200814502 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種電源供應器之準諧振控制電路及其 控制方法，尤指功率電晶體與變壓器接點於零電壓準位時 導通’減少功率電晶體開關切換損失者。 【先前技術】 準諧振返驰式交換電源供應器在市面上已普遍被使用 於返馳式交換電源供應器中，以降低導通時產生之開關切 換損失與電磁干擾雜訊。第-圖為f知返秘式準諧振於制 電路圖’稱作RCC (Ring Choke Converter^返馳式電路拓 請參考第-圖，當直流電源以電源開啟後，首先經一 私阻R1提供微小電流缓缓充電使功率電晶體Q1導通，— 次側電流開始流向返馳式變壓器T1、功率電晶體^和 流檢知電P且R10到一次側直流電㈣+的負極。功率恭日體 的截止動作由電晶體Q3所控制，當電晶體⑺基^ 屢達到動作電壓約G.7V時停止功率電晶體Qi 體Q3基極動作電壓是由電壓回授控制電路中之光輛入: υι於-次側端流過電阻R7、R8及電流檢知電阻咖2 的^流訊號與流過—次侧功率電晶體Q1㈣流檢知電阻 ::二=。Φ導通期間二次側因為繞組舆輸二: 極性相反之故，無法傳遞能量龍_ v〇而暫時 5 200814502 將能量儲存於返馳式變㈣T1中。功率電晶體Qi停止導 通後返馳式變㈣T1各繞組極性㈣反轉，二次爆組與 輸出整流二極體D1極性轉變成正向，而儲存於返馳式變、 壓器T1中的能量被釋放到輸出端V0,提供輸出端ν〇ς 需之負載與輸出電容C3之充電電流。返馳式變壓器T1中 的儲存能量釋放完畢時，二次側繞組流向輸出端v〇的電 流截止，輸出電容C3繼續供應電流給輸出端v〇維持所需 之負載電流。返馳式變壓器T1能量釋放完畢瞬間繞組極= 產生反轉，此時返馳式變壓器T1中一次側繞 φ «產生雜_㈣壓呈正錄麵。切率=體= 的洩極(DRAIN)電壓接近〇v時，功率電晶體φ的閘極亦 同時由輔助繞組供應電流經電容C2、電阻R2充電至高電 — 位時開始導通’直到控制截止動作之電晶體Q3基極電壓-到達0.7V時才關閉功率電晶體…此電路的缺點是工作 在輕載時無頻率限㈣路，頻率將自由調變至相當高的工 作頻率而產生車乂面的開關切換損失與因過高頻工作產生之 凡件Uf·生問題’同時亦難以符合greenmQde規範的輸入 功率損耗要求。 弟《—圖為第-圖> U， 、 ㈡知返馳式準諧振控制電路的動作 MUt ’tom為功率電晶體Q1的導通週期波形圖， Q1 IDS為功率電晶體Q1 $極(DRAIN)至源極(SOURCE) 為功率電晶體Q1泡極①RAIN)至 源極(SOURCE)電壓波形圖，vds_)為功率電晶體導’ «的電nE1則為返馳式變壓器T1初極繞組電壓> 6 200814502 的波形圖以及ID為經過二極體D1之電流波形圖。 第二圖為另一習知返4也式準諧振控制電路方塊圖，由 於其電路較為複雜無法將其周邊電路完整晝出，但與第四 圖的周邊電路相同，以下第三圖說明所提的功率電晶體是 外接的開關元件未在圖示中，其位置相對應於第四圖的2 率電晶體Q2,，如第三圖所示，該積體電路為改良之返馳 式準諧振控制電路。其係利用Demag接腳作為輔助繞組端 電壓的偵測輪入端與圖中一比較器1比較產生一導通脈衝 吼號。此導通脈衝訊號輸入至SR正反器2的s輸入端， 迫使控制電路輪出端3的Drv變為高電位使連接於控制電 路輸出端Drv之後的功率電晶體呈導通狀態。該電路截止 控制則由電壓回授控制電路中之光耦合器一次侧端FB接 腳的電流訊號經轉換電路轉換成一電壓訊號與流過一次側 功率電晶體的電流檢知訊號CS相比較，兩訊號利用一比 較器5比較產生截止脈衝訊號輸入至811正反器2的r反 • 向輸入端，迫使控制電路輸出端Drv變為低電位使功率電 晶體呈截止狀態。此外，内部有一固定8us的空白時間 (blanking time)使控制電路6可控制Drv導通於第一個導通 脈衡訊號或往後的導通脈衝訊號。如果第一個導通脈衝訊 號·出現在8us的空白時間之後，則功率電晶體由第一個導 通脈衝訊號控制成導通。否則只有在8us的空白時間之後 的導通脈衝訊號方能有效讓功率電晶體導通。其目的為防 止輕載時頻率調變過高而產生較高的開關切換損失，因為 此空白時間為固定8us值，所以輕載時工作頻率最高將調 7 200814502 變到fs=l/8uS=125KHz才停止頻率μ η L 、 、千上汁’由第二或往後的 ，通脈衝訊號產生時功率電晶體始導通。125如的工作頻 率點的頻率仍有很高的開關切換損失在截止瞬間產生，除 非負載更低到達輸出skip «紅作下方可因部分頻率降 低才減少此-截止瞬_開關切換損失。再參考第三圖所 不，為達成此-準諧振控制電路動作所需， 雜，焚 件數目多，成本較昂貴為其另一缺點。 ’、" 因此，如何發明出一種電源供 、/ π y、應之準諧振控制電路 制方法’以使控觀路簡單及減少功率電晶體開關 刀換時的損失’將是本發明所欲積極探討之處。 【發明内容】 …有鑑於上述習知之缺憾，創作人有感其未漆於完善， 叙驗_軸項產業多年之累積 =進而研發出—種電源供應器之準諧振控制電路及其 才工制方法，以期利用筒# ϋ — 電曰件組成控制電路，使功率 电曰曰體與雙£_點於㈣解 電晶體開__失的目的。 相減 > 功率 制恭腺；5 要目的在提供—觀職應1之準諧振控 電:法’其藉著由簡易電子元件組成的控制 ”电日日體與變壓器接點於零電壓準位時導通， 進而達到減少功率電晶體_切換損失的目的。 、·. 電路本ΐ=之目的係提供一種電源供應器之準_控制 H包括· m變壓器，其具有—初極繞組 200814502200814502 IX. Description of the Invention: [Technical Field] The present invention relates to a quasi-resonant control circuit for a power supply and a control method thereof, particularly when the power transistor and the transformer contact are turned on at a zero voltage level to reduce power The transistor switch switches the loss. [Prior Art] Quasi-resonant flyback switching power supplies have been commonly used in flyback switching power supplies in the market to reduce switching loss and electromagnetic interference noise generated during conduction. The first picture is the circuit diagram of the known quasi-resonant circuit. It is called RCC (Ring Choke Converter^Return to the circuit topology, please refer to the first figure. When the DC power supply is turned on, the first one is provided by a private resistor R1. The current is slowly charged to turn on the power transistor