M357125 - 1 » 五、新型說明： 【新型所屬之技術領域】 本創作疋有關於-種諧振換流器的控制電路，且特別是一種零電 壓切換諧振換流器的控制電路。 【先前技術】 • *尺寸液晶顯不器因製作成本及電源轉換效率要求，其冷陰極勞 光f 奐流器多採用 LIPS 架構，LIPS 為 LCD lntegrated Power Supply ⑩的簡稱LIPS架構直接由功率因數修正電路輸出典型值棚v高廢的 直流電壓供電給冷陰極魏燈換妨。在這種縫輸人情況下，使換 流器的功率開關具備零電屋切換及/或零電流切換特性，將可有效降低 開關的切換損失。财H通常採職振方式產生魏電壓和電流以提 供開關切換所需之零籠及/或零電流，雜換流㈣為雜換流器。 圖1為-種财的採用LIPS架構的冷陰極螢紐換流n之電路圖，此 冷陰極螢光燈換流器為一種具備零電壓切換特性的譜振換流器（以下 簡稱為零電壓切換魏触幻，而圖2為圖丨卿冷陰絲光燈換流 器的開關電路之信號波形圖。請同時參照圖】及圖2，冷陰極螢光燈 換流器1接收典型值為400V高屋的直流電壓Vdc，並將其轉成弦波形 式的交流電壓Vac以驅動冷陰極螢光燈2。 冷陰極縣燈換流H 1包括開關電路n、變顧12以及譜振電 路。在本，中’開關電路ii採用半橋式開關電路架構包括兩個由 N通道金氧半場效應電晶體所實現的功率開關ηι和112，在開關兩端 之間存在極間電容器113和114以及體二極體(bQdy diGde) 115和 116 ’其中體二極體us和116與開關和112反並接以提供電流 Idsl和Ids2反向流通路徑。變壓器〗2包括一次側的線圈121、二次 側的線圈122及漏電感器123。諧振電路採用串聯諧振並聯負載架構， 3 M357125 , * * 其包括漏電感123以及電容器131串聯耗接於變壓器12的二次側線 圈122兩端之間’而電容器131與作為負戴之冷陰極榮光燈2並聯耗 接。 控制信號Vgl和Vg2在兩開關ni和112上形成間源極電壓_ 和Vgs2 ’進而控制兩開關111和112交替地導通，將輸入之直流電壓 Vdc切成方波形式的交流電壓Vpl，其中控制信號Vgl和Vg2的頻率（或 切換頻率）is決定交流電壓Vpl的頻率為fs。交流電壓Vpl接著經過 變壓ϋ 12升壓以及舰電路進行雜後變成弦波形式的交流電壓— 春並驅動冷陰極螢光燈2。由於漏電感器123的電感值及電容器131的 電容值決定諧振電路的諧振頻率fr，且諧振電路依據所接收信號的頻 率(在本例中即切換頻率fs)與諧振頻率之關係而呈現電容性或電 感性’因此，設計切換頻率fs小於諧振頻率fr，使得採用串聯譜振 並聯負載架構的諧振電路呈電感性’進而造成交流電流Ip2落後交流 電壓Vac -相角差0 ’而交流電、流Ipl為變壓$ 12二欠側映射回一次 側之弦波電流，故交流電流Ipl亦落後交流電壓Vpl 一相角差必，此 相角差0就是使功率開關111和112具備零電壓切換特性的主要因素。 φ 當控制信號Vgl在高準位而控制開關111導通時，開關111兩端 跨壓Vdsl為零’交流電壓Vpl為Vdc/2，交流電流Ipl即為開關ηι 電流Ids：l。當控制信號Vgl在時間點tl變為低準位而控制開關1U 斷開的瞬間，由於電流必須是連續的，開關ηι電流Idsl不會瞬間變 為零，交流電流Ipl包含開關111電流Idsl及開關112電流(_Ids2)， 因此交流電流Ipl會與極間電容器113和114諧振，使導通的開關ηι 兩端跨壓Vdsl線性上升、預導通的開關112兩端跨壓Vds2線性下降。 當開關112兩端跨壓Vds2在時間點t2跨越零點時，與開關112反並 接的體二極體116導通，此時開關112等待控制信號Vg2變為高準位 (如在時間點t3)而導通即達成零電壓切換。同樣地，開關丨丨丨兩端跨 M357125 間點“跨越零點後，開關111等待控制信號變為高 ΤΐΐΓ ? 111 'σ 112 Vdsl ,： ^白為零，使得開關⑴和112在導通瞬間的切換損失皆為卩㈣ 時知’當變壓器12二次側的負載端電路呈電感性 關】 人侧的電流1ρ1落後電壓Vpw吏一次側的功率開 =11和112獲得零霞切換特性，在開關ιη和112導通瞬間所 in t為零。但是’也因為電流Ipl緖電壓Vpl，使開關 =112在斷開時存在切換損失；例如，以開關出為例，開關 時間點tl截止時，電流Idsl仍會持續流過開關⑴，直到開 i 111兩端跨M Vdsl在時間點t2上升到直流電壓Vdc為止因^ =llj在時間點tl到t2斷開時存在切換損失。再者，還因為電 Γ二洛後電壓Vpl，使得開關111 *112導通或斷開的控制電路（圖 時門任週期損失；例如，以開關112為例，開關112在 ^ 次侧賴Vpl變為他/2，鱗理應為負半週 月,量傳运棚，但—次側電流Ipl健處在正半週，必須等待 7電流Ipl由正半週跨越零點至負半猶，能量才能被真正的傳送 至一二人側的_電路’因此電流Ipl在時間點t3開始 區間就是控制電路的責任週期損失。責任週期損失越大，控制電路 111和112傳送能量的能力就越差，甚至可能造成傳送的 月匕里不足以驅動冷陰極螢光燈2。 【新型内容】 本創作的目的就是在提出一種零電麗切換譜振換流器的控制 可降低功率開關在斷開時的切換損失及控制電路的責任週期損失。 5 M357125 r * ' 為了達成上述目的及其它目的，本創作提出一種零電壓切換諧振 換流器b的控制電路，其中零電壓切換諧振換流器包括開關電路、變壓 器及譜振€路，_電路祕至變壓ϋ，變壓_接至譜振電路，譜 振電，耦接至負載，開關電路依據控制信號將輸入之直流電壓轉成交 流電2 ,交流電龜過顏H升壓及魏電路進行_後變成弦波形 式的交流f壓轉動貞載。零電壓切換魏換細的控制電路包括定 時電路、振盪11、邏輯控制電路、電流感·、全波整流ϋ以及重置 電路。，i馳接至定時電路’對定時電路進行充放電以產生斜波電 邏輯控制電路耦接至振蘯器及開關電路，依據斜波電壓產生控制 信號。電流感測器輕接以感測開關電路及變壓器之間的電流或譜^電 路的輸^或輸$雜賴並將越成錢。全波整流雜接至電 流感測器’對電壓錢進行全波整流，域生全波整流龍信號。重 置電路輕接至全波整流II及定時電路，通過比較全波整流 電壓設定值’在全波整流賴健大料驗定辦杨作， 波整流電壓信號小於電壓設定值時重置定時電路。 ^ 本創作之零電壓切換飾換流__電路採關測零電壓切 =振換流||中_電路及變壓器—次側之_電流或譜振電 t j出諧振電流，來剩電流接近零關時間以便調整斜波電 你甘!^ ’可轉持功率開關在導通時的零賴切換雜，還可降 =其在斷_的關電流進崎低功糊_場損失 除控制電路的責任週期損失。 岈丌為 下文 本創作之上述和其他目的、特徵和優點能更明顯易懂 特舉較佳實麵’麵合賴_，作詳細說明如下。 【實施方式】 圖3為依照本創作—實施例之零電壓切換諧振換流器的控制電路 6 M357125 I · . =¾路圖、，零電壓切換||振換流器例如是圖丨所示冷陰極螢光燈換流 器卜但並不以此為限’而圖4為圖3所示零電壓切換雜換流器及 其控制電路之信號波形圖。請同時參關丨至圖4，零電壓切換譜振 換流盗1的控制電路3包括誤差放大器3n、脈寬調變比較器312、振 盤器313、邏輯控制電路314、輸出驅動電路315、切換電路32、定時 電路33、重置電路34、電流峰值感測器35、電越測n 36以及全波 整流器37。 電流峰值感測器35、電流感測器36及全波整流器37用以感測零 籲電壓切換諧振換流器i的電流信號，並據以產生可供控制電路3進一 步使用的電麼信號。其中’電流峰值感測器35搞接至冷陰極榮光燈2， 感須懷過冷陰極螢光燈2的燈管電流Ilamp，並產生與燈管電流…即 大小成比例_授電壓’回授電壓Vf例如是燈管電流山即的峰 值或均方根值。另外’若不考慮雜散電容等非理想因素，因諧振電路 採用串聯諧振並聯負載架構，故變_ 12 —次側的電流邱、二次側 的電抓(或3白振電路之輸人諧減流）Ip2及燈管電流（或譜振電路之 輸出諸振電流）Ilamp為具有相同相位或電流零點位置之交流弦波電 壓因此電"IL感測器36可搞接於開關電路11及變壓器12 一次側之 •間以感測電流Ipl，或執接於變塵器12二次側及諧振電路的電感器131 之間以感測電流IP2，或柄接至冷陰極螢光燈2輸出端以感測流過冷 陰極螢光燈2的燈管電流n卿’然後據以產生與電流邱、汹或 11_成_的電壓信號Vi，電壓信號Vi接著經過全波整流器37的 整流後變為全波整流電壓信號yrec。 -般誤差放大器31卜脈寬調變比較器312、振盡器313、邏輯控 制電路314以及輸出驅動電路315乡被組合封裝成積體電路31，積體 ί HI 壓保護、過流保護、軟啟動等電路。誤差放大器 311負輸入知搞接至電流峰值感測器35以接收回授電壓^，其正輸入 7 M357125 端接收參考電屋vref，I 口„ 電壓Vref料、差放311通過比較回授龍Vf及參考 μ出誤差電髮Vea。