1301692 、、t案^有化學式時，請揭示最能顯示發明特徵的化學式： 八 九、發明說明： 【發明所屬之技術領域】 =月係提供一種错振型半橋式直流/交流轉換電 -捩ϊί:?應用於驅動液晶顯示器背光源之螢光燈管之 』電變流/交流轉換電路，其中特別是針對以陶究 流轉換電二光燈管而設計之諸振型半橋式直流/交 【先前技術】 =晶，示器（Llquid Crystal Dlsplay，lcd)具有薄形化 二因：較傳統的CRT不佔空間，應用於大型化的家 曰翻或么眾场所的看板，已經有逐漸普遍的趨勢。但液 ;;頁二匕的操作原理係利用其液晶材料的電光學特性，來 i=i°文字資訊的一種平面顯示器，其本身並不具備 、、因此需要一外加的背光源做為輔助，立常用 的背光源通常為螢光燈管之類的光源。巧補助“用 般間％為換流器（inverter)，該直流/交流轉 署陶:是壓電變壓器所構成譜振槽電路的遽波 電，用以將ί入的直流電壓源轉換成高壓的交流 2不會η *燈管。為了使螢光燈管的光源穩定，並 都：Γί::電壓的變動而改變亮度，因此其設計上大 由；丰回ί控制電路，以穩定螢光燈管的操作電流。 較d螢光燈管比起其它例如全橋式換流器需要 卜目此在很多低價位’小尺寸的設計中以半橋 式換〜益驅動螢光燈管成了很普遍的選擇。 振型圖為習知一繼壓電變壓器所構成的譜 光燈管換流器電路。如$1圖所示，-譜振 式直^交流螢光燈管換流器1⑽包括-直流電壓源 1301692 力率開關11GA、11〇Β、—譜振槽電路120、 螢先且e 〇、—螢光燈管電流偵測電路130、一積分哭 Γ/;Λ壓中控制,振盪器150“及一半橋式功率開關驅動； 率_ u〇A，以半橋式功率開關U〇A、U〇B包含兩個功 mV及一陶竟二？譜振槽電路12〇包括有-電感器 及陶瓷壓電變壓器122。該半橋式功率開關驅動 路160提供兩組驅動輸出信號RA和RB。 f連接關係如下所述：該直流電壓 輸出鳊電連接至該諧振槽電路120之輸入端。該諧 辰θ電路120之輸出端電連接至該螢光燈管170之-端。 和該電流偵測電路150耦接至該螢光燈管170 、、心、ρ; ; 1 40。螢光燈管中的交流信號經該螢光燈管電 控制= 140將該直流電壓信號積分後產生-電壓 率的脈波信號RD。該半橋式』1301692, t case ^ When there is a chemical formula, please reveal the chemical formula that best shows the characteristics of the invention: VIII, invention description: [Technical field of invention] = month provides a type of vibration-damping half-bridge DC/AC conversion electricity -捩ϊί:?Electrical converter/AC conversion circuit for fluorescent tubes that drive backlights for LCD monitors, especially for vibrating half-bridge DCs designed to convert electric two-lamps /交【前技术】=Llquid Crystal Dlsplay (lcd) has a thinning factor: the traditional CRT does not take up space, it is used in large-scale homes or kanbans in public places. A trend that is becoming more common. But the liquid; the operation principle of the page two is a flat-panel display that uses the electro-optical properties of its liquid crystal material to i=i° text information, which itself does not have, and therefore requires an additional backlight as an aid. A commonly used backlight is usually a light source such as a fluorescent tube. Coordination subsidy "% of the inverter is used, the DC / AC transfer pottery: is the piezoelectric wave transformer's spectral tank circuit chopper power, used to convert the input DC voltage source into high voltage The AC 2 does not η * the lamp. In order to stabilize the light source of the fluorescent tube, and both: Γί:: the voltage changes to change the brightness, so the design is large; Feng back ί control circuit to stabilize the fluorescent The operating current of the lamp. Compared with other, such as full-bridge converters, it is required to use a half-bridge type to drive the fluorescent tube in many low-priced 'small size designs. A very common choice. The vibration pattern is a spectral light tube converter circuit composed of a piezoelectric transformer. As shown in the $1 diagram, the spectral vibration type direct current fluorescent tube inverter 1 (10) Including - DC voltage source 1301692 force rate switch 11GA, 11 〇Β, - spectral tank circuit 120, fluorescing and e 〇, - fluorescent tube current detecting circuit 130, an integral crying /; Oscillator 150" and half bridge power switch drive; rate _ u 〇 A, with half bridge power switch U 〇 A, U 〇 B contains two One mv and one pottery two? The spectral tank circuit 12A includes an inductor and a ceramic piezoelectric transformer 122. The half bridge power switch drive 160 provides two sets of drive output signals RA and RB. The f connection relationship is as follows: The DC voltage output is electrically connected to the input of the resonant tank circuit 120. The output of the resonant θ circuit 120 is electrically coupled to the end of the fluorescent tube 170. And the current detecting circuit 150 is coupled to the fluorescent tube 170, the center, ρ; The AC signal in the fluorescent tube is electrically controlled by the fluorescent tube = 140 to integrate the DC voltage signal to generate a pulse signal RD of the voltage rate. The half bridge type
