| 摘要 |
PURPOSE:To reduce phase delay by detecting the time length between the adjacent preceding edge and the trailing edge of a rotating speed proportional signal and generating a control output in response to the detected result. CONSTITUTION:The first period detector 7a outputs a control output 8a in response to the variation in the time length between adjacent preceding edges and the second period detector 7b outputs a control output 8b in response to the variation in the time length between the adjacent trailing edges. An output selector 11 alternately selects the output 8a of the selector 7a and the output 8b of the selector 7b and outputs 8c. The output 8c is inputted as the output of a speed detector 4 through a filter 9 to a motor drive circuit. |