脈寬調變比較器312正輸入端耦接至誤 至放大器311輪屮敁杜，^σ 糊八細稍按主决 313以接收斜波麵v接=^電3壓—’其負輸入端搞接至振盈器 ^ ，s.„ ' St C、例如是鋸齒波或三角波），脈寬調變比較 v_。邏誤差電壓Vea及斜波電壓Vst輪出脈寬調變信號 和路314依據脈寬調變信號VPWm產生控制信號Vgl t山 制信號Vgl*賊通常須通過開汲極/開集極或圖騰柱等M357125 - 1 » V. New description: [New technical field] This creation has a control circuit for a resonant converter, and in particular a control circuit for a zero-voltage switching resonant converter. [Prior Art] • *Dimensional liquid crystal display device requires LIPS architecture for its manufacturing cost and power conversion efficiency. LIPS is LCD for Integrated Power Supply 10. The LIPS architecture is directly corrected by power factor. The circuit output is typical value shed v high waste DC voltage power supply to the cold cathode Wei lamp change. In the case of such a slot input, the switching of the power switch of the converter with zero house switching and/or zero current switching characteristics can effectively reduce the switching loss of the switch. Cai H usually uses the vibration mode to generate the Wei voltage and current to provide the zero cage and / or zero current required for switching the switch, and the miscellaneous commutation (4) is the hybrid converter. Figure 1 is a circuit diagram of a cold cathode fluorescent converter n using a LIPS architecture. The cold cathode fluorescent lamp converter is a spectral converter with zero voltage switching characteristics (hereinafter referred to as zero voltage switching). Wei touches the illusion, and Figure 2 shows the signal waveform of the switch circuit of the Tuyuqing cold cathode filament light converter. Please refer to the figure and Fig. 2, the cold cathode fluorescent lamp inverter 1 receives a typical value of 400V high house. The DC voltage Vdc is converted into an AC voltage Vac in the form of a sine wave to drive the cold cathode fluorescent lamp 2. The cold cathode lamp commutating H 1 includes a switching circuit n, a turn 12 and a spectral circuit. The 'switching circuit ii' uses a half-bridge switching circuit architecture including two power switches ηι and 112 implemented by N-channel MOSFETs, with inter-electrode capacitors 113 and 114 and body diodes between the two ends of the switch. The body (bQdy diGde) 115 and 116' wherein the body diodes us and 116 are connected in parallel with the switch and 112 to provide a reverse flow path of the currents Ids1 and Ids2. The transformer 2 includes the coil 121 on the primary side and the coil on the secondary side. 122 and leakage inductor 123. The resonant circuit uses a string Resonant parallel load architecture, 3 M357125, * * It includes leakage inductance 123 and capacitor 131 is connected in series between the two ends of the secondary side coil 122 of the transformer 12' and the capacitor 131 is connected in parallel with the cold cathode glory 2 as a negative wearer The control signals Vgl and Vg2 form a source-source voltage _ and Vgs2' on the two switches ni and 112 to control the two switches 111 and 112 to be turned on alternately, and cut the input DC voltage Vdc into an AC voltage Vpl in the form of a square wave. The frequency (or switching frequency) of the control signals Vgl and Vg2 determines the frequency of the AC voltage Vpl as fs. The AC voltage Vpl is then boosted by the transformer ϋ 12 and the ship circuit performs the ac ultrasonic wave in the form of a sine wave. Driving the cold cathode fluorescent lamp 2. The resonance value fr of the resonance circuit is determined by the inductance value of the leakage inductor 123 and the capacitance value of the capacitor 131, and the resonance circuit is based on the frequency of the received signal (in this example, the switching frequency fs) The relationship between the resonant frequencies is capacitive or inductive. Therefore, the