Duty C】、根據该脈波信號產生兩組固定工作週期(Fixed 110A、flU的控制信號R1和R2分別控制功率開關 乃是^ HI振型半橋式榮光燈管換流器電路之操作原理 可以將式功率開關11〇A、11〇B的高頻交互導通， 波的壓源' 110所輪出的直流電壓轉換成高頻脈 借振出’以供應後級的該諸振槽電路120輪入。該 電升公變壓尸％的功用乃是利用該電感器121和該陶竟壓 尸構成的滤波及升壓功能，將高頻的方波 170、。门’、间蹙的父流正弦波，以供應後級的該螢光燈管 如第1、2圖所示，由該電感器121及該陶瓷壓電變 1301692 壓器122所構成的該諧振槽電路 信號Μ有不同大小的輸出V〇i:v:不：率= 用改變該功率開關110A、11〇 ^，可以利 到螢光燈管的交流電流。 "頻羊的方式調整輸出 習知的實施例中的控制回路乃是配合諧振哭 圖所述的頻率特性將該換流器1〇〇的操作頻率: 、 該譜振槽電路120的譜振頻率F 操二上 器⑽的操作頻率大於言皆振頻· F3的頻率^乍该= =管^峨電路13。所她信號經由該；：二榮。 ，刀以產生對應於螢光燈管電流之—穩定的電制 Γ不=的壓控制信號RC控制該電壓控制振^心 生不同頻率的脈波信號RD。該電壓 電流變高時提高該電二= ，出頻率’在燈官電流變低時降低振盈頻率。該半 率：：驅動祕16〇利用不同頻率的脈波信號rd i且H:LRA':RB控制功率開關n°A、聰用固定而 其辑二而日*工/週期’以輪流導通方式達到提供營光燈 吕铋疋而且波形對稱的交流電流的目的。 琴電ΐ 一 Ϊ成：諧振型半橋式的直流/交流螢光燈管換流 在該直流電_ug是不同的輸人電壓情況 控制螢光燈管電流。但就實際應用上其缺點是當 ΐίΚϊΓ的電壓範圍較大時，在較高電壓下操作的 1〇〇得將該功率開關ll〇A、ιι〇Β的操作 在較遠離，槽電路120的譜振頻率(即操作頻 率遂大於F3)上使得整體效率變低。 =故’本發明鐾於習知技術之缺失，乃思及改良 „„ %心發明出本案之『諧振型半橋式直流/交流換流 器』。 【發明内容】 1301692 本發明之主要目的係提供-種諧振型半橋式直流/交 流換流器之電路設計，以同時變化功鱼鬥明4a 夂 支化力旱開關操作頻率以及 ¥通工作週』的方式調整輸出到螢光燈管的電流，以改善 習知的技術中所產生的在較高直流電 低的狀況。 以m兄下效率較 本發明之另一個目的将媒很 ,扪係钕供一種諧振型半橋式直流/ 父流換流益之電路設計，配合螢光燈管，提供 源的應用，並同時變化功帛開關操作㈣以及導通 期的方式調整輪：到螢光燈管的電流，以改善習知的技術 本發明提供-種諧振型半二直，^ , 牛橋式直〜/父流換流器之電 路3又计，k供驅動螢光燈管所需的對稱的交流 螢光燈管所需要的高電壓，莩動作 ”L 動 ^ ^ $决動作保蠖電路以及調光電路。 為達上述目的，本發明提供一種 直流/交流換流器係轉換一直产帝 ° 孓丰橋式 流電源用以驅動一螢光燈管，7包原含成為一交流電源，該交 一半橋式開關，係電連接該直 切換輸出一脈波訊號； ^源將该直流電源 一譜振槽電路，係電連接 管之間，將該脈波訊號升壓與該營光燈 該交流電源，電力給予該勞慮光皮燈以 控制益，係回授該螢光燈瞢 度調變與脈波頻率調變$ _ 輸出，美供一脈波寬 波頻率，以控制ΐ丰iK:可以同時調變脈波寬度與脈 本幸兄都可以在譜振頻率附近操作。 了解。 j ΰ不與坪細說明，俾得一更深入之 【實施方式】 請參閱第3圖# Α& 為本案較佳實施例之諧振型半橋式直 8 1301692 ^交流換流器電路示意、圖。如圖所示，―魏 流/交流換流器包括一直流電1 A，式直 3。2、-諸振槽電路303、3:二一4丰橋^功率開關 流谓測電路305、一營光燈管二 ' 一=光燈管電 官疮，傲抑^ Ί ®侦測電路306、一脈波 ^调…07、一電壓控制頻率三角波產生器3〇8 =式功率開關驅動電路309、_保護電路31〇 : 311以及一調光電路312。 砟f 口口 ，電連接關係如下所述：該直流電壓源3〇1輕接 =式功率開關302。該半橋式功率開關3() ^ =Γ槽電路3〇2之輪入端。該證振槽電路3。= 括有_!雷5:?^光燈官3〇4之-端，該諧振槽電路303包 括有一電感益321和一陶瓷壓電變壓器322。 :螢光燈管電流该測電路3〇5與該螢 分別耗接至該榮光燈管3。4之一端。該 ‘ill:電？:〇5與該螢光燈管端電㈣測電路306亦 ΐίίίΐ ^調變器3〇7,且該脈波寬度調變器_ 壓""fim:出信號si並透過電阻362接至該電 ==二角波產生器308。該脈波寬度調變器3〇7的 S16連接至該半橋式功率開關驅動電路3〇9 =式功率關驅動電路3G9㈣至該半橋式功率開關 開關財，該半橋式功率開關3°2包含兩個功率 =302A與删。該功率開關·可為一 p型 體場效電晶體（M〇SFET)，該功率開關3g2b可為 率門氧化半導體場效電晶體（M〇SFET)，但兩個功 :=T與雇並不限於M0SFET，亦可為各類電晶 篮開關，如BJT等。 ，本實施例㈣電磨控制頻率三角波產生$鳩 疋利用流出該電麼控制頻率三角波產生器3〇8的一定電屡 9 1301692 輸出端點S2到一接地電阻363的輸出電流幻以及 容359決定其操作頻率。該電流S3越高，頻率就合 二電二該接地電阻363 1聯至該^電壓輪出端二 “:電之電流大小係由一信號si來控制。因此 原來用來決定操作頻率輸出電流S3，便變成一部份 號S1所決定。在本實施例中t S1等於G伏特，該^ 壓控制頻率三角波產生器308的定電壓輸出端點S2而二， 則是接上了並聯到地的電阻，此時該電壓控制頻率三角1 產生益308的負載電阻最小，流出電流S3最大，所以頻率 最高。反之若是信號S1電壓升到接近該定 端 ，則流經外接電阻362電流變成零，則該電壓 率二角波產生益308的等效負載電阻變成只剩下原來的接 地電阻363，這時候流出電流S3變小，頻率也隨著降低。 整個電壓控制頻率三角波產生器3〇8產生的頻率在該接地 電阻363、5亥外接電容359以及該外接電阻固定的情 况下，會隨著信號S1的電壓變高而下降，變低而提高。 本實施例中的電壓控制頻率三角波產生器3〇8除了產生三 角波信號S17之外’也產生一與三角波同頻率的脈波信號 S18供半橋式功率開關驅動電路3〇9使用。然而在本發明 中不限於二角波信號之使用，凡任何斜坡（） 或疋錯齒波訊5虎皆適用於本發明。 而為了使系統操作頻率不低於該諧振槽電路3〇3的諧 振頻率，誤差放大器的輸出可以用一例如是曾納（Zene〇 二極體369的裝置限制住其最大的輸出電壓。 該螢光燈管電流偵測電路3〇5與該螢光燈管3〇4串 聯，並提供一信號S4用以指示該螢光燈管之導通狀況，以 及另一信號S5用以指示流過該螢光燈管之電流值。該螢光 燈管端電壓債測電路306與該螢光燈管3〇4並聯檢測出一 Y吕號S 6用以指示該螢光燈管之端電壓。 1301692 該脈波寬度調變器307包含一誤差放大器361、一積 分電阻365與一積分電容366所組成的一反相積分器以及 一比較器364之外。該脈波寬度調變器307更包括一電流 源367經由一開關368連接到該誤差放大器361的反相端 輸入端。 該半橋式功率開關驅動電路3 0 9包含有兩個驅動輸出 信號 POUT、NOUT。 該計時器311由兩組比較器381、382以及一電流源 383所組成。該調光電路3 12則包括一個調光頻率產生器 331，其產生的一三角波信號S7被送至一比較器332之非 反相輸入端以及一調先控制電壓S8被送入該比較器332之 反相輸入端，比較後產生一調光脈波信號S9，其中更包一 OR邏輯閘333，用以控制該調光脈波信號S9送出至該脈 波寬度調變器307中誤差放大器36丨輸入的時機。 在本實施例中，該計時電路3丨丨的計時方式是利用該 電流源383對一計時電容器384充電，使該計時電容器384 的端電壓S12隨時間的增加而上升。當該電容器384的電 壓S12超過一參考位準Vrefl前送出一重設信號su，而當 該計時電容器384的電壓S12上升到超過一參考位準Vref2 時送出一時間到（Tlme 0ut)信號s丨〇。該電流源383並受到 一指不系統電壓源的信號S13控制，當該系統電壓低於一 參考位準Vref3 _將該電流源、383 _閉，並將 器=的電MS12接地。透過這樣的設計可以使系統在每 一-人由零電Μ開始起動該直流電壓源3〇1時，該計時器 上的該計時電容器384都是由零電壓開始充電確保每 掉電源後再重新啟動時計時器311都重新計時。 在本實施例中螢光燈管電流谓測電路3〇 號S4和保護電路310中的-比較器374決定螢光；巧 導通，當該指示螢光燈管導诵产 疋否 且& ¥通仏號S4超過一參考位準 11 1301692Duty C], according to the pulse signal, two sets of fixed duty cycles are generated (Fixed 110A, flU control signals R1 and R2 respectively control the power switch is ^ HI vibration type half bridge glory lamp inverter circuit operation principle can be The high-frequency interaction of the power switches 11〇A, 11〇B is turned on, and the DC voltage of the voltage source '110 is converted into a high-frequency pulse by the vibration' to supply the vibration circuits 120 of the subsequent stage. The function of the electric riser is to use the filter and boost function of the inductor 121 and the pottery to suppress the sine of the high frequency square wave 170, the door ', and the parent's parent flow. The wave is supplied to the fluorescent tube of the subsequent stage. As shown in FIGS. 1 and 2, the resonant tank circuit signal composed of the inductor 121 and the ceramic piezoelectric transformer 1301692 is different in output. V〇i:v: No: Rate = By changing the power switch 110A, 11〇^, the AC current of the fluorescent tube can be benefited. "Frequency of the frequency adjustment of the control loop in the conventional embodiment Is the operating frequency of the inverter 1〇〇 in accordance with the frequency characteristics described in the resonant crying diagram: The spectral frequency F of the oscillating circuit 120 is higher than the frequency of the frequency F3. = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Producing