| 摘要 |
<p>PURPOSE:To shorten the time until the stable lighting and extend the lamp life by providing a ballast, with part or whole of a core constituted of a superconducting material. CONSTITUTION:A core 5 is constituted of a material indicating superconductivity at the temperature before a discharge lamp 4 is lighted, e.g., YBa2Cu3O7-x Immediately after the lamp 4 is started, a magnetic circuit type ballast has no inductance due to the Meissner effect of the core 5 and acts as a mere conducting wire. The current of the lamp 4 is increased without being restricted, and the light output quickly approaches the stable lighting. Superconductivity is further lost from the outer periphery of the core 5 by the synergetic action of the Joule heat by the large current of a conducting wire 6 and the magnetic field by the current, finally it has the fixed inductance, and the lamp 4 is set to the stable lighting state. Inductance is gradually increased after the lamp 4 is started, the current is gradually restricted continuously, a large current affecting the life of the lamp 4 is not fed for a long time. The time until the stable lighting is thereby shortened, and the lamp life can be extended.</p> |
