Power supply for magnetic bearing for turbo-molecular pump

摘要

A power supply for a magnetic bearing system of a motor driven shaft has a transformer to reduce an input voltage. The output voltage is rectified and smoothed, then inverted to provide an a.c. voltage for the motor during normal operation and to provide regenerative coupling back to the mains if the latter should fail temporarily. There is a DC/DC converter to provide current for the magnetic bearing, derived from the DC link between rectifier and inverter. There is a mains-connected AC/DC regulator to provide a voltage that is higher that from the DC/DC converter and a pair of diodes to prevent current backflow.