KR102135002B1 - Electronic ballast for discharge lamp - Google Patents

Abstract

Provided is an electronic ballast for a discharge lamp, which finds a frequency band in which resonance does not occur and switching losses are minimized so that a lamp operates at rated power. The electronic ballast for the discharge lamp includes: a lamp unit; a power supply circuit unit providing driving power to the lamp unit; a lamp driving circuit unit for driving the lamp unit by a high frequency oscillation operation by alternating switching of a plurality of switching elements; a resonant unit connected to the lamp driving circuit unit to form a resonant circuit for the oscillation operation. In this case, the lamp unit includes an acoustic resonance preventing circuit for preventing acoustic resonance.

Description

Electronic ballast for discharge lamp}

The present invention relates to an electronic ballast, and more particularly, to an electronic ballast having a constant power control and an automatic on-off function for a high-pressure discharge lamp.

High-intensity discharge lamp (HID) lamps have the advantage of high efficiency compared to other light sources, but their use is extremely limited and has not become universal. However, recently, due to the good color rendering and long life of the metal halide lamp, it has been used as a display light in department stores and large stores.

In particular, with the development of an electronic ballast for ceramic lamps, high light output, small size and weight, and improved power factor and THD (Total Harmonic Distortion). The structure of the electronic ballast for a metal halide lamp is a high-frequency inverter having a half-bridge structure, and serves to apply a sinusoidal high-frequency voltage to the lamp and control the lamp current.

LCC resonant inverters have been reported to have the best properties for the operation of HID lamps such as metal halide. The LCC resonant inverter has a large voltage gain, a relatively low input current, and a low sensitivity to input and load.

However, such high-frequency operation may cause acoustic resonance due to the physical structure of the lamp in a specific frequency band, resulting in arc shaking and, in severe cases, destruction of the arc tube. As a method of avoiding such an acoustic resonance phenomenon, there is a method of operating at a high frequency of 200 kHz or higher or finding a band in which an acoustic resonance does not occur in a frequency band of 200 kHz or lower and operating within this band.

High-frequency operation of 200 kHz or higher results in a large switching loss, and particularly, in the case of a large capacity, a burden on the switching element is increased, which is undesirable.

In addition, the electronic ballast has a problem in that it is difficult to be widely used as a magnetic ballast because of its high manufacturing cost.

In addition, since the acoustic resonance in the discharge tube causes a pressure change in the discharge tube and the arc discharge becomes unstable, the arc discharge becomes unstable, causing a phenomenon that the lamp luminous flux fluctuates, and in some cases, the arc can be extinguished. The discharge can destroy the discharge tube as it periodically hits the tube wall.

Also, different manufacturers have different internal pressures and differences in the mixing system of the encapsulated material, resulting in negative resonance. For example, even for lamps manufactured by the same company, differences in resonance bands occur depending on the working environment at the time of manufacture.

That is, even in the same size discharge tube, a difference in acoustic resonance band with a manufacturer may occur, and even in the case of a product of the same company, a difference in acoustic resonance band may occur depending on a manufacturing date or a manufacturing plant.

1. Korea Registered Utility Model No. 20-0299941 (Registration date: 2002.12.21) 2. Korean Registration Utility Model No. 20-0261558 (Registration Date: 2002.01.10)

The present invention has been proposed to solve the problems according to the above background, and to provide an electronic ballast for a discharge lamp that finds a frequency band that minimizes switching losses without resonating and causes the lamp to operate at rated power. There is this.

Another object of the present invention is to provide an electronic ballast for a discharge lamp, which can solve the problem of shortening the life of the lamp by increasing the lamp power of the ballast when the input voltage rises while providing a ballast for multi-lighting.

In addition, according to the present invention, the on/off function is added to the switching protection circuit, and when the day becomes dark or when the clouding blocks sunlight, the switching circuit automatically operates to turn on the lamp and check whether the ballast has failed. Another object is to provide an electronic ballast for a discharge lamp.

In addition, another object of the present invention is to provide an electronic ballast for a discharge lamp capable of improving light efficiency by driving a high frequency compared to low-frequency driving without distortion of the arc shape in the discharge tube even when the driving frequency is slightly different. have.

