KR20060019190A - Driving circuit for high intensity discharge lamp - Google Patents

Abstract

The present invention relates to a driving circuit of a high-voltage discharge lamp that prevents the flicker phenomenon even at a high frequency used as a xenon lamp that solves the EMI problem caused by the high-frequency surge, the rectification and resonant circuit unit 200, and the first An inverter side 400 for generating a high frequency signal by switching the first to fourth switching elements Q1 to Q4 under the control of the fourth to fourth switching control signals G1 to G4, and an output side signal is fed back to the output side When the power measured from the predetermined value is greater than or equal to the switching control signal (G1-G4) by generating a constant voltage and oscillation circuit unit 300 so that the output power is kept constant, and input AC power supply bridge diode circuits (BD1) High frequency rectifying unit 500 which converts into direct current rectified by BD4) and improves power factor and provides a stable DC voltage to the lamp, and high column for preheating lamp by high frequency current. A starter circuit unit 600 and a harmonic content minimizing circuit unit 700 for suppressing harmonic noise components, wherein the inverter unit 400 is configured by two or more switching elements to distribute onions. The furnace further includes an IGBT onion distribution circuit unit 300b which emits a switching control signal G1-G4 to the inverter unit 400 in response to the control signal from the constant voltage and the oscillation circuit unit 300.

High frequency, high pressure discharge, surge, harmonic content minimizing circuit, onion distribution

Description

Driving circuit for high-voltage discharge lamp {DRIVING CIRCUIT FOR HIGH INTENSITY DISCHARGE LAMP}

1 is a circuit diagram of a conventional driving circuit for a high-pressure discharge lamp.

2 is a block diagram of a driving circuit for a high-pressure discharge lamp according to the present invention.

3 is a detailed circuit diagram of a driving circuit for a high-pressure discharge lamp according to the present invention.

<Description of the symbols for the main parts of the drawings>

100: input power supply 200: rectification and resonant circuit

300: constant voltage and oscillation circuit portion 300a: constant current conversion circuit portion

300b: IGBT onion distribution circuit 400: ARC inverter

400a: high frequency step-down unit 500: high frequency rectifier

600: high frequency start circuit 700: harmonic content minimizing circuit

800: rectifier protection circuit 900: lamp

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic ballast for a high intensity discharge (HID) lamp, and more particularly to an electronic ballast for driving a high voltage high current high voltage discharge lamp such as a xenon search lamp at a high frequency.

A general electronic ballast includes a starting semiconductor element in a ballast, which preheats the electrode with its switching action or electrode heating winding, and starts the lamp by the semiconductor switching action, while the lamp is turned on by the lamp current and the electrode heating winding during lighting. As the ballast used in the circuit system to be heated, there are self-excited equations oscillated by its own LC resonant circuit and a perception equation using a separate oscillator.

General electronic ballasts have several advantages over conventional ballasts, but they are weak in voltage fluctuations and surge voltages, so they must have a built-in protection circuit and require special measures at start-up.

On the other hand, the general high-pressure discharge lamp has a high voltage, such as mercury lamp, high-pressure sodium lamp, metal halide lamp, and the inside of the tube becomes a high-temperature plasma state when turned on. In order to create such a high pressure discharge condition, an electronic ballast is mainly used in recent years, and there is a self-supporting electronic ballast for a high pressure discharge lamp such as PCT Publication No. WO99 / 51066.

First, the electronic ballast described in the above publication, the conventional conventional HID electronic ballast is composed of an input power supply unit, a converter unit, an inverter unit, an output matching unit, a buffer DC power supply unit, a power control unit and a gate transformer unit.

However, in general, high voltage discharge lamps are discharged at a relatively low current, whereas xenon lamps used for long-range research lighting or military and marine searchlights have high voltages ranging from 6 kV to 12 kV. In addition, instantaneous high current flows during lighting. In addition, in order to eliminate the flickering phenomenon, it is necessary to generate a high voltage of a high frequency by a high frequency starting circuit. This causes a surge current and a high frequency disturbance to other electronic equipments, and therefore, a certain high frequency component and a high voltage and The generation of surge current above a certain level is prohibited. Eventually, the interest in night events using searchlights was inevitable.

