| 摘要 |
An arrangement for restoring dial pulses which are received as binary signal elements in a binary signal. The mark/space ratio of the dial pulses and the allowable tolerance of this ratio is catered for by allowing a pulse "mark" to be comprised by 2, 3 or 4 binary signal elements A which are binary bits of one value, and allowing a pulse "space" to be comprised by 1, 2 or 3 binary signal elements Z which are binary bits of opposite value. The pulse "spaces" are reconstituted as a fixed duration (or 41 ms in the embodiment described), whereas the pulse "marks" are reconstituted with a variable duration (between 50-70 ms in the embodiment described). The arrangement functions using logic sequences which detect the signal transitions Z-A and A-Z in conjunction with signal element combinations ZZA or AZA which occur in sequentially received and stored signal elements. In Figure 1 a counter 23 counts out the reconstituted mark/space durations under the control of auxiliary counters 18, 33 and 34 which are controlled by A-Z and Z-A transition detectors 15 and 16 which receive signal element information from a store 4 in which successively received signal elements are stored. <IMAGE> |
