| 摘要 |
PURPOSE:To conduct sufficient preheating current through each filament electrode and to reduce the number of processes for winding a choke coil and miniaturize the coil. CONSTITUTION:A choke coil 11 which comprises first and second intermediate taps 13, 14 sequentially arranged from one end to the other end thereof, with the portion between the second intermediate tap 14 and the other end being formed into a filament heating coil portion, is provided. The choke coil 11 is connected at one end to one of the terminals of a power source 10 and the filament heating coil portion 11b is connected to one of the filament electrodes 12a of the discharge lamp and the first intermediate tap 13 is connected to the other terminal of the power source 10 via a starter switch 15 and the other filament electrode 12b of the discharge lamp 12. |
