GB962618A - Circuit for controlling a ferrite-core storage arrangement - Google Patents

Abstract

962,618. Magnetic storage circuits. STANDARD TELEPHONES & CABLES Ltd. March 1, 1963 [March 6, 1962], No. 8320/63. Heading H3B. The row and column circuits of a magnetic storage matrix are connected through a transformer to a high impedance current source, and any circuit discontinuity is signalled by an indicator which responds to abnormal increase in potential across the transformer. As shown in Fig. 2, the current source comprises a transistor T1 controlled by clock pulses at terminal E, and a transformer U couples the current source to the row and column selectors. If a fault occurs, the abnormal potential at terminal A fires a transistor T2, Fig. 4, and a potential is obtained at terminal B which operates the indicator through a bi-stable trigger circuit (not shown). An R, C integrating circuit is provided to prevent faulty operation by switching transients. The indicator is released by manually resetting the trigger circuit. To facilitate location of the fault in arrangements where row and column circuits are sequentially energized under the control of counters, Fig. 6 (not shown), the counter positions are shown in an indicating device which is disconnected automatically if a fault occurs. Separate transformers may be provided for the row and column circuits, Fig. 8, the respective transformer potential terminals A1, A2 being connected through a rectifier OR gate D1, D2 to transistor T2.