a voltage control signal RC corresponding to the current of the fluorescent tube - the stable electric system is not controlled. The voltage control signal is used to control the pulse signal RD of different frequencies. When the voltage current becomes high, the electric power is increased. The output frequency 'lower the vibration frequency when the lamp current is low. The half rate:: drive the secret 16 〇 use different frequency pulse signal rd i and H: LRA': RB control power switch n °A, Cong fixed And the second series of work / cycle 'to achieve the purpose of providing camp light Lu Wei and waveform symmetrical alternating current in turn-on mode. Qin ΐ Ϊ :: Resonant half-bridge DC / AC fluorescent The lamp is commutated in the direct current _ug is different input voltage conditions to control the fluorescent tube current. However, the practical disadvantage is that when the voltage range of ΐίΚϊΓ is large, the operation is performed at a higher voltage. The operation of the power switch ll 〇 A, ιι 在 is farther away, the slot circuit 120 The spectral frequency (ie, the operating frequency 遂 is greater than F3) makes the overall efficiency lower. Therefore, the present invention is in the absence of the prior art, and is considered to be improved. „% Heart invented the case of the resonant half-bridge type The present invention is directed to providing a resonant-type half-bridge DC/AC converter circuit design for simultaneously changing the power of the fish The current of the switch operating frequency and the pay-through working cycle adjusts the current output to the fluorescent tube to improve the low DC current generated by the prior art. The purpose is to provide a medium-sized, resonant-type half-bridge DC/parent-flow converter circuit design, with fluorescent tubes, to provide source applications, and to change the function of the power switch (four) and the conduction period. Adjusting the wheel: the current to the fluorescent tube to improve the conventional technology. The present invention provides a resonant type semi-two straight, ^, the circuit of the Niuqiao straight ~ / parent current converter 3, k for driving Symmetrical AC flashlight required for fluorescent tubes A high voltage required for the lamp, the operation of die of hunger "L ^ ^ $ movable holding californica decision operation circuit and dimming circuit. In order to achieve the above object, the present invention provides a DC/AC converter conversion system that has been produced by the Emperor. The Fengfeng Bridge type power supply is used to drive a fluorescent tube, and the 7 packs originally become an AC power source. a switch electrically connected to the direct switching output pulse signal; ^ source the DC power supply to a spectral oscillator circuit, between the electrical connection tubes, boosting the pulse signal with the camping light, the AC power, power Give the labor light lamp to control the benefits, the feedback of the fluorescent lamp temperament modulation and pulse frequency modulation $ _ output, the United States for a pulse wave wide wave frequency to control the ΐ i iK: can be simultaneously adjusted The variable pulse width and the pulse of the brother can operate near the spectral frequency. To understanding. j ΰ 与 与 坪 坪 坪 坪 坪 坪 坪 坪 坪 坪 坪 坪 坪 坪 坪 坪 坪 坪 坪 坪 【 【 【 【 【 【 【 【 谐振 谐振 谐振 谐振 谐振 谐振 谐振 谐振 谐振 谐振 谐振 谐振 谐振 谐振 谐振 谐振 谐振 谐振 谐振 谐振 谐振 谐振 谐振 谐振. As shown in the figure, the "Wei current / AC converter includes a constant current 1 A, straight 3. 2, - Zhenqi circuit 303, 3: 2 4 Fengqiao ^ power switch flow pre-measure circuit 305, a battalion Light tube two 'one = light tube electric acne, arrogant ^ Ί ® detection circuit 306, a pulse wave adjustment ... 07, a voltage control frequency triangle wave generator 3 〇 8 = type power switch drive circuit 309, _ protection circuit 31 〇: 311 and a dimming circuit 312.砟f mouth, the electrical connection relationship is as follows: the DC voltage source 3〇1 is lightly connected to the power switch 302. The half-bridge power switch 3() ^ = the wheel-in terminal of the slot circuit 3〇2. The snubber circuit 3. = Included: _! Ray 5: ?^ Light-emitting official 3〇4-end, the resonant tank circuit 303 includes an inductor 321 and a ceramic piezoelectric transformer 322. : Fluorescent tube current The measuring circuit 3〇5 and the firefly are respectively connected to one end of the glory lamp 3. 