201142567 六、發明說明： 【發明所屬之技術領域】 本發明係關於一種迴授控制電路及電源轉換電路，尤指一 種可以減少過衝現象之迴授控制電路及電源轉換電路。曰 【先前技術】 ' 請參見第一圖，為傳統之一種發光二極體驅動電路之電路 示意圖。發光二極體驅動電路包含一控制器1〇、一轉換 5〇及一發光二極體模組60。轉換電路50耦接一輸入電壓 Vin，而控制器1〇產生控制訊號Sc以控制轉換電路5〇 來'201142567 VI. Description of the Invention: [Technical Field] The present invention relates to a feedback control circuit and a power conversion circuit, and more particularly to a feedback control circuit and a power conversion circuit capable of reducing overshoot.曰 【Prior Art】 'Please refer to the first figure, which is a circuit diagram of a conventional LED driver circuit. The LED driving circuit comprises a controller 1 〇, a conversion 5 〇 and a illuminating diode module 60. The conversion circuit 50 is coupled to an input voltage Vin, and the controller 1 generates a control signal Sc to control the conversion circuit 5'.
自輸入電壓源Vin至-輸出端的電力大小。轉換電路5〇 出端耗接發光二極體模組60 ’以施加一輸出電壓v〇m到發 二極體模組60之上，使發光二極體模組6〇流經一輸出電流 lout而發光。輸出電流i〇ut同時流經一電流债 生一電流迴授訊號IFB。 座 控制器10包含一誤差放大器11、一三角波產生器、一 誤差補償電路13、一脈寬調變比較器18及一驅動電^ 19; 差放大器11接收電流迴授訊號IFB及一參考訊號Vr，並據此 產生一輸出訊號並經誤差補償電路13進行誤差補償後，成為 一誤差放大訊號Vcomp。三角波產生器12產生一三角波訊 至，寬調變比較器18。脈寬調變比較器18同時接收誤差放又 訊號Vcomp以據此產生一脈寬調變訊號至驅動電路19，而驅 ” 19則根據脈寬調變比較器丨8的脈寬調變訊號產生控制 訊號Sc。 一般而言，控制器10會將輸出電流1〇说穩定在一預定輸 出電流1〇’ 此時輸iti電壓VGUt也會穩定在_預定輸出電壓 =。:然而’誤差放大器11係、經過比較電流迴授訊號IFB及參 ^訊號Vf ’並觸職之誤i贿_償料13餅誤差補 償而調整誤差放大!峨ν_Ρ之準位。紐的雛控制過程 會使輸出電流I。錢輸出 Vout會在預定輸出電流1〇及預 定輸出電壓Vo上下震盪並逐漸趨近（即震幅變小）。 201142567 ，請參見第二圖，為第―圖所示發光二極體驅動電路於調光 過程的訊號波糊。軸電路19接收—調光職刪並 調光訊號DIM決定是否輸出控制訊號&。在時間點τι_τ4之 時間區間，調光訊號代表，，0Ν”，此時驅動電路19輸出控制訊 號Sc ;在時間點Τ4-Τ1之時間區間，調光訊號代表 ，，OFF”，此 時驅動電路19停止輸出控制訊號Sc。在時間點T4_T1之時間 區間，，因驅動電路19停止輸出控制訊號Sc使轉換電路5〇停 止傳送電力至發光二極體模組6〇,而使輸^電壓VQut於時間 點T5時逐漸下降至光二極體模組6〇的臨界電壓Vf，此時輸 出電流lout也降至零。這會造成電流迴授訊號IFB與參考訊 號Vr維持正誤差，而使誤差放大訊號Vc〇mp之準位上升至最 大準位值。而於時間點T1，驅動電路19重新輸出控制訊號 Sc時’由祕纽大喊v刪p之雜在最錄，使控制訊 號Sc的工作週期（Duty Cycle)也在最大值。 於時間點T2之後，輸出電流jout高於預定輸出電流1〇， 使誤差放大器11開始拉低誤差放大訊號Vcomp之準位。然 而，由於誤差補償電路13的誤差補償關係，誤差放大訊號 Vcomp無法直接下降至一誤差穩定值Vc〇mp〇 (此值為輸出電 流lout穩定預定輸出電流1〇時對應的誤差放大訊號Vc〇mp的 準位）。這導致此時的控制訊號Sc的工作週期過大，使輸出電 流lout仍繼續上升直至誤差放大訊號vcomp低於誤差穩定值 Vcompo ’使控制訊號sc的工作週期過低◦於後，輸出電流I〇ut 再度低於預疋輸出電流1〇，使誤差放大訊號Vcomp重新上升 並超過誤差穩定值Vcompo。上述過程將持續直至時間點T3， 輸出電流lout、輸出電壓Vout、誤差放大訊號Vcomp分別收 斂至對應的預定輸出電流1〇、預定輸出電壓Vo及誤差穩定值 Vcompo 為止。 因此，當進行發光二極體模組啟動或脈衝調光（Burst Dimming)時會造成明顯、嚴重的輸出電壓v〇ut及輸出電流 lout的過衝現象，而過大的電流及電壓過衝會造成發光二極體 201142567 瞬間發出過高亮度的亮光影響人眼視覺，除了降低電路的穩定 度之外、也縮短了發光二極體操作壽命，增加了電路或發光二 極體毀損的可能性。 【發明内容】 鑑於先前技術中因迴授控制的誤差補償造成嚴重的過衝 現象降低迴授控制的穩定度並增加了電路毀損之風險，本發明 針對迴授控制提供迴授控制電路中誤差放大訊號的初始值設 定，以降低迴授控制造成誤差放大訊號震盪的時間及幅度。因 此，本發明之迴授控制電路及電源轉換電路除了降低過衝的程 鲁度及時間’同時也達到更精確、穩定的迴授控制。 為達上述目的，本發明提供一種迴授控制電路，用以控制 一轉換電路將一輸入電壓轉換成一輸出電壓以驅動一負載。迴 授控制電路包含一迴授單元、一積分單元、一脈寬控制單元、 一第一開關以及一準位設定單元。迴授單元接收代表負載之狀 巧之一迴授訊號及一參考訊號，以據此產生一誤差訊號。積分 f元耦接迴授單元以根據誤差訊號產生一積分訊號^脈寬控制 單元根據積分訊號以產生一控制訊號以據此控制轉換電路將 輸入電壓轉換成輸出電壓。第一開關耦接於迴授單元及積分單 • 元之間，用以控制誤差訊號傳送至積分單元。準位設定單元耦 接積分單元’於第一開關導通時根據積分訊號決定一設定準 位’於第一開關截止時，將積分訊號之準位調整至設定準位。 本發明也提供一種電源轉換電路，用以驅動一發光二極體 模組。電源轉換電路包含一轉換電路以及一控制器。轉換電路 耦接發光二極體模組，用以將一電源之電力轉換以驅動發光二 極體模組。控制器係用以根據代表發光二極體模組流經之一電 流之一迴授訊號進行迴授控制以產生一脈寬調變訊號以控制 轉換電路使電流穩定於一預定電壓值。其中，控制器接收一調 光訊號’於調光訊號為一第一狀態時停止轉換電路轉換電源之 電力’於調光訊號為一第二狀態時將脈寬調變訊號之一工作週 201142567 期由預疋工作週期開始進行迴授控制。 -步與接下來的詳細說明皆為示範性質，是為了進 優點5,將/=的申請專利範圍。而有關本發明的其他目的與 優點，财後續的說明與圖示加以闡述。 【實施方式】 二參見第一圖’為根據本發明之一第一較佳實施例之一電 ΐίίί路之電路示意圖。電源轉換電路包含—控制器⑽以 換電路15G ’用以驅動—發光二極體模組16()。控制器 接收-嫌職FB，據此進行迴授控_產生一控制訊 號以控制轉換電路15()。