TW201206034A

TW201206034A - Over power protection (OPP) compensation circuit and flyback power supply

Info

Publication number: TW201206034A
Application number: TW099125022A
Authority: TW
Inventors: Zuo-Shang Yu; Tsung-Yen Lee
Original assignee: Tpv Electronics Fujian Co Ltd
Priority date: 2010-07-29
Filing date: 2010-07-29
Publication date: 2012-02-01
Also published as: TWI443946B

Abstract

An over power protection (OPP) compensation circuit for a flyback power supply with OPP function employing a wide range of input voltage includes a compensation winding, a rectifier and filter circuit, a compensation resistor and a switch circuit. A voltage corresponding to the wide range of input voltage is induced across the compensation winding on a primary side of a transformer. The induced voltage is input to the rectifier and filter circuit, the switch circuit and the compensation resistor to provide a bias voltage on a current sense (CS) pin of a pulse-width modulation (PWM) controller to compensate the drift of OPP points due to the wide range of input voltage. In light-load or no-load such as standby mode condition, the switch circuit is turned off to disable the OPP compensation circuit. The OPP compensation circuit can be used in a flyback power of a liquid crystal display product required for low standby power dissipation.

Description

201206034 六、發明說明：【發明所屬之技術領域】本發明是有關於一種具有過功率保護功能的返馳式電源，且特別是有關於一種採用寬範圍輸入電壓且採用過功率保護補償的返馳式電源。【先前技術】圖1為一種現有的返馳式（flyback)電源的電路圖。請參見圖 # 1，返馳式電源1採用寬範圍交流電壓Vac輸入。寬範圍交流電壓201206034 VI. Description of the Invention: [Technical Field] The present invention relates to a flyback power supply having an overpower protection function, and more particularly to a flyback using a wide range of input voltages and using overpower protection compensation Power supply. [Prior Art] Fig. 1 is a circuit diagram of a conventional flyback power supply. Referring to Figure #1, the flyback power supply 1 uses a wide range of AC voltage Vac input. Wide range AC voltage