Q1, and the secondary current starts to flow to the flyback transformer T1, the power transistor ^ and the current detection power P and the R10 to the primary side direct current (four) + the negative pole. The action is controlled by the transistor Q3. When the transistor (7) base reaches the operating voltage of about G.7V repeatedly, the power transistor Qi body Q3 base operating voltage is stopped by the light in the voltage feedback control circuit: υι于- The secondary side flows through the resistors R7, R8 and the current detection resistor 2 and the flow signal - the secondary power transistor Q1 (four) flow detection resistor:: two =. Φ during the secondary side because the winding is two : The opposite polarity, can not pass the energy dragon _ v 〇 and temporarily 5 200814502 The energy is stored in the flyback variant (4) T1. The power transistor Qi stops conducting and then returns to the change (4) T1 winding polarity (four) reverse, secondary explosion Group and output rectifier diode D1 polarity is converted to positive The energy stored in the flyback converter T1 is released to the output terminal V0, which provides the load of the output terminal ν〇ς and the charging current of the output capacitor C3. When the stored energy in the flyback transformer T1 is released The current flowing from the secondary side winding to the output terminal v〇 is cut off, and the output capacitor C3 continues to supply current to the output terminal v〇 to maintain the required load current. The energy of the flyback transformer T1 is released and the instantaneous winding pole = reversed. In the flyback transformer T1, the primary side winding φ «produces the impurity _ (four) pressure is the positive recording surface. When the shear rate = body = DRAIN voltage is close to 〇v, the gate of the power transistor φ is also supplied by the auxiliary winding. The current is turned on when the capacitor C2 and the resistor R2 are charged to the high-voltage position until the base voltage of the transistor Q3 that controls the cut-off operation - the power transistor is turned off when the voltage reaches 0.7V. The disadvantage of this circuit is that there is no frequency when operating at light load. Limit (four) way, the frequency will be freely tuned to a relatively high working frequency and the switch switching loss of the rut surface and the Uf·sheng problem caused by the over-high frequency operation are also difficult to meet the input work of the greenmQde specification. Loss requirement. Brother--The picture is the first picture> U, (2) The action MUt 'tom of the flyback quasi-resonant control circuit is the on-period waveform of the power transistor Q1, and the Q1 IDS is the power transistor Q1 $ pole (DRAIN) to the source (SOURCE) is the power transistor Q1 bubble 1RAIN) to the source (SOURCE) voltage waveform, vds_) is the power transistor guide '«, the electric nE1 is the flyback transformer T1 primary winding Voltage > 6 The waveform of the 200814502 and the ID are the current waveforms through the diode D1. The second figure is a block diagram of another conventional Q-type quasi-resonant control circuit. Because the circuit is more complicated, the peripheral circuit cannot be completely