design switching frequency fs is smaller than the resonant frequency fr, so that the resonant circuit using the series-series parallel load structure is electrically The inductive 'in turn causes the AC current Ip2 to lag behind the AC voltage Vac - the phase angle difference is 0', and the AC current, the current Ipl is the transformed voltage $12, and the under-side side maps back to the sinusoidal current of the primary side, so the AC current Ipl is also behind the AC voltage Vpl. The angular difference is 0. This phase angle difference of 0 is the main factor that makes the power switches 111 and 112 have zero voltage switching characteristics. φ When the control signal Vgl is at the high level and the control switch 111 is turned on, the voltage across the switch 111 is zero. 'AC voltage Vpl is Vdc/2, and AC current Ipl is the switch ηι current Ids:l. When the control signal Vgl becomes a low level at the time point t1 and the switch 1U is turned off, since the current must be continuous, the switch η1 current Ids1 does not instantaneously become zero, and the alternating current Ipl includes the switch 111 current Idsl and the switch 112 current (_Ids2), so the alternating current Ipl will resonate with the interpole capacitors 113 and 114, causing the on-off switch ηι to linearly rise across the voltage Vdsl, and the pre-conducting switch 112 across the voltage across the voltage Vds2 linearly decreases. When the cross-over voltage Vds2 across the switch 112 crosses the zero point at the time point t2, the body diode 116 that is in parallel with the switch 112 is turned on, and the switch 112 waits for the control signal Vg2 to become a high level (eg, at time point t3). On-line, zero voltage switching is achieved. Similarly, after the switch 丨丨丨 crosses the M357125 point “after crossing the zero point, the switch 111 waits for the control signal to become high 111 111 'σ 112 Vdsl , : ^ white is zero, so that the switches (1) and 112 switch at the turn-on instant. The loss is 卩 (4) When knowing 'When the load side circuit of the secondary side of the transformer 12 is inductively closed】 The current of the human side 1ρ1 is behind the voltage Vpw 吏 the power of the primary side is turned on = 11 and 112 to obtain the zero-sum switching characteristic, in the switch And 112 is turned on instantaneously, and t is zero. However, because of the current Ipl voltage Vpl, there is a switching loss when the switch=112 is turned off; for example, taking the switch output as an example, when the switch time point is cut off, the current Idsl is still It will continue to flow through the switch (1) until the end of the open i 111 crosses the M Vdsl at the time point t2 and rises to the DC voltage Vdc. Since ^=llj is disconnected at the time point t1 to t2, there is a switching loss. After the second voltage Vpl, the control circuit of the switch 111 * 112 is turned on or off (the gate of the gate is lost in any period; for example, taking the switch 112 as an example, the switch 112 is turned to V/2 in the second side, and the scale should be For negative half-week, the amount of transport shed, but - times The side current Ipl is in the positive half cycle, and must wait for the 7 current Ipl to cross the zero point from the positive half cycle to the negative half, so that the energy can be actually transmitted to the _circuit of one or two sides. Therefore, the current Ipl starts at the time point t3. It is the duty cycle loss of the control circuit. The greater the duty cycle loss, the worse the ability of the control circuits 111 and 112 to transfer energy, and may even cause insufficient transmission of the cold cathode fluorescent lamp 2 in the month of transmission. [New content] The purpose of the creation is to propose a zero-light switching spectral converter control to reduce the switching loss of the power switch when disconnected and the duty cycle loss of the control circuit. 