| 摘要 |
PROBLEM TO BE SOLVED: To provide a cycle measuring device, which can maintain the precise detecting accuracy adapting to a change of the detecting characteristic of a sensor. SOLUTION: Voltage pulse at a cycle, which is inversely proportional to the rotating speed of a gear 11, is supplied to a comparator 15 by a sensor 12 provided near the gear 11. This voltage pulse is compared with the reference value, which is output from a microcomputer (μP) by the comparator 15, and the output of the comparator 15 is applied to an auto save resister(ASR) of the microcomputerμP 16. The ASR detects a rise of the voltage pulse, and reads out the real time from a free-run timer, and computes the cycle on the basis of a difference between the real time and the time, which is read at the last time. This cycle can be accurately detected by determining a reference value on the basis of the computed cycle.
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