removed, but it is the same as the peripheral circuit of the fourth figure. The power transistor is an external switching element not shown in the figure, and its position corresponds to the 2-rate transistor Q2 of the fourth figure. As shown in the third figure, the integrated circuit is a modified flyback quasi-resonance. Control circuit. The detection wheel input terminal using the Demag pin as the auxiliary winding terminal voltage is compared with a comparator 1 in the figure to generate a conduction pulse apostrophe. The conduction pulse signal is input to the s input terminal of the SR flip-flop 2, forcing the Drv of the control circuit wheel terminal 3 to become high, so that the power transistor connected to the control circuit output terminal Drv is turned on. The circuit cut-off control is performed by the current signal of the primary side end FB pin of the optocoupler in the voltage feedback control circuit being converted into a voltage signal by the conversion circuit and compared with the current detection signal CS flowing through the primary side power transistor. The signal is compared with a comparator 5 to generate a cutoff pulse signal input to the r-inverting input terminal of the 811 flip-flop 2, forcing the control circuit output terminal Drv to be low to turn the power transistor into an off state. In addition, there is a fixed 8us blanking time inside so that the control circuit 6 can control the Drv to conduct the first conduction pulse signal or the subsequent conduction pulse signal. If the first on-pulse signal appears after a blank time of 8us, the power transistor is controlled to be turned on by the first on-pulse signal. Otherwise, only the on-pulse signal after the blank time of 8us can effectively turn on the power transistor. The purpose is to prevent high frequency switching loss when light load is too high, because the blank time is fixed 8us, so the highest working frequency will be adjusted when light load is 7 200814502 to fs=l/8uS=125KHz Only when the frequency μ η L , , and the thousands of juices are stopped from the second or the backward, the power transistor is turned on when the pulse signal is generated. If the frequency of the working frequency point is still high, the switching loss is still generated at the cut-off instant, unless the load is lower and the output skip_ is reduced. This can be reduced by the partial frequency reduction. Referring back to the third figure, in order to achieve the operation of the quasi-resonant control circuit, the number of miscellaneous, the number of incinerations, and the relatively high cost are another disadvantage. ', " Therefore, how to invent a power supply, / π y, the quasi-resonant control circuit manufacturing method 'to make the control path simple and reduce the loss of power transistor switching knife' will be the intention of the present invention Active discussion. [Summary of the Invention] ... In view of the above-mentioned shortcomings, the creators feel that they have not been perfected, and the accumulation of the industry has been accumulating for many years = and then developed a quasi-resonant control circuit for the power supply and its manufacturing system. The method, in order to use