5 M357125 r * ' To achieve the above and other purposes, The present invention proposes a control circuit for a zero-voltage switching resonant converter b, wherein the zero-voltage switching resonant converter includes a switching circuit, a transformer, and a spectral path, _ circuit secret to transformer ϋ, transformer _ connected to the spectrum The circuit, the spectral vibration, is coupled to the load, and the switching circuit converts the input DC voltage into an alternating current 2 according to the control signal, and the alternating current turtle passes the color H boost and the Wei circuit performs _ In the form of a sinusoidal wave, the AC f-pressure rotates the load. The zero-voltage switching control circuit includes a timing circuit, an oscillation circuit 11, a logic control circuit, a current sense, a full-wave rectification ϋ, and a reset circuit. The timing circuit 'charges and discharges the timing circuit to generate a ramp wave logic control circuit coupled to the vibrator and the switch circuit, and generates a control signal according to the ramp voltage. The current sensor is lightly connected to sense the switch circuit and the transformer The current or spectrum ^ circuit's input or loss will be more money. The full-wave rectification is connected to the current sensor's full-wave rectification of the voltage, and the domain-generated full-wave rectifier signal. The reset circuit is lightly connected to the full-wave rectification II and the timing circuit. By comparing the full-wave rectified voltage setting value, the reset timing circuit is reset when the wave rectification voltage signal is less than the voltage setting value. . ^ The zero voltage switching of this creation is commutated __The circuit is used to measure the zero voltage cut = the vibration commutation || the middle _ circuit and the transformer - the secondary side _ current or spectral vibration tj out of the resonant current, the residual current is close to zero Turn off the time in order to adjust the ramp wave you are willing! ^ 'The switchable power switch can be switched on when the switch is turned on, and can also drop = its off current in the _ low current paste _ field loss in addition to the responsibility of the control circuit Cycle loss. The above and other objects, features and advantages of the present invention will become more apparent and easy to understand. The detailed description is as follows. [Embodiment] FIG. 3 is a control circuit 6 of a zero voltage switching resonant converter according to the present invention - an embodiment, a M357125 I · . = 3⁄4 road map, a zero voltage switching | | a vibration converter, for example, as shown in the figure The cold cathode fluorescent lamp converter is not limited to this. FIG. 4 is a signal waveform diagram of the zero voltage switching hybrid converter and its control circuit shown in FIG. Please refer to FIG. 4 at the same time, the control circuit 3 of the zero voltage switching spectrum switching thief 1 includes an error amplifier 3n, a pulse width modulation comparator 312, a vibrator 313, a logic control circuit 314, an output driving circuit 315, The switching circuit 32, the timing circuit 33, the reset circuit 34, the current peak sensor 35, the electrical over-test n 36, and the full-wave rectifier 37 are provided. The current peak sensor 35, the current sensor 36, and the full-wave rectifier 37 are used to sense the current signal of the zero-voltage switching resonant converter i, and accordingly generate an electrical signal that can be used by the control