Electric lamp and discharge devices: systems – Periodic switch in the supply circuit – Silicon controlled rectifier ignition
Patent
1990-11-27
1992-08-18
Laroche, Eugene R.
Electric lamp and discharge devices: systems
Periodic switch in the supply circuit
Silicon controlled rectifier ignition
315219, 315DIG7, 315DIG4, H05B 3702
Patent
active
051402246
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to an apparatus for operating a discharge lamp, and more particularly, to an apparatus for operating a discharge lamp using a inverter circuit which has a soft start function and can positively light a discharge lamp at a start time by providing a constant output in spite of a variation in voltage of a power supply.
BACKGROUND ART
An apparatus for operating a discharge lamp and lighting fixture having such an apparatus for discharge lamp are conventionally known, the lighting device being adapted to light a discharge lamp by rectifying an electric output voltage of a commercial AC power supply and then inverting the rectified power by an inverter circuit. In the apparatus and lighting fixture, if a power supply voltage applied to the lighting device varies to an extent of 10%, then an electric current supplied to the discharge lamp varies to an extent of about 15%. Therefore, an output varies greatly against a variation of an input voltage.
Such a discharge lamp cannot be fully lit with a inverter circuit output.
Further, an apparatus for operating a discharge lamp, having a soft start function, has to employ a large capacity resistor, and thereby becomes complex in its circuit arrangement. It has, therefore, been difficult to manufacture a low-cost device of a soft start function type, in consideration of manufacturing costs.
DISCLOSURE OF INVENTION
It is accordingly the object of the present invention to provide a low-cost apparatus for operating a discharge lamp which has a soft start function and can provide a constant output against a power supply voltage variation, and can also provide a constant light output on a discharge lamp and can positively light the discharge lamp at a lighting time by controlling the output.
According to the present invention, there is provided an apparatus for operating a discharge lamp comprising:
a self-excited type inverter circuit means including a DC power supply, a feedback-controlled, saturable current transformer having primary and secondary windings and control winding, and two switching elements, is adapted to alternately operate the two switching elements by an output of the secondary winding of the saturable current transformer;
discharge lamp means for receiving an AC output from the inverter circuit means to effect lighting; and
output variable circuit means for varying an output of the inverter circuit means by varying a saturation time of the saturable current transformer in the inverter circuit means.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram showing an apparatus for operating a discharge lamp according to a first embodiment of the present invention;
FIG. 2 is a timing diagram for explaining the operation of a soft start circuit in the apparatus;
FIG. 3 is a characteristic curve showing a frequency-to-output relation of an inverter circuit in the apparatus of FIG. 1;
FIG. 4 is a circuit diagram showing an apparatus for operating discharge lamp according to a second embodiment of the present invention;
FIG. 5 is a circuit diagram showing an apparatus for operating discharge lamp according to a third embodiment of the present invention;
FIG. 6 is a circuit diagram showing an apparatus for operating discharge lamp according to a fourth embodiment of the present invention;
FIG. 7 is a view showing a soft start operation in full light and dimmed light on the apparatus of FIG. 6;
FIG. 8 is a characteristic curve showing a voltage-current relation of the apparatus of FIG. 6;
FIG. 9 is a circuit diagram showing an apparatus for operating discharge lamp according to a fifth embodiment of the present invention; and
FIG. 10 is a circuit diagram showing an apparatus for operating discharge lamp according to a sixth embodiment of the present invention.
BEST MODE OF CARRYING OUT THE INVENTION
The embodiments of the present invention will be explained below with reference to the accompanying drawings.
In FIG. 1, reference numeral 12 represents a commercial AC power supply which is connected to
REFERENCES:
patent: 3263122 (1966-07-01), Genuit
patent: 4437040 (1984-03-01), Bay
patent: 4513364 (1985-04-01), Nilssen
patent: 4553070 (1985-11-01), Sairanen
patent: 4644459 (1987-02-01), Nilssen
patent: 4677345 (1987-06-01), Nilssen
Inui Ken'ichi
Kakitani Tsutomu
LaRoche Eugene R.
Toshiba Lighting and Technology Corporation
Zarabian A.
LandOfFree
Apparatus for operating discharge lamp does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for operating discharge lamp, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for operating discharge lamp will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1251098