轉換電路15()之輸人端_一輸 入，壓源Vm，輸出端耦接發光二極體模組16〇，以根據控制 訊號Sc調控來自輸入電壓源Vin之電力大小，並轉換成適當 的一輸出電壓Vout以驅動該發光二極體模組，使流經發光二 極體模組的一輸出電流Iout穩定於一預定電流值。而輸出電流 lout同時也流過一電流偵測電阻丨65，以產生代表輸出電流1〇说 大小的迴授訊號FB。 控制器100包含一迴授單元111、一積分單元、一第 一開巧114、一準位設定單元115以及一脈寬控制單元116。 迴授單元111可以為一誤差放大器，非反相輸入端接收一參考 訊號Vr ,反相輸入端接收迴授訊號FB，以據此產生一誤差訊 號。積分單元113根據誤差訊號產生一積分訊號Vea，其一般 包含電容及電阻’根據實際應用的電路調整積分單元113'的電 壓增益對頻率的變化關係使控制器1〇〇的迴授控制有較佳的 暫態反應。第一開關114耦接於迴授單元111及積分單元113 之間，用以根據一調光訊號DIM控制誤差訊號傳送至積分單 元。當調光訊號DIM的狀態為代表「ON」時，第一開關114 導通’迴授單元111所產生的誤差訊號透過第一開關114傳送 至積分單元113 ;而當調光訊號DIM的狀態為代表「〇FFj時， 第一開關114截止，迴授單元111所產生的誤差訊號停止傳送 201142567 至積分單元113。準位設定單元115耦接積分單元113，於第 一開關114導通時根據積分訊號Vea決定一設定準位Vset，於 第一開關114截止時，將積分訊號Vea之準位調整至設定準位 Vset〇 脈寬控制單元116根據積分訊號Vea以產生一控制訊號 Sc以據此控制轉換電路150進行電壓轉換。脈寬控制單元116 包含一三角波產生器112、一脈寬調變比較器118及一驅動電 路119。三角波產生器112產生一三角波訊號至脈寬調變比較 器118之反相輸入端，而脈寬調變比較器U8的非反相輸入端 接收誤差放大訊號Vea以據此產生一脈寬調變訊號至驅動電 • 路119。驅動電路119同時接收調光訊號DIM。當調光訊號 DIM的狀態為代表「ON」時，驅動電路119則根據脈寬調變 比較器118的脈寬調變訊號產生控制訊號Sc;當調光訊號DIM 的狀態為代表「OFF」時’驅動電路119停止產生控制訊號Sc。 接者’凊參見第四圖’為根據本發明之準位設定單元之一 較佳實施例之電路示意圖。準位設定單元包^一*分壓器ιοί、 一第一放大器102、一第三開關1〇3、一準位儲存元件1〇4、 一第二放大器105、一反相器1〇6及一第二開關1〇7。請同時 參見第三圖’當調光訊號DIM的狀態為代表「on」時，第一 φ 開關114導通使積分訊號Vea經分壓器ιοί分壓後輸入第一放 大102之非反相輸入端。第一放大器102之反相輸入端與輸 出端輕接，且輸出端同時耗接準位儲存元件。準位儲存元 件104可以是一電容，透過第三開關1〇3耦接第一放大器1〇2。 此時第二開關103受調光訊號DI1V[控制而導通，使準位儲存 元件104與第一放大器1〇2組成一電壓隨耦器，以將積分訊號 Vea經分壓器101分壓後的準位儲存在準位儲存元件1〇4上以 形成設定準位Vset。調光訊號DIM同時經反相器1〇6反相後 控制第二開關107 ’使第二開關ίο?截止。 當調光訊號DIM的狀態為代表「〇FF」時，第一開關114 及第三開關1〇3截止，此時準位儲存元件1〇4已參考積分訊號 201142567The amount of power from the input voltage source Vin to the output. The output of the conversion circuit 5 consumes the LED module 60' to apply an output voltage v〇m to the LED module 60, so that the LED module 6 flows through an output current lout And glow. The output current i〇ut flows through a current bond and a current feedback signal IFB. The controller 10 includes an error amplifier 11, a triangular wave generator, an error compensation circuit 13, a pulse width modulation comparator 18, and a driving circuit. The difference amplifier 11 receives the current feedback signal IFB and a reference signal Vr. And generating an output signal according to this and performing error compensation by the error compensation circuit 13 to become an error amplification signal Vcomp. The triangular wave generator 12 generates a triangular wave to wide-tuning comparator 18. The pulse width modulation comparator 18 simultaneously receives the error release signal Vcomp to generate a pulse width modulation signal to the driving circuit 19, and the drive 19 generates the pulse width modulation signal according to the pulse width modulation comparator 丨8. Control signal Sc. In general, controller 10 will stabilize the output current 1 在一 at a predetermined output current 1 〇 ' At this time, the input voltage VGUt will also stabilize at _ predetermined output voltage =. However, 'error amplifier 11 After comparing the current feedback signal IFB and the control signal Vf 'and the fault of the job, the bribe _ compensation 13 cake error compensation and adjust the error amplification! 峨 ν Ρ 准 。 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽 纽The money output Vout will oscillate and gradually approach the predetermined output current 1〇 and the predetermined output voltage Vo (ie, the amplitude becomes smaller). 