circuit 3 for further use. Where the 'current peak sensor 35 is connected to the cold cathode glory 2, the sensor has to pass the lamp current Ilamp of the cold cathode fluorescent lamp 2, and produces a current proportional to the lamp current ... that is, the size of the voltage - feedback The voltage Vf is, for example, the peak value or the root mean square value of the lamp current mountain. In addition, if you do not consider non-ideal factors such as stray capacitance, because the resonant circuit uses a series resonant parallel load structure, it changes _ 12 - the current of the secondary side, the secondary side of the electric catch (or the input of the 3 white vibration circuit) Ip2 and the lamp current (or the output current of the spectral circuit) Ilamp is the AC sine wave voltage with the same phase or current zero position. Therefore, the IL sensor 36 can be connected to the switch circuit 11 and The first side of the transformer 12 senses the current Ipl, or is connected between the secondary side of the dust filter 12 and the inductor 131 of the resonant circuit to sense the current IP2, or the handle is connected to the output of the cold cathode fluorescent lamp 2. The terminal senses the lamp current flowing through the cold cathode fluorescent lamp 2 and then generates a voltage signal Vi with the current Qiu, 汹 or 11_, and the voltage signal Vi is then rectified by the full-wave rectifier 37. It becomes a full-wave rectified voltage signal yrec. The general error amplifier 31, the pulse width modulation comparator 312, the oscillating device 313, the logic control circuit 314, and the output driving circuit 315 are combined and packaged into an integrated circuit 31, and the integrated body HI HI voltage protection, over current protection, and soft Start the circuit. The negative input of the error amplifier 311 is connected to the current peak sensor 35 to receive the feedback voltage ^, the positive input 7 M357125 terminal receives the reference electric house vref, the first port „ voltage Vref material, the differential 311 is compared by the feedback dragon Vf And the reference μ error error is transmitted. The positive input end of the pulse width modulation comparator 312 is coupled to the rim of the amplifier 311, and the σ is slightly pressed by the main 313 to receive the ramp surface v. Electric 3 voltage - 'its negative input is connected to the vibrating device ^, s. „ ' St C, for example, sawtooth or triangular wave), pulse width modulation vs. v_. The logic error voltage Vea and the ramp voltage Vst rotate the pulse width modulation signal and the path 314 generates a control signal according to the pulse width modulation signal VPWm. The Vgl* mountain signal Vgl* thief usually has to pass the open pole/open collector or totem pole. Wait
Y15來加強其驅動能力。_ 4可知，斜波電壓VSt的 :士 0p*母個斜波的週期i/fop)決定功率開關111和112的最大導 二脈寬顯^號V_低準位部份的寬度決定功率開關111 ’通時間。當燈管電流Ilamp變大時，回授電壓Vf變大，使 誤差電壓Vea變小’進而脈寬調變信號v卿低準位部份的寬度變小， 控制信號vgi和Vg2高準位部份變*，故功率開關⑴和ιΐ2導通時 間變小’傳朗冷齡錢絲2 量變小而使辟驗n卿變小， 因此’通過積體電路31的回授控制可以穩定燈管電流Ilamp。 振盪器313依據定時電路33提供斜波電壓Vst。一般定時電路泊 至少包括-定時電容器（如331)及一定時電阻器（如332)，振盡器⑽ 依據疋時f阻H(如332)輪蚊電麟定時電容||(如331)充電， 時，容器（如331)跨壓上升到某定值(如3V)後停止充電並開始放電， 接著在料電容H(如331)跨壓下降到某定值(如Gv)後停止放電並開 始充電，如此在定時電容H(如331)上反覆充放電軸如圖4所示斜 波電壓Vst。在本例中，自於零電壓切換譜振換流器j是用來驅動冷 陰極螢光燈2，考慮到冷陰極螢光燈2在啟動時需要高達丨至2κν二 電壓，而在啟動成功後只需要4〇〇至8〇〇ν的電壓即可正常工作，故設 計斜波電壓Vst的頻率在啟動時為啟動頻率fst並在啟動成功後改為 工作頻率fop，其中啟動頻率fst較接近諧振頻率fr，使諧振電路提 8 M357125 供較同的&I，而工作頻率f〇p則相觸遠離譜振頻率對於串聯 諧振並聯負絲構的tf振電路*言，fQp<fst<fr。 、 為烫勞燈2在啟動時（或啟動成功前）’燈管電流ilafflp _。、，f流峰值感測器35輸出之回授電壓為零或低於 某值’控制電路3可利用切換電路&依據回授電㈣來判斷啟動成 功與否’在啟動時切換到第二定時電路以提供振蘯器313產生頻率為 健以，並在啟動成功後切制第—定時電路 '、。°產生頻率為工作頻率fop的斜波電壓Vst。因此， 疋ΐ電路ΐ包括第—定時電路及第二定時電路。第一定時電路包括第 一定時電容器331及第一定時電阻器332，若 且第-定時電阻器332電阻值制，則工作頻率 ί 第包括第二定時電容器333及第二定時電阻 益334右弟一疋時電容器咖電容值為C2且第二定時電阻器33 =為R2 ’則啟動頻率fst與1/(R2x⑵成比例其中r⑽他^。 