KR100625262B1 - Electronic ballast comprising a improved resonant output circuit - Google Patents

Abstract

The electronic ballast of the present invention includes a rectifying and smoothing unit 200 for rectifying an input AC signal and supplying a DC voltage, and a lighting unit for generating a oscillation at a given resonance frequency by receiving a voltage applied from the rectifying and smoothing unit, and turning on a lamp. An electronic ballast comprising: a 600; an inverter unit 400 that receives the rectified voltage from the rectifying and smoothing unit to cause resonance of the lighting unit; and a startup circuit unit 300 that performs initial startup of the inverter unit. The 600 includes resonant capacitors C9, C7 and C6 and an inductor L1, and a resonant voltage rising circuit capacitor C5 is connected to one side of the lamp in parallel with the resonant inductor L1. The resonant capacitors C7 and C6 are connected to the other side of the lamp, and a secondary side drive transformer N3 having one winding electrically connected to the resonant inductor L1, and the secondary side drive transformer N3. Primary inductively coupled with Further comprising a drive transformer (N1) and a third drive transformer winding (N2), said primary drive transformer (N1) is characterized in that connected to the other side of the lamp. Therefore, by the addition of the LC resonant circuit coil (L1) and the condenser (C5) and the simple configuration of changing the position of the primary winding (N1) of the drive transformer, it is possible to implement a ballast for high-voltage discharge fluorescent lamp.

Resonance Voltage Rising Circuit, High Pressure Discharge Fluorescent Lamp, Fluorescent Lamp for T5

Description

ELECTRONIC BALLAST COMPRISING A IMPROVED RESONANT OUTPUT CIRCUIT}

1 is a circuit diagram of a conventional fluorescent lamp driving circuit.

2 is a circuit diagram of a fluorescent lamp driving circuit according to the present invention.

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

100: input power supply 200: rectification and smoothing unit

300: start circuit 400: inverter

500: lighting unit of the conventional circuit 600: lighting unit of the circuit of the present invention

The present invention relates to an electronic ballast, and more particularly to an electronic ballast for a high-voltage discharge fluorescent lamp having a resonant voltage rising circuit of the LC resonant circuit.

An electronic ballast is a ballast which is used in a circuit system in which a ballast includes an element for starting, and starts a lamp by a switching action of a starting circuit and a switching circuit, and during lighting, an electrode is heated by a lamp current and an electrode heating winding. There is a self-explanatory formula relating to the present invention which is oscillated by a separate type oscillator and its own LC resonant circuit.

On the other hand, fluorescent lamps, such as T12, T10, T8, depending on the thickness of the tube diameter, but the fluorescent lamp for T5, which has been spotlighted as the next-generation main source of light recently appeared, such a small diameter fluorescent lamp has a small diameter Due to the high tube voltage (approximately 180-200V), the logistics cost is reduced and the garbage is reduced at the end of life, the efficiency is high, and it is neat during construction.However, general ballast circuits cannot be designed for lamp characteristics. There is a problem in that the ballast circuit is complicated by using a separate DC voltage boost circuit.

Another method of driving the small-diameter fluorescent lamp is to use a high frequency secondary winding transformer, the circuit configuration is simple, but the secondary winding transformer can not be designed small, the ballast size can not be reduced have.

The object of the present invention is to solve the problems of the prior art, which is inevitably designed to design a large and complex ballast as described above, and to drive a small diameter high-voltage discharge fluorescent lamp with a simple circuit and low cost. An electronic ballast for a fluorescent lamp having a resonant voltage rising circuit of an LC resonant circuit is provided.

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 electronic ballast according to the present invention for achieving the above object, the rectification and smoothing unit 200 for rectifying the input AC signal supplying a DC voltage, and the given resonance frequency supplied with the voltage applied from the rectifying and smoothing unit A lighting unit 600 oscillating to turn on the lamp, an inverter unit 400 for generating resonance of the lighting unit by receiving the rectified voltage from the rectifying and smoothing unit, and a starting circuit unit for initial starting of the inverter unit ( An electronic ballast including 300, wherein the lighting unit 600 includes resonant capacitors C9, C7 and C6 and an inductor L1, in parallel with the resonant inductor L1 on one side of the lamp. A capacitor C5 for resonant voltage rising circuit is connected, and the resonant capacitors C7 and C6 are connected to the other side of the lamp, and one side winding is connected to the resonant inductor L1 electrically. And a secondary transformer (N3), a primary side drive transformer (N1) and a secondary side drive transformer (N2) inductively coupled with the secondary side drive transformer (N3), wherein the primary side drive transformer (N1) is the ramp. It is characterized in that connected to the other side of the.