201142567, please refer to the second figure, which is the light-emitting diode driving circuit shown in the figure The signal wave of the dimming process. The axis circuit 19 receives the dimming operation and the dimming signal DIM determines whether to output the control signal & at the time interval τι_τ4, the dimming signal represents, 0Ν", at this time, the driver Circuit 19 output control No. Sc; at the time point Τ4-Τ1 time interval, the dimming signal represents, OFF", at this time, the drive circuit 19 stops outputting the control signal Sc. At the time interval T4_T1, the drive circuit 19 stops outputting the control signal Sc causes the conversion circuit 5 to stop transmitting power to the LED module 6〇, and causes the voltage VQut to gradually drop to the threshold voltage Vf of the photodiode module 6〇 at the time point T5, and the output current lout It also drops to zero. This causes the current feedback signal IFB to maintain a positive error with the reference signal Vr, and raises the level of the error amplification signal Vc〇mp to the maximum level value. At the time point T1, the drive circuit 19 re-outputs the control. When the signal Sc is screamed by the secret nucleus, the duplication of the control signal Sc is also at the maximum. After the time point T2, the output current jout is higher than the predetermined output current. , the error amplifier 11 starts to pull down the level of the error amplification signal Vcomp. However, due to the error compensation relationship of the error compensation circuit 13, the error amplification signal Vcomp cannot be directly reduced to an error stable value Vc 〇 mp 〇 (this value The output current lout is stabilized by the corresponding error amplification signal Vc〇mp when the predetermined output current is 1〇. This causes the duty cycle of the control signal Sc at this time to be too large, so that the output current lout continues to rise until the error amplification signal vcomp is low. After the error stable value Vcompo 'make the duty cycle of the control signal sc too low, the output current I〇ut is again lower than the pre-turn output current 1〇, so that the error amplification signal Vcomp rises again and exceeds the error stable value Vcompo. The output current lout, the output voltage Vout, and the error amplification signal Vcomp will respectively converge to the corresponding predetermined output current 1 〇, the predetermined output voltage Vo, and the error stable value Vcompo until time point T3. Therefore, when the LED module is activated or Burst Dimming, it will cause obvious and serious overshoot of the output voltage v〇ut and the output current lout, and excessive current and voltage overshoot will cause Light-emitting diode 201142567 Instantly emits high-brightness light that affects human vision. In addition to reducing the stability of the circuit, it also shortens the operating life of the LED, increasing the possibility of damage to the circuit or LED. SUMMARY OF THE INVENTION In view of the prior art, the serious overshoot phenomenon caused by the error compensation of the feedback control reduces the stability of the feedback