4 . The ‘ill: electricity? : 〇 5 and the fluorescent tube end (four) measuring circuit 306 also ΐ ί ί ί ί ί ί ί ί ί ί ί ί ί ί ί ί The electric == two-wave generator 308. S16 of the pulse width modulator 3〇7 is connected to the half bridge power switch drive circuit 3〇9=type power off drive circuit 3G9(4) to the half bridge power switch switch, the half bridge power switch 3° 2 contains two power = 302A and deleted. The power switch can be a p-type body field effect transistor (M〇SFET), and the power switch 3g2b can be a rate gate oxide semiconductor field effect transistor (M〇SFET), but two functions: =T and employment Not limited to M0SFET, it can also be various types of electric crystal basket switches, such as BJT. In the present embodiment, (4) the electric grinder control frequency triangle wave is generated by using the electric current to control the frequency of the triangular wave generator 3〇8, and the output current of the output terminal S2 to a grounding resistor 363 is determined by the output current illusion and capacity 359. Its operating frequency. The higher the current S3, the higher the frequency is. The grounding resistance 363 1 is connected to the voltage terminal 2 ": the current of the electric current is controlled by a signal si. Therefore, it is used to determine the operating frequency output current S3. Then, it is determined by a part number S1. In the present embodiment, t S1 is equal to G volt, and the voltage control frequency of the triangular wave generator 308 is outputted to the end point S2, and is connected to the ground in parallel. Resistor, at this time, the voltage control frequency triangle 1 generates the minimum load resistance of the benefit 308, and the outgoing current S3 is the largest, so the frequency is the highest. On the other hand, if the voltage of the signal S1 rises close to the fixed end, the current flowing through the external resistor 362 becomes zero, then The equivalent load resistance of the voltage rate two-wave generating benefit 308 becomes only the original grounding resistance 363, and the outgoing current S3 becomes smaller and the frequency also decreases. The entire voltage control frequency is generated by the triangular wave generator 3〇8. When the grounding resistors 363 and 5 are externally connected to the capacitor 359 and the external resistor is fixed, the frequency is lowered as the voltage of the signal S1 becomes higher, and the frequency is lower. The triangular wave generator 3〇8 generates a pulse wave signal S18 of the same frequency as the triangular wave for use by the half bridge power switch drive circuit 3〇9 in addition to the triangular wave signal S17. However, it is not limited to the two-angle wave signal in the present invention. For use, any ramp () or faulty toothed wave 5 is suitable for use in the present invention. To make the system operating frequency not lower than the resonant frequency of the resonant tank circuit 3〇3, the output of the error amplifier can be used, for example. It is Zener's (Zene〇 diode 369 device that limits its maximum output voltage. The fluorescent tube current detection circuit 3〇5 is connected in series with the fluorescent tube 3〇4 and provides a signal S4 for Indicating the conduction state of the fluorescent tube, and another signal S5 for indicating the current value flowing through the fluorescent tube. The fluorescent tube end voltage measuring circuit 306 is connected in parallel with the fluorescent tube 3〇4. A Y-S6 is detected to indicate the terminal voltage of the fluorescent tube. 1301692 The pulse width modulator 307 includes an error amplifier 361, an integral resistor 365 and an integrating capacitor 366. Integrator and a comparator 364 The pulse width modulator 307 further includes a current source 367 connected to the inverting input of the error amplifier 361 via a switch 368. The half bridge power switch drive circuit 309 includes two drive output signals POUT. The timer 311 is composed of two sets of comparators 381, 382 and a current source 383. The dimming circuit 3 12 includes a dimming frequency generator 331, and a triangular wave signal S7 is sent to the The non-inverting input terminal of the comparator 332 and a preset control voltage S8 are sent to the inverting input terminal of the comparator 332. After comparison, a dimming pulse signal S9 is generated, wherein an OR logic gate 333 is further included. The timing at which the dimming pulse signal S9 is sent to the input of the error amplifier 36 in the pulse width modulator 307 is controlled. In