In addition, high-voltage special lighting is necessary to create beautiful city by lighting up and night scenery lighting to direct the city's historic buildings and bridges, or for night special lighting such as beautiful event event or night broadcasting As a general commercial power source (220V), in order to generate a high-voltage power as described above, a large expensive transformer or the like must be used, and a huge power loss occurs, which leads to a large size of the rectifier and an increase in cost.

In order to solve the above problems, the inventors of the present invention have made the invention as described in Korean Patent No. 4730, which is named "Drive Circuit for High Voltage Discharge Lamps". According to the drive circuit for high-pressure discharge lamps, the commercial power source is once It is possible to generate high voltage and high current only by a small transformer by rectifying the high frequency oscillation pulse which is rectified by converting it into direct current and converting the converted direct current by the high frequency oscillation circuit again. Therefore, the small high efficiency and high frequency surge It was possible to provide a driving circuit for a high-voltage discharge lamp that is used as a search light that solves the problem of high frequency interference (EMI).

That is, when the patent invention is described in detail with reference to FIG. 1, the driving circuit for the high-voltage discharge lamp rectifies and resonates the input AC signal passing through the power stabilization unit 100 ′ and supplies a DC voltage 200 ′. ), An inverter unit 400 'which generates a high frequency signal by switching the first and second switching elements Q1 and Q2 under the control of the switching control signals G1 and G2, and an output side signal is fed back. When the power measured from the output side is greater than or equal to a predetermined value, the switching control signal for controlling the switching of the first and second switching elements is issued to maintain the output power constant, and the first time of the lamp 900 ' When turned on, by converting the constant voltage and oscillation circuit portion 300 'to start the oscillation operation to start switching of the switching element, and the input AC power to full-wave rectified DC through the bridge diode circuits BD1-BD4. High frequency rectifier 500 'for improving power factor and supplying a stable DC voltage to the lamp, high frequency start circuit 600' for preheating the lamp by high frequency current, and minimizing harmonic content rate circuit for suppressing harmonic noise components And a rectifier protection circuit 800 '.

In this case, the inverter unit 400 'is configured to switch the first and second transistors at a high frequency by controlling the switching control signals G1 and G2 from the constant voltage and the oscillation circuit 300', so that the inverter unit has a high frequency signal. Generates.

On the other hand, the discharge lamp is difficult to set the driving voltage to 48V or more because of its characteristics. Therefore, in order to discharge at a large power of several kW or more, the driving current must be a large current, and thus the cycle must be started large. However, in the high current system above 8kHz, the short wave distribution method has a limitation in removing flicker completely.

That is, the above-described invention of the present inventors uses the shortwave distribution method using only a pair (two) of switching elements Q1 and Q2, and therefore often causes flicker at high frequencies of 8 kHz or more.

The present invention has been made to solve the above problems of the prior art, and an object of the present invention is to provide a driving circuit of a discharge lamp capable of oscillation of several tens of kHz without the flicker phenomenon.

Further objects and effects of the present invention will become more apparent from the following detailed description of the invention described with reference to the accompanying drawings.

The driving circuit for lighting the high-voltage discharge lamp according to the present invention for achieving the above object, the rectifying and resonant circuit unit 200 for rectifying the input AC signal to supply a DC voltage; Inverter unit 400 for generating a high frequency signal by switching the first to fourth switching elements Q1, Q2, Q3, and Q4 by controlling the first to fourth switching control signals G1, G2, G3, and G4. ); When the output side signal is fed back and the power measured from the output side is equal to or greater than a predetermined value, the output power is kept constant by emitting the switching control signals G1-G4 for controlling the switching of the first to fourth switching elements. A constant voltage and oscillation circuit unit 300 to start an oscillation operation of starting switching of the switching element when the lamp is first turned on; A high frequency rectifier 500 for converting an input AC power into a direct current rectified by bridge diode circuits BD1-BD4 to improve power factor and supply a stable DC voltage to the lamp; A high frequency start circuit unit 600 for preheating a lamp by a high frequency current; And a harmonic content minimizing circuit portion 700 for suppressing harmonic noise components, wherein the inverter portion 400 comprises two pairs (four) or more switching elements to distribute onions, and the driving circuit includes: And an IGBT onion distribution circuit unit 300b which emits the switching control signals G1-G4 to the inverter unit 400 in response to the control signal from the constant voltage and the oscillation circuit unit 300.