the tube # ϋ - electric components to form a control circuit, so that the power electric body and the double point of the (four) de-electrical crystal open __ lost purpose. Subtraction > Power system Gong gland; 5 The purpose is to provide - the quasi-resonant control of the watch should be: the law 'by its control composed of simple electronic components' electric day and body and the transformer contact at zero voltage When the bit is turned on, the purpose of reducing the power transistor_switching loss is achieved. The purpose of the circuit is to provide a power supply. The control H includes · m transformer, which has a - primary winding 200814502
助繞組及一次極縫如 ^ 'C 出該電源供應器：二返細以儲存及轉換輸 組，·一第一時ί ;，一功率電晶體，其連接該初極繞 連接該第一比二，：=·!繞組、振盪電路，其 -電壓回授電路复且古—其連接該振盪電路； 4 口的路，其具有—光_合器， 連接該次極繞組；—電流檢知電阻，其光 …亥功羊電曰曰體，—第三比較器，其連接該 知勺 以及-驅動電路，其連接該第 _ ,， 該功率電晶體；其中’〜辅助植:;二亥弟二比較器及 較哭的i Μ 的電髮小於該第—比 :“的一弟一麥考電壓時，該第一比較器產生 旎，該脈衝訊號與該振盪電路產生一 ° &盡H舌-… 座生的鋸㈣波電壓訊號重 = 第一重疊訊號的電廢大於該 弟m弟二參考電壓時，該第二比較器產生 通訊號’該料訊號經由該驅動電路使該功率電 通’並使該返馳式變壓器儲存能量；當該電屢回 咸 ^該次極繞組的電路輸出端的電壓時，該光電 -電流訊號，該電流訊號與該電流檢知電阻產一〜 ==:第二重叠訊號，當該第二重叠訊二 也i大於該弟二比較斋的一第三參考電壓時，該 斋產生-截止訊號，該截止訊號經由該驅動電^ ^ 電晶體截止，並使該返馳式變壓器㈣存能i輪/功率 本發明之另-目的係提供一種電源供應器: 制電路的控制方法，包含： nt ⑴提供如摘述之該魏供赫、之準諧振控制電路； 9 200814502 (2)當該辅助繞組的電壓小於該第一比較器的一第—參考電 壓日守，使該第一比較器產生一脈衝訊號； ⑶f該脈衝訊號與該缝電路產生的—麵波龍訊號重 S·產生第重璺訊號，當該第一重疊訊號的電壓大於 該第二比較器的-第二參考電壓時，使該第二比較器產 生一導通訊號； ⑷使該導通訊號經由該驅動電路將該辨電晶體導通，並 使該返馳式變壓器儲存能量； ⑸t該麵回授電_知該她繞_電職出端的電壓 4，使該光電耦合器產生一電流訊號； ⑹訊雜該電流檢知電阻產生的—電流檢知訊號 於該第三錄器的-第：^^—重豐減的電壓大 產生-截止訊號4及4 第三比較器 ⑺該驅動電路將該功率電晶體截止，並 使該返馳式親轉能量輪出。 藉此，利用簡易電子元件钽 體與變壓器接點於零電壓準位日制電路，使功率電晶 體開關切換損失。 作通’進而減少功率電晶 【實施方式】 為使貴審查委員充分瞭解 效，兹藉由下述具體之實施例，並^之目的、特徵及功 發明做一 詳細說:月，說並配合所附之圖式’對本 200814502 ^第四圖為本發明之較佳具體實施例之電源供應器之準 二振&希]黾路圖，如圖所示，此準諧振控制電路由電源電 壓接卿供應控制所需之電壓，此準諧振控制電路包含 一欠壓保護電路 UVLO ( UNDER VOLRAGE LOCKOUT )， 以確保由起動電阻R1充電至電容C2,電源電壓vcc有足 夠電壓時才開始有輸出，防止電路工作異常損壞元件。一 包壓偵測接聊DEM，負責偵測出辅助繞組端電壓波形之波 • 合位置，電阻R8可調整偵測接腳DEM電壓。經由第—比 較斋7，若辅助繞組的電壓小於第一比較器的第一參考電 壓VREF1則產生一脈衝訊號，電阻R8使脈衝訊號與輔助 繞組屯壓波形之波谷同步。此脈衝訊號與振盪器產生之鋸 會波電壓訊號重疊產生一第一重疊訊號，其再與第二比較 器8=第二參考電壓VREF2比較。若第一重疊訊號的電^ 大於第二比較器8的第二參考電壓VREF2則產生一導通气 號，導通訊號與鋸齒波電壓訊號波形之波峰同步，導通訊 • 號經驅動電路（DRIVER CIRCUIT)使功率電晶體Q2，導 通。直流電源B+提供電流流經返馳式變壓器T1的初極繞 組、功率電晶體Q2’、電流檢知電阻R7,回到一次側直流電 源B+的負極（一次側接地端），返馳式變壓器τι儲存能量。 當該電壓回授電路感知該次極繞組的電路輪出端v〇的電 壓時，電壓回授控制電路中之光耦合器一次側端fb = 腳的電流訊號，與電流檢知電阻尺7，經電阻115、116產生的 電流檢知訊號重疊產生一第二重疊訊號，若第二重疊訊號 A 的電壓經第三比較器9比較後大於第三參考電壓 11 200814502 則產生一截止訊號到驅動恭 動电路將功率電晶體Q2,截止，並 使該返馳式變壓器的儲存 千g ^ 仔犯1輪出。振盪器產生之鋸齒波 電壓訊號可透過電阻信$ + _ 1_電谷值自由調整鋸齒波電壓斜 率，控制第一脈衝訊轳Φ ?日士 就出現時是否產生導通訊號，或延後 至往後的脈衝㈣出現時才產生導通訊號，以防止輕載時 頻率調變過高而產缝高的_切換損失。 第五圖為第四圖之本發明之較佳具體實施例之電源供 應裔之準谐振控制電路的動作波形圖，請參考第五圖，脈 衝.K號(PULSE SIGNAL)由>f貞測出輔助繞組端電壓波形· (VDS/VAUX)之波谷位置取得，導通訊號(〇N SK}nal)於第 一重豐吼5虎咼於第二參考電壓VREF2時產生。截止訊號 (OFF SIGNAL)則由電壓回授控制電路中之光搞合器仍於 -人侧端產生的電流訊號與流過一次侧功率電晶體q2，的 電流檢知訊號重疊與第三參考電壓VREF3比較時產生。第 五圖下方顯示輕負載導通落在第二個波谷，與上方高負載 導通落在第一個波谷有所不同。 第六圖為本發明之另一較佳具體實施例之電源供應器 之準諧振控制電路圖。其將第四圖中之比較器分別以電晶 體代替’第一、三參考電壓則利用電晶體基極動作電壓約 0.7V取代，第二參考電壓則利用兩個或以上的電阻分壓取 代，完成本發明之電源供應器之準諧振控制電路。 第七圖為本發明之較佳具體實施例之電源供應器之準 白振控制龟路的控制方法流程圖。