| 摘要 |
PROBLEM TO BE SOLVED: To make preheating of a filament with a structure having a minimum number of wirings with power supply circuit side. SOLUTION: A primary circuit 15 includes a capacitor 12 connected in series between a first filament F1 of a first discharge lamp 10 and a first filament F3 of a second discharge lamp 11 and a primary winding 13 of a flow splitting transformer T and power is supplied between one end of each first filament F1, F3 of the first and the second discharge lamps. A second circuit 16 is a secondary winding 14 of the flow splitting transformer T connected in series with a second filament F2 of the first discharge lamp 10 and a second filament F4 of the second discharge lamp 11. When power is supplied to the primary circuit 15 at light start-up, current flows also into the secondary circuit 16, and all the filaments are preheated, which dispenses with particular wiring for preheating. |