Vac 通過電磁干擾(ElectroMagnetic Interference，簡稱 EMI)濾波器11濾'除EMI雜訊，再通過橋式整流器12的整流及電容[3的濾波而轉換成寬範圍輸入電壓vin。寬範圍交流電壓Vac通常採用 90Vrms-264Vrms ’使得寬範圍輸入電壓vin約為i2〇v_37〇v。寬範圍輸入電壓Vin通過由器Ή、開關Q1及輸出整流渡波電路 13所組成的返驰式直流至直流轉換電路轉換成輸出電壓v〇ut提供到負載。返驰式電源1通過回饋電路丨4取樣輸出電壓v〇ut以產生與負載量對應的回饋電流Ic，再通過脈寬調變（Pulse_Width * Modulation，簡稱？觀)控制器U1根據其回饋端FB接收的與回饋電流Ic對應的回饋電壓Vfb，從其驅動端GATE輸出pwM信號Vgate 控制開關Q1的切換，進而調整輸出電壓V〇ut。為了確保輸出超載或短路時電源零件不受損壞或不產生安全隱患問通，電源通常設計有過功率保護(〇ver p〇wer pr〇tect丨〇n，簡稱opp)功月b。返规式電源i通過檢測電阻rs及p醫控制器ui 來提供0ΡΡ功能。檢測電阻RS檢測流過開關Q1的電流Ip以產生與電流Ip對應的檢測電壓VCS。檢測電壓Vcs通常需要通過由電阻R1及電谷C1所組成的低通濾波電路來濾除因開關qi切換所產 201206034 生的高頻雜訊’以避免PWM控制器U1誤動作。P腳I控制器ui根據其檢測端CS接收的濾波後的檢測電壓Vcsl，判斷電流ip的最大值是否有達到opp保護點來決定是否要停止從驅動端GATE輸出 PWM信號Vgate ’即停止電源轉換而關閉返驰式電源1。返驰式電源1設計用來提供固定的輸出電壓V〇ut到負載，故輸出功率與輸出電流有關，而輸出電流與流過變壓器T1次級繞組Nsl的次級電流有關，進而與流過變壓器T1初級繞組Npl的初級電流（即流過開關Q1的電流Ip)有關，因此可通過PWM控制器讥檢測並限制初級電流Ip的最大值來限制輸出功率，即提供〇pp功能。 PWM控制器U1提供的opp保護點大小主要與輸入電壓Vin有關即與父流電壓Vac有關。例如，在輸入9〇vrms的交流電壓vac 或120V的輸入電壓Vin時，〇pp保護點設計在權則在輸入 264Vrms的交流電壓Vac或37〇v的輸入電壓Vin時，〇pp保護點變為60W。由於輪入寬範圍電壓-(或㈣導致〇pp賴點的漂移，返馳式電源1職變壓器TW· Q1等元件要有足夠的設計裕度，以便輸出超載或短路時，在變壓器Ή社制飽合且流過 ^關Q1的電流Ιρ還未達到其規格最大值之前，PWM控制器U1就會開始進行0ΡΡ，以確保電源零件不受損壞或不裕紐了可麟加電麟収权外，射能^源攻3卞難展_。，2為圖1所示返驰式電源丨採用卿補償的電路圖。請參阻Rc2即ί在圖1所示返驰式電源1中加入補償電的檢列端J ^。兩端分別輕接電容C3正端和™控制器ϋ1 。輸^簡ln落於電阻Rc、R1和Rs上而產卜補 / Rs產#^Vln/(RC+R1+RS)，此補償電流IrC通過電阻R1 和Rs產生一龍疊加到檢測端CS對OPP保護點的漂移做補償(下 201206034 ' 稱0ΡΡ補償）。例如，在輸入90Vrms的交流電壓Vac或120V的輸入電壓Vin (下稱輸入90Vrms)時，在檢測端CS會得到較小的0ΡΡ 補償，在輸入264Vrms的交流電壓Vac或370V的輸入電壓Vin (下稱輸入264Vrms)時，在檢測端CS會得到較大的0ΡΡ補償，使得輸入90Vrms-264Vrms的交流電壓Vac或120V-370V的輸入電壓Vin (下稱輸入90Vrms-264Vrms)的高低兩端0ΡΡ保護點更接近。圖3為圖2所示返馳式電源2的0ΡΡ補償的實驗數據。請參見圖3，通過調整補償電阻Rc電阻值可發現：補償電阻RC電阻值在小於630ΚΩ時，輸入90Vrms-264Vrms的高低兩端0ΡΡ保護點差值較大’且0ΡΡ保護點在輸入264Vrms時反而比輸入90Vrms時大得多’ 0ΡΡ補償過度《補償電阻rc電阻值在63〇κω-1ΜΩ時，輸入90Vrms-264Vrms的高低兩端0ΡΡ保護點差值較小，0pp補償效果較好’但此時損耗在補償電阻Rc上的功耗約為136mW_2〇lmW，無法應用到要求低待機功耗的電子產品上。補償電阻Rc電阻值在 2. 2ΜΩ以上時’輸入9〇Vrms-264Vrms的高低兩端opp保護點差值較大，0ΡΡ補償不足，且補償電阻Rc電阻值越大則〇pp補償效果越差。補償電阻RC電阻值無窮大或開路時，相當於返馳式電源上未加入補償電阻Rc的情況，此時無opp補償。【發明内容】本發a月的目的就是在提出一種過功率保護(㈣補償電路，適馳式電源，可補償因輸入寬範圍電壓所導致的卿保護點 ^電路題且可在例如待機模式的輕載或空載情況下關閉0PP補償電:發:二二種 201206034 且可在例如待機模式的輕载妓载情況下關0ΡΡ補償電路。本發明提出-種0ΡΡ補償電路，適用於返馳式電源。返馳，(PWM)控制益。其中，變壓器包括設在其初級側的初級繞組及钟 φρΓ人，觸顿敝。她繞崎點她接以接收寬範圍輸入 h墾且、非打點端祕開_第—端。開關第二端接地。次級繞組 t點端接地且其非打點端輕接輸出整雜波電路輸人端。輸出整 Ί皮，路輸*端提供輸出電壓到負載。_電路取樣輸出電壓 t生”負載量對應的回饋信號。PWM控制器具有檢測端及化，通過檢測端檢測流過開關的電流以提供0ΡΡ，且通過回饋端接收回饋信號以控制開關的切換。接雷跋0。=償t包括補償繞組、整流遽波電路、補償電阻及開關端咖關電路第二端。開關電路第路輸出端’開關電路控制端耦接回饋端。當回饋信二小於預定值時，開關電路關斷，當回饋信號表示負载夏大於預疋值時，開關電路導通。本發明另提出-種返馳式電源，包括上述的變麗器、開關、輸出整流滤波電路、回饋電路、PWM控制II及〇PP補償電路。 m ^木用補仏繞組來感應出與寬範圍輸入電麈對應的電 =，此感應電壓再通秘赫波桃、開 =1器1，端提供-個偏細伽輸4翻電^所導致的負截，且柳崎類_載轉情況下（即、里”；核時），通過開關電路的關斷來關閉卿補償電 201206034 路故可應用到要求低待機功耗的液晶顯示產品返馳式電源當中。為讓本發明之上述和其他目的、特徵和優雜更明顯易懂，下文特舉較佳實施例，並配合所附圖式，作詳細說明如下。【實施方式】圖4為依照本發明一實施例的採用寬範圍輸入電壓且採用 0ΡΡ補償的返馳式電源的電路圖。請參見圖4，返馳式電源4即是在圖1所不返馳式電源1中加入0ΡΡ補償電路，其中0ΡΡ補償電 φ路包括補償繞組如2、整流濾波電路41、開關電路42及補償電阻 =。因此，返馳式電源4包括EMI濾波器u、橋式整流器丨2、電谷C3、返馳式直流至直流轉換電路(其包括變壓器T1、開關卬及輸出整流渡波電路13)、回饋電路14、酬控制器m、檢測電阻The Vac filters the EMI noise by the Electromagnetic Interference (EMI) filter 11 and converts it into a wide range of input voltages vin through the rectification of the bridge rectifier 12 and the filtering of the capacitor [3]. The wide range AC voltage Vac typically uses 90Vrms-264Vrms' such that the wide range input voltage vin is approximately i2〇v_37〇v. The wide range input voltage Vin is converted to an output voltage v〇ut by a flyback DC-to-DC conversion circuit composed of a device Ή, a switch Q1, and an output rectification wave circuit 13 to the load. The flyback power supply 1 samples the output voltage v〇ut through the feedback circuit 丨4 to generate a feedback current Ic corresponding to the load amount, and then passes the pulse width modulation (Pulse_Width * Modulation, referred to as the view) controller U1 according to its feedback end FB The received feedback voltage Vfb corresponding to the feedback current Ic outputs a switching of the pwM signal Vgate from the drive terminal GATE to control the switching of the switch Q1, thereby adjusting the output voltage V〇ut. In order to ensure that the power supply parts are not damaged or cause safety hazards when the output is overloaded or short-circuited, the power supply is usually designed with over-power protection (〇ver p〇wer pr〇tect丨〇n, referred to as opp). The return type power supply i provides a 0ΡΡ function through the detection resistor rs and the p medical controller ui. The sense resistor RS detects the current Ip flowing through the switch Q1 to generate a detection voltage VCS corresponding to the current Ip. The detection voltage Vcs usually needs to be filtered by a low-pass filter circuit composed of a resistor R1 and a valley C1 to filter the high-frequency noise generated by the switch qi 201206034 to avoid malfunction of the PWM controller U1. The P-pin I controller ui determines whether the maximum value of the current ip reaches the opp protection point according to the filtered detection voltage Vcsl received by the detection terminal CS to determine whether to stop outputting the PWM signal Vgate from the driver terminal GATE. Turn off the flyback power supply 1. The flyback power supply 1 is designed to provide a fixed output voltage V〇ut to the load, so the output power is related to the output current, and the output current is related to the secondary current flowing through the secondary winding Nsl of the transformer T1, and then flows through the transformer. The primary current of the T1 primary winding Npl (ie, the current Ip flowing through the switch Q1) is related, so the output power can be limited by the PWM controller 讥 detecting and limiting the maximum value of the primary current Ip, that is, providing the 〇pp function. The size of the opp protection point provided by the PWM controller U1 is mainly related to the input voltage Vin, that is, to the parent current voltage Vac. For example, when inputting an AC voltage vac of 9〇vrms or an input voltage Vin of 120V, the 〇pp protection point is designed such that when the input voltage Vin of the input voltage of 264Vrms or 37〇v is input, the 〇pp protection point becomes 60W. Due to the wide range voltage of the wheel - (or (d), the drift of the 〇pp point, the return-type power supply 1 transformer TW·Q1 and other components must have sufficient design margin, so that when the output is overloaded or short-circuited, Before the current Ιρ that saturates and flows through the Q1 has not reached its maximum specification, the PWM controller U1 will start 0ΡΡ to ensure that the power supply parts are not damaged or not ok. The shooting energy ^ source attack 3 卞 difficult exhibition _., 2 is the circuit diagram of the flyback power supply shown in Figure 1. Use the compensation circuit. Please block Rc2 ie add the compensation power in the flyback power supply 1 shown in Figure 1. The detection terminal J ^. The two ends are respectively connected to the positive terminal of the capacitor C3 and the TM controller ϋ1. The input and the simple LM fall on the resistors Rc, R1 and Rs and the yield is compensated / Rs is produced #^Vln/(RC+R1 +RS), this compensation current IrC is generated by the resistors R1 and Rs superimposed on the detection terminal CS to compensate the drift of the OPP protection point (hereinafter 201206034 '0 0 compensation). For example, input AC voltage of 90Vrms Vac or 120V When the input voltage Vin (hereinafter referred to as input 90Vrms), CS will get a small 0ΡΡ compensation at the detection terminal, and input 264Vrms of AC. When the input voltage Vin of Vac or 370V is pressed (hereinafter referred to as input 264Vrms), a large 0ΡΡ compensation is obtained at the detection terminal CS, so that the AC voltage Vac of 90Vrms-264Vrms or the input voltage Vin of 120V-370V is input (hereinafter referred to as input 90Vrms). -264Vrms) The 0两端 protection point is closer to the high and low ends. Figure 3 is the experimental data of the 0ΡΡ compensation of the flyback power supply 2 shown in Figure 2. See Figure 3, by adjusting the resistance of the compensation resistor Rc, you can find: the compensation resistor RC When the resistance value is less than 630 ΚΩ, the input voltage of 90Vrms-264Vrms has a large difference between the two ends of the 0ΡΡ protection point, and the 0ΡΡ protection point is much larger than the input 90Vrms when inputting 264Vrms. 0ΡΡOvercompensation “Compensation resistance rc resistance value is at When 63〇κω-1ΜΩ, the input of 90Vrms-264Vrms has a small difference between the two ends of the 0ΡΡ protection point, and the 0pp compensation effect is better. However, the power consumption of the loss on the compensation resistor Rc is about 136mW_2〇lmW, which cannot be applied to For electronic products with low standby power consumption, when the resistance value of the compensation resistor Rc is above 2. 2ΜΩ, the difference between the high and low ends of the input 9〇Vrms-264Vrms is large, the compensation of 0ΡΡ is insufficient, and the compensation resistor Rc is The larger the resistance is, the worse the 〇pp compensation effect is. When the compensation resistor RC resistance value is infinite or open, it is equivalent to the case where the compensation resistor Rc is not added to the flyback power supply, and there is no opp compensation at this time. The purpose of the month is to propose an over-power protection ((4) compensation circuit, a suitable power supply, which can compensate for the circuit protection problem caused by inputting a wide range of voltages and can be used in light load or no load conditions such as standby mode. Turn off the 0PP compensation power: send: two kinds of 201206034 and can close the 0ΡΡ compensation circuit in the case of light load, for example, standby mode. The invention proposes a kind of 0ΡΡ compensation circuit, which is suitable for a flyback power supply. Return, (PWM) control benefits. Among them, the transformer includes a primary winding disposed on the primary side thereof and a clock φρΓ人, which is touched. She circled her to receive a wide range of input h垦, and the non-dot end secret _ first end. The second end of the switch is grounded. The secondary winding is grounded at the t point and its non-tapping end is lightly connected to the output of the whole clutter circuit. The output is full, and the output terminal provides the output voltage to the load. The circuit sampling output voltage t generates a feedback signal corresponding to the load amount. The PWM controller has a detection terminal and a control. The detection terminal detects the current flowing through the switch to provide 0ΡΡ, and receives the feedback signal through the feedback terminal to control the switching of the switch. Connected to Thunder 0. = Compensation t includes compensation winding, rectification chopper circuit, compensation resistor and switch terminal circuit second end. Switch circuit output terminal 'switch circuit control end coupled to feedback end. When feedback letter 2 is less than scheduled When the value is changed, the switch circuit is turned off, and when the feedback signal indicates that the load summer is greater than the pre-depreciation value, the switch circuit is turned on. The present invention further proposes a flyback power supply, including the above-mentioned converter, switch, output rectification filter circuit, feedback Circuit, PWM control II and 〇PP compensation circuit. m ^Wood complement winding to induce electricity corresponding to a wide range of input = =, this induced voltage is then passed through the secret wave, open = 1 device, the end provides - A negative gamma loss 4 turns over the electricity caused by the negative cut, and the Liusaki class _ load case (ie, inside); nuclear time, through the switch circuit to close the Qing compensation power 201206034 road It requires low standby power used liquid crystal display products flyback power them. The above and other objects, features, and advantages of the present invention will become more apparent from [Embodiment] FIG. 4 is a circuit diagram of a flyback power supply using a wide range of input voltages and using 0 ΡΡ compensation, in accordance with an embodiment of the present invention. Referring to FIG. 4, the flyback power supply 4 is a 0ΡΡ compensation circuit added to the non-return type power supply 1 of FIG. 1, wherein the 0ΡΡ compensation electric φ circuit includes a compensation winding such as 2, a rectification and filtering circuit 41, a switching circuit 42 and compensation. Resistance =. Therefore, the flyback power supply 4 includes an EMI filter u, a bridge rectifier 丨 2, a valley C3, a flyback DC to DC conversion circuit (which includes a transformer T1, a switch 卬 and an output rectification wave circuit 13), and a feedback circuit 14 , compensation controller m, detection resistance

