Patent GB-592795-A (GB)
Title: Improvements in or relating to electric impulse producing apparatus
IPC: G08C19/18
Filed: 1944-05-19
Abstract: 592,795. Calculating - apparatus. NATIONAL CASH REGISTER CO. May 19, 1944, No. 9746. Convention date, Aug. 6, 1942. [Class 106 (i)] [Also in Group XL], To produce a. predetermined number of pulses, an electrical pulse producer is connected over gating means to a counter comprising a number of electron valves arranged' in denominational groups, data being entered. in the counter by operating selected valves. Pulses enter the counter in the lowest denomination until it is filled to capacity when the gating means is closed and stops the passage of further pulses. The selector counter, Figs. 4A-4F, consists of an electronic counter having three banks of gas-filled valves representing units, tens and hundreds. The units order, Figs. 4A, 4B, includes a trigger connected pair T1, T2, followed by a ring of five gas-filled valves, which are fired in succession every time the valve T2 conducts, the drop in anode potential of T2 as it conducts cutting off the amplifier valve 56 and applying a positive pulse through conductor 158 to the grids of all the valves. As the valve 54 fires, a transfer valve 55 also fires to provide a denominational transfer to the next bank of valves. The tens denominational order comprises a ring of ten gaseous valves, Fig. 4C, 4D, operating in sequence on receipt of the transfer pulses, the valve 00 sending out a transfer pulse to the hundreds order, also comprising a ring of 10 gas filled valves, Figs. 4E, 4F. Pulses generated by ' Oscillator ' valve 400 (Fig. 3) are applied to the anode of ' Gate ' valve 407. When the ' Start ' valve is fired the gate valve becomes conductive and high-frequency pulses are fed over the output conductors 58 and 444. The keys of the selector counter are set to the desired number of pulses to be transmitted, so that when that number of pulses have been applied, its three banks are filled to capacity, valve 000, (Fig. 4F) firing on the last pulse, thus firing the ' stop ' valve 346 and cutting-off the gate valve 407 so that no more pulses are transmitted. If, for example, it is desired to transmit 356 impulses the corresponding keys are operated. In the units bank, operation of an even-numbered key causes resistance 106 to be placed in the cathode circuit of valve T1, while the cathode of valve T2 is connected directly to earth so that T2 is rendered conductive. Operation of an odd-numbered key causes T1 to become conducting in a similar manner. Thus, when key 6 is operated, T2 conducts and also valve 51, since its grid is connected to a positive potential supply through conductor 162, switch 160, conductor 161 and terminal 172, so that valve 52 is primed. On the sixth pulse applied to the trigger pair of valves through pulse-sharpening valve 57 from terminal 58, valve 54 fires, the units denominational bank then being full to capacity and a transfer pulse applied to the tens order from valve 55. Since key 50 has been operated in the tens order, valves 40 is fired as its grid; is connected to the positivepotential supply through conductor 298, so that valve 50 fires on receipt of the transfer pulse. The transfer valve is fired again on the 16th impulse, causing valve 60 to fire and so on till the 56th impulse when valve 00 fires and a transfer pulse is applied to the hundreds denominational order, where valve 600 had been fired due to the application of a positive potential to its grid when key 300 was operated, so that valve 700 is fired. On the 356th impulse valve 000 fires and applies a positive pulse from terminal 345 to the grid of ' Stop ' valve 346 (Fig. 3), which fires and extinguishes the ' Gate ' valve 407. If no key is operated in the units order a Fugitive Digit ' valve 325, (Fig. 3), is fired before the pulses are applied so that a pulse is applied over conductor 320 from terminal 322 to the grid of the primed valve in the tens order, thus firing it. Valve 325 is normally prevented from firing by applying a negative potential to its grid from terninal 327, through switch 328, (Fig. 4B), which is held closed when a units key is operated. Thus, if the 30 key is operated, valve 60 is fired priming valve 70, which is fired when valve 325 conducts. On the 30th impulse, valve 00 fires and a transfer pulse sent out. If this correction were not made,.ten pulses more than are required would be transmitsed. If no key is operated in both tens and units orders the valve 90 will fire, since its grid is connected directly to. the positive supply through conductors 308, 298 and valve 00 fires on receipt of a pulse from the ' Fugitive Digit ' valve so that a transfer pulse is applied to the hundreds order. The operations described above are controlled by the relays I ... VI, Fig. 2. Solenoids I ... V are energized in succession, then I and II are de-energized, a holding circuit being prepared for III, IV and V when V was energized. When solenoid I is energized point 107 is disconnected from earth and resistance 106 placed-in the cathode circuit of either valve T1, or T2, depending on which key is operated. Positive potential from supply terminal 174 is applied through terminal 297 to the grid of the selected tens valve and through terminal 342 to the selected hundreds valve. On the energization of solenoid II positive potential is applied through terminal 172 to the grid of the selected units valve. Anode potential is applied through terminal 155 to the pulse-sharpening valve 57, valves T1, T2 and 56, Fig. 4A, and Oscillator valve 400 and valve 325, Fig. 3, when solenoid III is energized so that valve 400 starts to oscillate and one of the trigger valves is rendered conducting. Anode potential is applied through terminal 286 to the tens valves when solenoid IV is energized so that the selected valves fires and through terminal 185, to the units and hundreds valves when solenoid V is energized so that the selected valves fire. The positive potentials are removed from the grids of the selected valves when relays I and II are de-energized, point 107 is re-connected to ground, shorting out resistance 106 and anode potential is applied through terminal 212 to the ' Start ' valve which fires and renders the ' Gate ' valve conducting. At the same time as the ' Stop ' valve fires, a ' Key Release ' valve 445 fires and energizes solenoid VI through terminal 447 so that the key release solenoids 451, 452, 453 are energized and any depressed keys released. Specification 592,793 is referred to.