器夕35’ Ht32搞接至紐^ 313、定時電路33及電流峰值感測 開請和3歹22。，切換電路32為雙刀雙擲開關，即包括兩單刀雙擲 2啟：34包括比較器341以及開關342，用以在冷陰極螢光燈 率f ^調整斜波電壓Vst的時序(其頻率仍維持工作頻 H來達_低神剩在_ _城敎及㈣電路 的。開關_第-端鱗找時電路33的第—定時電 〜输至第一定時電路的第-定時電容器331第一端且 地:疋日^電容器331第二端搞接至接地端，開關342第二端轉接至接 地端。比較器341通過比較全波整流電壓信號Vre = 342 , ^^lJt , 雙载子接面電晶體。如圖4所示，當錢整流龍錢k大於或等 9 M357125 於電塵設定值Vth時，比較n 341輸出信號控綱g地斷開， 振盈器313耦接到第-定時電路並依據第一定時電阻器咖提供定】 二對第-疋電容器331充電；當全波整流電壓信號Vrec小於電 疋值Vth時，比較器341輸出信號控制開關3犯 = 的長短與糖織Vth有關，此時第一定時電容器 接至接地端’相當於重置第一定時電路(或對第一定時電容器如進 放電）’使得原本正在上升的斜波被強迫拉至接地端的零電位，^ 辨關必綱開，兩功率關⑴和112切崎的斜波電 …s進而控制開關111和112切出新的交流電墨Vpl，。若 值大於斜波· Vst，’則控制信號Vgl和啦騎任週期 號’將導致功率開關⑴和112可能同時導通而燒毁，因 此¥通時間td最短必須要保證功率開關⑴和112不會同時導通。 關‘二=’在V/1和1Pl波形圖中’功率開關在斷開瞬間其開 盆開關電u A = Vpl和Ipl波形圖中，功率開關在斷開瞬間 二舌1為：明顯地’電流值Π大於12。所以，本創作通 電路34在冷陰極螢光燈2啟動成功後—開始就重置調整斜波 »’降低神_在斷開時的酬電流大小，進而降低功率門 C啊，亦齡_電路3的纽軸敎 咖作功率開關在斷開瞬間其開關電流大小為12，仍铁會與功率 振，使被強迫_的功率_兩端跨 升*預導摘功率開_端跨壓線性下降，直 ;兩端跨壓為零時命令預導通的功率開關導通，因此功率開 零電壓切換特性。 料關仍具有 射'ϊΐ所述，本創作之零電壓切換諧振換流器的控制電路採用福 :=切換譜振換流器中開關電路及變壓器一次側之 白又电的輸入、輪以皆振電流，來判別電流接近零點的時間以便 M357125 . · ,. 序’可以保持功率開關在導通時的零電壓切換特 失，時的開關電流進叫低功率《的切換損 失同捋亦消除控制電路的責任週期損失。 、 雖然本創作已以較佳實施例揭露如上’然其並非用以限定 2任何«此技藝者，在不脫離本創作之精神和範_，當 ，耻糊狀紐翻當視請專利範 【圖式簡單說明】 圖1為-種ί見有的採用LIpS架構的冷陰極纟光燈才奥流器電路圖。 圖2為圖1所示冷陰極螢光燈換流器的開關電路之信號波形圖。 圖3為依照本創作一實施例之零電壓切換諧振換流器的控制電路 之電路圖。 圖4為圖3所示零電壓切換諧振換流器及控制電路之信號波形圖。 【主要元件符號說明】 1 :冷陰極螢光燈換流器 111、112 :功率開關 115、116 :體二極體 121 : —次側線圈 123 :漏電感器 2:冷陰極螢光燈 31 :積體電路 312 :脈寬調變比較器 11 :開關電路 113、114 :極間電容器 12 :變壓器 122 :二次側線圈 131 :電容器 3:控制電路 311 :誤差放大器 313 :振盪器 M357125 I I * ' 314 :邏輯控制電路 32 :切換電路 33 :定時電路 332 :第一定時電阻器 334 :第二定時電阻器 341 :比較器 35:電流峰值感測器 * 37:全波整流器 II、12 :開關電流值 Ip2 :變壓器二次侧電流 Vdc :直流電壓 Vgl、Vg2 :控制信號 Vdsl、Vds2 :開關兩端跨壓 φ Vref :參考電壓Y15 to strengthen its driving ability. _ 4 It can be seen that the ramp voltage VSt: the period of the 0p* parent ramp (i/fop) determines the width of the maximum conduction two-pulse width of the power switches 111 and 112. 111 'pass time. When the lamp current Ilamp becomes larger, the feedback voltage Vf becomes larger, the error voltage Vea becomes smaller, and the width of the low-level portion of the pulse width modulation signal v is smaller, and the control signals vgi and Vg2 are higher. The frequency change*, so the power switch (1) and ιΐ2 turn-on time becomes smaller. 'The amount of the cold-blooded money wire 2 becomes smaller and the test becomes smaller. Therefore, the feedback control of the integrated circuit 31 can stabilize the lamp current Ilamp. . The oscillator 313 supplies the ramp voltage Vst in accordance with the timing circuit 33. Generally, the timing circuit berth includes at least a timing capacitor (such as 331) and a certain time resistor (such as 332), and the oscillating device (10) is charged according to the f f resistance H (such as 332) mosquito electric timing capacitor || (such as 331) , when the container (such as 331) rises to a certain value (such as 3V), stops charging and starts to discharge, and then stops discharging after the material capacitor H (such as 331) drops across a certain value (such as Gv). The charging is started, so that the charging and discharging axis is reversed on the timing capacitor H (such as 331) as shown in Fig. 4 as the ramp voltage Vst. In this example, the zero-voltage switching spectral converter j is used to drive the cold cathode fluorescent lamp 2, considering that the cold cathode fluorescent lamp 2 needs to be up to 2 κν two voltages at startup, and the startup is successful. After that, only 4〇〇 to 8〇〇ν voltage is needed to work normally. Therefore, the frequency of the design ramp voltage Vst is the starting frequency fst at startup and is changed to the operating frequency fop after the startup is successful, wherein the starting frequency fst is closer. The resonant frequency fr is such that