Patent GB-583266-A (GB)
Title: Improvements in or relating to electric impulse producing apparatus
IPC: H03K3/78
Filed: 1944-05-19
Abstract: 583,266. Pulse generating circuits. NATIONAL CASH REGISTER CO. May 19, 1944, No. 9753. Convention date, May 26, 1943. [Class 40 (v)] Comprises an electronic impulse generator operating cyclically, each complete cycle producing a fixed number of impulses, and means to start the generator at any point in a cycle and automatic means to stop the operation after a desired number of impulses have been generated. Figs. 2, 3 and 4 show the units, tens and hundreds denomination, respectively of the, generator, the first ten units valves operating automatically in succession in a closed ring so as to produce an impulse every time a valve fires, the tens valves operating in succession upon receipt of impulses every time the tenth units valve fires, and the hundreds valves operating in succession on receipt of impulses from the first tens valve. The initiation of an operation is caused by the firing of valves 20, 21, 22, Fig. 1, in sequence. When the start -key 25 is closed, " start " valve 20 fires and applies a positive impulse through terminal 87, to the grid of " auxiliary " valve 200, Fig. 3, which fires and primes one of the tens valves, depending on which key is depressed, and also to the grid of the first hundreds valve, Fig. 4, which fires and primes one of the hundreds valves. Valves 21 and 22, Fig. 1, fire in succession after valve 20, with delays determined by condensers 54, 60, 59 so that an impulse is applied through terminals 70 and 84 to valve 74, Fig. 2, which fires. The rise of cathode potential of the valve 74 is applied to the grids of one of the units valves, depending on which key is operated, causing it to fire. This causes the units valve to fire cyclically in succession, for example, to transmit 161 impulses the " 1 " key in the units bank, " 6 " key in the tens bank, and " 1 " key in the hundreds bank are operated. In the tens bank the " 6 " key is connected to the cathode of the fourth valve so that the fifth valve is primed when tube 200 fires. In the same way the tenth valve in the hundreds bank is primed. In the units bank the valve 74 fires, applying one impulse through amplifier valves 120, 121 to positive and negative output conductors 122, 123, and through depressed key " 1" and terminal 65 to the grids of all the tons valves, thus firing the fifth valve, also through conductors 67, 104 to the grid of the first units tube which fires. When the tenth unit valve fires at the end of each succeeding cycle, an impulse is impressed through terminal 65 on to conductor 770 so that the tens valves fire in succession. On the 61st impulse, the first tens valve fires, causing an impulse to be applied through terminal 338 to the grids of the hundreds valves, firing the tenth valve, and on the 161st impulse the stop " valve 337 fires and a negative impulse is applied through rectifier 360 and terminal 107 to the first units valve to prevent it refiring. If no key is operated in the units bank, the anode of valve 23, Fig. 1, will be connected through terminal 78 to the positive supply 80, so that valve 23 fires after valve 22 and applies an impulse through terminal 65 to the tens valves. The second valve in the units bank fires after valve 74 which takes the place of the first valve. Specification 583,309 is referred to.