SOKUDOKENSHUTSUHOHOOYOBIKENSHUTSUSOCHI

摘要

PURPOSE:To detect speeds precisely and continuously from high-speed rotation to extremely-low-speed rotation by providing plural sampling times and counters for high-speed rotation and low-speed rotation. CONSTITUTION:A counter 9 counts pulses generated in proportion to the rotating speed of a rotating body for a time tauS after a sampling time tauS. A time width measuring circuit 10 for high-speed rotation counts pulse intervals in a sampling time tauL after the time tauS. Then, a time width measuring circuit 13 for low- speed rotation counts pulse intervals from a sampling time tauS2 to the next pulse. Respective counted values are supplyed to an arithmetic means 21 after a sampling time tauC to calculate the rotating speed by specific arithmetic. Thus, the speed is detected continuously and precisely from high-speed rotation to extremely-low-speed rotation.