The present invention provides an electronic ballast for a discharge lamp that finds a frequency band that minimizes switching loss and does not cause a resonance phenomenon to achieve the above-mentioned problem, so that the lamp operates at rated power.

The electronic ballast for the discharge lamp,

Lamp unit;

A power supply circuit unit providing driving power to the lamp unit;

A lamp driving circuit unit driving the lamp unit by a high-frequency oscillation operation by alternate switching of a plurality of switching elements; And

It characterized in that it comprises a; resonant unit that forms a resonance circuit for the oscillation operation in connection with the lamp driving circuit unit.

At this time, the lamp unit is characterized in that it comprises an acoustic resonance prevention circuit for preventing acoustic resonance.

In addition, the lamp driving circuit unit, lowering the power to be set in advance in one of the switching elements, the protection circuit unit for limiting the power supplied to the lamp unit for a predetermined time; characterized in that it comprises a.

In addition, it is characterized in that a time limiting timer for limiting the operation time to the predetermined time is installed on one input terminal of the switching element.

In addition, the resonant circuit is characterized by comprising a resonant inductor and a resonant capacitor. In this case, the second and third resonant capacitors of the resonant capacitor are connected in series, and the first resonant capacitor is connected in parallel to the second and third resonant capacitors.

In addition, the electronic ballast for the discharge lamp is characterized in that it comprises; an automatic on-off circuit unit for turning off one of the switching elements according to whether natural light is detected through an optical sensor.

In addition, the electronic ballast for the discharge lamp is characterized in that it comprises; a first indicator for displaying the presence or absence of a failure in the power supply circuit.

In addition, the electronic ballast for the discharge lamp, characterized in that it comprises a; a second indicator for displaying the presence or absence of a failure of the power supply to the lamp unit.

In addition, the lamp driving circuit portion includes a noise reduction circuit that attenuates high-frequency noise, and the noise reduction circuit includes capacitors connected in parallel to oscillation cores connected to input terminals of the plurality of switching elements. .

In addition, the lamp unit is a capacitor connected in the first series to the secondary winding and an inductor and a second resistor connected in series to the first resistor in parallel, and a third resistor is added in series to the second resistor. It is characterized by being connected.

In addition, a plurality of lamps are arranged in parallel in the lamp unit, and a capacitor is installed at each end of the lamp.

In addition, the electronic ballast for the discharge lamp, it characterized in that it comprises a; constant power control circuit for supplying the rated input power. At this time. In the constant power control circuit, a resistor is formed between a photo coupler and a transistor connected to an input terminal of the power supply circuit part, a capacitor is formed between the emitter of the transistor and the base of the transistor, and a diode and an inductor are formed on the collector side of the transistor. , Power generation core is configured.

On the other hand, another embodiment of the present invention, the lamp unit; A power supply circuit unit providing driving power to the lamp unit; A lamp driving circuit unit driving the lamp unit by a high-frequency oscillation operation by alternate switching of a plurality of switching elements; And a resonator unit connected to the lamp driving circuit unit to form a resonance circuit for the oscillation operation. The lamp unit includes an acoustic resonance prevention circuit for preventing acoustic resonance, and the lamp driving circuit unit is a 1:1 transformer. It provides an electronic ballast for a discharge lamp, characterized in that it comprises a.

At this time, a plurality of lamps are arranged in parallel in the lamp unit, and inductors, resistors, and capacitors are installed at each end of the lamp.

According to the present invention, it is possible to find a frequency band that does not cause resonance and minimizes switching loss, so that the lamp can operate at rated power.

In addition, another effect of the present invention is that it is possible to solve the problem that the lamp power of the ballast is increased and the life of the lamp is shortened when the input voltage rises while providing a ballast for multi-lighting.

In addition, as another effect of the present invention, the on/off function is added to the switching protection circuit, and when the day becomes dark or when the clouding blocks sunlight, the switching circuit operates automatically to turn on the lamp, and at the same time, whether the ballast is broken or not. It can be said that can be confirmed.

