| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a ventilator which can secure a target air volume, even if it is installed in a building where an exhaust resistance by outside wind differs or in a building where the pressure loss of an air circulation route differs, and at the same time, can prevent an excess air volume, and is simple and cheap in manufacturing cost. <P>SOLUTION: The ventilator includes a blower 1 which rotates a centrifugal fan 11 by a DC motor 12, and a motor control unit 2 which controls the DC motor 12, wherein when a static pressure becomes large and the actual motor rotation speed of the DC motor 12 is more than an established rotation speed, the value of a DC voltage supplied to the DC motor 12 is increased to increase the output of the motor such that the air volume increases so as to obtain the target air volume. In this state, when the static pressure becomes small and the actual motor rotation speed of the DC motor is less than the established rotation speed, the value of the DC voltage is made to be an original value to decease the output of the motor such that the air volume decreases so as to prevent the excess air volume. Moreover, since the value of the DC voltage supplied to the DC motor 12 is only increased/decreased according to the motor rotation speed, it is simple and is cheap in the manufacturing cost. <P>COPYRIGHT: (C)2012,JPO&INPIT |