the present embodiment, the timing circuit 3 is clocked by the current source 383 to charge a timer capacitor 384 such that the terminal voltage S12 of the timer capacitor 384 rises with time. A reset signal su is sent before the voltage S12 of the capacitor 384 exceeds a reference level Vref1, and a time (Tlme 0ut) signal s is sent when the voltage S12 of the timing capacitor 384 rises above a reference level Vref2. . The current source 383 is controlled by a signal S13 that is not a system voltage source. When the system voltage is lower than a reference level Vref3 _, the current source, 383_ is closed, and the electric MS12 of the device is grounded. Through such a design, when the system starts the DC voltage source 3〇1 from zero to zero, the timing capacitor 384 on the timer is charged by zero voltage to ensure that the power is restored after each power failure. The timer 311 is re-timed at startup. In the present embodiment, the fluorescent tube current pre-measure circuit 3 S S4 and the comparator 374 in the protection circuit 310 determine the fluorescence; the illuminating is turned on, when the indicator fluorescent tube guides the 诵 且 and &仏号S4 exceeds a reference level 11 1301692
Vref4時，該螢光燈管304被視為導通並送出指示螢光燈总 304是否導通信號S14。 1 & 該保護電路3 10包含一邏輯控制電路372，該保雙 -路310接受螢光燈管是否導通信號S14’計時器=時間】 (Tlme 〇ut)信號S10以及調光頻率產生器33丨產生的頻率作 ‘ 號S15，並根據這些信號決定保護動作的進行。 。 ••在正常狀況下，本實施例更詳細之操作如下所述· .當系統開始供電起動後，該計時器3丨丨開始對該計時 電谷益384充電’當該計時電容器384電壓未充電達到含玄 春參考位準Vref 1岫’由該計時器3 11送出的重設信號$ j j 使一開關368導通（turn on)，使得該電流源367連到該誤 差放大為361的反相輸入端，強迫反相輸入端電壓高過一 參考位準Vref5，迫使該誤差放大器361輸出S1為零，這 時候脈波寬度調變器307的輸出S16為零，電壓控制頻率 一角波產生為3 0 8的輸出最鬲頻率使操作頻率落在遠離諧 振器304諧振頻率的更高的頻率上。 當該計時電容器384上繼續充電到大於該參考位準 Vrefl之後，遠電流源開關368截止（turn off)，該脈、、古官；^ 調變器術開始運作，該誤差放大器361的反相^ j ^為該螢光燈管304尚未導通而成為一低於該參考位準 Vref5(本實施例中得再加上二極體352導通電壓）的狀況， 該誤差放大器361輪出該信號si，在負回授控制原理之下 逐漸上升，而在與該三角波S17比較後，由該比較器364 送出一脈波寬度調變信號s 1 6。該半橋功率開關驅動電路 309接收此該信號s 16和該脈波信號S 18，經運算產生兩組 k 5虎POUT、 N〇UT分別驅動半橋式功率開關3〇2a以及 302B。 该勞光燈管3 04未導通前，螢光燈管端電壓S19會因 該脈波寬度調變信號S16工作週期的逐漸變寬而且頻率逐 12 1301692 漸k低而升鬲。該螢光燈管端電壓偵測電路3〇6在偵測到 該指示螢光燈管端電壓信號S6超過一預設的參考位準 Vref5(本實施例中得再加上二極體352導通電壓）時，把該 誤是放大器361輪出S1變小，然後減少該脈波寬度調變信 號S1 6工作週期及提高其工作頻率以減少輸送到該螢光燈 ' 管端的電$。這減少電力輸送的結果若是造成在偵測到指 不螢光燈管端電壓信號S6小於該預設的參考電位v^f5(本 .^施例中得再加上二極體352導通電壓），然後使誤差放大 器361輸出S1變大。於是該螢光燈管端電壓S19就在這樣 φ 的負回授控制之下得到穩定調節。 一旦螢光燈管被足夠的電壓S19和時間下被點燃導 通、’，根據螢光燈管特性，該螢光燈管端電壓s丨6會驟降至 一半不到的導通操作電壓，使得該螢光燈管電壓偵測電路 306因為偵測不到一夠高電壓而失去作用。同時該螢光燈 官電流偵測電路305送出指示螢光燈管導通信號S4至該保 ^電路310,該指示螢光燈管電流信號S5至該脈波寬度調 變器307，使流經螢光燈管的電流透過負回授控制而穩定 在一預設值上。 在本實施例中二極體3 5 1及二極體3 5 2的作用是利用 _螢光燈管啟動電壓與導通後正常操作電壓相差甚大（例如 2〜2.5倍）的特性。在燈管未導通前，二極體352導通二極 • 體351截止，送到脈波寬度調變器307的信號是指示燈管 電壓的回授信號S 6。在燈管被點燃之後，燈管電壓s 1 9下 • 降，電流上升，結果二極體351導通二極體352截止，送到 脈波寬度調變器307的信號是指示燈管電流的回授信號 S5。如此設計可以使換流器在啟動時提供螢光燈管3〇4穩 定的高電壓，在點燃後提供螢光燈管穩定的電流。 本實施例的保護電路其詳細的操作狀況如下所述： 當螢光燈管自始就沒接上時，指示螢光燈管是否導通 13 1301692 4口號S 14會自啟動開始就送出指示螢光燈管不導通的訊息 ^亥數位控制邏輯372。在本實施例中，》了提供螢光燈 吕足夠的時間點燃，在另一個輸入信號時間到s丨〇的計時 結果是，，時間已經到了預設值，，到達之前保護電路31〇中的 數位控制邏輯372不理會指示螢光燈管不導通的訊息si4, 、旦 > 時間已經到了預設值，，，則另一組利用一數位計時器 1忒凋光頻率產生器331產生的該脈波信號sb開始計 犄，一旦該螢光燈管再經過預設的數個時鐘週期（cl〇ckAt Vref4, the fluorescent tube 304 is considered to be turned on and sends a signal indicating whether or not the fluorescent lamp total 304 is on. 1 & The protection circuit 3 10 includes a logic control circuit 372, which receives the fluorescent tube conduction signal S14' timer = time (Tlme 〇ut) signal S10 and the dimming frequency generator The frequency generated by 33丨 is 'S15', and the protection action is determined based on these signals. . • Under normal conditions, the more detailed operation of this embodiment is as follows: • When the system starts power supply, the timer 3丨丨 starts charging the timing electricity 384. When the voltage of the timing capacitor 384 is not charged The reset signal $jj sent by the timer 3 11 is turned on, so that a switch 368 is turned on, so that the current source 367 is connected to the inverting input with the error amplified to 361. End, forcing the inverting input terminal voltage to be higher than a reference level Vref5, forcing the error amplifier 361 output S1 to be zero. At this time, the output S16 of the pulse width modulator 307 is zero, and the voltage control frequency is generated as a corner wave of 3 0. The output maximum frequency of 8 causes the operating frequency to fall at a higher frequency away from the resonant frequency of the resonator 304. After the timing capacitor 384 continues to be charged to be greater than the reference level Vref1, the far current source switch 368 is turned off, and the