| 摘要 |
<p>The present invention comprises a correlation designator (26) that designates a correlation wherein the supply current supplied to an inverter circuit (6) changes in proportion to the voltage applied to the inverter circuit (6), a supply current level controller (17) that controls the average current supplied to the inverter circuit (6) so that the average current will have the supply current level indicated by the correlation designator (26), whereby a highly precise airflow/static pressure characteristic can be realized with very little change in the airflow, even if there is a change in static pressure, as in pressure loss, etc.</p> |
