Patent GB-1146948-A (GB)
Title: Time division multiplex channel pulse distributor
Inventor: GIORDANO AMES FILOMENA
IPC: H04J3/04
Filed: 1967-03-17
Abstract: 1,146,948. Multiplex pulse signalling. INTERNATIONAL STANDARD ELECTRIC CORP. 17 March, 1967, No. 12673/67. Heading H4L. A time division multiplex channel pulse distributer wherein one or several groups of channels sampled at a first repetition rate are combined with one or several groups of channels sampled at a second repetition rate, comprises a first means to produce for each frame a first plurality of channel pulses having the first repetition frequency and a second means coupled to the first means to produce for each frame a second plurality of channel pulses having the second repetition rate together with third means coupled to the first and second means to produce frame synchronizing pulses. Multiplexing.-The output of a master clock 4, Fig. 1, having a basic repetition frequency of 100.8 kc./s. is supplied to a delay line 5 providing output A, Fig. 2. The output of clock 4 is also supplied to a divider 6 producing 33À6 kc./s. timing signals B, and signals B are divided at 7 to produce two time displaced 16.8 kc./s. signals C, D. Clock 4 is connected directly to a frequency divider 8 producing 11À2 kc./s. signals N and these signals are further divided at 9 to produce 5.6 kc./s. signals T. A first group of Channel pulses E at 16. 8 kc/s. is provided by the coincidence of pulses A, B, C at gate 10 to trigger a blocking oscillator 11 which supplies a delay line distributer 12 having ten taps controlling ten modulators 13 receiving signals from ten sources 14 to be time division multiplexed. The outputs of modulators 13 are supplied via OR gates 15, 16, 17 to a mixer 18. A second group of pulses F at this repetition rate is provided by the coincidence of pulses A, B, D at gate 19 to supply a tapped delay line 21 similarly controlling the multiplexing of ten signals originating from sources 23 via OR gates 24, 16, 17. A third group of channel pulses H also at the repetition rate of 16À8 kc./s. is produced by the coincidence in AND gate 25 of pulses A and pulses G provided by the end output of delay line 12 via pulse stretcher 26 and multiplexing of ten signals from source 30 takes place via OR gates 31, 16, 17. A fourth group of channel pulses J at 16.8 kc./s. produced by the coincidence in AND gate 32 of pulses A and the output I of a stretcher fed from the end tap of delay line 21 controls the multiplexing of ten signals from source 36 via OR gates 38, 16, 17. Thus the first timing means 1 produces four groups of ten channels each at a repetition rate of 16À8kc./s. The outputs of delay lines 28, 35 are coupled via stretchers 39, 40 to an OR gate 41 in the second timing means 2 so that pulses M at a repetition rate of 33.6 kc./s. are supplied to AND gates 42, 45, 49. The coincidence of pulses A, N, M, at AND gate 42 produces pulses Q which trigger a blocking oscillator 43 supplying a delay line distributer 44. Similarly AND gate 45 (pulses R) supplies delay line 48 via blocking oscillator 47 on the coincidence of pulses A, M and O (pulses N delayed at 46), and AND gate 49 (pulses S) supplies delay line 52 via blocking oscillator 51 on the coincidence of pulses A, M and P (pulses O, delayed at 50). The channel pulses produced by this means have a repetition rate of 11À2 kc./s. Distributers 48, 52 co-operate with modulators 54, 53 respectively and control the multiplexing of two groups of ten signals 56, 55 via OR gates 59, 17. The distributer 44 co-operates with modulator 60 to control the multiplexing of eight signals from source 61 via OR gates 59, 17, the last two channel pulses from distributer 44 being used to generate a framing signal. Tap nine of delay line 44 and the output T of divider 9 are coupled to AND gate 64 which in conjunction with the output of tap ten of delay line 44 controls a frame sync. signal generator 65 to produce pulses 11 of larger amplitude than the remaining pulses. Pulses A control signal generator 63 producing a " fine sync. signal " CC for each group of channel pulses. The outputs of generators 63, 65 are supplied to the mixer 18 and the output of mixer 18 is supplied to a storage or transmission means 67. Demultiplexing.-The frame sync. signal is separated by an amplitude discriminator, Fig. 3 (not shown), and in conjunction with the " fine sync. " pulses controls a master clock and divider chain generating channel pulses to control distributers in a similar manner to that described with reference to Fig. 1. Modification.-An arrangement which may be switched to operate as a multiplexing or demultiplexing system, Fig. 4 (not shown), uses common timing pulse generating circuits of the type previously described.