| 摘要 |
PURPOSE:To facilitate work in changing over the operation by allowing the degree of opening of a minor guide vane to follow up that of a major guide vane. CONSTITUTION:The sensed value of the current number of revolutions of a runner is compared with the reference value, and the deviation obtained is compared at a comparator 24 with a deviation of an adjuster 23 which is to adjust the degree of opening of a major guide vane 2, and then output signal from this comparator 24 will control said major guide vane to an optimum opening. The signal from a degree-of-opening sensor 2a is compared with a signal from a degree-of-opening sensor 3a for minor guide vane 3, and a servo motor 31 is driven for the purpose of follow-up of the minor guide vane 3 to major guide vane 2. Accordingly it is not required to couple the major guide vane 2 with minor guide vane 3 mechanically to contribute to accomplishment of easy changing-over of the operation. |
