| 摘要 |
PURPOSE:To prevent erroneous operation of a control device caused by induction noise by providing a control unit using signal with lower frequency than the operation frequency of a frequency converter. CONSTITUTION:There is provided a frequency converter 12 and a controller 13. In this converter 12, a commercial power supply 1 is connected to an input terminal of full wave rectifier through a power switch 2, while filter circuits 4-6 and a drive circuit 11 and the like are provided. The controller 13 is composed of an ON-OFF control circuit 16 and the like for supplying an ON-OFF signal to the circuit 11. The signal frequency connecting parts of the controller 13 is set lower than the operation frequency range. It is thus possible to improve the reliability as well as to stabilize the operation of the controller at all times. |