Preferably, the harmonic content minimizing circuit unit 700 includes capacitors C4 and C5 for absorbing surge voltages connected in parallel to both ends of the lamp electrode, and resistors R6 connected in parallel to both ends of the lamp electrode. ) And a high frequency noise reduction circuit comprising a parallel circuit of varistor ZNR2, a parallel circuit of varistor ZNR6 and capacitor C6 grounded at one side connected to the negative terminal of the lamp, and a positive terminal of the lamp. One connected side is composed of a grounded varistor ZNR7.

More preferably, the high frequency rectifier includes first to fourth bridge diodes BD1 to BD4, and the first terminal and the second terminal of each bridge diode are connected via resistors R2-R5, respectively. The first terminal of the first bridge diode BD1 and the first terminal of the second bridge diode BD2 and the second terminal of the third bridge diode BD3 and the second terminal of the fourth bridge diode BD4 are mutually connected. Connected, the second terminal of the first bridge diode BD1 and the first terminal of the third bridge diode BD3 and the second terminal of the second bridge diode BD2 and the first terminal of the fourth bridge diode BD4. The terminals are connected to each other, and the secondary side of the output transformer TR2 is connected to the second terminal of the first bridge diode BD1 and the first terminal of the fourth bridge diode BD4, respectively, and the second bridge diode. The first terminal of the BD2 is a positive terminal of the lamp 900 through the waveform shaping element TR3. And the first terminal of the fourth diode bridge (BD4) is directly of said lamp (900) is made is connected to the terminal side, ()

The high frequency starting circuit 600 has an input side connected to the + terminal P21 and the-terminal P22 of the high frequency rectifying unit 500, and the output side has an instantaneous high voltage induction coil LC1 of the harmonic content minimizing circuit unit 700. One input terminal is connected to the primary side of the fifth high frequency transformer TR5 through the start switch SW1 or SW2 and the other input terminal is connected through the RC parallel circuits R7, C7, and C8. On the secondary side of the high frequency transformer, the variable capacitor (VCT) is connected in parallel, and the instantaneous high pressure induction coil (LC1) of the harmonic content minimizing circuit unit 700 for starting the lamp through the series connection capacitor (C9, C10, C11) again. ) Is connected.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to FIGS. 2 and 3.

2 is a schematic block diagram of a driving circuit for a high-pressure discharge lamp according to the present invention, Figure 3 is a detailed circuit diagram.

2 and 3, the driving circuit for the high-voltage discharge lamp according to the present invention, the input power supply unit 100, the rectifying and resonant circuit unit 200, the constant voltage and oscillation circuit unit 300, the ARC inverter unit The conventional circuit part of the 400, the high frequency rectifying part 500, the high frequency starting circuit part 600, the harmonic content minimizing circuit part 700, and the rectifier protection circuit part 800 are all basic, but the detail circuit is different.

In addition, in the inverter unit 400 of the present invention, unlike the inverter unit 400 'of the prior art, two pairs (four) of switching elements Q1, Q2, Q3, and Q4 are used, and these are IGBT onion distribution circuit units. Onion distribution is performed by the four pairs of control signals generated by different parallax from 300b. On the other hand, a constant current for supplying a constant voltage and a constant voltage to the oscillation circuit unit 300 by converting a current of a part of the output of the high frequency step-down unit 400a, which step-downs the high voltage of the ARC inverter unit 400 and passes it to the high-frequency rectifying unit 500. The conversion circuit unit 300a is coupled to the constant voltage and oscillation circuit unit 300 for supplying the oscillation pulses to the IGBT onion distribution circuit unit 300b.

The driving circuit for the high-pressure discharge lamp of the present invention will be described in more detail with reference to FIG.

First, the input power supply unit 100 is for supplying a stable power, such as the input power supply unit 100 ′ of FIG. 1, but in this embodiment, a transformer of 200-240V is used by using a no-fuse switch (NFB). By passing through (TR1), the phase voltage and phase current of the AC three-phase alternating current are kept constant, and the phase deviation which is the voltage difference between phases is removed. However, the present invention is not necessarily limited to three-phase alternating current as in the present embodiment.

Next, the input stabilized AC power is rectified through the bridge diodes D1-D6 of the rectification and resonant circuit unit 200, and the rectified voltage is the diode D2, the smoothing resistor R1, and the capacitor C7. Is smoothed by In addition, since the one side terminal of the capacitor is connected in series to the time constant compensation resistor R1-1, the rectified voltage is preferably filtered by the noise filters C12 and C13.

