Patent GB-1162016-A (GB)
Title: Apparatus for the Digital Processing of Pulse Trains
Inventor: KOVANIC PAVEL
IPC: G06F9/00
Filed: 1966-11-16
Abstract: 1,162,016. Electric digital calculator. CESKOSLOVENSKA AKADEMIE VED. 16 Nov., 1966 [18 Nov., 1965], No. 51345/66. Heading G4A. In Fig. 3 a first pulse train of rate n 1  at reference frequency is applied to the input 11 of a pulse counter 4 generating sync. pulses when the count reaches number N c  previously stored through input 14. The sync. pulses pass to distributer 5 supplied to control stores 1, 2, 3, and a second pulse train of rate n 2  at unknown frequency is applied to input 12 of store 1 which is charged over the interval from annulment to arrival of a terminating sync. pulse; also initiating a computing interval. The count A 1  over the sampling interval is passed over 16 to store 3 where the count A 2  of store 2 passed over 17 is subtracted therefrom; a number N 0  being applied to input 13 of store 2 at the commencement of operation. Parts A 1 K 1 , A 2 K 2  of the contents of stores 1, 2 are added to (or subtracted from) the contents of store 3, so that the positive number A 1 K 1  + A 2 K 2  is subtracted from the absolute value of A - A 2 , without change in content of stores 1, 2. The operations of combining the numbers (A 1 ) K 1  and (A 2 ) K 2  with the contents of store 3, are cyclically repeated until such content of the store approaches zero and then changes in sign, when the computation interval terminates. At each addition distributer 5 pulses output 20, so that form additions over the computation interval, A 1  - A 2  + (K 1 A 1  + K 2 A 2 ) m#0 y and m is proportional to the relative deviation of the contents of the stores 1, 2. Distributer 5 clears counter 4 and stores 1, 3 after elapse of the computation interval, and opens the input gates of counter 4 and stores, enabling a subsequent sampling interval to recommence. In a modification (Fig. 2, not shown) feedback connections enable fractions of the contents of stores 1, 2 also to be added to such contents during the computation interval, and it is shown that if the stored counts at the end of sampling are denoted by A 20 , A 10 , In Fig. 3 a train of timing pulses is applied at regular intervals to input 11 at rate f 1  and a further train of unknown rate n is applied to input 12. Gates 21, 23 are inserted in the connections of input 11 to counter 4 and store 1, and gates 22, 24 in the corresponding connections of input 12. Gates 25, 26 are inserted in the feedback paths of stores 1, 2. It is shown that by selective operation of the gates according to a table also giving values of constants n 0 , Al 0  and A2 0  in terms of N c , N 0  and f, the pulse output m represents a selected one of the following operations: In conjunction with an automatic regulating system wherein regulated values are defined as pulse rates n and operational values by number m, the inserted pulse rate value may be varied by changing the number N 0  content of store 2 by closure of gate 26 for a predetermined time; in response to an external source or a fedback output signal. Closure for a specific number of cycles per sampling interval increases or decreases No and thus n 0  exponentially in dependence on the ordinal number of the sampling interval, and thus enables automatic regulating of a constant period applied to the exponentially varying power of a nuclear reactor. Figs. 4, 5 show application to the control of a nuclear reactor wherein sync. pulses from a source (not shown) define stable sampling intervals of length #. (A pulse train representing number No from block 27 determines the frequency of adding of number A 2 .K 2  and togeter with a number k 2  determines the regulated period). The number determined by pulse train m from store 3 controls the regulating bar of reactor 7 over circuit 6, and reactor 7 opens or closes a first feedback path 3 such that at a constant period of the reactor (i.e. at a constant frequency of closing the second feedback path) over store 2 through gate 26). The number N in store 1 increases or decreases at the end of each sampling interval so as to follow the input reference number N 0 , and the corresponding number of impulses m is generated to control the reactor: Automatic control of output is obtained (Fig. 5) by a similar device in which feedback across store 2 is opened or closed at gate 26, T transmitting to store 2 the same values as to store 3 T. The number of pulses m generated in the course of one computation interval is reversed in proportion to period T of the reactor so that The number N originally in store 1 is transferred to store 2, so that the contents of store 2 follow the reactor output, and the period and output of the reactor are displayed on digital indicator 28.