control and increases the risk of circuit damage. The present invention provides error amplification in the feedback control circuit for the feedback control. The initial value of the signal is set to reduce the time and amplitude of the error amplification signal caused by the feedback control. Therefore, the feedback control circuit and the power conversion circuit of the present invention achieve a more accurate and stable feedback control in addition to reducing the overshoot and time of the overshoot. To achieve the above object, the present invention provides a feedback control circuit for controlling a conversion circuit to convert an input voltage into an output voltage to drive a load. The feedback control circuit includes a feedback unit, an integration unit, a pulse width control unit, a first switch, and a level setting unit. The feedback unit receives a feedback signal representing a load and a reference signal to generate an error signal accordingly. The integral f-element is coupled to the feedback unit to generate an integral signal according to the error signal. The pulse width control unit generates a control signal according to the integrated signal to thereby control the conversion circuit to convert the input voltage into an output voltage. The first switch is coupled between the feedback unit and the integration unit to control the transmission of the error signal to the integration unit. The level setting unit is coupled to the integrating unit to determine a set level according to the integral signal when the first switch is turned on. When the first switch is turned off, the level of the integral signal is adjusted to the set level. The invention also provides a power conversion circuit for driving a light emitting diode module. The power conversion circuit includes a conversion circuit and a controller. The conversion circuit is coupled to the LED module for converting power of a power source to drive the LED module. The controller is configured to perform feedback control according to a feedback signal of one of the currents flowing through the LED module to generate a pulse width modulation signal to control the conversion circuit to stabilize the current to a predetermined voltage value. Wherein, the controller receives a dimming signal 'stopping the power of the conversion circuit to convert the power when the dimming signal is in a first state'. when the dimming signal is in a second state, the pulse width modulation signal is one of the working weeks 201142567 Feedback control is started from the pre-work cycle. - The steps and the detailed descriptions that follow are exemplary in nature, in order to advance the advantage 5, the scope of the patent application of /=. Other objects and advantages of the present invention are set forth in the following description and illustration. [Embodiment] FIG. 2 is a circuit diagram of an electric circuit according to a first preferred embodiment of the present invention. The power conversion circuit includes a controller (10) for switching the circuit 15G' to drive the LED module 16(). The controller receives the spoof FB and, based on this, performs a feedback control to generate a control signal to control the conversion