KR100431077B1 - Driving circuit for high intensity discharge lamp - Google Patents

Abstract

The present invention provides a rectifying circuit for rectifying an input AC signal and supplying a DC voltage to provide a driving circuit of a high-voltage discharge lamp used as a XENON LAMP light that solves the EMI problem caused by high-frequency surges. Resonant circuit unit 200; An inverter unit 400 for generating a high frequency signal by switching of the first and second switching elements Q1 and Q2 under the control of the switching control signals G1 and G2; The output signal is fed back so that the output power can be kept constant by emitting the switching control signal for controlling the switching of the first and second switching elements when the power measured from the output side is equal to or greater than a predetermined value. A constant voltage and oscillation circuit unit 300 for starting an oscillation operation to start switching of the switching element when the lamp is 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 rate minimizing circuit portion 700 which suppresses harmonic noise components.

Description

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

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic ballast for High Intensity Discharge (HID) lamps, and more particularly to a self-contained electronic ballast for driving a high voltage high current high voltage discharge lamp such as a xenon searchlight.

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 the perception equation related to the present invention 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 of the above publication will be described with reference to FIG.

A conventional HID electronic ballast as shown in FIG. 1 includes an input power supply unit 1, a converter unit 2, an inverter unit 3, an output matching unit 4, a buffer DC power supply unit 5, and a power control unit. (6) and the gate transformer section (7).

The input power supply 1 is composed of a fuse FUSE, a varistor ZNR, a capacitor C301-C303, and a transformer TR1 so as to stabilize the voltage of the AC power, and stabilizes the power supply voltage.

The AC voltage stabilized in the input power supply is applied to the converter section 2 of the next stage, rectified by the bridge diodes D301-D304, smoothed by the choke coil TR2 and the capacitor C304, and rectified. DC current is applied to the inverter section 3 which is the next stage.

The inverter unit 3 applies the voltage charged by the first and second switching transistors K1 and K2 to which the rectified DC power is applied and the rectified DC power to the diak to turn on the diac D311. The second capacitor C313 (when the diamond is turned on, the switching transistor K2 is also turned on), and the first and second gate waveform shaped integrated circuits IC1 to which the resonance signal detected by the gate transformer TR5 is applied. IC2). That is, at the start of the lamp, if the diaak D311 is turned on by the voltage charged in the second capacitor C313, the second switching transistor K2 is switched and the free resonance signal is output to the output matching section 4. Is here. The gate transformer TR5 detects a signal of the resonant circuit and applies it to the first and second gate waveform shaping integrated circuits IC1 and IC2. The integrated circuit again applies an applied signal to the gate of the first switching transistor K1 to pass the control voltage in the gate protection zener diode to the voltage source and the current source, and positively goes to the gate until the reflected signal voltage increases. A gate voltage signal is applied, and when the voltage decreases, the first transistor is turned on as the potential on the gate is higher than the potential on the gate transformer TR5, thereby reducing the gate potential to the negative gate potential to the potential of the voltage source. As a result, since the first and second switching transistors are switched in synchronization with the reflected signal, their output causes resonance and continuously oscillates. Resistor R302 and R303 are used as an initial signal generator together with the diaak D311 and capacitor C313, and resistors R304 and diode D312 eliminate the initial signal generation. The capacitors C311 and C312 suppress the voltage rise rates of the switching transistors K1 and K2.

The output matching section 4 has a resonant coil TR4 for determining the time constant, first to third resonant capacitors C307-C309, and a winding ratio matching the tube voltage (when the voltage is high, the winding ratio is high). The output transformer TR3 returns the generated reflected power to the buffer DC power supply unit 5 when the output is not in a resonance state.

The buffer DC power supply unit 5 includes first and second diodes D307 and D308 for inputting the reflected power generated from the output matching unit 4, and third and third sources in which the input power is charged to reduce the ripple component of the DC voltage. Fourth condenser (C305, C306), third and fourth diodes (D305, D306) for compensating the charging voltage to the third and fourth capacitors through the first and second diodes while the DC voltage is at a low level. Is done.

The power control unit 6 includes a first operational amplifier U2, a first resistor R315, a second operational amplifier U1, a second resistor R307, and a third resistor R306. The first operational amplifier U2 detects the value detected from the first DC current detection resistor R301 and the second and third DC voltage detection resistors R308 and R309 in the output control integrated circuit IC3. The current of the gate transformer TR5 is finally controlled by controlling the second current source A2 by a value multiplied by the calculated value. The controlled current is converted into a voltage in the first resistor R315, and the second operational amplifier U1 calculates the voltage with a reference voltage. The calculated result is output to the second resistor R307, and the output value is set as the power setting value in the third resistor R306 and input to the first operational amplifier U2.

