| 摘要 |
PURPOSE:To simplify the release of a permanent current without overheating and burning a superconductive coil and a permanent current switch. CONSTITUTION:When current is supplied to a superconductive coil 1, if a mechanical permanent current switch 21 is kept opened, no current will flow through the permanent switch circuit even if the superconductive coil 1 is subjected to the normal conductive transfer, accordingly, a thermal permanent current switch 22 is prevented from overheating. Moreover, the resistance of a discharge resistor 3 is not restricted by the value of the resistance when the thermal permanent current switch 22 is opened and this makes it possible to set a high resistance, whereas the magnetic energy of the superconductive coil 1 is mostly consumed in the discharge resistor 3. As a result, the superconductive coil 1 is never overheated. When the permanent current condition is released, it is only necessary to open the thermal permanent current switch 22. Since the switch takes partial charge of the extinction of arc, the mechanical permanent current switch 21 is not burned by the arc and the superconductive coil 1 can be demagnetized. |