The onion filter inverter 400, which is the next stage, is connected to the noise filter circuit. In this case, when the resonant circuit is configured as an RLC series-parallel resonant circuit, the amount of electrical energy radiated from the power source to the lamp is controlled, and the high frequency surge characteristics and power factor are improved by maintaining a stable pulse with a large change.

In particular, the inverter unit 400 of the present invention is formed by a plurality of (for example four) transistors Q1, Q2, Q3, Q4, and the first transistor Q1 and the third transistor Q3. Is inserted between the upper potential terminal P11 and one terminal P13 of the transformer TR2, and the second transistor Q2 and the fourth transistor Q4 are lower than the other terminal P14 of the transformer TR2. It is inserted into the potential terminal P12.

The reset diodes D7, D8, D9, and D10 are connected between the source / drain terminals of the first transistor Q1 to the fourth transistor Q4, and the upper potential terminal P11 and the lower potential terminal P12 are connected to each other. The constant voltage holding capacitors C2 and C3 are connected to each other.

The one side and the other terminal P13, P14 naturally become the primary terminal of the step-down transformer TR2 on the output side. In addition, the switching control signals G1, G2, G3, and G4 from the constant voltage and oscillation circuit 300 are provided at the gate terminals of the first to fourth transistors, and the constant voltage and oscillation circuit 300 are provided at the emitter terminals of the respective transistors. The reset control signals E1, E2, E3, and E4 from are applied via the IGBT onion distribution circuit unit 300b.

The high frequency step-down unit 400a is a voltage value of the high-frequency AC signal obtained by the inverter unit 400 from DC 220V by the voltage drop output side transformer TR2 in consideration of the rated voltage of the lamp or less (in this case 48V). Dropped to.

On the other hand, the constant voltage and the oscillation circuit 300 is applied to the rectified DC voltage of the rectified and resonant circuit unit 200 as a power source is a drive power source of 20V and 8V, for example through an appropriate voltage divider (not shown) inside Driven by the second side signal of the transformer TR2 of the output side of the high frequency step-down part 400a, and the switching of the first to fourth transistors is performed when the power measured from the output side of the rectifier is greater than or equal to a predetermined value. By controlling the high frequency (19kHz to 37kHz), the output power can be kept constant.

In addition, high frequency start is performed by the high frequency start circuit 600 at the time of initial lighting, which will be described in more detail as follows.

In other words, the starting current is necessary for the high-pressure discharge lamp. In the past, it was not possible to use it for several km of moving light due to the breakdown of the circuit due to the high voltage at the start of the high-pressure discharge lamp. The lamp capacity, which is a high voltage of 12,000V and uses a current of 1 mA to several mA of moisture, has an effect of prolonging lamp life and preventing circuit breakdown even when starting a high-voltage discharge circuit.

That is, when the xenon lamp is turned on, an overvoltage overcurrent is applied due to a transient phenomenon, which may adversely affect the blackening of the lamp. Therefore, a lamp preheating of a high frequency current of about 0.05 to 0.8 seconds is required. The circuit adopts a circuit using an LC circuit and a hybrid IC to prevent blackening to extend the life of the lamp.

The input side of the high frequency start circuit 600 of the present invention may be connected to both terminals of the input power supply 100, but in this embodiment is connected to the + terminal P21 and the-terminal P22 of the high frequency rectifier 500. The output side is connected to the instantaneous high pressure induction coil LC1 of the harmonic content minimizing circuit portion 700. In addition, one input terminal is connected to the primary side of the fifth high frequency transformer TR5 through the manual switch SW1 and the relay auto switch SW2, which are starting switches, and the other input terminal is connected through the RC parallel circuits R7, C7, and C8. Connected. Secondary side of the fifth high frequency transformer is connected to the variable capacitor (VCT) in parallel, the instantaneous high-voltage induction of the harmonic content minimizing circuit portion 700 for starting the lamp through the series connection capacitor (C9, C10, C11) It is connected to the coil LC1.