circuit 15(). The input end of the conversion circuit 15() is input, the voltage source Vm, and the output end is coupled to the LED module 16A to regulate the power from the input voltage source Vin according to the control signal Sc, and is converted into an appropriate one. An output voltage Vout is used to drive the LED module to stabilize an output current Iout flowing through the LED module to a predetermined current value. The output current lout also flows through a current detecting resistor 丨65 to generate a feedback signal FB representing the magnitude of the output current. The controller 100 includes a feedback unit 111, an integration unit, a first activation 114, a level setting unit 115, and a pulse width control unit 116. The feedback unit 111 can be an error amplifier, the non-inverting input terminal receives a reference signal Vr, and the inverting input terminal receives the feedback signal FB to generate an error signal accordingly. The integrating unit 113 generates an integral signal Vea according to the error signal, which generally includes a capacitor and a resistor. The voltage gain of the integrating unit 113' is adjusted according to the circuit of the actual application. The feedback control of the controller 1 is better. Transient response. The first switch 114 is coupled between the feedback unit 111 and the integrating unit 113 for transmitting an error signal to the integrating unit according to a dimming signal DIM. When the state of the dimming signal DIM is "ON", the error signal generated by the first switch 114 turning on the feedback unit 111 is transmitted to the integrating unit 113 through the first switch 114; and when the state of the dimming signal DIM is representative When 〇FFj, the first switch 114 is turned off, and the error signal generated by the feedback unit 111 stops transmitting 201142567 to the integrating unit 113. The level setting unit 115 is coupled to the integrating unit 113, and according to the integral signal Vea when the first switch 114 is turned on. Determining a set level Vset, when the first switch 114 is turned off, adjusting the level of the integral signal Vea to the set level Vset, the pulse width control unit 116 generates a control signal Sc according to the integral signal Ve to control the conversion circuit accordingly. The voltage conversion unit 116 includes a triangular wave generator 112, a pulse width modulation comparator 118, and a driving circuit 119. The triangular wave generator 112 generates a triangular wave signal to the inverse of the pulse width modulation comparator 118. The input terminal, and the non-inverting input terminal of the pulse width modulation comparator U8 receives the error amplification signal Vea to generate a pulse width modulation signal to the driving circuit 119. The circuit 119 receives the dimming signal DIM at the same time. When the state of the dimming signal DIM is "ON", the driving circuit 119 generates the control signal Sc according to the pulse width modulation signal of the pulse width modulation comparator 118; when the dimming signal is When the state of the DIM is "OFF", the drive circuit 119 stops generating the control signal Sc. The connector '凊' is