the resonant circuit raises 8 M357125 for the same &I, while the operating frequency f〇p touches away from the spectral frequency. For the series resonant parallel negative negative tf oscillator circuit, fQp<fst<fr . , for the burnt lamp 2 at the start (or before the start is successful) 'lamp current ilafflp _. The feedback voltage outputted by the f-stream peak sensor 35 is zero or lower than a certain value. The control circuit 3 can use the switching circuit & according to the feedback power (4) to determine whether the startup is successful or not. The timing circuit is configured to provide the frequency generated by the vibrator 313 and to cut the first timing circuit after the startup is successful. ° The ramp voltage Vst at the operating frequency fop is generated. Therefore, the 疋ΐ circuit ΐ includes a first timing circuit and a second timing circuit. The first timing circuit includes a first timing capacitor 331 and a first timing resistor 332. If the first timing resistor 332 has a resistance value, the operating frequency ί includes the second timing capacitor 333 and the second timing resistor 334. When the condenser capacitor value is C2 and the second timing resistor 33 = R2 ', the starting frequency fst is proportional to 1/(R2x(2) where r(10) is ^. 夕 35 35' Ht32 is connected to the button ^ 313, timing circuit 33 And the current peak sensing is open and 3歹22. The switching circuit 32 is a double-pole double-throw switch, that is, includes two single-pole double-throwing 2: 34 includes a comparator 341 and a switch 342 for the cold cathode fluorescent lamp rate. f ^ adjust the timing of the ramp voltage Vst (the frequency still maintains the working frequency H to reach _ low God remaining in the _ _ _ 敎 and (4) circuit. Switch _ first-end scale finding circuit 33 of the first - timing electricity ~ lose The first end of the first-timing capacitor 331 of the first timing circuit and the second end of the capacitor 331 are connected to the ground, and the second end of the switch 342 is switched to the ground. The comparator 341 compares the full-wave rectification. The voltage signal Vre = 342 , ^^lJt , the bi-carrier junction transistor. As shown in Figure 4, When the money rectification dragon money k is greater than or equal to 9 M357125 at the electric dust setting value Vth, the comparison n 341 output signal control g is disconnected, and the vibrator 313 is coupled to the first timing circuit and provided according to the first timing resistor The second pair of first-tantalum capacitors 331 are charged; when the full-wave rectified voltage signal Vrec is less than the electric enthalpy value Vth, the output of the comparator 341 outputs a signal to control the switch 3 to be related to the sugar woven Vth, and the first timing capacitor is connected. To the ground terminal 'equivalent to reset the first timing circuit (or to the first timing capacitor such as the input and discharge) 'so that the rising ramp is forced to pull to the zero potential of the ground, ^ discrimination must be open, two power off (1) and 112 Kawasaki's ramp wave...s and then controls switches 111 and 112 to cut out a new AC ink Vpl. If the value is greater than the ramp · Vst, 'the control signal Vgl and the ride cycle number' will cause the power switch (1) and 112 may be turned on at the same time and burned out, so the shortest time td must ensure that the power switches (1) and 112 are not turned on at the same time. Off 'two=' in the V/1 and 1Pl waveform diagrams, the power switch is turned on at the moment of disconnection. Basin switch electric u A = Vpl and Ipl In the figure, the power switch is at the moment of disconnection, and the two tongues 1 are: obviously the 'current value Π is greater than 