In other words, the lamp capacity using a high voltage of 1,500-12,000V and a current of 1 mA to several mA of moisture is proportionally adjusted to the pole force of the secondary side variable capacitor (VCT) and the induction coil recovery of the instantaneous high pressure induction coil (LC1). Using a high voltage power supply suitable for the lamp will extend the lamp life. For example, if the interpolation force of VCT is 0.2mm, 3500V is applied, if the interpolation force of VCT is 1mm, 6500V is applied, and if the interpolation force of VCT is 1.2mm, 3500V is applied to the lamp, and LC1 induction coil recovery When 2 circuits are used, the power of 7.3A is applied to 9000V and the number of induction coils of LC1 is 3 to 4, and 2A power is applied to the lamp from 3500 to 13000V.

Therefore, the power source including the high frequency reflection component input through the input side is first charged while absorbing the high frequency components reflected by the RLC resonant circuits R7, C7 and C8 including the parasitic inductor. When the capacitor is sufficiently charged, the capacitor is boosted to high pressure in the third high frequency transformer TR1. In this case, when the start switch SW1 is 'turned on', the lamp 900 is turned on while a large current (for example, 140A) flows at a time. After the turn-on, the high frequency start circuit is disconnected and the high frequency rectifier 500 The high pressure direct current of is continuously supplied to the lamp. In this case, the rough high frequency voltage value is determined by the number of turns of the high frequency transformer, but finer adjustment is made by adjusting the variable capacitor (VCT).

On the other hand, according to the constant voltage and oscillation circuit 300 of the present invention, since the rectified voltage of ± 30V fluctuation of the input voltage is supplied to the ARC rectifier circuit at a constant high frequency DC voltage, the output can be obtained evenly, and the lamp life is greatly extended.

Therefore, the switching of the first to fourth transistors Q1 to Q4 is performed at high frequency by the control of the switching control signals G1 to G4 from the constant voltage and the oscillation circuit 300, whereby the inverter unit reaches 19 kHz to 37 kHz. Generate a high frequency signal. For example, when the ARC inverter unit 400 outputs an alternating current of 19-37 kHz and 800-1200 V, the step-down transformer TR2 of the high frequency step-down unit 400a receives the primary side alternating current of 28-42 V and 4-37 A. The secondary side AC will be output.

Furthermore, in the first half period, current flows in the direction of "high potential terminal P11-first transistor Q1-step-down transformer TR2-fourth transistor Q4-lower potential terminal P14". In the second half cycle, the current flows in the direction of "high potential terminal P11-third transistor Q3-step-down transformer TR2-second transistor Q2-lower potential terminal P14". Because of the distribution, flicker does not occur even at high frequencies.

In addition, the secondary side of the output side transformer TR2 is connected to the high frequency rectifier 500. The high frequency rectifier is composed of four bridge diodes BD1-BD4. The first terminal and the second terminal of each bridge diode are connected through a series circuit of varistors ZNR1-ZNR4 and resistors R2-R5, respectively, and the first and second bridge diodes of the first bridge diode BD1. The first terminal of BD2 is connected at the contact point P23, and the second terminal of the third bridge diode BD3 and the second terminal of the fourth bridge diode BD4 are connected at the contact point P24, and the first bridge diode BD1 is connected. The first terminal of the second terminal and the third bridge diode (BD3) of the () and the second terminal of the second bridge diode (BD2) and the first terminal of the fourth bridge diode (BD4) are at the contact P22 Interconnected. In addition, a secondary side of the output transformer TR2 is connected to the second terminal of the first bridge diode BD1 and the first terminal of the fourth bridge diode BD4, respectively, and the first terminal of the second bridge diode BD2 is connected. The terminal is connected to the positive terminal of the lamp 900 which is one end of the harmonic content minimizing circuit 700 through the choke coil TR3, which is a waveform shaping element, and the second instantaneous high voltage of the fourth bridge diode BD4. It is connected to the (-) side terminal of the said lamp 900 which is the other end of the harmonic content rate minimizing circuit 700 via the induction coil LC1.

Reference numeral CT1 is a current sensing element connected to the constant current conversion circuit unit 300a, and terminals P25 and P26 are intentionally formed shunt contacts for checking current from outside the circuit.

In detail, the constant current conversion circuit 300a of the present invention adjusts the current according to the high voltage discharge lamp, and the constant voltage and oscillation circuit 300 controls the frequency oscillation in an optimal state, and responds to the oscillation signal in response to the IGBT. The onion distribution circuit unit 300b emits the optimum inverter 400 control signals G1-G4 to induce the optimum lamp driving voltage and current to the lamp 900.