pulse, the official is turned on, and the error amplifier 361 is inverted. ^ j ^ is a condition that the fluorescent tube 304 has not been turned on to become lower than the reference level Vref5 (in this embodiment, the diode 352 is turned on), the error amplifier 361 rotates the signal si And gradually rising under the principle of negative feedback control, and after comparing with the triangular wave S17, a pulse width modulation signal s 16 is sent by the comparator 364. The half-bridge power switch drive circuit 309 receives the signal s 16 and the pulse signal S 18 , and generates two sets of k 5 tigers POUT and N〇UT to drive the half-bridge power switches 3〇2a and 302B, respectively. Before the light tube 3 04 is not turned on, the fluorescent tube end voltage S19 is increased due to the gradual widening of the pulse width modulation signal S16 and the frequency is gradually lowered by 12 1301692. The fluorescent tube end voltage detecting circuit 3〇6 detects that the fluorescent tube end voltage signal S6 exceeds a predetermined reference level Vref5 (in this embodiment, the diode 352 is turned on again) In the case of voltage, the error is that the amplifier 361 turns S1 to be small, and then the pulse width modulation signal S16 is reduced in duty cycle and its operating frequency is increased to reduce the amount of electricity supplied to the fluorescent lamp's tube terminal. If the result of reducing the power transmission is caused to detect that the voltage signal S6 of the fluorescent tube is less than the preset reference potential v^f5 (this embodiment is further added with the diode 352 conduction voltage) Then, the error amplifier 361 output S1 is made larger. Thus, the fluorescent tube terminal voltage S19 is stably adjusted under the negative feedback control of φ. Once the fluorescent tube is ignited and turned on by sufficient voltage S19 and time, according to the characteristics of the fluorescent tube, the fluorescent tube terminal voltage s丨6 will be suddenly reduced to less than half of the conduction operating voltage, so that The fluorescent tube voltage detecting circuit 306 is disabled because it does not detect a sufficiently high voltage. At the same time, the fluorescent lamp current detecting circuit 305 sends an indication fluorescent tube conduction signal S4 to the protection circuit 310, and the fluorescent tube current signal S5 is sent to the pulse width modulator 307 to flow through The current of the fluorescent tube is stabilized by a negative feedback control to a predetermined value. In the present embodiment, the functions of the diode 3 5 1 and the diode 3 5 2 are such that the starting voltage of the fluorescent tube is very different from the normal operating voltage after the conduction (for example, 2 to 2.5 times). Before the lamp is not turned on, the diode 352 is turned on by the diode 351, and the signal sent to the pulse width modulator 307 is the feedback signal S6 of the indicator tube voltage. After the lamp is ignited, the lamp voltage s 1 9 drops and the current rises. As a result, the diode 351 turns on the diode 352 and the signal sent to the pulse width modulator 307 is the current of the indicator tube current. Grant signal S5. This design allows the converter to provide a stable high voltage of the fluorescent tube 3〇4 at startup, providing a stable current to the fluorescent tube after ignition. The detailed operation of the protection circuit of this embodiment is as follows: When the fluorescent tube is not connected from the beginning, it indicates whether the fluorescent tube is turned on. 13 1301692 4 The slogan S 14 will send the indication fluorescent light from the start. The lamp does not conduct the message ^Hai digit control logic 372. In the present embodiment, "the fluorescent lamp is provided with sufficient time to ignite, and the timing of the other input signal time to s丨〇 is that the time has reached the preset value, and the protection circuit 31 is in the state before the arrival. The digital control logic 372 ignores the message si4 indicating that the fluorescent tube is not conducting, and the time has reached the preset value, and the other group uses the one-digit timer 1 to generate the generated by the withering frequency generator 331. The pulse signal sb starts counting, once the fluorescent tube passes a preset number of clock cycles (cl〇ck
