| 摘要 |
PURPOSE:To surely detect the installed state of all filaments by use of a simple detecting circuit in an inverter type discharge lamp lighting device of two-lamp parallel lighting. CONSTITUTION:In an inverter type discharge lamp lighting device of two-lamp parallel light having a DC closed circuit from a DC power source E to a capacitor C4 through a resistance R3, a filament f4, a DC continuing element R5, a filament f3, an inductor L2, an inductor L1, a filament f1, a DC continuing element R5, a filament f2, a diode D3 and a resistance R4, detection of the installed state of filaments is conducted by one DC closed circuit containing all the filaments, whereby a detecting circuit can be realized with a circuit structure easier than in the past, and the effect that any filament, when dropped off, can be surely detected is provided. |
