Converter deriving test valve proportional to PRF - has storing frequency conversion circuit generating auxiliary pulse train with PRF higher than input pulse train

摘要

The converter derives a test value after conversion of a pulse train p.r.f. The convertor has a storing frequency conversion circuit generating an auxiliary pulse train whose pulse repetition frequency is higher than that of the input pulse train, but inversely proportional to the spacing of last two pulses in the input train. The auxiliary pulse train frequency is converted into the test value. The pulse train is generated by two scanning sensors (12, 14) responding to marks on a movable part (10). They are staggered w.r.t. each other in the direction of movement of the parts. The storing frequency conversion circuit responds to the time interval between the appearance of pulses in the two sensors (12, 14).