| 摘要 |
PURPOSE:To ascertain of low nnmber of revolutions of a rotating shafts by digital computing process of a detection signal of a rotating shaft through a digital computing circuit and comparing with the reference setting value the digital signal also. CONSTITUTION:When a number of revolutions of shaft exceeds the reference setting value side, an input 60 pulses for a revolution is divided into an output signal of 6 pulses per rotation by a divider 7a and delivered to the first counter 8a as a clock signal as an input. In the first counter 8a, the clock signal from the divider 7a is counted within a gate time of one-shot 11c delivered at a rate of one pulse per 10sec. The gate time generated every 10sec from the one-shot 11c reduces in the divider 7c to 1/10<6>a 1MHz signal delivered from an oscillator 13 and further, to 1/10 by the divider 7b and delivered as a one-shot pulse of 10sec period via on one-shot multivibrator 11c. On the other hand, in a setting apparatus, when a shaft revolution rate is assumed to be 3rpm, it is set by 2-digit sets of B. C. D. codes, for example, ''LLLLLLHH'' and an output signal B and an output signal A of the first counter 8a are subjected to digital computation is a comparator 10. |