In addition, the power control unit 6 includes a first comparator U3, a fourth resistor R311, a second comparator U4, a fifth resistor R314, a first switch SW1, and a third comparator U5. It further includes. The detection value of the temperature sensor is input to the first comparator U3, and the comparison value of the first comparator U3 is set by the fourth resistor R311. If the detection temperature is higher than the set value in the first comparator U3, the output of the first operational amplifier U2 is cut off. In addition, the detection value of the photosensor is input to the second comparator U4, the comparison value of the second comparator U4 is set by the fifth resistor R314, and the detected external illuminance is the second comparator U4. If it is higher than the set value in, the output of the first operational amplifier U2 is cut off. In addition, when the signal of the first switch SW1 is input, the output blocking of the first operational amplifier U2 is removed. In addition, since the value of the current controlled by the second current source A2 is changed to the voltage at the first resistor R315, the voltage value is compared with the reference voltage by the third comparator U5, so that a large amount of current When the output of the first operational amplifier (U2) is cut off.

In addition, the power control unit 6 includes a timer for interrupting the output of the first operational amplifier when the lamp does not light up within the desired re-lighting time, and a sixth resistor R316 and a sixth resistor for determining a time constant for setting the time. 5 further includes a condenser C315 and an undervoltage circuit breaker that blocks the output of the first operational amplifier when the power supply voltage is small.

The gate transformer TR5 of the gate transformer unit 7 detects the resonance signal from the output matching unit 4 and applies the detected signals to the first and second gate waveform shaping integrated circuits IC1 and IC2.

Therefore, according to the prior art as described above, the switching transistor K2 is initially switched by the initial start-up units C313, D311, R302, and R303 of the inverter unit 3 so that the resonant circuit C307- of the output matching unit 4 is switched. The free resonance of C309 and TR4 is started, and when the start is made, the initial signal is removed by the initial signal removing units R304 and D312, and the output matching unit lights the lamp while continuously resonating at the disclosed resonance frequency.

The reflected power generated when the output of the output matching section 4 is not in the resonance state is controlled by the third and fourth capacitors C305 by the first and second diodes D307 and D308 of the buffer DC power supply section 5. , C306 is reflected, and the charging voltage is compensated by the third and fourth diodes D305 and D306. In addition, the output current is detected by the resistor R315 to set the desired output current, and compared with the signal detected by the input power detectors R301, R308, R309, and multiplier to control the gate transformer TR5. do.

However, among HID lamps, general high-voltage discharge lamps are discharged at a relatively low current, whereas xenon lamps used for long-range illumination search lights and military and marine searchlights, such as those used for night events and landscape lighting, have a high voltage of 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), a large expensive transformer, etc. should be used to generate high voltage power as described above, and enormous power loss occurs, which leads to a larger rectifier and a higher cost. According to the driving circuit for a high-voltage discharge lamp according to the present invention, the high-voltage voltage by only a small transformer by rectifying the high-frequency oscillation pulse of the commercial power supply once rectified and converted to direct current and the converted direct current oscillated by the high frequency oscillation circuit again. It is possible to generate a current, so power loss As a minimum there and bring cost savings.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a driving circuit of a high-voltage discharge lamp that is used as a search light that solves the problem of small size, high efficiency and high frequency disturbance (EMI) caused by high frequency surge. To provide.

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.

1 is a circuit diagram of a conventional electronic ballast for a high pressure discharge lamp.

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

FIG. 3 is a detailed circuit diagram of the high frequency starting circuit of FIG. 2. FIG.

4 is an external view of the high-pressure discharge lamp unit according to the present invention.

5 is an external view of a ballast for a high-pressure discharge lamp according to the present invention.

6 to 10 are waveform diagrams of input waveforms of a driving circuit for a high-pressure discharge lamp according to the prior art and the present invention.

6 is an input oscillation pulse waveform diagram at no load;

7 and 8 are input waveform diagrams of a driving circuit for a high-pressure discharge lamp according to the prior art and the present invention, respectively, during operation,

9 and 10 are input waveform diagrams of a driving circuit for a high-pressure discharge lamp according to the prior art and the invention at the time of starting, respectively.