shown in the fourth figure' as a circuit diagram of a preferred embodiment of the level setting unit according to the present invention. The level setting unit includes a voltage divider ιοί, a first amplifier 102, a third switch 1〇3, a level storage element 1〇4, a second amplifier 105, an inverter 1〇6, and A second switch 1〇7. Please also refer to the third figure. When the state of the dimming signal DIM is "on", the first φ switch 114 is turned on, so that the integral signal Vea is divided by the voltage divider ιοί and then input to the non-inverting input terminal of the first amplification 102. . The inverting input of the first amplifier 102 is connected to the output terminal, and the output terminal simultaneously consumes the level storage element. The level storage element 104 can be a capacitor coupled to the first amplifier 1〇2 through the third switch 1〇3. At this time, the second switch 103 is controlled to be turned on by the dimming signal DI1V, so that the level storage element 104 and the first amplifier 1〇2 form a voltage follower to divide the integrated signal Vea by the voltage divider 101. The level is stored on the level storage element 1〇4 to form a set level Vset. The dimming signal DIM is simultaneously inverted by the inverter 1〇6 to control the second switch 107' to turn off the second switch ίο?. When the state of the dimming signal DIM is "〇FF", the first switch 114 and the third switch 1〇3 are turned off, and the level storage element 1〇4 has referenced the integral signal 201142567.
Vea而儲存了設定準位Vset。而調光訊號DIM經反相器i〇6 反相後控制第二開關107使其導通。此時，第二放大器105的 輸出端耦接連接點Se(即耦接至積分單元113)，且放大器ι〇5 的輸出端同時搞接反相輸入端’而非反相輸入端搞接準位儲存 元件104以接收設定準位Vset。因此，第二放大器1〇5將調整 積分單元113所產生的積分訊號Vea的準位至與設定準位Vset 相同。 在本實施例中，準位儲存元件104係參考分壓後的積分訊 號Vse之準位來決定設定準位vset，因此設定準位vset低於 積分訊號Vse之準位。實際應用時，設定準位Vset與積分訊 號Vea的準位比例關係可以是接近1的值，例如：12或〇 8°， 而不影響本發明之優點。 ，再來，請參見第五圖，為第三圖及第四圖所示電路於調光 過程的訊號波形圖。在本實施例中，以設定準位Vset小於積 分訊號Vea解位為例進行說明。於時間點u，調光訊號DM 剛由代表「OFF」的低準位轉為代表「⑽」的高準位。此時， 輸出電壓Vout由臨界電壓Vf上升，輸出電济l _從零準位開 3升。，而積分訊號Vea設定準位Vset處開始上升。因此， ，制磁Se的工作週_—預定卫倾期（對應於設定準位 tilt進行迴授控制。於時間點t2，輸出電流_到達預 ^出電流I。，此時積分訊號Vea到達—峰值。而由於積分$ 唬Vea係由一設定準位Vset開始上升，而 積^號Vea的最大值開始’故此峰值不“達 二，輸出電壓v〇ut、輸出電流上積二號 _剛由代表「〇N」的高準位轉為代表Ί ，分訊號Vea被調整為與設定雜—° 停止產生’使轉換電路停止傳送雷Λ f似號Sc 及輸出電流lout開始下降。於時門戟時’輸出電壓Vout 降至臨界電壓W，此時輸出電壓V-下 201142567 ϊί，為根據本發明之一第二較佳實施例之-電 實==，路額外增加-驅動開關=接= 電路於調㈣加'?1!時參見第七圖，為第六圖所示電源轉換 時丄„ 170導通，此時電源轉換電路的操作與第三圖所 =電路綱。而當調光訊號DIM代表「OTF」時，驅動開 JJ 170截止，使輪出電流I〇ut無法流經電流偵測電阻165至 η中斷轉換_ 150提供電力至發光二極體模組16〇 如此’輪出電壓vout神位能繼續維持於預定輸出 巧v°。於下1期調光訊號DIM轉為代表「〇N」時，更 快達到平衡。 1 、 ^ *ί上所述，本發明完全符合專利三要件：新穎性、進步性 二ft的巧用性。本發_上文中已以較佳實施例揭露，然 … 技術者應理解的是，該實施例僅用於描繪本發明，而 =解讀為關本發明之綱ϋ意的是，舉凡與該實施例 之變域置換’均應設為涵蓋於本個之範翻。因此， 本發明之保魏圍當町文之申請專概圍所界定者為準。 % 【圖式簡單說明】 ==圖為傳統之一種發光二極體驅動電路之電路示意圖。 圖為第一圖所示發光二極體驅動電路於調光過程的訊號 波形圖。 第一圖，根據本發明之一第一較佳實施例之一電源轉換電路 之電路示意圖。 ，I圖為根據本發明之準位設定單元之一較佳實施例之電路 不意圖。 =士圖為第三圖及第四圖所示電路於調光過程的訊號波形圖。 八圖為根據本發明之一第二較佳實施例之一電源轉換電路 之電路示意圖。 201142567 第七圖為第六圖所示電源轉換電路於調光過程的訊號波形圖。 