Patent GB-601147-A (GB)
Title: Improvements in or relating to apparatus for generating electrical impulses
IPC: H03K3/78
Filed: 1945-02-15
Abstract: 601,147. Producing electric pulses. NATIONAL CASH REGISTER CO. Feb. 15, 1945, No. 8093/47. Convention date, Dec. 27, 1943. Divided out of 601,122, [Group XIX]. [Class 40 (vi)] [Also in Group XIX] An electrical-impulse generator is adapted to operate through a predetermined number of complete cycles under the control of a recycling unit preset to the predetermined number, the generator emitting, in each cycle, impulses representing in number and denominational value each digit of a multidenominational quantity, the generator comprising a plurality of banks of electronic devices, the devices in each bank operating automatically in sequence, the number of devices operated in each bank being equal to the corresponding digit of the multi-denominational quantity. The generator banks operate from the highest downwards. Each bank comprises nine gas-filled triodes 1 ... 9, Fig. 1, a byepass triode D and a " transfer " triode T which initiates the operation of the next lower bank. The number of impulses to be produced in the bank is determined by depressing a digit key 89, each such key moving to the left a bar 90 to apply earth through a line 77 to the grid of the I triode, to relieve a negative bias thereon and thus prime the triode. The I triode then will fire when an impulse is received at a terminal 78 connected to the I and D triodes only. The I triode sends an impulse to-an output line 108 and also fires the 2 triode. This extinguishes the 1 triode, gives another impulse on the output line and fires the 3 triode. When a triode corresponding to a depressed digit key fires, the impulse is routed by a switch on the key to the grid of the D triode, which fires and in turn fires the T triode which gives an impulse at a point 115 connected to the input terminal of the next lower bank. If no digit key is depressed, the grid bias of the D triode, instead of the 1 triode, is relieved and this D tube fires to fire the T tube as stated when the initiating impulse is received at the terminal 78. Recycling control unit. This comprises several denominations, each having nine gasfilled triodes 1 ... 9, Fig. 4, a " delay " triode and a " transfer " triode and controlled by a set of numeral keys. The operation is initiated by the arrival of an impulse at an input terminal 375, the impulse originating as described in Specification 601,122. This impulse is applied to the grids of both the 1 and the transfer triodes. If no numeral key has been depressed, the grid bias on the transfer triode is relieved by an earth connection to a point 428 through key-operated switches, this triode fires to give an impulse at a point 371 to start off a lower denomination of the recycling control unit. The impulse generator is thus not operated at this time. If, however, any numeral key is in depressed condition, earth is removed from the grid of the transfer triode and applied to the 1 triode which is thus primed to fire upon the arrival of the initiating impulse. This produces an impulse on an output line 417 connected to the input terminal 78, Fig. 1, of the generator to set this in operation. The 2 triode, Fig. 4, of the recycling unit is primed and will fire when an impulse arrives at a second input terminal 188 connected to the 2 ... 9 triodes. This last impulse arrives, as described in Specification 601,122, when the generator has performed one complete cycle. The firing of the 2 recycling triode, Fig. 4, generates another impulse on the output line 417 to initiate another complete cycle of the generator. When the recycling unit has produced impulses equal in number to the value of the numeral key depressed, the priming potential is switched by a switch on the key to the grid of the delay triode. This latter, instead of the next triode in the 1 ... 9 sequence, thus fires upon the arrival of the next impulse at the second input terminal 188. This action is followed at once by the firing of the transfer triode which may start the operation of another denomination of the recycling control unit as described in Specification 601,122. Specifications 592,174, 593,728 and 601,148 also are referred to.