Title:
FILAMENT LAMP LIGHTING DEVICE
Document Type and Number:
Japanese Patent JP3304894
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To eliminate the effects of harmonic distortions imparted to the power supply side of a filament lamp lighting device which dims a plurality of filament lamps.
SOLUTION: Lamp-lighting control circuits 2-1 to 2-n are provided to correspond to a plurality of filament lamps 4-1 to 4-n. The lamp-lighting control circuits 2-1 to 2-n supply input currents to the filament lamps 4-1-4n when switching elements Tr1 to (n) are turned on, and keep the current flowing through the filament lamps 4-1 to 4-n by means of the energy stored in an inductance L, when the switching elements are turned off. By repeating these turning on and offs, the output currents of approximately the same waveform as the input current waveform are supplied as a whole. A control part 3 controls the output currents varying the duty of the on/off signals of the switching elements Tr1 to(n) and supply the differently timed on/off signals to the lamp- lighting control circuits 2-1 to 2-n.
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Inventors:
Takayuki Sugano
Application Number:
JP27334298A
Publication Date:
July 22, 2002
Filing Date:
September 28, 1998
Export Citation:
Assignee:
Ushio, Inc.
International Classes:
H05B37/02; H05B39/04; (IPC1-7): H05B37/02
Domestic Patent References:
| JP4126393A | ||||
| JP8162257A |
Attorney, Agent or Firm:
Shunichiro Nagasawa
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