| 摘要 |
A magnetic levitation type vacuum pump includes an electromagnet magnetically levitating a rotor by a magnetic force, an electromagnet driving circuit supplying an electromagnet current including a magnetic levitation control current component and a carrier wave current component having a frequency band higher than the magnetic levitation control current component to the electromagnet coil, a levitated position detecting circuit detecting the carrier wave current component and generating a levitated position signal of the rotor, a magnetic levitation control circuit inputting a current command of the magnetic levitation control current component to the electromagnet driving circuit based on the levitated position signal. The electromagnet coil has a primary coil and a secondary coil connected in parallel with the primary coil. An interrupting circuit connected in series with the secondary coil for the carrier wave current component passing therethrough and interrupting the magnetic levitation control current component is further included. |
