GB780449A - Binary counting circuits - Google Patents

Abstract

780,449. Electronic counting apparatus. NATIONAL CASH REGISTER CO. March 30, 1955 [May 3, 1954], No. 9231/55. Class 106 (1). [Also in Groups XXXIX and XL (c)] In an electric binary counting circuit comprising serially connected bi-stable ferroresonant devices representing successive binary stages, each device having a single trigger pulse input circuit, an output circuit of each device is connected to the input circuit of the succeeding device through a control circuit including a coincidence gate controlled by one or more potentials derived from preceding device(s) and by negatively going voltage pulses to be counted simultaneously supplied to each gate, the gate producing a triggering output pulse in response to an incoming voltage pulse whenever the applied potentials are effectively positive relatively to the incoming pulse. The binary counter shown in Fig. 1 includes stages AO, A1, A2 ... each comprising a ferro-resonant flipflop circuit, similar to those described in Specification 767,371, [Group XXXIX], having a symmetrical triggering input, magnetic amplifier buffer outputs, a zero-resetting switch and a lamp 50 for indicating when the flip-flop is in the " 1 " condition. The right-hand outputs AO, A1 ... , which carry a substantial A.C. voltage for " 0 " and not for " 1 " (see Fig. 6), are connected to diode gates G1, G2 ... whose outputs are connected to the trigger inputs of the next higher stages. The pulses C to be counted, Figs. 1 and 6, are applied to the trigger input of the first stage AO and to the gates (see Group XL (c)) and each gate is connected to the output (such as G1 of the preceding gate (if any). In operation, only if the other input(s) to a gate are at Ov, the negative pulse C causes capacitor 18, 30 ... in the output circuit to discharge rapidly to apply a sharp negative trigger-pulse to stage A1, A2 .... (The capacitor being charged at a slower rate limited by high resistance 15, 26 ....) Fig. 6 shows the output waveform from the flip-flops and gates when 6 pulses C are counted from the initial zero condition.