| 摘要 |
PURPOSE: To instantly complete polarity conversion of a lamp at once without extinguising the lamp and carry out polarity conversion of a plurality of lamps only by one unit of polarity converting apparatus by using a time programmed relay or utilizing semiconductor for the relay in the case polarity conversion is carried out to meet a dark end effect at the time of d.c. lighting of a fluorescent lamp. CONSTITUTION: At the time of d.c. current lighting of a fluorescent lamp, a time programmed relay (4-1) starts driving and carries out polarity conversion of the lamp after a prescribed time presses. Further, a lamp programmed relay (4-2) starts driving in the same way after a prescribed time presses and turns off an electric power source for the relay 4-1. At that time, the relay 4-1 returns to the condition of the former stage. Polarity conversion of the lamp is repeatedly carried out every prescribed time. |
