JPH0633676Y2 - Discharge lamp lighting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a discharge lamp lighting device having a large power source.

[Prior Art] Usually, a commercial transformer is often used in order to convert from a commercial power source to a voltage necessary for lighting a discharge lamp. However, in the case of a large power such as a 4 kW power source, using a commercial transformer causes the transformer to become large in size and increase in weight, resulting in a large scale device. Therefore, a constant voltage circuit may be required using a diode, a capacitor, or the like.

FIG. 3 is a block diagram showing a schematic configuration of a main part of a discharge lamp lighting device using a conventional voltage doubler circuit.
Is a rectifying / smoothing circuit, 3 is a chopper circuit that controls the output voltage by varying the pulse width, 4 is a polarity switching circuit in which a full bridge circuit is composed of a plurality of transistors, and 5 is a discharge lamp that lights at 360 V (hereinafter referred to as a lamp). ).

In FIG. 3, a 200 V AC power supply 20 is boosted by a power supply circuit 1 composed of a transformer T ₁ , diodes D ₁₁ , D ₁₂ , capacitors C ₁₁ , C ₁₂ , resistors R ₁₁ , R ₁₂ , and is rectified and smoothed by a rectifying and smoothing circuit 2. After rectifying and smoothing, the chopper circuit selects the pulse cycle, and the polarity switching circuit turns ON / OFF to turn on the lamp 5.

[Problems to be Solved by the Invention] As described above, in the conventional single-phase voltage doubling circuit, it is preferable to use a lamp with relatively low power consumption.
For a high-power V lamp, an input current of about 40 A is required, so that the breakdown voltage and capacity of each element such as diode and capacitor used in this voltage doubler circuit are required to be considerably large. is there.

The present invention has been made in order to solve such a conventional problem. In addition to using a large and heavy transformer such as a commercial transformer, an input current is made small and an element having a small withstand voltage and a small capacitance is used. It is an object of the present invention to provide a discharge lamp lighting device equipped with a voltage doubler circuit.

[Means for Solving the Problems] In order to achieve the above object, the discharge lamp lighting device of the present invention uses a three-phase AC power supply, and a power supply circuit in which a voltage doubler circuit is configured to boost the power supply voltage. Parts.

[Operation] By having the above configuration, the entire lighting device can be made small and lightweight, and the input current can be small.

[Embodiment] FIG. 1 is a block diagram showing an outline of a main part of a discharge lamp lighting device according to an embodiment of the present invention. 10 is a 200V three-phase AC power supply, 11 is a noise prevention circuit including a noise filter, 12 is a voltage doubler circuit, 13 is a chopper circuit, 14 is a polarity switching circuit, Q ₁ and Q ₂ are triacs as a soft start unit, R ₁ and R ₂ are resistors, and D ₁ , D ₂ , D ₃ and D ₄ , D ₅ ,, D ₆ ,, D ₇ ,, D ₈ , D ₉ are the first
2nd, 3rd, 4th, 5th, 6th, 7th, 8th, 9th diodes, C ₁ , C
₂ , ₂ , C ₃ , and C ₄ are capacitors, and C ₁ , C ₂ , and C ₃ are referred to as first, second, and third capacitors. And the first, second, ..., ninth diodes
The circuit configured by D ₁ , D ₂ , ... D ₉ and the first, second, and third capacitors C ₁ , C ₂ , C ₃ is the voltage doubler circuit 12.

Further, FIG. 2 (a) shows a voltage waveform diagram after the output voltage of the voltage doubler rectifier circuit of FIG. 1 is smoothed by the _fourth smoothing capacitor C ₄ , and FIG. 2 (b) is the same ( It is a voltage waveform diagram in which the voltage of a) is turned on / off in a very short cycle in the chopper circuit 13 and divided into strips, and FIG. 7 (c) is a choke in the chopper circuit 13 of the voltage of FIG. It is a voltage waveform diagram smoothed by the coil L.

Next, this embodiment will be described with reference to FIGS. 1 and 2.

First, the voltage the voltage doubler rectifying circuit 12 of 200V from the three-phase AC power source 10, ripple-like voltage DC560V such as FIG. 2 when boosted to voltage doubler (a) is connected to an end of the capacitor C ₄ Applied to both ends of the chopper circuit 13. In the chopper circuit 13, the input ripple-shaped DC voltage of 560V is
After being converted into a pulse that turns ON / OFF in a very short cycle as shown in FIG. 2B and the output voltage is controlled by varying the pulse width, the second voltage is controlled by the choke coil L in the chopper circuit 13. The voltage is smoothed as shown in FIG. 7C, and the DC voltage of 360 V as an average value is obtained. This voltage is input to the polarity switching circuit 14 composed of a full bridge circuit composed of a plurality of transistors, and the square wave current of the lamp 5 is obtained. Therefore, the lamp 5 is lit by the starter (not shown) and reaches a stable state, and the lamp voltage is 360V.
Reach

[Effects of the Invention] As described above, the discharge lamp lighting device of the present invention uses the three-phase AC power supply, and the power supply voltage is boosted by the voltage doubler circuit.
Since it is rectified, there is no need to use a large transformer,
Since the device can be made smaller and the input current is smaller than when using a single-phase power supply, use each element used in the noise filter, triac, and each element used in the voltage doubler circuit that has a smaller withstand voltage and capacity. You can

[Brief description of drawings]

FIG. 1 is a block diagram showing the outline of the main part of a discharge lamp lighting device according to an embodiment of the present invention, and FIG. 2 (a) is an electrolytic capacitor for smoothing the output voltage of the voltage doubler rectifier circuit of FIG. The voltage waveform diagram after smoothing with, the figure (b) shows the voltage of the figure (a) in a very short cycle in the chopper circuit.
Voltage waveform diagram divided into strips by turning it on and off, the same figure (c)
FIG. 3B is a voltage waveform diagram after smoothing the voltage shown in FIG. 3B by a choke coil in the chopper circuit, and FIG. 3 is a block diagram showing a schematic configuration of a main part of a discharge lamp lighting device using a conventional voltage doubler circuit. Is. In the figure. 10: Three-phase AC power supply 11: Noise prevention circuit 12: Double voltage circuit 13: Chopper circuit 14: Polarity switching circuit

Claims (1)

[Scope of utility model registration request] 1. A voltage doubler circuit connected to a three-phase AC power supply,
A discharge lamp lighting device comprising a chopper circuit and a polarity switching circuit, wherein the voltage supplied to the discharge lamp is controlled by the chopper circuit, wherein the voltage doubler circuit includes first and second input lines for each of the three-phase AC power supplies. , The respective anodes of the respective third diodes are respectively connected, and the respective anodes of the fourth, fifth and sixth diodes are respectively connected to the respective cathodes of the first, second and third diodes, Furthermore, between the cathode of the first diode and the anode of the second diode, and between the cathode of the second diode and the third diode.
First, second, and third capacitors are connected to the anode of the diode, and between the cathode of the third diode and the anode of the first diode, respectively, and the fourth, fifth, and The side connecting the cathodes of the sixth diodes is connected to one terminal of the fourth capacitor, and the anodes of the seventh, eighth, and ninth diodes are connected to the other terminal of the fourth capacitor. The anodes of the first, second, and third diodes are connected to the cathodes of the seventh, eighth, and ninth diodes, respectively, and the chopper is connected to both ends of the fourth capacitor. A discharge lamp lighting device having a circuit connected thereto.