配合第四圖，其中該方 法包括以下步驟： 12 200814502 (1)提供如第四圖所示之電源供應器之準諧振控制電 路； (2) 當辅助繞組的電壓小於第一比較器7的第一參考 電壓時，使第一比較器7產生一脈衝訊號；The auxiliary winding and the primary pole joint such as ^ 'C out of the power supply: two return fine to store and convert the input group, · a first time ί;, a power transistor, which is connected to the first pole to connect the first ratio Second, :=·! Winding, oscillating circuit, its voltage feedback circuit is complex and ancient - it is connected to the oscillating circuit; 4-port circuit has - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Resistor, its light...Haigong sheep electric body, the third comparator, which connects the spoon and the drive circuit, which connects the _, the power transistor; wherein '~ auxiliary plant:; The second comparator and the crying i Μ are smaller than the first ratio: when the first comparator generates a chirp, the pulse signal and the oscillator circuit generate a ° & H tongue-... seat saw (four) wave voltage signal weight = the first overlap signal is greater than the brother's second reference voltage, the second comparator generates the communication number 'the material signal through the drive circuit to make the power The electric flux 'and the energy stored in the flyback transformer; when the electricity is back to the salt When the voltage at the output of the circuit is at the time of the photoelectric-current signal, the current signal and the current detecting resistor are produced by a ===: second overlapping signal, when the second overlapping signal is also greater than the first one of the second When the reference voltage is three, the fast-cut signal is turned off, the cut-off signal is turned off via the driving transistor, and the fly-back transformer (4) is stored in the power wheel/power. The other purpose of the present invention is to provide a power supply. The control method of the circuit comprises: nt (1) providing a quasi-resonant control circuit as described in the above; 9 200814502 (2) when the voltage of the auxiliary winding is less than a reference of the first comparator - reference The voltage is controlled to cause the first comparator to generate a pulse signal; (3) f the pulse signal and the surface-wave signal generated by the slit circuit reproduce S· generate a first signal, when the voltage of the first overlapping signal is greater than the first When the second reference voltage of the comparator is the second reference voltage, the second comparator generates a pilot communication number; (4) causing the conductive communication signal to conduct the differential crystal through the driving circuit, and causing the flyback transformer to store energy; (5) Face feedback _ know that she around the _ electric power out of the voltage 4, so that the optocoupler generates a current signal; (6) the current detection resistor generated by the current detection signal in the third recorder - the first: ^ ^ - a large voltage is generated - the cutoff signals 4 and 4 are the third comparator (7). The drive circuit turns off the power transistor and turns the flyback type of the inversion energy. Thereby, the simple electronic component is used. The transformer is connected to the zero-voltage level of the day-to-day circuit to make the power transistor switch switch loss. "To reduce the power of the electric crystal" [Embodiment] In order to fully understand the effectiveness of the review committee, the following specific implementation For example, the purpose, characteristics and merits of the invention are