Patent GB-791272-A (GB)
Title: Improvements in or relating to pulse generators
Inventor: HARRIS LIONEL ROY FRANK
IPC: H04Q11/04
Filed: 1953-02-17
Abstract: 791,272. Pulse supply systems. POSTMASTER GENERAL. March 3, 1954 [Feb. 17, 1953], No. 4473/53. Class 40 (4). A system for generating a set of pulse trains comprises N leads, each pulse train being present on a combination of R of the leads and being unique to that combination. By this means NC R  pulse trains may be carried on N leads. The pulse trains when required are obtained from coincidence gates fed by the appropriate combinations of R leads. In one embodiment, Fig. 1, trigger devices TGD1/1 ... TGD1/4 are operated in turn each being restored by a clock pulse over lead PL1, restoration of each trigger circuit effecting the operation of the next through an end of signal device ESD (e.g. a differentiating circuit). When TGD1/4 restores it restores a trigger device TGD2/1 (assumed previously to be operated) thereby operating. TGD1/2 and also TGD2/2. The chain TGD1/2 ... TGD1/4 then steps as before and when TGDl/4 again releases TGD2/2 releases so operating TGD2/3 and TGD1/3. Thus as TGD2/1 ... TGD2/4 operate in turn the lower chain goes through cycles of 4, 3, 2 and 1 pulses respectively, whereafter the whole process is repeated, the upper chain being connected in a ring. A suitable start pulse may be applied over L5. The pulses emitted on the various leads a ... h are illustrated in Fig. 2 from which it is clear that pulses in any of ten positions may be obtained by combining a with e, f, g or h, b with f, g or h, c with g or h or d with h. A further economy in leads may be effected by combining e with b on lead B, f with c on lead C and d with g on lead D. Lead A takes pulses from lead a and E from lead h. Combinations from leads A ... E taken two at a time give pulses in any one of the ten positions. An arrangement is described, Fig. 3(a) (not shown) for overcoming the disadvantage that TGD1/4 must at one stage operate twice in rapid succession. Arrangements for preventing more than one pulse circulating in the upper ring may be provided as described in Specification 707,401, [Group XL (c)]. A generalized system of this nature is outlined for feeding <SP>N</SP>C R  pulse trains to N leads. R groups of trigger devices are provided, the first being stepped by clock pulses, each of the other groups being stepped by the last trigger of the preceding group and on the operation of the qth trigger of any group it is arranged that the qth triggers of all preceding groups are operated. The pulse leads receive pulses from R successively numbered triggers in the different groups (except the end leads, e.g. A, E, Fig. 1, which clearly receive pulses from less than R triggers). In a modification, Fig. 4(a), five memory devices MD1 ... MD5 are in part controlled by three auxiliary memory devices AMD1 ... AMD3. Termination of a pulse over L1 operates AMD1 and MD2. AMD1 operates MD1. Clock pulses over PL1 release any of the operated devices MD1 ... MD5 thus stepping the operated condition along from MD2 to MD5. Device MD1 is reoperated every time by a stimulus from AMD1. When MD5 operates it applies a slightly delayed release pulse over lead L4 to release AMD1. When MD5 restores simultaneously with MD1, AMD2 operates and also MD3. The chain MD3 ... MD5 then steps with MD2 pulsing each time due to the stimulus from AMD2. On the next cycle MD4, MD5 pulse in turn MD3 pulsing each time. Finally MD4, MD5 operate together so producing a signal over L1 which initiates the cycle afresh. Waveforms on A ... E are produced similar to those shown in Fig. 2 with the exception that the long pulses are chopped into units. A generalized system of this type is also described for applying appropriate combinations of pulse trains to N leads whereby NC R  pulse trains can be derived. A detailed circuit arrangement is provided, Fig. 1 (Complete) (not shown) corresponding to the arrangement of Fig. 4(a) in which the memory devices MD1 ... MD5 are triggered blocking oscillators and the auxiliary devices AMD1 ... AMD3 are condensers. In a further method, Fig. 5(a), triggers MD1 ... MD5 pulse leads A ... E which are connected through small delay lines SDN1 ... SDN5 to coincidence gates connected in pairs to produce pulse trains on leads PL1 ... PLIO slightly delayed with respect to the pulse trains carried on A ... E. These are applied via decoupling devices DM1 ... DM5 to pairs of gates OG1, RG1 ... OG5, RG5. The pulses applied to any decoupling circuit are phased one earlier than the pulses required to be produced on the corresponding one of the pulse leads A ... E. Thus if a pulse from PL4 is applied to DM2, coincidence with the rest clock pulse in OG2 triggers MD2 to initiate a pulse on lead B in position 5 of the cycle. When the pulse received from DM2 terminates, RG2 passes the next clock pulse to restore MD2 to terminate the pulse on lead B.