Patent GB-654313-A (GB)
Title: Improvements in or relating to electronic counting circuits
Inventor: BAKER GEORGE THOMAS
IPC: H03K23/82
Filed: 1948-08-26
Abstract: 654,313. Counting-apparatus. BRITISH TELECOMMUNICATIONS RESEARCH, Ltd. Aug. 26, 1948, No. 22560. [Class 106 (i)] A multi-denominational electronic counter, adapted to deliver a signal after receiving a preset number of pulses, comprises a cascade arrangement of cyclically-operating electronic counting circuits, one for each denomination. Each denomination may feed into the next at the preset digit (Fig. 1), the output pulse being taken from the highest denomination. Alternatively (Fig. 2), interdenominational feed may occur at a fixed digit, e.g. " 0," and the output taken through toggle circuits between the denominations and controlled by the preset digits. UD, TD and HD are cyclically - operating decade counters for units, tens and hundreds, as described in Specification 632,411, and the tube anodes are connected to the studs of digit selector switches U, T and H. In Fig. 1, the input pulses are applied to UD whilst the arms of switches U and T are taken to the inputs of TD and HD. The arm of switch H receives a pulse when the input pulses total the number preset on the switches U, T and H and this is taken to the output OP. The output pulse could reset the counter to initiate a fresh count, and such an arrangement could be used for counting small articles into containers, the input pulses being obtained photo-electrically. In Fig. 2 coupled-triode toggle circuits A and B between the stages are normally biassed towards the lower denomination. The input to TD and HD is taken from the " 0 " anode of UD and TD respectively so that each is pulsed at successive counts of ten in the preceding denomination. Points P1 and P2 of toggle circuit A are connected to the selector switch arms U1 and T1, whilst the same points P1 and P2 of toggle circuit B are connected respectively to an anode A1 of circuit A and the selector switch arm H1. Assuming the number 473 to be set on the three switch arms, the action is as follows : U1 delivers pulses to P1 at counts of 003, 013, 023, &c. but without effect, since A is already biassed towards UD. When 070 is reached in TD, T1 applies a pulse at P2 which transposes the circuit A so that, when the next pulse is applied by U1 at 073, A restores and, in so doing, its anode A1 applies a pulse to P1 of toggle B. Further pulses are applied to P1 at counts of 173, 273, &c. but all without effect since B is already biassed towards TD. At 400, however, the arm of H1 receives a pulse from HD which is applied to P2 of toggle B so that toggle B is transposed ready to be restored by the next pulse from toggle A. This' occurs at the preset count of 473 and the anode A1 of toggle B then delivers a pulse to the output OP. The second switch levels T2 and H2 of the tens and hundreds digit selector switches are for byepassing the toggles A and B for zero settings, since pulses then occur simultaneously at P1 and P2 and the sequence would be lost if the toggles were included. To avoid coincident pulses when zero is set in the units, the zero stud of the second switch level U2 is connected to anode 9 of UD instead of anode O.