Cycle)後^還是不導通，則該數位控制邏輯372送出停止輸 出的彳5號S20到該半橋式功率開關驅動電路3〇9，停止 該半橋式功率開關302八與3〇2B之導通。在本實施例中， 路停止功率開關繼續導通，整個換流器必需關 得電源重新啟動才能解除保護。 當螢光燈管在操作中損壞開路時，指示螢光燈 k號S14會送出相千恶也政μ 、盆 ^ ^ 邏鞋⑺上 不導通的訊息到該數位控制 你械。"數位控制邏輯接收該計時器311之信號S10。 f控制邈輯372在該信號S10未送入時是不動作的。 輯操過前述預設的點燃時間，則該數位控制邏 ί二 光燈管導通信號S14指示螢光燈管不導 :清形下，利用一數位計時器以低頻 生的-脈波信號S15計時，一日替朵” = 12產 時鐘调细^丨】广 旦螢先燈官超過預設的數個 372 = )後還是不導通，則該數位控制邏輯 ^出停止輸出的信號S20到該半橋式Λ皇 路309，停止兮本捧—，“曰 牛橋式功率開關驅動電 伶止4 +橋式功率開關302Α與302Β導通。 ，在本實施例中，一但保護電路停止功率開關繼庐γ， 正個換流器必需關掉電源重新啟動才能解除保護。、，導 本實施例更包括一調光電路3丨2，調光 比螢光燈管3G4操作頻率低的頻率 ^ =用— 光燈管304於技士 a 让利片止或恢復對螢 304輸运電力。利用明暗比例的調整達到調整勞： 14 1301692 燈管则亮度的目土也，而為了避免頻率過低造成人眼閃燦 的感文，一般都將調光頻率控制在大於200Hz以上。本實 施例的調光電路的調光功能是被兩個信號所決定啟動。三 是該指示螢光燈管是否導通信號S14，一是該計時器3ιι 的該時間到信號S10。當該指示螢光燈管是否導通信號S14 指示螢光燈管導通或是該計時器311得該時間到信號S10 指示時間到。控制調光信號輸出的一開關336才會導通 (Turn on)。調光電路中的調光電壓S21是一比參考位準 Vref5更高的電位。當調光電路中的調光電壓S2l經控制 開關336、335與一電阻334與該脈波寬度調變器3〇7連接 上時，该脈波寬度調變器307的誤差放大器361輸出電壓 S1變小，造成系統停止電力輸送至負載。而當調光脈波信 號S9截止（Turn Off)該開關335時，調光電壓與該脈波 寬度調變307開路（open circuit)，系統恢復電力供應。 本實施例中調光頻率產生器331產生一三角波S7。控制不 同亮度的不同大小電壓輸入調光控制信號S8與該三角波 SJ經比較态332比較後會產生一脈寬大小不同的亮度控制 #號S9。本實施例利用一低頻率控制每一週期中停止或恢 復電力供應的比例可以達到調整亮度的效果。而利用螢光 燈官導通與否決定調光開始的時機，可以保障螢光燈管有 足夠而且連續的電力在足夠的時間内被點燃。 、在本實施例中，為減少因為利用低頻率以明滅的調光 方式與LCD内部時脈產生干擾，調光控制信號S8也可以 換成一由LCD相關時脈所產生的低頻脈波。當調光控制信 號S8的波幅大於三角波S7波峰而且小於三角波s7波谷時 則決定亮度的信號S9其頻率及亮暗比例便完全變成由當 凋光控制信號S8的頻率及工作週期（Duty Cycle)所決定。 如此便可有效降低因為調光與LCD不同操作頻率所產生的 視覺上的差頻干擾。 15 1301692 奋^ 了提仏對稱性佳的交流電流驅動螢光燈管3〇4， 相二ϊί中的半橋式功率開關302在系統穩定操作時是以 相冋的ν通工作週期，以180。相位差輪流導通。 本發=係以利用陶瓷壓電變壓器驅動螢光燈管為本案 進行說明，然而並不侷限應用於利用陶瓷壓 二态動螢光燈管，任何種類之變壓器，或由電感電 谷、、且成的諧振槽電路皆適用於本發明所揭露之技術。 本案得由熟知此技術之人士任施匠思而為諸般修飾， 以白不脫如附申請專利範圍所欲保護者。 【圖式簡單說明】 第1圖為習知一種諧振型半橋式直流/交流螢光燈管換 流器電路。 ' 第2圖係係一典型諧振槽電路之操作頻率與輸出電壓的對應關 係圖。 " 第3圖係為本案較佳實施例之諧振型半橋式直流/交漭 螢光燈管換流器電路示意圖。 【主要元件符號說明】 100習知的諧振型半橋式直流/交流螢光燈管換流哭 ⑽直流電壓源 U〇A、110B半橋式功； 關 120諧振槽電路 Π〇螢光燈管 130螢光燈管電流偵測電路 14〇 積分器 150 電壓控制振盪器 1 60半橋式功率開關驅動電路 121 電感器 122 陶瓷壓電變壓器 3 01 直流電壓源 3 02 半橋式功率開關 16 1301692 302A功率開關 302B功率開關 305 306 307 308 309 310 312 322 332 334 336 352 361 363 365 366 367 369 373 374 382 383 384 385 303諧振槽電路 3〇4螢光燈管 螢光燈管電流偵測電路 勞光燈管端電壓偵測電路 脈波寬度調變器 電壓控制頻率三角波產生器 半橋式功率開關驅動電路 保護電路 調光電路 陶瓷壓電變壓器 比較器 電阻 開關 二極體 誤差放大器 電阻 積分電阻 電阻 電流源 曾納（Zener )二極體 邏輯控制電路 比較器 比較器 比較器 電流源 電容 計時器 電感器 調光頻率產生器 GR邏輯閘 開關 一極體 外接電容 電阻 比較器 電容 開關 311 321 331 333 335 351 359 362 364 3 66 368 POUT、NOUT 驅動輪出信號 17After the cycle is still not turned on, the digital control logic 372 sends the 彳5 S20 of the stop output to the half-bridge power switch drive circuit 3〇9, and stops the conduction of the half-bridge power switch 302 and 3〇2B. . In this embodiment, the road stop power switch continues to be turned on, and the entire converter must be powered off to restart the protection. When the fluorescent tube is damaged in the open circuit during operation, the indicator flashing light k No. S14 will send a message that is not conductive on the opposite side of the tube, and the non-conducting message on the basin (7) to the digital control device. " The digital control logic receives the signal S10 of the timer 311. The f control command 372 does not operate when the signal S10 is not sent. The operation of the preset ignition time, the digital control logic light tube conduction signal S14 indicates that the fluorescent tube is not guided: in the clear shape, using a digital timer to generate the low-frequency pulse signal S15 Timing, one day for the flower" = 12 production clock finer ^ 丨 广 广 广 广 广 广 广 广 广 广 广 广 广 广 广 广 广 广 372 372 372 372 372 372 372 372 372 372 372 372 372 372 372 372 372 372 372 372 372 372 372 372 372 Half-bridge type Λ皇路309, stop 兮本捧—, “Yiu Niu bridge type power switch drive electric 伶 4 + bridge power switch 302 Α and 302 Β conduction. In this embodiment, once the protection circuit stops the power switch and continues to γ, the positive inverter must be turned off and restarted to release the protection. The embodiment further includes a dimming circuit 3丨2, and the dimming frequency is lower than the operating frequency of the fluorescent tube 3G4. ^=With the light tube 304, the technician is allowed to stop or resume the transmission of the fluorescent 304. electric power. Adjust the brightness and darkness to adjust the labor: 14 1301692 The brightness of the tube is also the same, and in order to avoid the low frequency of the eye caused by the human eye, the dimming frequency is generally controlled above 200Hz. The dimming function of the dimming circuit of this embodiment is activated by two signals. The third is to indicate whether the fluorescent tube is turned on by the signal S14, and the other is the time of the timer 3 ι to the signal S10. When the indication fluorescent