In addition, another effect of the present invention is that even if the driving frequency is slightly different, the shape of the arc in the discharge tube is not distorted but becomes straight and the optical efficiency can be improved by driving at a high frequency compared to the low frequency driving.

1 is a circuit diagram of an electronic ballast for a discharge lamp according to an embodiment of the present invention.
2 is a circuit diagram of a lamp unit according to another embodiment of the present invention.
3 is a circuit diagram of a lamp unit according to another embodiment of the present invention.

The present invention can be applied to various changes and can have various embodiments, and specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

In describing each drawing, similar reference numerals are used for similar components. Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from other components.

For example, the first component may be referred to as a second component without departing from the scope of the present invention, and similarly, the second component may be referred to as a first component. The term "and/or" includes a combination of a plurality of related described items or any one of a plurality of related described items.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains.

Terms such as those defined in a commonly used dictionary should be interpreted as having meanings consistent with meanings in the context of related technologies, and should not be interpreted as ideal or excessively formal meanings unless explicitly defined in the present application. Should not.

Hereinafter, an electronic ballast for a discharge lamp according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a circuit diagram of an electronic ballast 100 for a discharge lamp according to an embodiment of the present invention. Referring to FIG. 1, the electronic ballast for a discharge lamp 100 includes a power supply circuit unit 110 providing driving power, a constant power control circuit unit 120 controlling constant power, and a plurality of switching elements provided therein. Supply to the lamp driving circuit unit 130 for driving the lamp unit 160 by the high-frequency oscillation operation by alternating switching, the automatic on-off circuit unit 140 for turning on and off according to the brightness of natural light, and the lamp unit 160 It may be configured to include a protection circuit unit 150 for controlling a power supply for a predetermined time, a resonance unit 170 in connection with the lamp driving circuit unit 130 to form a resonance circuit for the oscillation operation.

In the power supply circuit unit 110, a fuse F1 is connected to one end N of the AC power supply terminal, and the surge voltage removing element TNR and the high frequency of the AC voltage are connected between both ends L and N of the AC power supply terminal. Noise removing inductor (T1) for removing noise and capacitors (C1, C2, C3) connected in series/parallel are connected, and at the rear end of the inductor (T1) and capacitors (C1, C2, C3, C4) The bridge diode BD1 for rectifying the AC voltage is connected. In addition, a thermistor (NTC: Negative Temperature Coefficient) is disposed at the input terminal of the bridge diode BD1 for temperature control.

The fuse F1 is designed to open when an overvoltage of a predetermined allowable value is applied from an AC voltage. And, the surge voltage removing element (TNR) absorbs the surge voltage mixed in the AC power supply, and the noise removing inductor (LFT) and capacitors (C1, C2, C3) are high-frequency noise components included in the AC voltage. Remove it.

In addition, a ground (FG: Floating Ground) that is not directly grounded on the circuit may be configured between the capacitor C2 and the capacitor C3.

In addition, an inductor T2 for improving power factor and a capacitor C27 for improving power factor are connected to the output terminal of the bridge diode BD1. The power factor improving inductor T2 and the capacitor C27 are connected in parallel. In addition, an indicator LD1 and a resistor R21 for indicating the presence or absence of a failure at the output terminal of the bridge diode BD1 are configured. The resistor R21 is configured at the front end of the indicator LD1, and the capacitor C5 is configured in parallel.

In addition, a diode D1 and capacitors C19 and C20 of the resonator 170 are connected to the output terminal of the power factor improving inductor T2. Resistor R1, R2, R22, switching element Q1 and switching element Q2 are connected to the output terminal of diode D1.

The resistors R22, R1 and R2 are connected in parallel with each other, and the resistors R1 and R2 are connected to the switching element Q1 side. The switching element Q1 and the switching element Q2 may use a Field Effect Transistor (FET), but are not limited thereto, and a MOSFET (Metal Oxide Semiconductor FET), IGBT (Insulated Gate Bipolar Mode Transistor), or the like may also be used. The oscillation cores T1-a and T1-b are connected to switch the applied voltages to the switching element Q1 and the gates of the switching element Q2. The oscillation cores T1-a and T1-b are windings interlocked with the inductors T1-c and T1-D. The oscillation cores T1-a and T1-b are primary windings, T1-c are secondary windings, and T1-D are tertiary windings. That is, it is a structure in which a primary winding, a secondary winding, and a tertiary winding are formed on a troidal core.