Rs、低通濾波電路（其包括電阻R1及電容及〇pp補償電路。返驰式電源4細寬範圍技f壓Vac輸人。寬範圍交流電壓Vac 通過fMI濾波器U濾除EMI雜訊，再通過橋式整流器12的整流及電容C3的濾波而轉換成寬範圍輸入電壓Vin。寬範圍交流電壓Rs, low-pass filter circuit (which includes resistor R1 and capacitor and 〇pp compensation circuit. The flyback power supply 4 has a wide range of technology and the voltage is VV input. The wide range AC voltage Vac filters the EMI noise through the fMI filter U. It is converted into a wide range of input voltage Vin by the rectification of the bridge rectifier 12 and the filtering of the capacitor C3. Wide range AC voltage

Vac通常採用9〇Vrms_264Vrms，使得寬範圍輸入電壓約 • 120V-370V。寬範圍輸入電壓Vin通過返驰式直流至直流轉換電路轉換成輸出電壓Vout提供到負載。變壓器T1包括設在其初級侧的初級繞組Npl和補償繞組Np2及設在其次級側的次級繞組此丨。初級繞組Npl打點端耦接電容⑺正端以接收寬範圍輸入電壓Vin且其非打點端耦接開關Q1第一端。開關Q1第二端通過檢測電阻RS接地 (初級側地）。補償繞組Np2打點端耦接整流濾波電路41輸入端且其非打點端接地(初級側地）。次級繞組Nsl打點端接地(次級側地) 且其非打點端耦接輸出整流濾波電路13輸入端。輸出整流濾波電 9 201206034 路13輸出端提供輸出電壓v〇ut到負載。在本實施例中，輸出整流滤波電路13包括整流二極體及由兩電容與一電感所組成的clc 低通濾、波器。回饋電路14取樣輸Μ壓Vout以產生與負載量對應的回饋信號Ic。在本實施例中，回饋電路14包括電阻R2〜r5、電容c2、光耦合器U2及並聯穩壓器U3，其中光耦合器ϋ2包括發光二極體 IR及光電晶體ΡΤ，並聯穩壓器U3具有陽極端Α、陰極端κ及參考端R，並聯穩壓器U3例如是型號TL431積體電路，其内部電路示意圖如圖5所不。請同時參見圖4及圖5，回饋電路14通過電阻 R3和R4取樣輸出電壓vout，取樣後的輸出電壓—η輸入到並聯穩壓器U3的參考端R。並聯穩壓器U3通過其内部運算放大器 0P1將取樣後的輸出顏Voutl和其内部參考電壓源所提供的參考傾Ml兩者縣異放大並輸㈣應極較lb驅動其内部電晶體Q4，進而產生對應的流過電晶體Q4的電流lf，因此電流If大小對應於負載量。電流If通過光轉合謂的發光二極體 IR在其光電晶體PT產生對應的集極電、流Ic，因此電流k大小對應於負載量’可作為回饋信號來調整開關Q1的_，進而調整輸出電壓Vout。另外’電阻R5及電容C2串接於並聯穩壓器U3輸入的參考端R及輸出的陰極端K之間，提供―饋電路做頻率補償。 PWM控制器U1具有檢測端cs、回饋端FB及驅動端GATE。pWM 控制器in it過檢測端cs輕接檢測電阻Rs以檢測流過開關以的初級電流Ip’進而提供變壓器T1初級側過電流保柳如贈 Protection，簡稱0CP) ’即提供變壓器T1次級側輸出的〇pp。剛控制器U1通過回饋端FB將電流形式_饋信號(下稱回館電流） Ic轉換成對應的f壓形式的_錢(下稱_賴）。在檢測端CS檢測到初級電流Ip未達龍p保護點時，剛控制器m 201206034 根據檢測端CS接收的檢測電壓vcs/vcsl及回饋端FB接收的回於電壓Vfb ’從驅動端GATE輸出PWM信號Vgate控制開關qi的切換，進而調整輸出電壓Vout。在檢測端CS檢測到初級電流ip達到〇cp 保護點時PWM控制器ui，停止從驅動端GATE輪出PWM信號ygate，即停止電源轉換而關閉返馳式電源1，輸出電壓v〇ut為零。 PWM控制器U1例如是型號LD7576積體電路，其内部電路示意圖如圖6所示。請參見圖6，PWM控制器讥包括上拉電阻Rfb^ PWM比較器CMP1 ’其中上拉電阻Rfb第一端耦接供電電壓Vbias，上拉電阻Rfb第二端耗接回饋端fb且通過兩二極體及兩電阻輕接Vac typically uses 9〇Vrms_264Vrms, allowing a wide range of input voltages from approximately 120V to 370V. The wide range of input voltage Vin is converted to an output voltage Vout through a flyback DC to DC conversion circuit to the load. The transformer T1 includes a primary winding Npl and a compensation winding Np2 provided on the primary side thereof and a secondary winding provided on the secondary side thereof. The primary winding Npl dot is coupled to the positive terminal of the capacitor (7) to receive a wide range of input voltages Vin and its non-dot terminal is coupled to the first end of the switch Q1. The second end of the switch Q1 is grounded via the sense resistor RS (primary side ground). The tapping end of the compensation winding Np2 is coupled to the input end of the rectifying and filtering circuit 41 and its non-tapping end is grounded (primary side ground). The secondary winding Nsl is grounded (secondary side) and its non-injected end is coupled to the input of the output rectifying and filtering circuit 13. Output Rectifier Filter 9 201206034 The 13 output of the channel provides the output voltage v〇ut to the load. In this embodiment, the output rectifying filter circuit 13 includes a rectifying diode and a clc low-pass filter and a waver composed of two capacitors and an inductor. The feedback circuit 14 samples the output voltage Vout to generate a feedback signal Ic corresponding to the amount of load. In this embodiment, the feedback circuit 14 includes resistors R2 r r5, a capacitor c2, an optocoupler U2, and a shunt regulator U3. The photocoupler ϋ2 includes a light emitting diode IR and a phototransistor ΡΤ, and a shunt regulator U3. It has an anode terminal 阴极, a cathode terminal κ and a reference terminal R. The shunt regulator U3 is, for example, a model TL431 integrated circuit, and its internal circuit schematic is as shown in FIG. Referring to FIG. 4 and FIG. 5 simultaneously, the feedback circuit 14 samples the output voltage vout through the resistors R3 and R4, and the sampled output voltage η is input to the reference terminal R of the parallel regulator U3. The shunt regulator U3 uses its internal operational amplifier OP1 to differentially amplify and output the sampled output Voutl and its reference voltage source provided by its internal reference voltage source (4) to drive its internal transistor Q4 in comparison with lb. A corresponding current lf flowing through the transistor Q4 is generated, so the current If size corresponds to the amount of load. The current If generates a corresponding collector current and current Ic in the photonic crystal PT through the light-emitting diode IR, so the current k magnitude can be adjusted as a feedback signal to adjust the switch Q1, and then adjust Output voltage Vout. In addition, the resistor R5 and the capacitor C2 are connected in series between the reference terminal R input from the shunt regulator U3 and the cathode terminal K of the output, and a feed circuit is provided for frequency compensation. The PWM controller U1 has a detection terminal cs, a feedback terminal FB and a drive terminal GATE. The pWM controller in the over-detection terminal cs is connected to the detection resistor Rs to detect the primary current Ip' flowing through the switch to provide the transformer T1 primary side overcurrent protection, such as Protection (0CP), which provides the transformer T1 secondary side output. 〇pp. The controller U1 converts the current form_feed signal (hereinafter referred to as the return current) Ic into the corresponding f-form _ money (hereinafter referred to as _ 赖) through the feedback terminal FB. When the detection terminal CS detects that the primary current Ip is not reached, the controller m 201206034 outputs PWM from the driving terminal GATE according to the detection voltage vcs/vcsl received by the detection terminal CS and the return voltage Vfb received by the feedback terminal FB. The signal Vgate controls the switching of the switch qi, thereby adjusting the output voltage Vout. When the detection terminal CS detects that the primary current ip reaches the 〇cp protection point, the PWM controller ui stops the PWM signal ygate from the driving end GATE, that is, stops the power conversion and turns off the flyback power supply 1, and the output voltage v〇ut is zero. . The PWM controller U1 is, for example, a model LD7576 integrated circuit, and its internal circuit diagram is shown in FIG. Referring to FIG. 6, the PWM controller includes a pull-up resistor Rfb^ PWM comparator CMP1', wherein the first terminal of the pull-up resistor Rfb is coupled to the power supply voltage Vbias, and the second terminal of the pull-up resistor Rfb is coupled to the feedback terminal fb and passes through two or two Polar body and two resistors

