To provide a method and a device for eliminating filament hot shock in a lamp filament, in particular a small filament light source of a high- efficiency infrared-ray reflecting coating halogen lamp or the like in plugging or carrying a current.
A voltage reduction circuit 14 for reducing a voltage applied to the lamp filament for a prescribed period, and a timing circuit 12 started every time a lamp is turned on and used for controlling the prescribed period for the voltage reduction circuit to reduce the voltage applied to the lamp filament are installed. A one-time latch circuit 32 for allowing the timing circuit to be operable in lighting, for bringing the timing circuit into a non-operation state, after the voltage reduction circuit has continuously operated for a prescribed period, and for permanently brining the timing circuit into a non- operation state or even thereafter may also be included as an option.
LIESZKOVSZKY LASZLO V
HOEGLER LEONARD E
COLLINS EDWARD J
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