A connection line is generated at the intermediate point of the switching element Q1 and the switching element Q2, a diode D3 is disposed on this connection line, a resistor R1 is connected to the input terminal of the diode D6, and an output terminal of the diode D6. The oscillation core T1-a and resistor R2 are connected to, and the capacitor C01 and zener diodes Z5, Z6, Z1, and Z2 are connected in parallel with the oscillation core T1-a. The capacitor C01 and the zener diodes Z5 and Z6 become a noise reduction circuit 131. Zener diodes Z5 and Z6 are arranged in opposite directions. On the other hand, resistors R3, R4, and R5 are connected in series to the output terminal of the oscillation core T1-a and are arranged up to the input terminal of the switching element Q1. The noise reduction circuit 131 is disposed between the resistor R3 and the resistor R4, and the zener diodes Z1 and Z2 are disposed between the resistor R4 and the resistor R5. The capacitor C01 is connected in parallel to the oscillation core T1-a to attenuate high frequency noise, thereby reducing the acoustic process.

Zener diodes Z1 and Z2 are also arranged in opposite directions. In addition, a diode D20 is disposed between the output terminal of the resistor R5 and the input terminal of the switching element Q1. Therefore, if the voltage is equal to or higher than the predetermined voltage, the diode D20 is conducted to be connected to the input terminal of the resistor R3. That is, it performs a function of preventing an abnormal voltage from being applied to the gate of the switching element Q1. In addition, a capacitor C10 is formed between the source and the drain of the switching element Q1. The capacitor C10 serves to suppress noise and peak voltage. In FIG. 1, it is illustrated that only the switching element Q1 is connected, but the capacitor C10 may be connected to the switching element Q2.

Similarly to the input terminal side of the switching element Q2, the oscillating core T1-b, the capacitor C02, and the zener diodes Z7, Z8, Z3, Z4 are connected in parallel with the oscillation core T1-b. The capacitor C02 and the zener diodes Z7 and Z8 become the noise reduction circuit 132. Zener diodes Z7 and Z8 are arranged in opposite directions. On the other hand, resistors R7, R8, and R9 are connected in series to the output terminal of the oscillation core T1-b, and are arranged up to the input terminal of the switching element Q2. In addition, the capacitor C02 is connected in parallel to the oscillation core T1-b to attenuate high frequency noise, thereby reducing acoustic resonance.

The noise reduction circuit 132 is disposed between the resistor R7 and the resistor R8, and the zener diodes Z7 and Z8 are disposed between the resistor R7 and the resistor R8. Zener diodes Z3 and Z4 are also arranged in opposite directions. In addition, a diode D30 is disposed between the output terminal of the resistor R8 and the input terminal of the switching element Q2. Therefore, if the voltage is equal to or higher than the predetermined voltage, the diode D30 is conducted to be connected to the input terminal of the resistor R7.

In the case of the switching element Q2, when the diac DA1 is connected to the gate terminal and a predetermined voltage or more is applied, the current continues to flow thereafter. The diaac DA1 is connected to the soft circuit unit 150 which controls the power supplied to the lamp unit 160 through a diode D4 for a predetermined time. Of course, the other end of the DAAC DA1 is connected to the input end of the Zener diode Z3. Diaac DA1 is a trigger element.

The oscillation core T1-a and the oscillation core T1-b alternately generate high and low voltages. Incidentally, when one oscillation core T1-a is high, the other oscillation core T1-b is low, and when one oscillation core T1-a is low, the other oscillation core T1-b is high. Becomes.

