| 摘要 |
PURPOSE:To protect a superconducting magnet against instantaneous power interruption without requiring a backup power supply by connecting a superconducting switch in parallel with a superconducting coil and performing ON/OFF control of the superconducting switch according to existence of output from a power supply. CONSTITUTION:When an AC power is outputted stably from a power supply 11, a superconducting switch 17 is turned OFF and initial energy storing process is executed. Upon instantaneous interruption of the power supply 11 during initial energy storing process, production of AC power from the secondary winding 12b of a transformer 12 is interrupted and no DC output is fed from a rectifying circuit 18. Consequently, the superconducting switch 17 is turned ON quickly and the exciting current I for a superconducting coil 14 flows continuously through a closed circuit comprising the superconducting coil 14 and the superconducting switch 17 which no variation thus preventing quenching. |
