| 摘要 |
PURPOSE:To operate with optimum power by calculating various factors indicating a load state from the load current and the rotating speed of a fan motor, and regulating the speed of the motor based on the calculated result. CONSTITUTION:A fan motor has a variable speed motor 38 and a fan 39, and a controller 40 receives a signal 41S from a speed detector 41 and a signal 42S from a current detector 42, and detects a rotating speed and a load current. A speed controller 40 of the motor 38 calculates various factors indicating the load state from the speed and the current, such as air volume Q or static pressure H, and operates the motor based on the calculated results. Thus, an optimum suction force responsive to the load state is obtained without pressure sensor or without air volume sensor. |