In general, when the power is higher than the rated input power, a high voltage is applied to the switching elements Q1 and Q2 to increase the current flowing through the lamp, which may shorten the lamp life or damage the lamp. Therefore, in order to prevent this, one embodiment of the present invention constitutes the constant power control circuit 120. The constant power control circuit 120 is connected to both ends of the bridge diode BD1, and an output terminal includes a capacitor C5, a resistor R21, and an indicator LD1. The resistor R21 and the indicator LD1 are connected in series, and the capacitor C5 is connected in parallel to the resistor R21 and the indicator LD1 connected in series. In addition, a resistor R19 and a zener diode Z9 are connected in series to the front end of the capacitor C5. The indicator LD1 may be a light emitting diode (LED).

The resistor R21 and the capacitor C26 are connected to the input terminal of the bridge diode BD1, and the resistor R21 and the capacitor C26 are connected in parallel. The Zener diode Z9, the resistor R21, and the capacitor C26 may be connected to the photo coupler PC. Incidentally, when the power applied to the input terminal of the bridge diode BD1 rises, the voltage is charged to the capacitor C26 as much as it rises from the zener diode Z9. Therefore, the photo coupler PC detects the increased voltage and operates the transistors Q8 and Q9 to change the impedance of the power generation cores T1-D to achieve a constant voltage.

A resistor R20 is formed between the photo coupler PC and the transistor Q9, and a capacitor C27 is formed between the emitter of the transistor Q8 and the base of the transistor Q9, and the transistor Q9 A diode D16, an inductor L1, and a power generation core T1-D are formed on the collector side.

An automatic on-off circuit 140 is configured to turn on and off according to the brightness of natural light. Incidentally, when the day is bright, the illuminance rises, and when natural light is detected through the optical sensors (CDS, PT), the voltage generated at the emitter of the transistor (Q7) activates the transistor (Q5) to trigger the trigger pulse (DA1). If not, the switching element Q2 is not activated. Conversely, when the day becomes dark and the illuminance of natural light falls, natural light detection by the optical sensors (CDS, PT) is not performed. Therefore, the transistor Q5 does not operate because no voltage is applied to the emitter of the transistor Q7, so that the DIACH DA1 generates a trigger pulse so that the lighting is performed. Here, PT is a photo transistor.

The oscillation core T1-c is disposed at a point where the source of the switching element Q1 and the drain of the switching element Q2 match, and the resonant inductors T4 and T3 are connected to the output terminal of the oscillation core T1-c. The resonant capacitors C20, C19, and C18 are connected to the output terminals of the resonant inductors T4 and T3, thereby generating a resonant circuit. Among the resonant capacitors C20, C19, and C18, the resonant capacitors C20 and C19 are connected in series, and the resonant capacitor C18 is connected in parallel to the resonant capacitors C20 and C19. In the resonator 170, diodes D6 and D7 are arranged in series to prevent reverse voltage flow.

In addition, a smoothing circuit 171 may be configured in the resonator 170. The smoothing circuit 171 may include an inductor DC, diodes D8, D9, and D10, and capacitors C21 and C22. When the smoothing circuit 171 is completely smoothed, the power factor decreases to partially smooth it.

The lamp unit 160 includes first to nth lamps LAM1, LAMP2, ...LAMPn in parallel, and capacitors C34, C35, C36, and C37 are connected to both ends of each lamp. In addition, a capacitor C25 connected in series to the secondary winding T4-b and an inductor L2 and a resistor R19 connected in series to this resistor R18 are connected in parallel, and connected to the resistor R19. The resistor R20 is further connected in series.

In addition, lamps are connected in parallel to the secondary winding T4-b of the resonant inductor T4 so that the first to nth lamps LAM1, LAMP2,...LAMPn are supplied with power. The lamps (LAM1, LAMP2,...LAMPn) can be high pressure mercury lamps, high pressure sodium lamps, metal halide lamps, ultra high pressure mercury lamps, ultra constant discharge (UCD) lamps, xenon lamps, high intensity discharge (HID) lamps, etc. have.