Now, the high frequency rectifier circuit 500 converts the input AC power into a direct current rectified by the bridge diode circuits to improve the power factor and supply a stable DC voltage to the lamp. That is, when high frequency AC 19-37 kHz alternating current is passed through the high speed diode bridge circuit of the high frequency rectifying part 500, a high frequency is contained in pure DC, and a waveform is shaped while passing through the choke coil TR3.

On the other hand, harmonic content rate minimizing circuit 700 is connected to both ends of the lamp. In the harmonic content minimizing circuit 700, as shown in the lower right of FIG. 3, capacitors C4 and C5 for absorbing a surge voltage are connected in parallel to the lamp anode. That is, the capacitors C4 and C5 together with the reactor component of the output transformer TR2 and the resistance components R2-R5 of the high frequency rectifier 500 effectively absorb the surge components by forming a substantial RLC resonance circuit. . In addition, a high frequency noise attenuation circuit including a parallel circuit of the resistor R6, the varistor ZNR2, and the capacitor C12 is connected in parallel between both electrodes of the lamp, and the varistor ZNR6 having one side grounded at the negative end of the lamp. ) And a capacitor (parallel circuit of C16) are connected, and a varistor (ZNR6) having one side grounded to the anode terminal of the lamp is connected, that is, prior to the driving circuit of the present inventors, the DMX 512 signal system was adopted for event event lighting. Bar, it has been recognized that the use of the high-frequency discharge lamp driving circuit for the high-voltage discharge lamp of the present invention by eliminating the radio interference disturbances containing high-frequency components by developing a built-in EMI minimizing circuit Reducing the content of 0.8% or less solves the EMI problem and does not adversely affect surrounding electronic precision devices. Flicker does not occur even at frequencies above 8kHz.

In other words, the harmonic content minimizing circuit 700 includes a harmonic component in the DC component, and minimizes the harmonic components in the capacitors C4, C5, and the varistor ZNR5, while eliminating the capacitor C6 and the varistors ZNR6, ZNR7. So that harmonics flow out to ground.

Finally, the rectifier protection circuit 800 will be described. The input side information is measured by measuring one side voltage of the smoothing capacitor C1 of the rectifying and resonant circuit unit 200 and one side voltage of the noise filters C12 and C13. The inverter unit receives power information from the secondary side of the transformer TR4 connected to the power supply terminal, and generates a gate control signal to the constant voltage and oscillation circuit unit 300 when the rectifier shows abnormal oscillation or abnormal voltage. To protect the rectifier through the switching transistor (Q1-Q4) of (400). The rectifier protection circuit needs to protect the rectifier from overtemperature of the rectifier through a thermostat (not shown) as well as overvoltage or overcurrent. In addition, it is desirable to include a display driving circuit.

The operation of the driving circuit for the high-voltage discharge lamp according to the present invention is described above. The high-frequency voltage (for example, 19 kHz to 37 kHz, 1.2 kV) excited by the inverter circuit 400 is caused by the high-frequency rectifying circuit 500. It is rectified and changed to DC power, and at the same time, it is changed to high voltage by the high frequency start circuit 600 and applied to the lamp. The voltage of about 80V is continuously applied to both ends of the lamp before the lamp is started. When the high-pressure discharge in the lamp is started by starting, a high voltage of about 6-12 kV is applied to both ends of the lamp, and the lamp is started to light by discharging the high voltage of about 5 kW momentarily. Once the lamp is turned on, a voltage of about 30 V is continuously applied to both ends of the lamp, and at this time, a current of about 140 A flows between the lamp electrodes.

On the other hand, when the noise component such as surge is limited to within 10% compared to the high frequency power signal applied to the lamp, the problem of EMI is solved. When the harmonic content minimizing circuit 700 according to the present invention is used, the noise is reduced. The content of is limited to up to 0.8%, which makes it possible to solve the EMI problem that adversely affects other electronic devices.

In addition, by the onion distribution method it is possible to prevent the flicker phenomenon at high frequencies.

Although the present invention has been described above with reference to one embodiment shown in the accompanying drawings, the present invention is not limited thereto, and various modifications may be made within a range easily understood by those skilled in the art. Therefore, the limitation of the present invention should be limited only by the following claims.

