GB883757A - Improvements relating to the storage of digital information - Google Patents

Abstract

883,757. Digital data-storage apparatus. ROE & CO. Ltd., A. V. March 20, 1959 [March 25, 1958; June 5, 1958], Nos. 9511/58 and 17971/58. Class 106 (1). [Also in Group XL (c)] A digital data-storage unit comprises a capacitor which is charged or maintained charged at regular intervals and means for discharging the capacitor between said regular intervals. Capacitor c charges fully during the negative part of an A.C. waveform and normally, i.e. while storing the digit O, remains almost completely charged because of rectifier w during the positive part of the waveform. If, however, the digit 1 is entered by discharge of c during the positive half-cycle then c recharges during the succeeding negative half-cycle so causing transistor t to conduct and discharging capacitor c<SP>1</SP> in an associated unit which is fed with A.C. of opposite phase. The stored digit may be stepped round a closed ring in this manner. The base of the transistor may be connected through a rectifier to earth. Two units may be combined to form an OR-gate, Fig. 5, or an AND-gate, Fig: 6. Two units can also be crosscoupled, Fig. 7, so that both transistors are cut off when the circuit stores O and the transistors assume conducting state alternately when the circuit stores 1. This oscillation is maintained by a stream of pulses applied to terminal m, the stream being interrupted when the circuit is to be cleared.