<Description of Symbols for Main Parts of Drawings>

1 input power supply 2 converter 3 inverter

4 output matching unit 5 buffer DC power supply unit 6 power control unit

7: gate transformer

100: input power supply 200: rectification and resonant circuit

300: constant voltage and oscillation circuit 400: ARC inverter

500: high frequency rectifier 600: high frequency start circuit

700: Harmonic content rate minimizing circuit portion 800: Rectifier protection circuit portion

900: lamp

Driving circuit for a high-pressure discharge lamp according to the present invention for achieving the above object, the rectifying and resonant circuit portion 200 for rectifying the input AC signal to supply a DC voltage; An inverter unit 400 for generating a high frequency signal by switching of the first and second switching elements Q1 and Q2 under the control of the switching control signals G1 and G2; The output signal is fed back so that the output power can be kept constant by emitting the switching control signal for controlling the switching of the first and second switching elements when the power measured from the output side is equal to or greater than a predetermined value. A constant voltage and oscillation circuit unit 300 for starting an oscillation operation to start switching of the switching element when the lamp is 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 which suppresses harmonic noise components.

Preferably, the harmonic content minimizing circuit includes capacitors C10 and C11 for absorbing surge voltages connected in parallel to both ends of the lamp electrode, resistors R6 and varistors connected in parallel to both ends of the lamp electrode. A high frequency noise attenuation circuit composed of a parallel circuit of the ZNR2 and the capacitor C12, a parallel circuit of the varistor ZNR3 and the capacitor C13 having one side connected to the cathode terminal of the lamp grounded, and an anode side of the lamp. One side connected to the terminal is characterized by consisting of a grounded varistor (ZNR4).

More preferably, the high frequency rectifying unit includes first to fourth bridge diodes BD1-BD4, and the first terminal and the second terminal of each bridge diode are connected through the 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 interconnected. The first terminal of the second bridge diode BD3 and the second terminal of the first bridge diode BD1 and the first terminal of the second bridge diode BD2 and the first terminal of the fourth bridge diode BD4 are connected. Are 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 second terminal of the second bridge diode BD2, respectively, and the first terminal of the first bridge diode BD1 is connected. The terminal is connected to the (+) side terminal of the lamp 900 through the high frequency start circuit unit 600 and the first terminal of the fourth bridge diode BD4 is directly connected to the (-) side terminal of the lamp 900. Lose,

The high frequency start circuit 600 includes a first high frequency transformer TR3 for boosting, LC parallel circuits R7, C14 and C15 on the primary side of the first goth wave transformer, and the high frequency induction second high frequency transformer ( TR4) and a pole spacing control unit of the variable capacitor VC1 for fine adjustment between the first and second high frequency transformers TR1 and TR2.

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

2 is a circuit diagram of a driving circuit for a high-pressure discharge lamp according to the present invention, Figure 3 is a detailed circuit diagram of the high frequency start circuit portion of FIG.

As shown in Figure 2, the driving circuit for the high-pressure discharge lamp according to the present invention, the input power supply 100, the rectifying and resonant circuit 200, the constant voltage and oscillation circuit 300, ARC inverter 400, It is composed of a high frequency rectifying unit 500, a high frequency starting circuit 600, a harmonic content rate minimizing circuit 700, and a rectifier protection circuit 800. Reference numeral 900 is a xenon lamp for searchlights used in military and marine search, transition lighting and night event events, for example.

The present invention adopts a self-contained high frequency oscillation method, which uses a method of initially driving the feedback oscillation circuit by conducting the DIAC at a predetermined voltage or more using the DIAC. The image lighting rectifier according to the present invention adopts a self-contained method in preparation for a failure rate, obtains a stable output voltage current, and adopts a rectifier circuit using a high frequency diode again to supply a stable voltage and current to the lamp.

First, since the input power supply unit 100 is the same as the input power supply unit 1 of the conventional ballast circuit for a high-pressure discharge lamp of Figure 1, a detailed description thereof will be omitted.

Next, the input stabilized AC power is rectified through the bridge diodes D1-D4 of the rectification and resonant circuit unit 200, and the rectified voltage is smoothed by the diode D2 and the smoothing capacitor C7. In addition, since one of the potential terminals of the capacitor is connected in series to the resistor R1, the rectified voltage is preferably filtered by the noise filters C5, C6, and C7. The inverter section 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.

The inverter unit 400 is composed of two transistors Q1 and Q2, and diodes D6 and D7 and capacitors C8 and C9 in parallel between the source / drain terminals of the first and second transistors Q1 and Q2. Are respectively connected in parallel, and the primary side of the output-side transformer TR2 is connected to the output terminal of the second transistor Q2. In addition, control signals G1 and G2 from the constant voltage and the oscillation circuit 300 are applied to the gate terminals of the first and second transistors.

