ANORDNING FOR METNING AV IMPULSFOLJDSFREKVENSEN I EN FORSTA IMPULSFOLJD

摘要

1482158 Digital frequency measurement TELDIX GmbH 17 Oct 1974 [23 Oct 1973] 45096/74 Heading H3H Digital measurement of the frequency of pulses input at 111 is obtained by counting clock pulses, generated at 32, in a backwards counting counter 31 for a whole number of periods of the pulses input at 111, said whole number being automatically selected so that the count in counter 31 reaches at least a predetermined number, and the frequency of the clock pulses being varied in proportion to the reciprocal of the square of the period of the input pulses at 111. The pulses from 111 are counted in a second backwards counting counter 34, circuit 221 giving output pulses when counter 34 has counted 1, 2, 4, 8 &c. pulses from 111, and the next pulse from circuit 221 following the setting of flip-flop 51 by counter 31 reaching the predetermined number blocks further counting in both counters and transfers their counts to stores 35 and 36, the counters and flip-flop 51 being then reset. Circuit 37 divides the content of store 35 by the content of store 36, by positional shifting, to give the required frequency-measuring signal.