| 摘要 |
PURPOSE:To restrain the consumption of amalgams for starting when making a lamp starting circuit for the use in connection with a direct current by providing the amalgams for starting which are included in the electrodes of a fluorescent lamp in a cathode side against the direct current for preheating. CONSTITUTION:A fluorescent lamp 11 which is provided with electrodes 16, 17 including amalgams 27a, 27b for starting at both ends of a glass tube coated with a phosphor film in the inner surface of the tube is burned by the use of an inverter circuit 22 and is preheated by a starting circuit 24 consisting of an electronic switch 25 such as an SSS element etc. and a diode 26 in starting. At this time, the amalgams 27a, 27b for starting are provided in an electrode lead wire 15 which is a minus side when a direct current for preheating flows. Accordingly, it is possible to prevent the consumption of the amalgams which become a red heat state due to the collision of thermions discharged from the cathode side of the electrodes 16, 17 in preheating, and thus it is possible to improve the lamp life. |