described in detail: month, said and in conjunction with the attached drawing '. This 200814502 ^ fourth figure is a quasi-secondary vibration of the power supply of the preferred embodiment of the present invention. As shown in the figure, the quasi-resonant control circuit is supplied with the voltage required for control by the power supply voltage. The quasi-resonant control circuit includes an undervoltage protection circuit UVLO (UNDER VOLRAGE LOCKOUT) to ensure Starting resistor When R1 is charged to capacitor C2, the output voltage vcc starts to have an output when it has enough voltage to prevent the circuit from abnormally damaging the component. A package detection and interrogation DEM is responsible for detecting the wave position of the auxiliary winding terminal voltage waveform, and the resistor R8 can adjust the detection pin DEM voltage. Via the first comparison, if the voltage of the auxiliary winding is smaller than the first reference voltage VREF1 of the first comparator, a pulse signal is generated, and the resistor R8 synchronizes the pulse signal with the valley of the auxiliary winding voltage waveform. The pulse signal overlaps with the saw wave voltage signal generated by the oscillator to generate a first overlap signal, which is then compared with the second comparator 8 = the second reference voltage VREF2. If the first overlapping signal is greater than the second reference voltage VREF2 of the second comparator 8, a pilot vent number is generated, and the conduction signal is synchronized with the peak of the sawtooth voltage signal waveform, and the DRIVER CIRCUIT is driven. The power transistor Q2 is turned on. The DC power supply B+ supplies current through the primary winding of the flyback transformer T1, the power transistor Q2', the current detection resistor R7, and returns to the negative pole of the primary side DC power supply B+ (primary ground terminal), the flyback transformer τι Store energy. When the voltage feedback circuit senses the voltage of the circuit winding terminal v〇 of the secondary winding, the voltage feedback device in the voltage feedback control circuit has a primary side terminal fb=the current signal of the foot, and the current detecting resistance ruler 7, The current detection signals generated by the resistors 115 and 116 overlap to generate a second overlapping signal. If the voltage of the second overlapping signal A is greater than the third reference voltage 11 200814502 after being compared by the third comparator 9, a cutoff signal is generated to drive the driver. The dynamic circuit cuts off the power transistor Q2 and causes the flyback transformer to store one kilogram. The sawtooth wave voltage signal generated by the oscillator can freely adjust the slope of the sawtooth wave voltage through the resistance signal $ + _ 1_ electric valley value, and control whether the first pulse signal Φ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ The pilot signal is generated when the following pulse (4) occurs to prevent the _ switching loss when the frequency modulation is too high at the light load and the seam is high. Figure 5 is a diagram showing the operation waveforms of the power supply quasi-resonant control circuit