| 摘要 |
PROBLEM TO BE SOLVED: To light a fluorescent lamp stably by using a leakage type transformer to which a high voltage free from kick voltage generation motion can be continuously applied until lighting of the lamp is started as a ballast in a lighting circuit and arranging a proximity conductor in the vicinity of a section between electrodes of the fluorescent lamp. SOLUTION: Contacts 13, 17 and 15, 19 are closed, a voltage of voltage adjustment type alternating current power supply 12, 16 is applied to transformers for preheating 14, 18, and a preheating voltage is applied to filaments 2, 3 to preheat the filaments 2, 3. When a temperature of the filaments 2, 3 reaches a dischargeable temperature due to preheating, a contact 9 for aging lighting is closed, and a voltage of a voltage adjustment type alternating current power supply 11 having a commercial frequency is applied to the primary side of a leakage type transformer 7 so that secondary open voltages are continuously applied to both ends of a fluorescent lamp 1 and the fluorescent lamp 1 starts lighting. A lamp current becomes substantially a secondary short current due to voltage drop of leakage impedance. Moreover, when a proximity conductor is arranged in the vicinity of a section between electrodes, the lamp is lit at a specific voltage. |
