| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of controlling a motor by suppressing the high-frequency noise and a vacuum cleaner using the method. SOLUTION: The vacuum cleaner comprises an electric blower 110 with a centrifugal fan, resonance type mufflers 111 and 112 with a plurality of recesses 113 to resonate with a plurality of frequencies determined by the integral multiple of the product of the number of blades and the rotational frequency of the centrifugal fan, a rotational frequency detecting means 215 for detecting the rotational frequency of the electric blower 110, and a control means 214 for receiving signals from the rotational frequency detecting means 215 and controlling the rotational frequency so that the rotational frequency of the electric blower 110 approximates a predetermined target rotational frequency. The control means 214 controls the rotational frequency of the electric blower 110 so that the rotational frequency is fixed at a rotational frequency corresponding to the resonance frequency of the resonance type mufflers 111 and 112. As a result, the high-frequency noise generated in the frequency can be muffled. COPYRIGHT: (C)2007,JPO&INPIT
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