JPH09320786A - Inverter-type discharge lamp-lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inverter type discharge lamp lighting system for light modulation, capable of reducing harmonic input current in the light modulation of a discharge lamp by arranging a device which converts commercial power source into DC voltage, applies the DC voltage to a plurality of luminaires, and varies DC output voltage. SOLUTION: A DC voltage variable device 2 containing an active filter smoothing circuit rectifies a commercial power source 1 into DC voltage, applies the DC voltage to inverter-type luminaires 3, 4, 5, and a discharge lamp is lit. By varying DC output variable resistance 21 inside the DC voltage variable device 2, the discharge lamps of the luminaires 3, 4, 5 are light-modulated. Input current substantially sine wave containing almost no harmonic components flows in the power source 1 by using the active filter smoothing circuit. Thus, an inverter-type discharge lamp-lighting system for light modulation capable of reducing harmonic input current can be obtained.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dimming inverter type discharge lamp lighting device in which a harmonic input current is reduced during dimming. 2. Description of the Related Art Conventionally, as shown in FIG. 2, a lighting device of this type has a dimmer built in between a power source and a discharge lamp lighting fixture, and controls the phase of the power supply voltage by the dimmer to emit light. I have dimmed the lights. However, in such a dimming method, the dimming is performed by controlling the phase of the power supply voltage.
The harmonic content of the current flowing through the power supply is high, which adversely affects other electronic devices. [Means for Solving the Problems] In order to obtain an input current with a low harmonic content rate during dimming, the discharge lamp lighting device is an active filter smoothing circuit, and dimming controls the DC output voltage of this active filter smoothing circuit. This is done by changing the variable resistance. A commercial power source is rectified by a DC voltage variable device including an active filter smoothing circuit, and this is used as a power source to connect to a plurality of inverter type discharge lamp lighting devices. During normal lighting, the sine wave input power flows to the commercial power supply due to the operation of the active filter. For dimming, the DC output is varied by varying the output voltage variable resistance of the DC voltage varying device, and the output of each discharge lamp is varied according to the magnitude of this voltage, and dimming can be performed. Since the dimming is performed by changing the DC output,
The input current of the commercial power supply is almost sinusoidal and does not include harmonics. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention. Commercial power supply 1
When is turned on, the DC voltage rectified by the DC voltage varying device 2 including the active filter smoothing circuit is applied to each of the inverter type lighting fixtures 3, 4 and 5, and the discharge lamp is turned on. Next, the DC output variable resistor 2 in the DC voltage variable device
Invariable discharge lamp lighting fixture 3 by changing 1
-Discharge lamps 4 and 5 are dimmed. At this time, due to the active filter smoothing circuit, a substantially sinusoidal input current containing almost no harmonic component flows through the power supply 1. As described above, according to the present invention, since the dimming can be performed by varying the DC voltage, it is possible to provide an inverter type discharge lamp lighting device having a low harmonic content rate in a commercial power source.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional dimming method. DESCRIPTION OF SYMBOLS 1 ... Commercial power supply 2 ... DC voltage varying device 21 ... Variable resistance 3/4/5 ... Inverter type lighting fixture

Claims (1)

[Claims] 1. A DC voltage changing device that converts a commercial power supply to a DC voltage and can change the DC voltage; and a DC output voltage of the DC voltage changing device that uses the DC voltage changing device as a power source and a plurality of discharge lamp fixtures as loads. By doing so, an inverter type discharge lamp lighting device capable of dimming the output of the discharge lamp fixture. 2. The DC voltage variable device is composed of a step-up chopper circuit that rectifies and smoothes a commercial power supply and includes an inductance element and a switching element, an active filter control IC that controls the chopper circuit, a DC output variable resistor, and the like. The inverter type discharge lamp lighting device according to claim 1, wherein the direct current output can be changed by making a current flowing through the sine wave substantially sinusoidal and varying the direct current output variable resistance. 3. The inverter type discharge lamp lighting device according to claim 1, wherein each of the plurality of discharge lamp fixtures includes an inverter device for generating a high frequency output by a DC power source.