of the preferred embodiment of the present invention in the fourth figure. Please refer to the fifth figure, pulse number K (PULSE SIGNAL) by >f The voltage waveform of the auxiliary winding terminal (VDS/VAUX) is obtained by the valley position, and the pilot communication number (〇N SK}nal) is generated when the first weight 吼 5 is at the second reference voltage VREF2. The OFF SIGNAL is caused by the current signal generated by the light-gathering control circuit in the voltage feedback control circuit and the current detection signal flowing through the primary-side power transistor q2, and the third reference voltage Produced when VREF3 is compared. The bottom of Figure 5 shows that the light load conductance falls on the second trough, which is different from the upper high load turn-on in the first trough. Figure 6 is a diagram showing a quasi-resonant control circuit of a power supply of another preferred embodiment of the present invention. The comparators in the fourth figure are replaced by transistors respectively. The first and third reference voltages are replaced by a transistor base operating voltage of about 0.7V, and the second reference voltage is replaced by two or more resistors. The quasi-resonant control circuit of the power supply of the present invention is completed. Figure 7 is a flow chart showing the control method of the quasi-white vibration control turtle path of the power supply of the preferred embodiment of the present invention. With the fourth figure, the method comprises the following steps: 12 200814502 (1) providing a quasi-resonant control circuit of the power supply as shown in the fourth figure; (2) when the voltage of the auxiliary winding is smaller than that of the first comparator 7 a reference voltage, causing the first comparator 7 to generate a pulse signal;
(3) 使脈衝訊號與振盪電路產生的鋸齒波電壓訊號重 $產生一第一重豐訊號，當第一重疊訊號的電壓大 於等於第二比較8的第二參考電壓時，使第二比 較器8產生一導通訊號； (4)使導通訊號經由驅動電路將功率電晶體，導通， 並使返驰式變壓器T1儲存能量； (5)當電壓回授電路感知該次極繞_電路輸出端v〇 的電壓時，使光箱合器m產生一電流訊號； ⑹使電流減與電流檢知電麵的電流檢知訊 號重疊產生第二重疊訊號’當第二重疊訊號的電壓 =於弟二比較器？的第三參考電壓時，使第三比較 器9產生一截止訊號；以及 ⑺使截止訊號經*軸電路將功率電晶止， 並使返龍nT1的儲魏量輪^ 步性完全符合專利三要件:新穎性、進 ^生和產t上的可個性。叫魏和進 月係利用簡易電子元件喊控制 ，本餐 髮器接點於零電壓準位時導通 ；^電晶體與變 開關切換損失的目…業上的少功率電晶體 發明所衍生的產品，當可充：言’利用本 刀滿足目珂市場的需求。 200814502 本發明在上j + = + 術者應理解的3中已以較佳實施例揭露，㈣f本項技 讀為限制样=奸施例伽於财本發明’而不應解 效之變化盘m乾圍。應注意的是，舉凡與該實施例等 太旅日日、、均應設為涵蓋於本發明之範疇内。因此， 本舍明之保護範窗# 维。 阁§以下文之申請專利範圍所界定者為 【圖式簡單說明】 I —圖為白知返馳式準諧振控制電路圖。 弟一圖為第一 _ + 形圖。 固之省知返馳式準諧振控制電路的動作滋 第三圖為另一習 弟四圖為本發日月 振控制電路圖。 第五圖為第四_ 器之準諧振控制電 知返馳式準諧振控制電路方塊圖。 之車父佳具體實施例之電源供應器之準諧 之本發明之較佳具體實施例之電源供應 路的動作波形圖。 第六圖為本發明之另 準諧振控制電路圖。 一較佳具體實施例之電源供應器之 第七圖為本發明之較佳具體實施例之電源供應器之準譜 振控制電路的控制方法流程圖。 巧 【主要元件符號說明】(3) causing the pulse signal and the sawtooth voltage signal generated by the oscillating circuit to regenerate a first heavy signal, and when the voltage of the first overlapping signal is greater than or equal to the second reference voltage of the second comparison 8, the second comparator is made 8 generating a pilot communication number; (4) causing the pilot communication number to turn on the power transistor via the driving circuit, and causing the flyback transformer T1 to store energy; (5) when the voltage feedback circuit senses the secondary pole winding_circuit output terminal v When the