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 secondary side signal of the output transformer TR2, and when the power measured from the output side of the rectifier is greater than or equal to a predetermined value, the switching of the first and second transistors is performed at a high frequency (25 kHz to 37 kHz). By controlling, 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 detail with reference to FIG. 3.

As shown in Figs. 2 and 3, the input of the high frequency start circuit 600 is connected to both ends P1 and P2 of the input power supply 100. One input terminal is connected to the primary side of the first high frequency transformer TR3 through the start switch SW1 and the other side through the LC parallel circuits L1, C14 and C15. In the secondary side of the first high frequency transformer, the variable capacitor VC1 is connected in parallel, and is connected to the primary side of the second high frequency transformer TR4 through the capacitor C16. One side P3 of the output terminal on the secondary side is connected to the high frequency rectifying unit 500, and the other side P4 is connected to the positive terminal of the lamp 900.

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 L1, C14 and C15 including the parasitic resistance. When the capacitor is sufficiently charged, the capacitor is boosted to high voltage in the primary high frequency transformer TR1 and further boosted to 1200V in the secondary high frequency transformer TR4. 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. At this time, 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 VC1.

An oscillation circuit portion (not shown) similar to the conventional oscillation circuit portion of FIG. 1 is started to start an oscillation operation for starting switching of the transistor, which can be easily implemented by those skilled in the art with reference to the related art of FIG. 1. There will be. In other words, ± 30V fluctuation of the input voltage is supplied to the ARC rectifier circuit at a constant high frequency DC voltage, so that the output can be obtained evenly, greatly extending the lamp life.

Therefore, the switching of the first and second transistors is performed at high frequency by the control of the switching control signals G1 and G2 from the constant voltage and the oscillation circuit 300, so that the inverter unit generates high frequency signals ranging from 25 kHz to 37 kHz.

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 via resistors R2-R5, respectively, and the first terminal of the first bridge diode BD1 and the first terminal of the second bridge diode BD2 are connected to each other. The second terminal of the three bridge diode BD3 and the second terminal of the fourth bridge diode BD4 are connected to each other, and the second terminal of the first bridge diode BD1 and the first terminal of the third bridge diode BD3 are connected to each other. Then, 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 second terminal of the second bridge diode BD2, respectively, and the first terminal of the first bridge diode BD1 is connected. The terminal is connected to one terminal P3 on the output side of the high frequency start circuit unit 600 (the other terminal P4 on the output side of the high frequency start circuit unit 600 is connected to the (+) side terminal of the lamp 900). ), The first terminal of the fourth bridge diode BD4 is directly connected to the negative terminal of the lamp 900.

That is, the high frequency rectifying circuit converts the input AC power into full-wave rectified DC through the bridge diode circuits, thereby improving the power factor and supplying a stable DC voltage to the lamp. In addition, since the overvoltage overcurrent is applied due to the transient phenomenon when the xenon lamp is turned on, it may adversely affect the blackening of the lamp, and thus, a lamp preheating with 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.

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. 2, capacitors C10 and C11 for absorbing a surge voltage are connected in parallel to the lamp anode. That is, the capacitors C10 and C11, 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 composed of a parallel circuit of the resistor R6, the varistor ZNR2, and the capacitor C12 is connected in parallel between the two electrodes of the lamp, and the varistor ZNR3 having one side grounded at the cathode end of the lamp. And a parallel circuit of the capacitor C13 are connected, and a varistor ZNR4 having one side grounded is also connected to the positive terminal of the lamp. That is, the conventional event event lighting has been adopted as the DMX 512 signal system, it has been recognized that the use of the high-voltage discharge lamp driving circuit of the present invention is not available yet, because the interference to other devices due to high frequency surge. EMI is solved by eliminating the radio wave interference containing high frequency components to reduce the harmonic content to 0.8% or less, and does not adversely affect the surrounding electronic precision equipment.

Finally, the rectifier protection circuit 800 is described, which is similar to the conventional rectifier protection circuit 6 of FIG. That is, one side voltage of the smoothing capacitor C4 of the rectifying and resonant circuit unit 200 and one side voltage of the noise filter C5-C7 are measured to receive input side information, and another two side of the output side transformer TR2 is received. Switching of the inverter unit 400 by receiving the output side information from the difference side coil and generating gate control signals G1 'and G2' to the constant voltage and oscillation circuit unit 300 when the rectifier shows abnormal oscillation or abnormal voltage. The rectifier is protected through on / off of the transistors Q1 and Q2, which will be easily realized by those skilled in the art by the conventional protection circuit 6 of FIG. 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.