PWM比較器CMP1負輸入端，因此回饋端叩接收的回饋電壓Vfb 通過兩二極體及兩電阻取樣後產生電壓Vfb2輸入pwM比較器CMpi 負輸入端’電壓Vfb2對應於回饋電壓Vfb。另外，檢測端cs接收的濾波後的檢測電壓Vcsl通過領先前緣屏蔽（Leading Edge Blanking’簡稱LEB)模組將檢測電壓Vcsl波形前緣屏蔽一小段時間以避免開關Q1切換所產生的高頻雜訊造成PWM控制器讥誤動作’ LEB模組處理後的檢測電壓Vcs2再通過與内部一斜率補償電壓Vslope疊加後產生電壓Vcs3輸入PWM比較器CMP1正輸入端。 PWM控制器U1還包括0CP比較器ΟΪΡ2，其中0CP比較器CMP2 正輸入端通過LEB模組耦接檢測端CS，0CP比較器CMP2負輸入端耦接參考電壓Vref2，因此通過LEB模組處理後的檢測電壓Vcs2 輸入0CP比較器CMP2正輸入端。PWM比較器CMP1及〇CP比較器 CMP2的輸出通過或閘〇Rl的或運算處理後，再與内部時脈信號 Vclk —起通過PWM產生模組產生從驅動端GATE輸出的pwM信號 Vgate 〇圖7為圖4所示返馳式電源在不同負載量的控制時序圖。請同時參見圖6及圖7’當PWM控制器111内部時脈信號Vclk傳送一 201206034 5發時，觸控制器仍從驅動端識輸出的蘭信號 „间準位而控制開_導通。此時流過開關Q1的初級增加’使檢測電麼Vcs * Vcsl開始上升，進而使電垩CS3開始上升。當電屡㈣大於電屡繼時，顺控制The PWM comparator CMP1 has a negative input terminal. Therefore, the feedback voltage Vfb received by the feedback terminal 取样 is generated by sampling the two diodes and the two resistors. The voltage Vfb2 is input to the pwM comparator CMpi. The negative input terminal voltage Vfb2 corresponds to the feedback voltage Vfb. In addition, the filtered detection voltage Vcsl received by the detecting terminal cs shields the leading edge of the detection voltage Vcs1 by a Leading Edge Blanking (LEB) module for a short period of time to avoid the high frequency miscellaneous generated by the switching of the switch Q1. The signal causes the PWM controller to malfunction. The detection voltage Vcs2 processed by the LEB module is then superimposed with the internal slope compensation voltage Vslope to generate a voltage Vcs3 input to the positive input terminal of the PWM comparator CMP1. The PWM controller U1 further includes an 0CP comparator ΟΪΡ2, wherein the positive input end of the 0CP comparator CMP2 is coupled to the detection terminal CS through the LEB module, and the negative input end of the 0CP comparator CMP2 is coupled to the reference voltage Vref2, and thus processed by the LEB module. The detection voltage Vcs2 is input to the positive input terminal of the 0CP comparator CMP2. The output of the PWM comparator CMP1 and the 〇CP comparator CMP2 is processed by the OR operation of the gate R1, and then the PWM signal generation module generates the pwM signal Vgate outputted from the driving terminal GATE together with the internal clock signal Vclk. It is the control timing diagram of the flyback power supply shown in Figure 4 at different load levels. Please also refer to FIG. 6 and FIG. 7'. When the internal clock signal Vclk of the PWM controller 111 transmits a 201206034 5 transmission, the touch controller still controls the open signal _ conduction from the blue signal of the drive terminal. The primary increase of the switch Q1 ' makes the detection voltage Vcs * Vcsl start to rise, and then the power 垩 CS3 starts to rise. When the power is repeated (four) is greater than the power relay, the control