voltage of 〇 is used, the light box combiner m generates a current signal; (6) the current is subtracted from the current detecting signal of the current detecting surface to generate a second overlapping signal 'When the voltage of the second overlapping signal is compared with the second What? The third comparator 9 causes the third comparator 9 to generate a cutoff signal; and (7) causes the cutoff signal to be electrically crystallized by the *axis circuit, and the returning of the returning nT1 is fully in compliance with the patent three Essentials: novelty, entry and production of personality. Wei and Jin Yue are using simple electronic components to shout control, the meal is connected to the zero voltage level when conducting; ^ transistor and variable switch switching loss ... the industry's low power transistor invention derived products, when Rechargeable: Words 'use this knife to meet the needs of the market. 200814502 The present invention has been disclosed in the preferred embodiment in the above-mentioned j + = + The operator should understand, (4) f This technical reading is a restricted sample = traits gamma in the invention of the invention 'can not be resolved Wai. It should be noted that the date of travel, such as this embodiment, should be included in the scope of the present invention. Therefore, Ben Sheming's protection window #维. § § § § § 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 The picture of the younger brother is the first _ + shape chart. The action of the solid-state-return-type quasi-resonant control circuit is shown in Figure 3. The third picture shows the circuit diagram of the other month. The fifth figure is a block diagram of the quasi-resonant control of the fourth _ device, which is known as the flyback quasi-resonant control circuit. The action waveform of the power supply path of the preferred embodiment of the present invention is the quasi-harmonic of the power supply of the specific embodiment of the present invention. Figure 6 is a diagram of an alternative quasi-resonant control circuit of the present invention. A seventh embodiment of a power supply of a preferred embodiment is a flow chart of a control method for a quasi-spectro-control circuit of a power supply according to a preferred embodiment of the present invention. Qiao [Main component symbol description]
Rl、R2、R5、R6、R7、R8 電阻 Q1功率電晶體 14 200814502 τι返驰式變壓器 R7 ’電流檢知電阻 R10電流檢知電阻 Β+直流電源 Q2、Q3電晶體 Q2’功率電晶體 U1光耦合器 D1二極體 VO輸出端 C2、C3、C5 電容 1比較器 2 SR正反器 3輸出端 5比較器 6控制電路 7、8、9比較器 VCC電源電壓 UVLO欠壓保護電路 DEM電壓偵測接腳 VERF1第一參考電壓 VERF2第二參考電壓 VERF3第三參考電壓 DRIVER CIRCUIT 驅動電路 FB電壓回授端 15 200814502 (1)-(7)步驟Rl, R2, R5, R6, R7, R8 resistor Q1 power transistor 14 200814502 τι flyback transformer R7 'current detection resistor R10 current detection resistor Β + DC power supply Q2, Q3 transistor Q2 'power transistor U1 light Coupler D1 diode VO output C2, C3, C5 Capacitor 1 Comparator 2 SR Forward/Reactor 3 Output 5 Comparator 6 Control Circuit 7, 8, 9 Comparator VCC Supply Voltage UVLO Undervoltage Protection Circuit DEM Voltage Detector Test pin VERF1 first reference voltage VERF2 second reference voltage VERF3 third reference voltage DRIVER CIRCUIT drive circuit FB voltage feedback terminal 15 200814502 (1)-(7)