Preferably, a choke coil CH1 is inserted between the one side of the lamp and the connection point of the LC elements L1 and C5 for the resonance voltage rising circuit.

Prior to describing the electronic ballast of the present invention, a circuit of a conventional electronic ballast for a T5 fluorescent lamp will be described with reference to FIG.

As shown in FIG. 1, the conventional electronic ballast includes a voltage stabilizer 100, a rectification and smoothing unit 200, a starter circuit unit 300, an inverter unit 400, and a lighting unit 500. .

The voltage stabilization unit 100 receives a two-phase AC power in the form of a general AC power supply through two terminals A and B. The alternating current is filtered and stabilized through a parallel circuit of the varistor TNR and transformer LF1 functioning as a filter through the fuse F1 and again by a filter circuit consisting of three capacitors C1-C3. The power stabilized by the filter circuit is applied to the next stage rectification and smoothing unit 200.

The rectification and smoothing unit 200 is full-wave rectified by the bridge diodes D1-D4, and smoothed and filtered by the capacitors C4, the diodes D5, D6, and D7 and the smoothing capacitors EC1 and EC2. The rectified and smoothed voltages are applied to the start circuit unit 300 and the inverter unit 400, which are the next stages.

The inverter unit 400 includes first and second switching transistors Q1 and Q2 to which a rectified DC power is applied and acts as a trigger element, resistors R8 and R4 connected to gate terminals of the respective switching transistors, and Second and third transformer circuits N3 and N2 connected to the gate terminals of the respective switching transistors, and diodes D13 and ZD2 D12 and ZD1 for maintaining a constant voltage. The primary side N1 of the transformer circuits N2 and N3 is connected to one side of the lamp LAMP of the lighting unit 500 to detect the output of the lamp.

및

) 은 각각, 인버터부의 트리거소자로서 작용하는 MOSFET(Q2, Q1)의 소스 및 드레인에 접속되는 바, 양 트리거 소자(Q1, Q2)의 다른 입력단자는 접속되어 있으며, 동시에 상기 접속점에는 드라이브 트랜스의 일차측 권선(N1)이 접속된다. 또한, 상기 트리거소자의 게이트는 각각 저항(R8)(R4)을 통해 상기 드라이브 트랜스의 2차측 및 3차측 권선들(N3)(N2)이 접속된다. 도면 부호 D13 및 D12는 역류방지용 다이오드이고, ZD2 및 ZD1은 정전압 다이오드이다.That is, the contact point of the inverter unit 400

And

Are connected to the source and the drain of the MOSFETs Q2 and Q1 respectively serving as trigger elements of the inverter section, and the other input terminals of both trigger elements Q1 and Q2 are connected, and at the same time, the connection point of the drive transformer The primary winding N1 is connected. In addition, the gate of the trigger element is connected to the secondary side and tertiary side windings N3 and N2 of the drive transformer through resistors R8 and R4, respectively. Reference numerals D13 and D12 denote non-return diodes, and ZD2 and ZD1 denote constant voltage diodes.

단자 및

단자에 접속되며, 다이악(DIAC)이 상기 저항(R1)과 콘덴서(C4)의 접속점 및 트리거소자(Q1)의 게이트에 접속된다. 또한, 상기 저항(R1)과 콘덴서(C4)의 접속점 및 트리거소자(Q1)의 드레인단자 간에는 상기 시동회로의 동작을 정지시키기 위한 다이오드 회로(D11)가 접속된다. On the other hand, the output DC voltage of the rectifying and smoothing unit 200 is applied to the start circuit unit 300 at the same time. That is, the parallel circuit of the resistor R5 and the capacitor C5 and the series circuit of the resistor R1 and the capacitor C4 are the start circuit unit.

Terminals and

It is connected to the terminal, and the diac DIAC is connected to the connection point of the resistor R1 and the capacitor C4 and the gate of the trigger element Q1. Further, a diode circuit D11 for stopping the operation of the start circuit is connected between the connection point of the resistor R1 and the capacitor C4 and the drain terminal of the trigger element Q1.

Each lamp LAMP of the lighting unit 500 has one electrode connected to the primary winding N1 of the driving transformer through the choke coil CH1 and CH2, and the other terminal is connected to an output voltage distribution capacitor ( It is connected to the connection terminal of C7, C6. That is, the other side of the lamp LAMP is connected to the output terminal and the ground terminal of the rectifying and smoothing unit 200 through the parallel circuits C7 and D9 (C6 and D10) of the capacitor and diode, respectively, and the two electrodes of the lamp In the liver, capacitors C9 and C10 for impedance and resonance adjustment are respectively inserted.