輸出的簡信號此時為低準位而控制開關Q1 關斷。此時流過開關Q1的初級電流Ip為零’使檢測電壓^及 VCSl為零’義使龍Vcs3為零。當電壓Vcs2大於參考雜Vref2 夺表示檢利至ij變壓器T1初級側有過電流問題，即變壓器η次級側輸出會有過功率問題，因此_控制龍停止從驅動端g纖輸出PWM信號Vgate ’ _返馳式電源4。#電壓μ小於參考電愿Vref2時，表示沒有過電流及過功率問題，PWMS制器U1從驅動端GATE輸出PWM信號Vgate。請再參見圖4，0ΡΡ補償電路包括補償繞組Np2、整流滹波電路^、開關電路42及補償電阻Rc。其中，補償繞組Np2設在變壓β T1初級側，其打點端耦接整流濾波電路41輸入端且其非打點端接地(初級側地）。補償電阻Rc第一端耦接pWM控制器讥的檢測端CS，補償電阻RC第二端耦接開關電路42第二端422。開關電路42第一端421耦接整流濾波電路41輸出端，開關電路犯控制端423耦接PWM控制器U1的回饋端FB。當回饋信號表示負載量小於預定值時，開關電路42關斷，當回饋信號表示負載量大於預定值時，開關電路42導通，其中本例回饋信號採用回饋電壓The output simple signal is now at a low level and the control switch Q1 is turned off. At this time, the primary current Ip flowing through the switch Q1 is zero 'so that the detection voltages ^ and VCS1 are zero', so that the dragon Vcs3 is zero. When the voltage Vcs2 is greater than the reference miscellaneous Vref2, it means that the primary side of the transformer T1 has an overcurrent problem, that is, the secondary side of the transformer η has an over-power problem, so the _ control dragon stops outputting the PWM signal Vgate from the driver terminal g1. _Return-type power supply 4. #电压μ is less than the reference. When the power is Vref2, it means there is no overcurrent and overpower problem. The PWMS U1 outputs the PWM signal Vgate from the drive terminal GATE. Referring again to FIG. 4, the 0ΡΡ compensation circuit includes a compensation winding Np2, a rectifying chopper circuit ^, a switching circuit 42 and a compensation resistor Rc. The compensation winding Np2 is disposed on the primary side of the voltage change β T1 , and the dot end is coupled to the input end of the rectifying and filtering circuit 41 and the non-injecting end thereof is grounded (primary side ground). The first end of the compensation resistor Rc is coupled to the detection terminal CS of the pWM controller ,, and the second end of the compensation resistor RC is coupled to the second end 422 of the switch circuit 42. The first end 421 of the switching circuit 42 is coupled to the output of the rectifying and filtering circuit 41, and the switching circuit 423 is coupled to the feedback end FB of the PWM controller U1. When the feedback signal indicates that the load amount is less than the predetermined value, the switch circuit 42 is turned off. When the feedback signal indicates that the load amount is greater than the predetermined value, the switch circuit 42 is turned on, wherein the feedback signal of the present example uses the feedback voltage.

Vfb。直流輸入電壓Vin通過開關Q1的切換在初級繞組Npi上產生一交流電壓V见)1 ’並在補償繞組Np2上感應產生一交流電壓（下稱感應電壓）Vnp2，Vnp2=VnplxNp2/Npl，此感應電壓v叩2再通過整流滤波電路41的整流渡波後產生一直流電壓乂叩2，。由於直流 12 201206034 電壓Vnp2錢細輸人電壓Vin有關，因此可模仿先前技術的做法’在開關電路42導通時，直流電壓Vnp2，落於電阻Rc、R1和 =上而產生一補償電流Irc，Irc=Vnp2，/(Rc+Rl+Rs)，此補償電 /;IL 1 rc通過電阻R1和Rs產生—電壓疊加到檢測端CS做0ΡΡ補償。在本實施例中，整流濾波電路41包括整流二極體D1及電容 C4整⑽_一極體di陽極端耦接整流濾波電路41輸入端，整流二，體D1陰極端搞接電容以第—端及整流據波電路^輸出端，電 =C4第二端接地。開關電路42包括第一型開關敗及第二型開關其中第一型開關Q2控制端收到高準位信號時導通且在收到低準，信號時關斷，而第二型開關⑽控制端收到低準位信號時導通 f收到高準位信號時關斷。第一型開_2第一端輛接第二型開控制鳊’第一型開關Q2第二端接地(初級側地），第一型開 =2控制端搞接開關電路42控制端423。第二型開關Q3第一端 42第開關山電路42第一端421 ’第二型開關03第二端耗接開關電路隹丰貫施例中招7 I ^ 土闭剛w田N通道場效應電晶體所賓Vfb. The DC input voltage Vin generates an AC voltage V see) 1 ' on the primary winding Npi through the switching of the switch Q1 and induces an AC voltage (hereinafter referred to as an induced voltage) Vnp2, Vnp2=VnplxNp2/Npl, on the compensation winding Np2. The voltage v 叩 2 is further generated by the rectification wave of the rectifying and filtering circuit 41 to generate a DC voltage 乂叩2. Since the DC 12 201206034 voltage Vnp2 is related to the fine input voltage Vin, it can be imitated in the prior art. When the switching circuit 42 is turned on, the DC voltage Vnp2 falls on the resistors Rc, R1 and = to generate a compensation current Irc, Irc. =Vnp2, /(Rc+Rl+Rs), this compensation power /; IL 1 rc is generated by the resistors R1 and Rs - the voltage is superimposed on the detection terminal CS to compensate for 0 。. In this embodiment, the rectifying and filtering circuit 41 includes a rectifying diode D1 and a capacitor C4. The anode end of the dipole body is coupled to the input end of the rectifying and filtering circuit 41, and the rectifying body 2 is connected to the cathode end of the body D1. The terminal and the rectifier circuit circuit ^ output terminal, the electric=C4 second end is grounded. The switch circuit 42 includes a first type switch and a second type switch. The first type switch Q2 is turned on when the control terminal receives the high level signal and is turned off when the low level signal is received, and the second type switch (10) is controlled. When the low level signal is received, the turn-on f turns off when it receives the high level signal. The first type is opened and the first end is connected to the second type. The control unit is connected to the second end of the first type switch Q2 (primary side ground). The first type open = 2 control end engages the control end 423 of the switch circuit 42. The second type switch Q3 first end 42 the first end of the switch circuit 42 421 'the second type switch 03 the second end of the switch circuit 隹贯贯施 7 I I I I I I I I I I I I I I I I I I Transistor

