| 摘要 |
PURPOSE:To compensate for the change of the capacity of a fan along with the change of load characteristic, by correcting the desired rotational frequency of a fan motor according to the load characteristic after its fluctuation, when the load characteristic of the fan is fluctuated against a reference. CONSTITUTION:By a micro-computer 5, based on a deviation between the rotational frequency of a fan motor 2 and a previously set desired rotational frequency, a phase time according to a phase angle when a power source is ON is controlled, and control signal for turning the rotational frequency of the fan motor 2 into the desired rotational frequency is directed to a control unit 6, as the output. Besides, by the micro-computer 5, based on the phase time when the controlling power source is, ON and a reference phase time, the change of the load characteristic of a cross flow fan 1 is detected, and according to the load characteristic after the change, the desired rotational frequency is corrected. Based on the control signal of input from the micro-computer 5, by the control unit 6, the phase time when the power source is ON is changed. |
