MAGNETIC BEARING DEVICE INCLUDING EXCITATION DRIVE CONTROL CIRCUIT HAVING FIRST POWER SOURCE AND SECOND POWER SOURCE FOR GENERATING POTENTIAL LOWER THAN THAT OF FIRST POWER SOURCE, AND PUMP DEVICE EQUIPPED WITH MAGNETIC BEARING DEVICE

摘要

PURPOSE: A magnetic bearing device and a pump device equipped with the same are provided to control the position of a rotor by strong forces and reduce vibrations and noises generated from the pump device. CONSTITUTION: A magnetic bearing device comprises a rotor; a position control unit for controlling radial position and/or axial position of the rotor by an electromagnet; and an excitation drive control circuit for excitation driving the electromagnet and controlling the excitation drive of the electromagnet. The excitation drive control circuit includes a first power source for generating a first potential; a second power source for generating a second potential lower than the first potential; an excitation drive unit for selecting the first power source or the second power source, and performing excitation driving of the electromagnet by the current supplied from the selected power source; and a selection control unit for selecting the power source to be selected by the excitation drive unit in accordance with a predetermined operation mode.