When power is first applied from the power supply circuit 110 to the lamp 160, a high AC voltage is generated in the secondary winding T4-b of the resonant inductor T4. The protection circuit unit 150 may be configured to control the power supply time supplied to the lamp. The protection circuit 150 converts the high alternating voltage to DC to connect the voltage and current to the resistors R11 and R12, and connects the diodes D13 and D14 in series/parallel to adjust the voltage to a low voltage, thereby protecting the resistors R13 and 14 and capacitors. It is connected to the thyristor (SCR) via (C14). In addition, a resistor R11, a diode D13, a resistor 15, and a diaac DA2 connected in series to the secondary winding T4-a are connected to the input terminal of the switching element Q6. Of course, the capacitor C15 is disposed in front of the resistor R15. Diaac DA2 is a trigger element.

Therefore, when the secondary side is opened or shorted after the presence or absence of the lighting of the lamps LAMP1 to LAMPn is confirmed, the voltage induced on the secondary side of the resonance inductor T3 rises. This raised secondary side organic voltage is half-wave rectified while passing through the diode D13, and the half-wave rectified voltage is charged in the capacitors C14 and C15 for smoothing.

The voltage charged in the capacitor C15 conducts the diaac DA2 to generate a trigger signal, and the transistor Q6 is operated for a few seconds to stop the switching circuit. While the transistor Q6 is stopped, the voltage charged in the capacitor C14 is applied to the gate of the thyristor SCR. In addition, since the voltage charged in the capacitor C33 is discharged by being connected to the anode of the thyristor SCR, the voltage is not applied to the capacitor C33, and no trigger signal is generated in the dieac DA1, so that the switching circuit is stopped. .

With continued reference to FIG. 1, an indicator LD2 and a resistor R16 are also configured to indicate if the problem is on the lamp. One end of the indicator LD2 is connected to the secondary winding T4-b through a resistor R12 and a diode D14.

Although the lamp driving circuit unit 130 and the protection circuit unit 150 are separately illustrated in FIG. 1, the protection circuit unit 150 may be included in the lamp driving circuit unit 130. In addition, the inductor for improving power factor (T2), the resonant inductors (T4, T3), oscillation cores (T1-a, T1-b), etc. shown in FIG. 1 mean a configuration in which an inductor and a transformer are combined.

2 is a circuit diagram of a lamp unit according to another embodiment of the present invention. Referring to FIG. 2, a capacitor C9 may be configured in parallel to the resonant inductor T4.

3 is a circuit diagram of a lamp unit according to another embodiment of the present invention. In general, an earth leakage breaker could block operation at 30 mA, but recently, because of the stability of the earth leakage, the blocking function is widely used at 15 mA. Therefore, in one embodiment of the present invention, a resonant inductor T4 that is distributed to the resonant circuit when the radio frequency is turned on is used as a 1:1 transformer. The 1:1 transformer means that the primary winding and the secondary winding are 1:1.

When the separation distance between the ballast and the lamp becomes long, leakage current flows so much that the earth leakage breaker can be prevented from being blocked. Of course, in this case, inductors L2, L3, L4, L5, resistors R19, R20, R21, R22, and capacitors C34, C35, C36, C37 are installed at both ends of the lamps LAMP1, LAMP2. In other words, the 1-1 inductor L2, the 1-1 resistor R19, and the 1-1 capacitor C34 are sequentially arranged in series on the left side of the first lamp LAMP1, and the first on the opposite right side. The -2 capacitor C35, the 1-2th resistor R20, and the 1-2th inductor L3 are sequentially arranged in series. Of course, similarly, on the left side of the second lamp LAMP2, the 2-1 inductor L4, the 2-1 resistor R21, and the 2-1 capacitor C36 are sequentially arranged in series and opposite right side. The 2-2 capacitor (C37), the 2-2 resistor (R22), and the 2-2 inductor (L35) are sequentially arranged in series.

