KR200316990Y1 - Electronic ballast for instantaneously re-lighting metal-hallide lamp - Google Patents

Abstract

The present invention is an electronic ballast for a metal halide lamp composed of an AC input unit 10, DC-DC converter 20, flyback converter 30, inverter 40, igniter 50, the igniter 50 ) Is instantaneously applied to the primary winding of T4 by receiving a high voltage generating transformer T4 for generating a high voltage secondary winding voltage from a relatively small primary winding voltage and a voltage output from the flyback converter 30. An electronic ballast for instantaneous restarting of a metal halide lamp configured to include a spark gap for generating a high voltage in the secondary winding of T4 by flowing a large discharge current.

Description

Electronic ballast for instantaneous re-lighting of metal halide lamps {Electronic ballast for instantaneously re-lighting metal-hallide lamp}

The present invention relates to an electronic ballast which allows the metal halide lamp to instantly re-ignite even in a hot state immediately after turning off.

Metal halide lamps used in high intensity discharge (HID) lamps have a mild white color, especially the color rendering index of the lamp is 70-90, which is high color rendering and the object can be clearly identified. Widely used in lighting, it is about 3.56 times the light bulb and 4.7 times the halogen lamp. In addition, since the arc tube of the metal halide lamp is designed to be very small, it has the advantage of having a small size and can be manufactured in various standards, thereby facilitating the selection of a lamp suitable for a use place.

On the other hand, halogen lamps, which are heat radiating light sources, can be instantaneously turned on among the lamps used for artificial lighting.However, due to the loss due to heat generation, the power consumption is large and the light efficiency is relatively low, such as 16 [㏐ / W]. It has a low disadvantage.

However, the metal halide lamp, which is a high-pressure discharge lamp, can achieve the same brightness with 25% of the power consumption of the halogen lamp and the light efficiency is as high as 75 [㏐ / W]. For example, as shown in the table below, the luminous flux of a 300 [W] halogen lamp is about 5000 [mW], whereas the luminous flux of a 70 [W] metal halide lamp is more than 5000 [mW]. In addition, metal halide lamps have a longer lifespan than halogen lamps and have the advantage of being able to adjust the color temperature at will.

Luminous flux (lm) Color temperature (K) Life (h) Halogen lamp 300W 5000 3000 K 2000 Metal Halide Lamp70W 4900-5200 3100-4000 10000

However, while metal halide lamps have such advantages, they are turned on once due to their discharge characteristics, and when the lamp is turned off and the power is turned off, the lamp heats up again before it cools down (this is called "instantaneous restart"). The disadvantage is that the lamp will not turn on while it is cooling (about 5 minutes). Thus, despite the advantages of metal halide lamps, they are constrained to be used in places where on / off should be frequent.

In order to make up for the above drawbacks, the necessity of developing an electronic ballast for metal halide lamps capable of instantaneous restarting even when the lamp is hot has emerged. Developed.

Therefore, the present invention has been proposed to solve the above-mentioned conventional problem, that is, the metal halide lamp is not turned on when the arc tube of the lamp is hot due to the discharge characteristics, and is turned on only when the arc tube cools down. In order to make the transformer, the transformer having a large first and second winding ratio must be used, and thus the size of the igniter can be increased, and the efficiency of the ballast can be reduced due to many windings. Therefore, to reduce the size of the igniter and to make the secondary winding small, the primary voltage should be increased by using a spark gap with a high conduction voltage. Therefore, the spark gap conduction voltage for increasing the primary voltage can be obtained by using the secondary winding of the flyback converter. Therefore, using this high voltage igniter (approximately 15-25kV is required for instantaneous restart), the arc tube of the metal halide lamp can be turned on even when it is hot, replacing the inefficient halogen lamp and in the place where ON / OFF is frequent. Provides an electronic ballast for a wide range of metal halide lamps.

1 is a schematic block diagram of the present invention.

2 is a circuit diagram of a specific embodiment of the present invention.

<Description of Drawing>

10: AC input

20: DC-DC converter

30: Flyback Converter

40: inverter

50: Igniter

<Configuration>

The general configuration of the embodiment according to the present invention is as shown in FIG. Referring to FIG. 1, the present invention provides an AC input unit 10 for removing an EMI component by an EMI filter when AC power is input; A DC-DC converter 20 including a rectifying unit rectifying the input and filtered AC input, a power factor improving unit for switching the rectified DC voltage to improve the power factor, and a constant voltage unit maintaining the constant power factor improved voltage; A flyback converter 30 for controlling the power to be applied to the metal halide lamp L by switching the constant voltage output from the DC-DC converter 20 and adjusting its duty; An inverter (40) for converting the DC voltage output from the flyback converter (30) into a low frequency square wave AC voltage current to remove the acoustic resonance phenomenon generated in the lamp (L) when supplied to the lamp (L); It is composed of an igniter 50 for applying a voltage from the inverter 40 to apply a high voltage pulse to the lamp (L) to light the lamp (L).