An electronic ballast in accordance with the present invention is now described with reference to FIG.

The difference between the electronic ballast according to the present invention of FIG. 1 and the electronic ballast of the prior art of FIG. 1 lies in the difference between the lighting unit 600. In FIG. 2, elements having the same functions as those of FIG. 1 are assigned the same member numbers and description thereof will be omitted.

)에 접속되어, LC 공진회로(L1, C5)를 이루게 된다.In the lighting unit 600 of the electronic ballast according to the present invention, unlike the lighting unit 500 of the prior art, the primary winding N1 of the driving transformer is connected to the other terminal of the lamp and the output voltage distribution capacitor C7. Is inserted between the connection terminals of C6, and the coil L1 and the capacitor C5 for the resonant circuit are connected to the connection points of the choke coils CH1 and CH2, respectively. Power stage

) To form LC resonant circuits L1 and C5.

On the other hand, when the elements L1 and C5 of the resonant output circuit are in the same position as described above, there is a possibility that the circuit may be broken due to self-oscillation at no load. In order to prevent this, the position of the primary side N1 of the oscillation coil is connected to the limit capacitor so that the oscillation is stopped because no voltage is induced to the oscillation coil at no load.

Hereinafter, operations of the voltage stabilizer 100, the inverter 400, and the lighting unit 600 will be described.

The supply voltage stabilized by the voltage stabilizer 100 is converted into a DC power supply by the rectification and smoothing unit 200 and applied to the inverter unit 400 and the starter circuit unit 300. Is charged in the charging capacitor, and when the charged voltage exceeds a predetermined value, the trigger diode (DIAC) is turned on by the time constant of the RC circuit to operate the second switching transistor (Q1). The motor is started by the resonance of the furnaces L1, C9 (or C8), C7, and C6.

When the lighting is turned on by the operation of the second switching transistor Q1, the voltage induced in the self oscillating coils N1, N2, and N3 is changed by the time constants of the windings of the first and second switching transistors Q2, The driving voltage is supplied to Q1) to continue oscillation, and once started, the charging voltage at both ends of the capacitor is discharged by the discharge circuit portions D11 and R1, and further starting operation is prohibited.

At this time, when the initial oscillation, the LC resonance voltage is applied to both ends of the capacitor (C9) (C8), while the LC resonance is made to increase the resonance voltage by LC resonance between the coil (L1) and the capacitor (C5), then choke coil (CH1, The resonant current is controlled by CH2 and the capacitors C9 (or C10, C7 and C6), and the lamp is supplied with a proper voltage and current, thereby achieving normal lamp discharge.

At this time, if another choke coil is used in parallel instead of the choke coils CH1 and CH2, it is possible to drive a plurality of lamps.

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 ballast according to the present invention, by the addition of the LC resonant circuit coil (L1) and the condenser (C5) and by the simple configuration of changing the position of the primary winding (N1) of the drive transformer, It is possible to implement a ballast for a high-pressure discharge fluorescent lamp.

Claims (2)

A rectifying and smoothing unit 200 for rectifying an input AC signal to supply a DC voltage, a lighting unit 600 for receiving a voltage applied from the rectifying and smoothing unit and oscillating at a given resonance frequency to turn on a lamp; An electronic ballast comprising an inverter unit 400 which receives the rectified voltage from the rectifying and smoothing unit to cause resonance of the lighting unit, and a starting circuit unit 300 which performs initial startup of the inverter unit. The lighting unit 600, Resonant capacitors (C9, C7, C6) and the inductor (L1) including a resonant inductor (L1) in parallel with the resonant inductor (L1) is connected to the capacitor for resonant voltage rising circuit (C5), the other side of the lamp The resonance capacitors C7 and C6 are connected to the A secondary side drive transformer N3 having one winding electrically connected to the resonant inductor L1, a primary side drive transformer N1 and a tertiary side drive transformer N2 inductively coupled to the secondary side drive transformer N3; ), Wherein the primary drive transformer (N1) is connected to the other side of the lamp; and an electronic ballast for a high voltage discharge fluorescent lamp having an improved resonance output circuit. The method of claim 1, A choke coil (CH1, CH2) is inserted between the one side of the lamp and the connection point of the LC element (L1, C5) for the resonance voltage rising circuit.

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