100: electronic ballast for discharge lamps
110: power supply circuit
120: constant power control circuit
130: lamp driving circuit
140: automatic on-off circuit
150: protection circuit
160: lamp unit
170: resonator
131,132: first and second noise reduction circuit
161: acoustic resonance prevention circuit

Claims (13)

A lamp unit 160;
A power supply circuit unit 110 providing driving power to the lamp unit 160;
A lamp driving circuit unit 130 driving the lamp unit 160 by a high-frequency oscillation operation by mutual switching of a plurality of switching elements Q1 and Q2; And
Includes; a resonator unit 170 that forms a resonance circuit for the oscillation operation in connection with the lamp driving circuit unit 130;
The lamp unit 160 includes an acoustic resonance prevention circuit 161 for preventing acoustic resonance,
The lamp unit 160 includes a capacitor C25 connected in the first series to the secondary winding T4-b and an inductor L2 and a second resistor R19 connected in the second series to the first resistor R18. ) Is connected in parallel, the third resistor (R20) to the second resistor (R19) is an electronic ballast for a discharge lamp, characterized in that further connected in series.
According to claim 1,
The lamp driving circuit unit 130, the protection circuit unit 150 for lowering the power supplied to the lamp unit 160 to a predetermined power to one of the switching elements (Q1, Q2) (Q2) for a certain period of time Electronic ballast for a discharge lamp, characterized in that it comprises a.
According to claim 2,
An electronic ballast for a discharge lamp, characterized in that a time limit timer is provided at the input terminal of one of the switching elements (Q1, Q2) to limit the operation time to the predetermined time.
According to claim 1,
The resonant circuit is composed of resonant inductors (T4, T3) and resonant capacitors (C18, C19, C20), and the second and third resonant capacitors (C19, C20) of the resonant capacitors (C18, C19, C20) are in series. And the first resonant capacitor (C18) is connected to the second and third resonant capacitors (C19, C20) in parallel.
According to claim 1,
And an automatic on/off circuit unit 140 that turns off one of the switching elements Q1 and Q2 according to whether natural light is detected through the photosensors CDS and PT. ballast.
According to claim 1,
Electronic ballast for a discharge lamp comprising a; first indicator (LD1) for indicating the presence or absence of a failure of the power supply circuit 110.
According to claim 1,
And a second indicator (LD2) indicating whether a power supply to the lamp unit 160 is defective.
According to claim 1,
The lamp driving circuit unit 130 includes noise reduction circuits 131 and 132 that attenuate high-frequency noise, and the noise reduction circuits 131 and 132 are oscillation cores T1 connected to input terminals of the plurality of switching elements Q1 and Q2. The electronic ballast for a discharge lamp, characterized in that it comprises a capacitor (C01, C02) connected in parallel to each of -a,T1-b).
delete According to claim 1,
Discharge characterized in that a plurality of lamps (LAMP1 to LAMPn) are arranged in parallel in the lamp unit 160, and capacitors (C34, C35, C36, C37) are installed at each end of the lamps (LAMP1 to LAMPn). Electronic ballast for lamps.
According to claim 1,
Includes; a constant power control circuit 120 for supplying rated input power, the constant power control circuit 120, a photo coupler (PC) and a transistor (Q9) connected to the input terminal of the power supply circuit 110 A resistor R20 is formed therebetween, a capacitor C27 is formed between the emitter of the transistor Q8 and the base of the transistor Q9, and a diode D16 and an inductor L1 are formed on the collector side of the transistor Q9. ), Electronic ballast for a discharge lamp, characterized in that the power generation core (T1-D) is configured.
A lamp unit 160;
A power supply circuit unit 110 providing driving power to the lamp unit 160;
A lamp driving circuit unit 130 driving the lamp unit 160 by a high-frequency oscillation operation by mutual switching of a plurality of switching elements Q1 and Q2; And
Includes; a resonator unit 170 that forms a resonance circuit for the oscillation operation in connection with the lamp driving circuit unit 130;
The lamp unit 160 includes an acoustic resonance prevention circuit 161 for preventing acoustic resonance,
The lamp driving circuit 130 includes a 1:1 transformer,
In the lamp unit 160, a plurality of lamps LAMP1 to LAMPn are arranged in parallel, and inductors L2, L3, L4, L5 for each end of the lamps LAMP1 to LAMPn, resistors R19, R20, R21 , R22), and capacitors (C34, C35, C36, C37) are installed electronic ballast for a discharge lamp, characterized in that installed. delete

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