JPS6030099A - Discharge lamp dimming firing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] (Technical field) The present invention provides a discharge lamp dimming lighting device 1' using an inverter.
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(Best Technology) Conventionally, as a means for controlling the output of an impark having an electrical oscillation system that converts the flow from the current to the current, a switch 6 connected in parallel to the current limiting element 4 is used as shown in FIG. There is a method of controlling the output power by turning off the current limiting element 4, but this method has the following drawbacks.

Now, the current limiting element 4 is set to control the power of the discharge lamp 5, which is the output load, to a certain dimming ratio.

Here, if the number of discharge lamps 5 changes and the output impedance changes, the previously set current limiting element 5 will not be able to match the target dimming ratio. For example, in an inverter lighting device that lights only one lamp, if the dimming current limiting element 4 is set so that the dimming ratio is 50q6, then one discharge lamp is added in parallel. When using a parallel two-lamp lighting device, the load impedance is halved compared to when one lamp is used, and 1
In the current limiting element 4 for dimming when lights are on, even if the switch 6 is turned off to switch to dimming, the dimming ratio is higher than when dimming 91 lights. This is similar to the case with centralized inverter lighting devices, etc.
In a discharge lamp lighting device (an example of which is shown in Fig. 2) that enables multiple lighting with a parallel circuit of two discharge lamps connected in series, the lamp e! 1. The dimming ratio fluctuates greatly depending on the change, which was a major drawback in its implementation. In addition, in the figure,
1 is a commercial power supply, 2 is a full-wave rectifier, and 3 is an inverter.

(Object of the Invention) The present invention has been made in view of the above points, and its purpose is to provide an IF lamp dimming lighting device that can maintain a constant dimming ratio regardless of the number of loaded lights in the lighting device. There is something to do.

(Disclosure of the Invention) The present invention divides the output winding of an inverter into two parts, uses the output waveform from one output winding as a fundamental wave, and lights up the rated output, and the other output winding has an opposite phase. It is characterized in that dimming is possible by superimposing it on the basic waveform and reducing the output voltage.

3rd Nd This is a circuit diagram showing an embodiment of the present invention, and is an oscillation transformer l] of an inverter 10 that changes from DC to AC →φ.
The next winding is Nl + N2. Here, the two secondary windings NI + N2 are insulated from each other. Then, one of the two large windings tfA (hereinafter referred to as the basic winding) N+ke,
It is connected in parallel with the circuit in which the current limiting element 12 and the discharge lamp are connected in series, and the other secondary winding C and the following are called control windings) N
2 is connected in parallel with the basic winding N1 via a coil and a coil 14. Here, the connection method is as follows: both windings N1.
Connect so that the polarity of N2 is reversed ([]).

Next, the operation will be explained. Now, when the switch 14 is turned off, the voltage v3 applied to the discharge lamp 13 is the Yagi winding 't=r.

This state is the rated lighting state in the Kitsu example. Therefore, when the switch f14 is turned on, the secondary winding output rlli and the voltage are generated not only by the basic winding N but also by the control winding N2.

Since the voltage from the control winding N2 is in opposite phase to the voltage from the basic winding N, the voltage a] is reduced by superimposing them. This becomes the wamp applied voltage. That is, this state becomes a dimming lighting state. Note that tal in FIG. 4 shows the output waveform by the basic winding NI, 161 in the same figure shows the output waveform by the control winding N2, and tc+ in the same figure shows the superimposed output waveform at the time of dimming.

(Effects of the Invention) According to the present invention, changes in the load impedance due to the number of lights greatly affect the impedance of the current limiting element for dimming, which is different from the conventional example in which the dimming ratio is greatly improved depending on the number of lights. In contrast, even when the current limit for dimming changes, the dimming ratio changes by <1, making it possible to obtain stable dimming regardless of the number of lights.

[Brief explanation of the drawing]

1 and 2 are circuit diagrams of a conventional example, FIG. 3 is a circuit diagram showing an embodiment of the present invention, and FIG. 41 is an operation waveform diagram of the controller. Patent Applicant Matsushita Electric Works Co., Ltd. Agent: Toshimaru Takemoto (and 2 others) Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] In a discharge lamp lighting device which inputs a 11+ DC" [tL pressure and supplies an AC output of an inverter having an electrical oscillation system to a discharge lamp, two of the oscillation transformers of the inverter
The secondary winding is divided into two, and a series circuit of a current limiting element and a discharge lamp is connected in parallel to the secondary winding of the power to be divided into two, and the other secondary winding edge is connected in parallel with the secondary winding in an opposite phase to the secondary winding. A discharge lamp 1υ1"j light lighting device, characterized in that it is connected via a switch element.