| 摘要 |
To provide a large fan filter unit (FFU) at low cost. With respect to each motor (e.g., synchronous motor) 3A-3C of a number of FFUs set in, for example, a clean room, a rectifying circuit 21 and an operation control circuit 22 are arranged commonly, and inverters 23A-23C, motor control circuit 24A-24C and detection parts 25A-25C are independently arranged, whereby the number of circuits or wiring is reduced. Accordingly, even if the scale is enlarged, the cost is never increased. |
