Schaltungsanordnung zum Entzerren von Fernschreibzeichen

986,005. Telegraphy. KOKUSAI DENSHIN DENWA KABUSHIKI KAISHA. Jan. 30, 1962 [Jan. 30, 1961; Feb. 20, 1961], No. 3466/62. Heading H4P. A telegraph exchange connects the active inputs of a set of connections I 1 -I n to desired outputs O 1 -O n via a multiplex channel including a time divisional multiplex regenerative repeater. Calling inputs sampled by a unit 1 are compared with a " list " of engaged calling inputs in a register 48, and if an active input which is not registered is found it is assumed to be a new call and a " proceed to select " signal is sent to the caller. The caller transmits the number of the desired station, and this together with the caller's number is entered in the register 46 and associated with a vacant channel found by a line finder 45. The numbers are translated into binary code at 47 and passed to a connecting memory 48 where they are stored in a position associated with the vacant channel. The memory 48 controls the selecting of the input and output units 1 and 3. A signal sender 49 produces " proceed to select," engaged signals &c. Regeneration.-Each input signal (Fig. 4a), consisting of a 5 bit start stop signal 7¢ units long, is sampled by the unit 1 to generate the pulse train shown in Fig. 4b. Similar trains delayed by fraction of a pulse gap tp are superimposed to provide an input for the regenerative repeater 2 (detailed in Fig. 3, not shown). The repeater is constructed as a six-figure binary counter arranged to count the pulses of each signal on a time shared basis. A feedback loop ensures that the counter cycles in groups of-for example-eight pulses as they would with the perfect signals shown in Figs. 4a and 4b. The element 1 (Fig. 4A) for example is sampled near its centre and this output is produced and maintained for a correct element length as shown at 1 in Fig. 4 (i). Codes other than 5-unit start stop are mentioned. Several sets of similar apparatus may be arranged side by side and work transferred from one to another, e.g. during repairs.