【主要元件符號說明】 先前技術： 控制器10 誤差放大器11 三角波產生器12 誤差補償電路13 脈寬調變比較器18 驅動電路19 轉換電路50 發光二極體模組60 輸入電壓源Vin 控制訊號Sc 輸出電壓Vout 輸出電流lout 電流偵測電阻65 電流迴授訊號IFB 參考訊號Vr 誤差放大訊號Vcomp 誤差穩定值Vcompo 預定輸出電流Ιο 預定輸出電壓Vo 臨界電壓VfVea stores the set level Vset. The dimming signal DIM is inverted by the inverter i〇6 to control the second switch 107 to be turned on. At this time, the output end of the second amplifier 105 is coupled to the connection point Se (ie, coupled to the integration unit 113), and the output end of the amplifier ι〇5 simultaneously engages the inverting input terminal instead of the inverting input terminal. The bit storage element 104 receives the set level Vset. Therefore, the second amplifier 1〇5 will adjust the level of the integral signal Vea generated by the integrating unit 113 to be the same as the set level Vset. In the present embodiment, the level storage element 104 determines the set level vset by referring to the level of the divided integrated signal Vse, so that the set level vset is lower than the level of the integral signal Vse. In practical applications, the proportional relationship between the set level Vset and the integral signal Vea may be a value close to 1, for example: 12 or 〇 8°, without affecting the advantages of the present invention. , again, please refer to the fifth figure, which is the signal waveform diagram of the circuit shown in the third and fourth figures during the dimming process. In this embodiment, the setting of the set level Vset is smaller than that of the integral signal Vea. At time point u, the dimming signal DM has just been converted from a low level representing "OFF" to a high level representing "(10)". At this time, the output voltage Vout rises from the threshold voltage Vf, and the output battery l _ opens 3 liters from the zero level. And the integral signal Vea sets the level Vset to start rising. Therefore, the working week of the magnetism Se_-the predetermined guarding period (corresponding to the set level tilt to perform the feedback control. At the time point t2, the output current_ reaches the pre-current I. At this time, the integral signal Vea arrives - Peak value. Since the integral $ 唬Vea starts to rise from a set level Vset, and the maximum value of the product number Vea starts, so the peak value does not reach two, the output voltage v〇ut, the output current on the product No. 2 _ just represented The high level of "〇N" is converted to the representative Ί, and the signal signal Vea is adjusted to be set to 杂-° stop generating 'to make the conversion circuit stop transmitting the lightning Λf like the number Sc and the output current lout starts to fall. 'The output voltage Vout falls to the threshold voltage W, at which time the output voltage V- is 201142567 ϊί, which is a second embodiment of the invention - the electric real ==, the path is additionally increased - the drive switch = the connection = circuit When adjusting (4) plus '?1!, refer to the seventh figure. When the power conversion is shown in the sixth figure, 170„170 is turned on. At this time, the operation of the power conversion circuit and the circuit diagram of the third figure are used. When the dimming signal DIM stands for "OTF", the drive opens JJ 170 cutoff, so that the wheel current I〇ut is not The current detecting resistor 165 to the η interrupt conversion _ 150 provides power to the LED module 16 so that the 'rounding voltage vout position can continue to maintain the predetermined output by v°. The next stage dimming signal DIM When it is changed to "〇N", the balance is reached faster. 