As described above, according to the driving circuit for the high-pressure discharge lamp according to the present invention, the high-frequency rectifying driving circuit is adopted, the efficiency is high (saving more than 30% power consumption and little power consumption at no load), and lamp life It can be extended by more than 20%, and especially flickering can be completely prevented even at high frequencies, and the lamp can be turned on immediately, and the brightness at the time of lighting can be maximized. It does not adversely affect other electronic equipment due to high frequency disturbances, and it has reduced the capacity weight by 1/3 compared to the linear type (trans type), which is used for foreign event events and military searchlight lighting equipment, and driving xenon lamp very close to natural light Stabilization electronics can be adopted.

Claims (4)

As a driving circuit for lighting a high voltage discharge lamp, Rectification and resonant circuit unit 200 for rectifying the input AC signal to supply a DC voltage; Inverter unit 400 for generating a high frequency signal by switching the first to fourth switching elements Q1, Q2, Q3, and Q4 by controlling the first to fourth switching control signals G1, G2, G3, and G4. ); When the output side signal is fed back and the power measured from the output side is equal to or greater than a predetermined value, the output power is kept constant by emitting the switching control signals G1-G4 for controlling the switching of the first to fourth switching elements. A constant voltage and oscillation circuit unit 300 to start an oscillation operation of starting switching of the switching element when the lamp is first turned on; A high frequency rectifier 500 for converting an input AC power into a direct current rectified through bridge diode circuits BD1-BD4 to improve power factor and supply a stable DC voltage to the lamp; A high frequency start circuit unit 600 for preheating a lamp by a high frequency current; And A harmonic content minimizing circuit portion 700 for suppressing harmonic noise components, The inverter unit 400 is composed of two or more (four) switching elements, thereby performing onion distribution, The driving circuit further includes an IGBT onion distribution circuit unit 300b which emits the switching control signals G1-G4 to the inverter unit 400 in response to the control signal from the constant voltage and the oscillation circuit unit 300. Driving circuit for high voltage discharge lamp. The method of claim 1, The harmonic content minimizing circuit portion 700, Capacitors C4 and C5 for absorbing surge voltages connected in parallel to both ends of the lamp electrodes; A high frequency noise reduction circuit comprising a parallel circuit of a resistor R6 and a varistor ZNR2 connected in parallel to both ends of the lamp electrode; A parallel circuit of a varistor (ZNR6) and a capacitor (C6) grounded at one side connected to the cathode end of the lamp; And a varistor (ZNR7) having one side connected to the positive terminal of the lamp grounded. The method according to claim 1 or 2, The high frequency rectifying unit includes first to fourth bridge diodes BD1 to BD4, and the first terminal and the second terminal of each bridge diode are connected through the resistors R2-R5, respectively, and the first bridge diode BD1. And a first terminal of the second bridge diode BD2 and a second terminal of the third bridge diode BD3 and a second terminal of the fourth bridge diode BD4 are connected to each other. The second terminal of the diode BD1 and the first terminal of the third bridge diode BD3 and the second terminal of the second bridge diode BD2 and the first terminal of the fourth bridge diode BD4 are connected to each other, In addition, a secondary side of the output transformer TR2 is connected to the second terminal of the first bridge diode BD1 and the first terminal of the fourth bridge diode BD4, respectively, and the first terminal of the second bridge diode BD2 is connected. The terminal is connected to the positive terminal of the lamp 900 and the fourth bridge through the waveform shaping element TR3. The first terminal of the diode (BD4) is connected directly to the negative terminal of the lamp 900, the drive circuit for a high-pressure discharge lamp, characterized in that. The method according to claim 1 or 2, The high frequency starting circuit 600 has an input side connected to the + terminal P21 and the-terminal P22 of the high frequency rectifying unit 500, and the output side has an instantaneous high voltage induction coil LC1 of the harmonic content minimizing circuit unit 700. One input terminal is connected to the primary side of the fifth high frequency transformer TR5 through the start switch SW1 or SW2 and the other input terminal is connected through the RC parallel circuits R7, C7, and C8. On the secondary side of the high frequency transformer, a variable capacitor (VCT) is connected in parallel, and an instantaneous high pressure induction coil (LC1) of the harmonic content minimizing circuit unit 700 for starting the lamp through the series connection capacitors C9, C10, and C11 again. Drive circuit for a high-pressure discharge lamp, characterized in that connected to.

Images