螫恭二可由’雙載子接面電晶體所實現。第二型開關Q3由PNF 門面電晶體所實現’但亦可由P通道場效應電晶體所實現。 a此還包括触R6和R7錢在第—型 ^分壓提供第二型_Q3導通所需⑽壓，另外還包括電阻R8 R9以便取_饋健Vfb，轉躺_電壓咖控制第一型 2 Q2導通或關斷，電容C5用以壚除高頻雜訊。另外，補償繞且補if數較佳為—圈，因為補償繞組％2圈數越多則成本越高，的==應刚壓vnp2越高’損耗在補償槪上請同時參見圖4及圖7，在tl期間，輸出負載量不變，返驰 13 201206034 式電源4輸出電流不變，此時變麈器T1輸出功 ===，下降，由於p_咖的的回饋電麗Vfb門私μ電机1f及Ic開始下降會使在回饋端FB上出的PWM信號$ U_動端_輸器τ!輸㈣顿始狀，躺錄大，使變壓 =_，輸㈣壓_上升到tl _的準位，電準位不變’使回饋電壓Vfb開始保持較高的大的責i週=，，輸出_信號vg_始保持較吏變壓益T1輸出功率等於電源4輸出功率。小，购、，舰_4輸出電流變瞬間上升Hi τ率電源4輸出解，輸出電壓Vout 因此MM^二二開始上升’使回饋電壓恤開始下降，觀信號㈣的責任週_減小，出力率開始減小，進而使輸出電壓Vout下降。及/Ic在二：^vout下降到t1期間的準位，電流Π 準位不變，因此‘饋電壓Vfb開始保持較低的小責任週期 ς J^U1輸出的剛信號Vgate開始保持較期不變’使變壓器T1輸出功率等於電源4輸出功率。出負大時’回饋電壓Vfb上升，當輸、貝電壓Vfb下降’0ΡΡ補償電路利用了輕重載 201206034 變化引起回饋電壓vfb變化的特性來設計開關電路42控制〇pp補償電路的導通或關斷。例如，設計輸出負錢小於預定值時，返馳式電源4必然工作在待機模式而為輕載或空載，此時電流ic會在較高的準位不變，使回饋電壓Vfb在較低的準位不變，因此可設計回饋電壓Vfb取樣後的電壓咖將使第一型開關Qi關斷，進而^吏開關電路42關斷，不再進行opp補償，即此時opp補償電路幾乎沒有雜，故可細到要求低職功耗的液晶顯示產品返馳式電源虽中。而輸出負載量大於預定值時，返馳式電源4必然工作在正常模式而為重載，此時電流Ic會在較低的準位不變使回饋電壓Vfb在較尚的準位不變，因此可設計回饋電璧乂化取樣後的電壓Vfbl將使第一型開關qi導通，進而使開關電路42導通，故補償繞組Np2的感應電壓Vnp2可通過導通的開關電路42及補侦電阻Rc在檢測端CS提供一個偏壓補償opp保護點的漂移。圖8為圖4所示返驰式電源4的0ΡΡ補償的實驗數據，其是在補償繞組Np2圈數為1圈且開關電路42導通為前提下的量測結果。請參見圖8，通過調整補償電阻Rc電阻值可發現：補償電阻 Rc電阻值在3. 9ΚΩ以下時，輸入90Vrms-264Vrms的高低兩端opp 保護點差值較大，且0ΡΡ保護點在輸入264Vrms時反而比輸入 90Vrms時大得多，opp補償過度。補償電阻Rc電阻值在4 3ΚΩ -5. 6ΚΩ時，輸入90Vrms-264Vrms的高低兩端0ΡΡ保護點差值很小，0ΡΡ補償效果很好，且此時損耗在補償電阻Rc上的功耗約為 9.78mW-12.73mW。補償電阻RC電阻值在9.1ΚΩ以上時，輸入 90Vrms-264Vrms的高低兩端opp保護點差值較大，opp補償不足，且補償電阻Rc電阻值越大則opp補償效果越差。補償電阻Rc電阻值無窮大或開路時，相當於返驰式電源1未加入補償電阻Rc的情況，此時無0ΡΡ補償。 201206034 Μ由於本發明的0ΡΡ補償電路在補償繞組Np2圈數為丨圈且補償電阻Rc t阻值可適度補償0ΡΡ的設計下，損耗在補償電阻Rc 上的功耗僅為lGmW左右，因此，對於待機功耗要錄*嚴格(如低於0. 5W)的液晶顯示產品’其opp補償電路設計可以考慮不增加開關電路42以降低成本。若不增加開關電路42，則將整流渡波電路41輸出端改成直接耦接補償電阻Rc第二端。但是，對待機功耗要求較嚴格(如低於G.3W或甚至更低）敝晶顯示產品，·其 0ΡΡ補償電路設計則需要增加開關電路42，以便在待機模式下關閉0ΡΡ補償電路，此時0PP補償電路幾乎沒有功耗，使低於〇. 3W 或甚至更低的待機功耗較容易實現。螫 Kung II can be realized by 'double-carrier junction transistor. The second type of switch Q3 is implemented by a PNF facade transistor 'but can also be implemented by a P-channel field effect transistor. a) also includes the touch of R6 and R7 money in the first-type ^ partial pressure to provide the second type _Q3 conduction required (10) pressure, in addition to the resistor R8 R9 in order to take _ feed health Vfb, lie _ voltage coffee control first type 2 Q2 is turned on or off, and capacitor C5 is used to remove high frequency noise. In addition, the compensation winding and the complement if number is preferably - circle, because the more the number of windings of the compensation winding %2, the higher the cost, the == should be the higher the voltage vnp2, the loss is on the compensation 请, please also refer to Figure 4 and Figure 7. During the tl period, the output load is unchanged, and the output current of the 201206034 type power supply 4 is unchanged. At this time, the output of the converter T1 is ===, and the drop is due to the feedback of the p_ coffee. The μ motor 1f and Ic start to drop, so that the PWM signal on the feedback end FB can be outputted by the PWM signal $ U_ _ _ 器输输输 , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , To the level of tl _, the electric level does not change, so that the feedback voltage Vfb starts to maintain a high level of responsibility. i, the output _ signal vg_ begins to maintain a higher pressure than the output voltage of T1. . Small, purchase, ship _4 output current changes instantaneously Hi τ rate power supply 4 output solution, output voltage Vout, so MM ^ 22 starts to rise 'to make the feedback voltage shirt start to fall, view signal (four) responsibility week _ reduce, output The rate begins to decrease, which in turn causes the output voltage Vout to drop. And /Ic in the second: ^vout drops to the level during t1, the current Π level does not change, so the 'feed voltage Vfb begins to keep a small small duty cycle ς J ^ U1 output just signal Vgate begins to remain unchanged Change 'to make transformer T1 output power equal to power supply 4 output power. When the negative voltage is large, the feedback voltage Vfb rises, and when the input and output voltages Vfb fall '0', the compensation circuit uses the characteristic of the change of the feedback voltage vfb caused by the change of the light and heavy load 201206034 to design the switch circuit 42 to control the turn-on or turn-off of the 〇pp compensation circuit. For example, when the design output negative money is less than the predetermined value, the flyback power supply 4 must work in the standby mode and be light load or no load. At this time, the current ic will be unchanged at a higher level, so that the feedback voltage Vfb is lower. The level of the change is unchanged, so the voltage after sampling the feedback voltage Vfb can be designed to turn off the first type switch Qi, and then the switch circuit 42 is turned off, no opp compensation is performed, that is, the opp compensation circuit is almost no Miscellaneous, it can be fine to the low-power LCD display products back-up power supply. When the output load is greater than the predetermined value, the flyback power supply 4 must work in the normal mode and be heavy. At this time, the current Ic will remain at a lower level, so that the feedback voltage Vfb does not change at a higher level. Therefore, the voltage Vfbl after the feedback sampling can be designed to turn on the first type switch qi, thereby turning on the switching circuit 42, so that the induced voltage Vnp2 of the compensation winding Np2 can pass through the switching circuit 42 and the detecting resistor Rc. The detection terminal CS provides a bias to compensate for the drift of the opp protection point. Fig. 8 is an experimental data of 0 ΡΡ compensation of the flyback power supply 4 shown in Fig. 4, which is a measurement result on the premise that the number of turns of the compensation winding Np2 is one turn and the switch circuit 42 is turned on. Referring to Figure 8, by adjusting the resistance value of the compensation resistor Rc, it can be found that when the resistance value of the compensation resistor Rc is less than 3. 9 Ω, the difference between the high and low ends of the input 90Vrms-264Vrms is larger, and the 0ΡΡ protection point is at the input 264Vrms. The time is much larger than when 90Vrms is input, and the opp is overcompensated. When the resistance value of the compensation resistor Rc is 4 3 Κ Ω -5. 6 ΚΩ, the difference between the high and low ends of the input 90Vrms-264Vrms is small, and the compensation effect is good, and the power consumption of the loss on the compensation resistor Rc is about 9.78mW-12.73mW. When the compensation resistor RC resistance value is above 9.1 ΚΩ, the difference between the high and low ends of the input 90Vrms-264Vrms is large, the opp compensation is insufficient, and the larger the compensation resistance Rc resistance value is, the worse the opp compensation effect is. When the compensation resistor Rc has an infinite value or an open circuit, it is equivalent to the case where the flyback power supply 1 is not added with the compensation resistor Rc. 201206034 ΜBecause the 0ΡΡ compensation circuit of the present invention has a design in which the compensation winding Np2 turns to a circle and the compensation resistance Rc t can be appropriately compensated by 0ΡΡ, the power consumption of the loss on the compensation resistor Rc is only about 1GmW, therefore, Standby power consumption should be recorded * strict (such as less than 0. 5W) liquid crystal display products 'its opp compensation circuit design can be considered without increasing the switching circuit 42 to reduce costs. If the switching circuit 42 is not added, the output end of the rectification wave circuit 41 is changed to directly couple the second end of the compensation resistor Rc. However, the standby power consumption is more stringent (such as lower than G.3W or even lower), and the 0ΡΡ compensation circuit design needs to increase the switching circuit 42 to turn off the 0ΡΡ compensation circuit in the standby mode. The 0PP compensation circuit has almost no power consumption, making standby power consumption lower than 〇. 3W or even lower easier to implement.