In the above, the operation of the driving circuit for the high-voltage discharge lamp according to the present invention will be described. The high-frequency voltage (for example, 25 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.

Figure 4 shows an example of the actual appearance of the high-pressure discharge lamp unit according to the present invention, Figure 5 shows an example of the actual appearance of the ballast for the high-pressure discharge lamp according to the present invention.

6 to 10 are waveform diagrams of input waveforms of a driving circuit for a high-voltage discharge lamp according to the prior art and the present invention. FIG. 6 is an input oscillation pulse waveform diagram at no load, and FIGS. 7 and FIG. 8 is an input waveform diagram of a driving circuit for a high voltage discharge lamp according to the prior art and the present invention during operation, respectively, and FIGS. 9 and 10 are inputs of a driving circuit for a high voltage discharge lamp according to the prior art and the present invention at the start, respectively. This is a waveform diagram. The waveform diagram was measured by "Mecronics LT224". In each waveform diagram, yellow (No. 1) represents the input voltage waveform, green (No. 2) represents the input current waveform, and red below (No. 3) is the output. The voltage waveform and blue (number 4) represent the output current waveform. The output power value is calculated at the bottom.

That is, it can be seen that the input oscillation pulse at no load (which can be considered before ramp operation) has almost no distortion or surge component. This is because almost no surge occurs from the output side. However, in the case of the conventional apparatus as shown in Fig. 7, when a load is applied (during operation), it is understood that many harmonic surge components are reflected on the input side and included in the input side input and output waveforms on the input and output of the input side. Can be. On the contrary, in the driving circuit according to the present invention, the harmonic surge component on the output side is absorbed by the harmonic content rate minimizing circuit part 700 or the like, even though the output (about 7 kW) is larger than that of the conventional apparatus (about 3 kW). As a result, the harmonic surge component is hardly reflected to the input side.

Even at start-up, it can be seen that the surge component in the input and output in the conventional apparatus of FIG. 9 is much larger than the surge component in the input and output in the drive circuit of the present invention in FIG. This is especially noticeable on the input side due to the influence of reflected harmonic surge components.

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 the flickering phenomenon can be suppressed as much as possible, and the lamp can be turned on immediately, the brightness at the time of maximization can be maximized, and the surge and radio interference minimization circuit is adopted to other electronic equipment. It does not adversely affect high-frequency disturbances, and reduces the capacity weight by 1/3 compared to the linear method (trans method), which is used for event events and military searchlights in foreign countries, and adopts the Xenon lamp driving stabilization electronic circuit which is very close to the natural light. This became possible.

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; An inverter unit 400 for generating a high frequency signal by switching of the first and second switching elements Q1 and Q2 under the control of the switching control signals G1 and G2; The output signal is fed back so that the output power can be kept constant by emitting the switching control signal for controlling the switching of the first and second switching elements when the power measured from the output side is equal to or greater than a predetermined value. A constant voltage and oscillation circuit unit 300 for starting an oscillation operation to start switching of the switching element when the lamp is 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 And a harmonic content rate minimizing circuit portion 700 for suppressing harmonic noise components. The method of claim 1, The harmonic content minimizing circuit, Capacitors C10 and C11 for absorbing surge voltages connected in parallel to both ends of the lamp electrode; A high frequency noise reduction circuit comprising a parallel circuit of a resistor R6, a varistor ZNR2, and a capacitor C12 connected in parallel to both ends of the lamp electrode; A parallel circuit of a varistor (ZNR3) and a capacitor (C13) grounded at one side connected to the cathode end of the lamp; And a varistor (ZNR4) 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 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 second terminal of the second bridge diode BD2, respectively, and the first terminal of the first bridge diode BD1 is connected. The terminal is connected to the (+) side terminal of the lamp 900 via the high frequency start circuit unit 600 and the first terminal of the fourth bridge diode BD4 is directly connected to the (-) side terminal of the lamp 900. Driving circuit for high-pressure discharge lamp, characterized in that. The method according to claim 1 or 2, The high frequency start circuit 600 includes a first high frequency transformer TR3 for boosting, RLC parallel circuits R7, C14, and C15 on the primary side of the first goth wave transformer, and the high frequency induction second high frequency transformer ( TR4) and a pole spacing control unit of a variable capacitor (VC1) for fine adjustment between the first and second high frequency transformer (TR1, TR2).