tube is turned on, the signal S14 indicates that the fluorescent tube is turned on or the timer 311 has obtained the time until the signal S10 indicates the time is up. A switch 336 that controls the output of the dimming signal is turned on. The dimming voltage S21 in the dimming circuit is a potential higher than the reference level Vref5. When the dimming voltage S2l in the dimming circuit is connected to the pulse width modulator 3〇7 via the control switch 336, 335 and a resistor 334, the error amplifier 361 of the pulse width modulator 307 outputs the voltage S1. Smaller, causing the system to stop power delivery to the load. When the dimming pulse signal S9 turns off the switch 335, the dimming voltage and the pulse width are 307 open circuit, and the system restores the power supply. In this embodiment, the dimming frequency generator 331 generates a triangular wave S7. The voltage input dimming control signal S8 of different magnitudes controlling different brightnesses is compared with the triangular state SJ by the comparison state 332 to generate a brightness control #No. S9 having a different pulse width. This embodiment can achieve the effect of adjusting the brightness by using a low frequency control to stop or restore the power supply ratio in each cycle. Whether or not the fluorescent lamp is turned on or not determines the timing of dimming, and it is ensured that sufficient and continuous power of the fluorescent tube is ignited in sufficient time. In this embodiment, in order to reduce interference with the internal clock of the LCD by using a low frequency to clear the dimming mode, the dimming control signal S8 can also be replaced with a low frequency pulse generated by the LCD related clock. When the amplitude of the dimming control signal S8 is larger than the triangular wave S7 peak and smaller than the triangular wave s7 trough, the frequency and the brightness ratio of the signal S9 determining the brightness are completely changed by the frequency and duty cycle of the withering control signal S8. Decide. This effectively reduces the visual difference interference caused by dimming and different operating frequencies of the LCD. 15 1301692 奋 了 了 仏 仏 仏 的 的 的 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流 交流. The phase difference turns on in turn. This is a description of the case where a fluorescent tube is driven by a ceramic piezoelectric transformer. However, it is not limited to the use of a ceramic-voltage two-state fluorescent tube, any type of transformer, or an inductor, and The resulting resonant tank circuit is suitable for use in the techniques disclosed herein. This case has been modified by people who are familiar with the technology, and is intended to be protected as intended. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a conventional resonant half-bridge DC/AC fluorescent tube converter circuit. Figure 2 is a diagram showing the relationship between the operating frequency and output voltage of a typical resonant tank circuit. " Fig. 3 is a schematic diagram of a resonant half-bridge DC/crossover fluorescent tube converter circuit of the preferred embodiment of the present invention. [Main component symbol description] 100 conventional resonant half-bridge DC/AC fluorescent tube commutation crying (10) DC voltage source U〇A, 110B half-bridge function; Off 120 resonant tank circuit Π〇 fluorescent tube 130 fluorescent tube current detection circuit 14〇 integrator 150 voltage controlled oscillator 1 60 half bridge power switch drive circuit 121 inductor 122 ceramic piezoelectric transformer 3 01 DC voltage source 3 02 half bridge power switch 16 1301692 302A Power Switch 302B Power Switch 305 306 307 308 309 310 312 322 332 334 336 352 361 363 365 366 367 369 373 374 382 383 384 385 303 Resonant Slot Circuit 3〇4 Fluorescent Tube Fluorescent Tube Current Detecting Circuit Lamp end voltage detection circuit pulse width modulator voltage control frequency triangle wave generator half bridge power switch drive circuit protection circuit dimming circuit ceramic piezoelectric transformer comparator resistance switch diode error amplifier resistance integral resistance resistance current source Zener diode logic control circuit comparator comparator comparator current source capacitor timer inductor dimming frequency generator GR logic A diode switch external resistor capacitor capacitance switching comparator 311 321 331 333 335 351 359 362 364 3 66 368 POUT, NOUT signal drive wheels 17