| 摘要 |
A method and a device are described by which in pulse trains with variable pulse periods the period and the frequency of the two last-occurring pulses can be determined after each respective pulse in a very short time. To this end, clock pulses with invariable frequency are summed up in a counter whose output is compared to the output signals of a memory in which a table is stored. The table contains period-length values allocated to which are the corresponding frequency values as addresses of the storage locations of the memory. The memory is addressed via a further presettable counter which, in the event of a positive comparative result, will be advanced to a different address in each case. The advancing continues until the occurrence of the next following pulse of the pulse train. After each pulse of the pulse train, the first counter is reset to zero, while the further counter is set to a predetermined address value.
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