GB1187936A - Chronometric Device. - Google Patents

Abstract

1,187,936. Measuring time intervals. COMPAGNIE GENERALE d'ELECTRICITE. 14 June, 1968 [16 June, 1967], No. 28594/68. Heading G4H. To measure the time interval between two pulses at inputs A, B (Fig. 5) two pulses E are generated coincident with the clock pulses D immediately following the input pulses, clock pulses M being counted in a counter 17 for the time interval between the two pulses E, a vernier member 18 determining the time intervals t 1 , t 2 between the first input pulse and the first pulse E and the second input pulse and the second pulse E respectively and forming a count in counter 42 representing t 1 -t 2 to modify the count in counter 17. In the embodiment described a distributer 183 (Fig. 4a) in the vernier member 18 receives the pulses E via an inverter 182 and distributes them to N AND gates 181. The input pulses are also distributed via graded delays 185 to the AND gates so that binary coded signals representing the time intervals t 1 and t 2 are obtained at the outputs of the gates. The signals are respectively stored in register 21 (Fig. 5) and via an inverter 39 in register 22 the stages of which are initially preset to "1", register 22 accumulating pulses as register 21 is counted down to zero so that a count of t 1 + (1-t 2 ) is fed to auxiliary counter 42. To compensate for the additional one the start of the count in counter 17 is delayed by delay 34. The counts in the counters 17, 42 are combined in a counter 45. To measure very short time intervals (Fig. 6, not shown) the second input pulse may be delayed by a fixed time and the start of counting in the counter 17 similarly delayed.