12. Therefore, the original circuit 34 after the cold cathode fluorescent lamp 2 is successfully started - resets and adjusts the ramp wave» 'Reducing the amount of recharge current of God _ when disconnected, and then lowering the power gate C, _ _ circuit 3's shaft axis power switch at the moment of disconnection, its switching current is 12, still iron and power vibration So that the forced _ power _ both ends rises * pre-lead power off _ end cross-voltage linearly decreases, straight; when the cross-voltage is zero, the pre-conducting power switch is turned on, so the power-on zero voltage switching characteristic. The material gate still has the radiation 'ϊΐ, the control circuit of the zero-voltage switching resonant converter of the present invention adopts:= switching the switching circuit of the spectral converter and the white and electric input of the transformer side, the wheel and the The current is used to determine the time when the current is close to zero so that M357125. ·,. The sequence 'can maintain the zero-voltage switching of the power switch when it is turned on, and the switching current is low and the power is switched. The switching loss also eliminates the control circuit. Loss of responsibility cycle. Although the present invention has been disclosed in the preferred embodiment as above, it is not intended to limit any of the "artists", and does not deviate from the spirit and scope of this creation. Brief description of the formula] Figure 1 is a circuit diagram of a cold cathode fluorescent lamp using the LIPS architecture. 2 is a signal waveform diagram of a switching circuit of the cold cathode fluorescent lamp inverter shown in FIG. 1. 3 is a circuit diagram of a control circuit of a zero voltage switching resonant converter in accordance with an embodiment of the present invention. 4 is a signal waveform diagram of the zero voltage switching resonant converter and the control circuit shown in FIG. [Main component symbol description] 1 : Cold cathode fluorescent lamp inverters 111, 112: power switches 115, 116: body diode 121: - secondary side coil 123: leakage inductor 2: cold cathode fluorescent lamp 31: Integrated circuit 312: Pulse width modulation comparator 11: Switch circuit 113, 114: Interelectrode capacitor 12: Transformer 122: Secondary side coil 131: Capacitor 3: Control circuit 311: Error amplifier 313: Oscillator M357125 II * ' 314: logic control circuit 32: switching circuit 33: timing circuit 332: first timing resistor 334: second timing resistor 341: comparator 35: current peak sensor * 37: full-wave rectifier II, 12: switching current Value Ip2: transformer secondary side current Vdc: DC voltage Vgl, Vg2: control signal Vdsl, Vds2: cross-over voltage across the switch φ Vref : reference voltage
Vst、Vst’ ：斜波電壓Vst, Vst': ramp voltage
Vi :電壓信號Vi: voltage signal
Vth :電壓設定值 fs :切換頻率 fop :工作頻率 td .導通時間 315 :輸出驅動電路 321、322 :單刀雙擲開關 331 :第一定時電容器 333 :第二定時電容器 34 :重置電路 342 :開關 36 :電流感測器 Idsl、Ids2 :開關電流 Ipl :變壓器一次側電流 I lamp :燈管電流 Vac :交流弦波電壓 Vgsl、Vgs2 :閘源極電壓 Vf :回授電壓 Vea、Vea’ ：誤差電壓 Vpwm :脈寬調變信號 Vrec :全波整流電壓信號 Vpl、Vpl’ ：變壓器一次側電壓 fst :啟動頻率 tl〜t5 :時間點 0 :相角差 12Vth: voltage set value fs: switching frequency fop: operating frequency td. On time 315: output drive circuit 321, 322: single-pole double-throw switch 331: first timing capacitor 333: second timing capacitor 34: reset circuit 342: switch 36: current sensor Ids1, Ids2: switch current Ipl: transformer primary current I lamp: lamp current Vac: AC sine wave voltage Vgsl, Vgs2: gate source voltage Vf: feedback voltage Vea, Vea': error voltage Vpwm: pulse width modulation signal Vrec: full-wave rectified voltage signal Vpl, Vpl': transformer primary side voltage fst: starting frequency t1 to t5: time point 0: phase angle difference 12