When the AC input power 220V is input to the AC input unit 10, the EMI filter is removed from the EMI filter, and the DC-DC converter 20 detects the power factor improvement and the output voltage caused by the switching, so that the output voltage is constant, and the DC-DC converter ( The output voltage of 20 is input to the flyback converter 30. The flyback converter 30 controls the power applied to the metal halide lamp L by adjusting the duty by switching. The output of the flyback converter 30 is input to the half bridge inverter 40. The half bridge inverter 40 supplies a low frequency square wave voltage current to eliminate the acoustic resonance phenomenon of the lamp L. The high voltage igniter 50 for instantaneous restarting, which is a key component of the present invention, is a high voltage igniter for not only lighting a lamp normally but also turning the lamp on and turning off the lamp arc tube in a hot state.

<Example>

Hereinafter, embodiments of the present invention will be described in detail with reference to the igniter 50 with reference to the specific circuit diagram shown in FIG. 2.

It is well known that an igniter is required to light a metal halide lamp. The igniter output voltage of a typical electronic ballast is less than about 4kV, so it is not possible to re-light it in the hot state right after the lamp goes out. A high voltage of about 15-25 kV or higher is required to instantiate the lamp while it is hot.

Therefore, to instantiate a metal halide lamp, a high voltage igniter of 15-25 kV should be used. The high voltage igniter is manufactured by winding both primary and secondary windings in one box of the bobbin surrounding the core as in the conventional ballast. Due to this high relationship, it is difficult to insulate between windings, so a new type of igniter must be used. In this new type of igniter, it is preferable that the bobbin divides the high voltage to divide the high voltage so as to easily insulate the insulation, and the core uses a BAR core to reduce the inductance value.

In addition, in order to make the high voltage igniter voltage, a transformer having a large first and second winding ratio must be used, and thus the size of the igniter becomes large and the ballast efficiency decreases due to the large number of turns. Therefore, in order to reduce the size of the igniter and to reduce the number of secondary windings, a spark gap having a high conduction voltage should be used to increase the primary voltage.

In the present invention, the spark gap conduction voltage for increasing the primary voltage can be obtained by using the secondary winding of the flyback converter 30. In the detailed circuit of Fig. 3, the spark gap GAP1 conduction voltage is formed by the secondary winding of the transformer T3 of the flyback converter 30, the diode D4 and the capacitor C7, and the voltage is RC-corrected to the capacitor C10 through the resistor R3. When the voltage is charged according to the number, and the charged voltage becomes higher than the spark gap voltage, the spark gap is conducted and a momentary large discharge current flows through the primary winding of the igniter high-voltage generating transformer T4. A high voltage is generated in the secondary winding according to the primary and secondary winding ratios so that the lamp L is turned on.

As described above, according to the present invention, since the igniter of the electronic ballast for metal halide lamps can generate a high voltage with a relatively small size, instantaneous restarting is possible immediately after the metal halide lamp is turned off, and the halogen is inefficient. It can replace the lamp and can be used extensively in frequent on / off areas, which can reduce the wasted time waiting for unnecessary power consumption and re-lighting.

Claims (3)

AC input unit 10 for removing the EMI component by the EMI filter when AC power is input; A DC-DC converter 20 including a rectifying unit rectifying the input and filtered AC input, a power factor improving unit for switching the rectified DC voltage to improve the power factor, and a constant voltage unit maintaining the constant power factor improved voltage; A flyback converter 30 for controlling the power to be applied to the metal halide lamp L by switching the constant voltage output from the DC-DC converter 20 and adjusting its duty; An inverter (40) for converting the DC voltage output from the flyback converter (30) into a low frequency square wave AC voltage current to remove the acoustic resonance phenomenon generated in the lamp (L) when supplied to the lamp (L); In the electronic ballast for a metal halide lamp, consisting of an igniter 50 for applying a voltage from the inverter 40 to apply a high voltage pulse to the lamp L to light the lamp L, The igniter 50 receives a high voltage generating transformer T4 for generating a high voltage secondary winding voltage from a relatively small primary winding voltage and a voltage output from the flyback converter 30 to receive the primary of the T4. And a spark gap to generate a high voltage in the secondary winding of T4 by instantaneously flowing a large discharge current to the winding, thereby generating a high voltage in the secondary winding of the T4. The electronic ballast of claim 1, wherein the high pressure generated in the secondary winding of the high pressure generating transformer (T4) is about 15 to 25 kV. The method according to claim 1 or 2, wherein the high-pressure generating transformer (T4) Bobbin is provided with a number of winding compartments, the core is a BAR core, characterized in that the electronic ballast for instantaneous lighting of the metal halide lamp.