1 , ^ *ί, the present invention fully complies with the three requirements of the patent: novelty, progressiveness, and the skill of the second ft. The preferred embodiments are disclosed, and it should be understood by those skilled in the art that the embodiment is only used to describe the present invention, and that the interpretation of the present invention is intended to be a substitute for the variable domain of the embodiment. It should be set to cover the scope of this article. Therefore, the definition of the application for the Weiweidang Town of Wenbao of the present invention shall prevail. % [Simple description of the schema] == The picture is a traditional light-emitting diode The circuit diagram of the body drive circuit. The figure shows the signal waveform of the light-emitting diode drive circuit in the dimming process shown in the first figure. First, a power conversion circuit according to a first preferred embodiment of the present invention. Circuit diagram. I diagram is the level setting list according to the present invention. The circuit of a preferred embodiment is not intended. The diagram is a signal waveform diagram of the circuit shown in the third and fourth figures during the dimming process. Eight diagrams are one of the second preferred embodiments according to one of the present inventions. Circuit diagram of the power conversion circuit 201142567 The seventh diagram is the signal waveform diagram of the power conversion circuit shown in the sixth figure during the dimming process. [Main component symbol description] Prior art: Controller 10 Error amplifier 11 Triangle wave generator 12 Error compensation Circuit 13 Pulse Width Modulation Comparator 18 Drive Circuit 19 Conversion Circuit 50 LED Module 60 Input Voltage Source Vin Control Signal Sc Output Voltage Vout Output Current lout Current Sense Resistor 65 Current Feedback Signal IFB Reference Signal Vr Error Amplification Signal Vcomp error stable value Vcompo predetermined output current Ιο predetermined output voltage Vo critical voltage Vf
時間點 Ή、T2、T3、T4、T5 調光訊號DIM 本發明： 控制器100 迴授單元111 三角波產生器112 201142567Time point Ή, T2, T3, T4, T5 dimming signal DIM The present invention: Controller 100 feedback unit 111 Triangle wave generator 112 201142567
積分單元113 第一開關114 準位設定單元115 脈寬控制單元116 脈寬調變比較器118 驅動電路119 轉換電路150 發光二極體模組160 電流偵測電阻165 驅動開關170 • 迴授訊號FB 控制訊號Sc 輸入電壓源Vin 輸出電壓Vout 輸出電流lout 參考訊號Vr 積分訊號Vea 調光訊號DIM 設定準位Vset ^ 分壓器101 第一放大器102 第三開關103 準位儲存元件104 第二放大器105 反相器106 第二開關107 連接點Se 時間點 tl、t2、t3、t4 預定輸出電流Ιο 預定輸出電壓Vo 11 tsIntegral unit 113 First switch 114 Level setting unit 115 Pulse width control unit 116 Pulse width modulation comparator 118 Drive circuit 119 Conversion circuit 150 Light-emitting diode module 160 Current-sense resistor 165 Drive switch 170 • Feedback signal FB Control signal Sc input voltage source Vin output voltage Vout output current lout reference signal Vr integration signal Vea dimming signal DIM setting level Vset ^ voltage divider 101 first amplifier 102 third switch 103 level storage element 104 second amplifier 105 Phaser 106 second switch 107 connection point Se time point t1, t2, t3, t4 predetermined output current Ιο predetermined output voltage Vo 11 ts