知上所述，本發額制補償繞組來感應出與寬壓對應的電壓，此感應電壓再通過整流毅電路償電阻在讓控制器的檢測端提供—個偏壓補償因輸 Z 電源當中 =導致的0ΡΡ保護點漂移問題，且在例如待機模式的輕載或空載情況下（即負載量小於就_)，通·關電路_關= ippf^路，故可應關要求低賴雜的㈣雖然本發明已以較佳實施例揭露如上，鱗發明，任何«此技藝者，衫難本發明之精、疋士可作些許之更動誠飾’因此本發明之保護範2 1 專利範醜界定者鱗。視细之申請【圖式簡單說明】圖1為-種現有的採用寬範圍輸入電壓但返馳式電源的電路圖。木用〇即補償的圖圖2為圖1所示返驰式電源採用Gpp補償的電路 201206034 圖3為圖2所示返馳式電源的0PP補償的實驗數據壓且採用圖4為依照本發明一實施例的採用寬 0ΡΡ補償的返馳式電源的電路圖。 ’入電圖5為圖4所示並聯穩壓器的内部電路示音圖。圖6為圖4所示PWM控制器的内部電路示音圖。圖7為圖4所示返馳式魏在不同負载量的控制時序圖。Knowing that the compensation winding is used to induce the voltage corresponding to the wide voltage, the induced voltage is then supplied to the detection end of the controller through the rectifying circuit to compensate the resistance. The resulting 0ΡΡ protection point drift problem, and in the case of, for example, light load or no load in the standby mode (ie, the load is less than _), the on/off circuit _ off = ippf^ road, so the requirements can be low (4) Although the present invention has been disclosed in the preferred embodiment as above, the scale invention, any of the skilled person, the shirt is difficult to the essence of the invention, the gentleman can make a little more sleek decoration 'so the protection of the invention 2 1 patent ugly Define the scales. Application of the details [Simplified description of the drawings] Figure 1 is a circuit diagram of a conventional wide-range input voltage but a flyback power supply. FIG. 2 is a circuit for using the Gpp compensation of the flyback power supply shown in FIG. 1 . FIG. 3 is an experimental data pressure of the 0PP compensation of the flyback power supply shown in FIG. 2 and FIG. 4 is used according to the present invention. A circuit diagram of a flyback power supply employing a wide 0 ΡΡ compensation for an embodiment. </ br> Figure 5 is an internal circuit diagram of the shunt regulator shown in Figure 4. Figure 6 is a diagram showing the internal circuit of the PWM controller shown in Figure 4. FIG. 7 is a timing chart of control of the flyback type shown in FIG. 4 at different load amounts.

圖8為圖4所示返馳式電源的〇pp補償的實驗數據。【主要元件符號說明】FIG. 8 is experimental data of 〇pp compensation of the flyback power supply shown in FIG. [Main component symbol description]

卜2、4 :返馳式電源 12 :橋式整流器 14 :回饋電路 42 :開關電路 422 :開關電路的第二端 C1〜C5 :電容 CMP2 : 0CP比較器 0P1 :運算放大器 Q1 :開關 Q3 :第二型開關 R1〜R9 :電阻Bu 2, 4: flyback power supply 12: bridge rectifier 14: feedback circuit 42: switch circuit 422: second end of the switch circuit C1 to C5: capacitor CMP2: 0CP comparator 0P1: operational amplifier Q1: switch Q3: Type 2 switch R1~R9: resistance

Rfb :上拉電阻 T1 :變壓器 11 : EMI濾波器 13 :輸出整流濾波電路 41 :整流濾波電路 421 .開關電路的第一端 423 :開關電路的控制端 CMP1 : PWM比較器 D1 :整流二極體 0R1 :或閘 Q2 :第一塑開關 Q4 :電晶體Rfb: pull-up resistor T1: transformer 11: EMI filter 13: output rectification filter circuit 41: rectification filter circuit 421. The first end of the switching circuit 423: the control terminal CMP1 of the switching circuit: PWM comparator D1: rectifying diode 0R1: or gate Q2: first plastic switch Q4: transistor

Rc :補償電阻Rc: compensation resistor

Rs :檢測電阻Rs : Sense resistor

Npl :初級繞組 17 201206034Npl: primary winding 17 201206034

Np2 :補償繞組 U1 : PWM控制器 FB : PWM控制器的回饋端 U2 :光耦合器 PT :光電晶體 A:並聯穩壓器的陽極端 R:並聯穩壓器的參考端Np2 : compensation winding U1 : PWM controller FB : feedback terminal of PWM controller U2 : optical coupler PT : photoelectric crystal A: anode terminal of shunt regulator R: reference terminal of shunt regulator

Ic :光電晶體的集極電流Ic : collector current of photoelectric crystal

Ip :初級電流Ip: primary current

Vac :寬範圍交流電壓Vac : Wide range AC voltage

Vclk :時脈信號Vclk: clock signal

Vcsl :濾波後的檢測電壓Vcsl: filtered detection voltage

Vcs3 : PWM比較器正輸入端電壓Vcs3 : PWM comparator positive input voltage

Vfbl :取樣後的回饋電壓Vfbl: feedback voltage after sampling

Vgate : PWM 信號Vgate : PWM signal

Vnpl :初級繞組上的交流電壓Vnpl: AC voltage on the primary winding

Vnp2’ ：整流濾波後的感應電壓Vnp2' : rectified and filtered induced voltage

Voutl :取樣後的輸出電壓Voutl: output voltage after sampling

Vrefl、Vref2 :參考電壓 tl〜t5 :期間Vrefl, Vref2: reference voltage tl~t5: period

Ns 1 :次級繞組 CS · PWM控制器的檢測端 GATE : PWM控制器的驅動端 IR :發光二極體 U3 :並聯穩壓器 K:並聯穩壓器的陰極端 lb :電晶體的基極電流Ns 1 : Secondary winding CS · Detection terminal of the PWM controller GATE : Drive terminal IR of the PWM controller : Light-emitting diode U3 : Shunt regulator K: Cathode terminal of the shunt regulator lb : Base of the transistor Current

If :發光二極體的正向電流If : the forward current of the light-emitting diode

Ire :補償電流Ire : compensation current

Vbias :供電電壓Vbias: supply voltage

Vcs :檢測電壓Vcs: detection voltage

Vcs2:0CP比較器正輸入端電壓 Vfb :回饋電壓Vcs2: 0CP comparator positive input voltage Vfb: feedback voltage

Vfb2:PWM比較器負輸入端電壓 Vin :寬範圍輸入電壓 Vnp2 :補償繞組上的感應電壓 Vout ··輸出電壓 Vp :觸發信號 Vslope :斜率補償電壓Vfb2: PWM comparator negative input voltage Vin: Wide range input voltage Vnp2: Inductive voltage on the compensation winding Vout ·· Output voltage Vp : Trigger signal Vslope : Slope compensation voltage

Claims

201206034 七、申請專利範圍：201206034 VII. Patent application scope:

L -種過功轉護補償，適_—返馳式電源，該返驰式電源包括一變壓器、一開關、一輸出整流據波電路、一_電路及-脈寬調變控·，該魏H包括設在其她_一初級繞組及設在其次級_-次級繞組，該她敝打點端柄接以接收-寬範圍輸入電壓且其非打點端搞接該開關第一端，該開關第二端接地，該次减吨_接地且其物關爐該輸出整流滤波電路輸入端，該輪出整流濾波電路輸出端提供一輸出電麗到-負載，該回饋電路取樣該輸出電壓以產生與該負載量對應的-_信號’該脈寬調變控㈣具有—檢測端及一回饋端，通過驗測端制麵該關的歧以提供過功率保護，且通過該回綱接收該_信號以控制該關的切換，該過功率保護補償電路包括：一補彳員繞組，设在該變壓器初級側，其非打點端接地； -整流遽波電路，其輸人端紐翻償繞組打點端；一補Ί員電阻’其第一端輕接該檢測端；以及 -開關電路’ 4開關電路第—端柄接該整流遽波電路輸出端，該開關電路第二端祕該補償電阻第二端，該開關電路控制端搞接該回饋端’當該回饋信號表示該負載量小於一預定值時’該開關電路嶋’當該回齡絲示該貞載量大於該預定值時，該開關電路導通。 2·如申4專利範ϋ第1項所述之過功轉護補償電路，其中該補償繞組圈數為一圈。 3.如申請專利翻第1項所述之過功轉護補償電路，其中該整 201206034 流遽波電路包括-整流二極體及— 耦接該整流舰電路輸人端，該整極體陽極端卜端及細峨嶋端====電容 4. 如申請專利範圍第丨項所述之關電路包括-第-型開關及一第二===開控制端收到高準位信號時導通，該 i開關在其低準位信號時導通，該第—型開關第:端控= 開關電路控_，該第二侧目第控制端耗接該關第一端耦接該開關電路第— 鳊，該第一型開關第二端輕接該開關電路第二端。 5. 如申μ專利範ϋ第4項所述之過功率保護補償電路，其令該 -型開關由Ν通道場效應電晶體或卿雙載子接面電晶體^ 現’該第二型開關由Ρ通道場效應電晶體或ρΝρ雙载子晶體所實現。 6. 如申請專娜㈣丨項所述之過功率賴補償電路，其中該脈寬調變控制器包括一上拉電阻及一脈寬調變比較器，該上拉電阻第一端耦接一供電電壓，該上拉電阻第二端耦接該回饋端及該脈寬調變比較器負輸入端，該脈寬調變比較器正輸入端耦接 _ 該檢測端’當該脈寬調變比較器正輸入端電壓大於該脈寬調變比較器負輪入端電壓時，該脈寬調變控制器控制該開關關斷，當該脈寬調變控制器内部一時脈信號傳送一觸發信號時，該脈寬調變控制器控制該開關導通。 7. 如申請專利範圍第1項所述之過功率保護補償電路，其中該脈寬調變控制器包括一過電流保護比較器，該過電流保護比較器正輸入端耦接該檢測端，該過電流保護比較器負輸入端耦接一 20 201206034 參考電壓，當該過電流保護比較器正輸入端電壓小於該參考電壓時’該脈寬調變控制器輸出一脈寬調變信號控制該開關的切換，當該過電流保護比較器正輸入端電壓大於該參考電壓時，該脈寬調變控制器停止輸出該脈寬調變信號。 8. 如申請專利範圍第1項所述之過功率保護補償電路，其中該脈寬5周變控制器通過該檢測端輕接一檢測電阻以檢測流過該開關的電流，該開關第二端通過該檢測電阻接地。〇汗 9. 如申請專利範圍第w所述之過功率保護補償電路，其中當該返馳式電源工作在賴模式時，朗·絲示該貞載量= 該預定值’當該返馳式電源工作在正常模 . 示該負載量大於該預定值。 xu爾域表 10. —種返驰式電源，包括：一開關；一輸出整流;慮波電路；一 Si繞==級侧的一初級繞組及設在其次級側的塵且其非打點端输該_第—端寬fc圍輸入電次級繞組打點端接地且l /開關第二端接地，該路輸入知該輸出整流觀f n皮電負載；知供一輸出電壓到一 -回饋電路，取樣信號；該輸出電H生與該負裁量對應的一回饋一脈寬調變控制器，且古檢測流過該開關的電流:提端’通過該檢測端手保護’且通過該回饋端 201206034 接收該回饋錢以控制該開關的切換；以及一過功率保護補償電路，包括： -補償繞組，設麵初級側，其非打點端接地，· -整流濾、波電路，其輪人輪接該補償齡打點端； -補償電阻’其第-端輕接該檢測端；以及 .開關電路，該開關電路第喷端，該開關電路第二端_=^ =輪4 路=接該回饋端，當該dL-type over-current protection compensation, suitable for _-return-type power supply, the fly-back power supply includes a transformer, a switch, an output rectification data circuit, a _ circuit and - pulse width modulation control, the Wei H includes a primary winding disposed at the other side and a secondary winding disposed at the secondary side thereof, the tapping end handle is connected to receive a wide range of input voltages and the non-tapping end thereof is coupled to the first end of the switch, the switch The second end is grounded, the ton is _ grounded and the object is turned off, the output rectifying and filtering circuit input end, the output of the rectifying and filtering circuit provides an output electric current to the load, and the feedback circuit samples the output voltage to generate The -_signal corresponding to the load amount (4) has a detecting end and a feedback end, and provides an over-power protection by detecting the difference of the end face, and receiving the _ The signal is used to control the switching of the switch. The over-power protection compensation circuit comprises: a supplemental winding, which is arranged on the primary side of the transformer, and the non-tapping end is grounded; - a rectifying chopper circuit, and the input end turns over the winding winding End; a supplemental resistor's light at its first end The detecting end; and the switching circuit '4 switch circuit first end handle is connected to the rectifying chopper circuit output end, the second end of the switch circuit is the second end of the compensating resistor, and the switch circuit control end engages the feedback end ' When the feedback signal indicates that the load amount is less than a predetermined value, the switch circuit is turned on when the back-length wire indicates that the load amount is greater than the predetermined value. 2. The over-current protection compensation circuit according to claim 1, wherein the number of windings of the compensation winding is one turn. 3. The patent application system of claim 1, wherein the entire 201206034 flow chopper circuit comprises a rectifier diode and a coupling end of the rectifier ship circuit, the integral pole body Extreme terminal and fine terminal ====capacitor 4. As shown in the scope of the patent application, the circuit includes - the - type switch and a second == = open control terminal receives the high level signal Turning on, the i switch is turned on when its low level signal is turned on, the first type switch is: the end control = the switch circuit control _, the second side of the control end is connected to the first end of the switch coupled to the switch circuit - The second end of the first type switch is lightly connected to the second end of the switch circuit. 5. The overpower protection compensation circuit of claim 4, wherein the type switch is made of a channel field effect transistor or a double carrier interface transistor. It is realized by a channel field effect transistor or a ρΝρ bipolar crystal. 6. The application of the power-dependent compensation circuit according to the item (4), wherein the pulse width modulation controller comprises a pull-up resistor and a pulse width modulation comparator, wherein the first end of the pull-up resistor is coupled to the first end a power supply voltage, the second end of the pull-up resistor is coupled to the feedback end and the negative input end of the pulse width modulation comparator, and the positive input end of the pulse width modulation comparator is coupled to the detection terminal ′ when the pulse width modulation When the positive input voltage of the comparator is greater than the negative wheel input voltage of the pulse width modulation comparator, the pulse width modulation controller controls the switch to be turned off, and when the pulse width modulation controller internally transmits a trigger signal to a clock signal The pulse width modulation controller controls the switch to be turned on. 7. The overpower protection compensation circuit of claim 1, wherein the pulse width modulation controller comprises an overcurrent protection comparator, and the positive input of the overcurrent protection comparator is coupled to the detection end, The negative input terminal of the overcurrent protection comparator is coupled to a 201206034 reference voltage. When the positive input voltage of the overcurrent protection comparator is less than the reference voltage, the pulse width modulation controller outputs a pulse width modulation signal to control the switch. Switching, when the positive input voltage of the overcurrent protection comparator is greater than the reference voltage, the pulse width modulation controller stops outputting the pulse width modulation signal. 8. The overpower protection compensation circuit according to claim 1, wherein the pulse width 5-cycle variable controller is connected to the detection resistor through the detection terminal to detect a current flowing through the switch, the second end of the switch Ground through the sense resistor. 〇 9 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. The power supply operates in a normal mode. The load is greater than the predetermined value. Xuer domain table 10. A flyback power supply, comprising: a switch; an output rectification; a wave circuit; a Si winding == a primary winding on the side of the stage and a dust disposed on the secondary side thereof and its non-tapping end The input _ first-end width fc is connected to the input secondary end of the electric secondary winding and the second end of the switch is grounded, and the input of the input is known to be an output voltage to the fn-skin electric load; a sampling signal; the output electric H generates a feedback-to-pulse width modulation controller corresponding to the negative discretion, and detects the current flowing through the switch: the tip end is 'protected by the detecting end' and passes through the feedback end 201206034 Receiving the feedback money to control the switching of the switch; and an over-power protection compensation circuit, comprising: - a compensation winding, a primary side of the surface, a non-tapping end grounding, a rectifying filter, a wave circuit, and a wheeled person Compensation compensating end; - compensating resistor 'the first end is connected to the detecting end; and the switching circuit, the switching circuit is the first end of the switching circuit, the second end of the switching circuit is _=^ = the round 4 is connected to the feedback end, When the d

量亥預疋值時，該開關電路導通。亥負栽 22The switching circuit is turned on when the amount is pre-valued. Hai negative plant 22