and the output in a sense conductor is detected by an amplifier 28 after passing through a transformer 33 and low-pass filter 27. The x conductors may each be a printed conductive strip, Fig. 2, passing through each aperture in association with the y select, inhibit I and sense S conductors. The winding pattern for minimizing capacitive-coupled noise is used in Fig. 1 and is shown more clearly in Fig. 5A-5F. Fig. 5A shows how the inhibit pulse is deformed and reformed during transmission due to the distributed capacitive coupling with the sense conductor, Fig. 5B shows the loops of the inhibit conductor as viewed from the rear of the matrix and Fig. 5C shows the corresponding loops of the sense conductor. By winding the sense winding in the combined progressive and retrogressive manner shown, capacitive couplings between sections of the sense and inhibit conductors are in forward and reverse order as indicated by the respective letters a and b in Fig. 5D. As the inhibit pulse deformation changes along the conductor, the overall coupled noise for respective groups of conductor sections A is not the same and is indicated at A +, A<SP>1</SP> + and A - , A<SP>1</SP> - in Fig. 5E. These groups in turn are in forward and reversed relationship to give an overall suppression pattern for resultant noise signals as indicated by B +, B<SP>1</SP> + and B -, B<SP>1</SP> - in Fig. 5F. A modification is described, Figs. 11-13, in which the matrix is formed by two submatrices, each inhibit and sense conductor I.S. being common to a row in each submatrix such as row i and row (i + 1) as shown in Fig. 11. The various sense conductor sections are arranged in forward and reversed groups as previously described to give an overall suppression pattern indicated by B +, B<SP>1</SP> + and B - B<SP>1</SP> - . In a modification, Fig. 12, the sense conductor threading the two rows is crossed over at the centre of each row, this arrangement being stated to minimize the effects of capacitive coupling between the conductor loops. An alternative arrangement is shown in Fig. 13 in which the pattern B +, B<SP>1</SP> + and B -, B<SP>1</SP> - is changed to reduce noise arising from capacitive coupling with conductors in adjacent rows.