【正文】 s remendation for the 135V chipset with transient voltage suppression diode clamp. But his evaluation board generally reflected voltage to be lower than the value at around 110V. Both types have their advantages and disadvantages: Category: shortings against overvoltage, low duty cycle is small, a large pulse current transformer primary. Advantages: small transformer leakage inductance, electromagnetic radiation and low ripple index higher switch loss, the conversion efficiency is not necessarily lower than the second. The second category: a large number of shortings of power loss, a large number of transformer leakage inductance, the ripple worse. Advantages: Some strong against overvoltage, large duty cycle, lower transformer losses and efficiency higher. Reflected voltage flyback power supply and a determining factor Reflected voltage flyback power supply with a parameter related to that is the output voltage, output voltage, the lower the larger the transformer turns ratio, the greater the transformer leakage inductance, switch to withstand higher voltage breakdown switch is possible to absorb power consumption is higher, has the potential to permanently absorb the circuit power device failure (particularly with transient voltage suppression diode circuits). In the design of lowvoltage lowpower flyback power output optimization process must be handled with care, its approach has several: 1, using a large core of a power level lower leakage inductance, which can improve the lowvoltage flyback power conversion efficiency, reduce losses, reduce output ripple and improve multioutput power of the cross regulation in general is mon in household appliances with a switch power, such as CDROM drive, DVB settop boxes. 2, if the conditions were not increased core, can reduce the reflected voltage, reducing the duty cycle. Reduce the reflected voltage can reduce the leakage inductance but may reduce the power conversion efficiency, which is a contradiction between the two, must have an alternative process to find a suitable point, replace the transformer during the experiment can detect the transformer original side of the antipeak voltage, peak voltage to minimize the antipulse width, and magnitude of the work safety margin increase converter. Generally reflected voltage 110V when appropriate. 3, enhance the coupling, reducing losses, the introduction of new technologies, and the routing process, transformers to meet the security specifications will between the primary and secondary side to insulation measures, such as pad tape, plus side air insulation tape. These will affect the performance of transformer leakage inductance?？偨Y(jié)逆變電源設(shè)備廣泛應(yīng)用于科學(xué)研究、經(jīng)濟(jì)建設(shè)、國防設(shè)施及人民生活等各個(gè)方面，是電子設(shè)備和機(jī)電設(shè)備的基礎(chǔ)。變壓器T二次側(cè)的輸出電壓為矩形波，采樣繞組輸出電流經(jīng)二極管整流后變?yōu)橹绷鞲鶕?jù)繞組比，采樣電路輸出電壓與一次側(cè)電壓成正比關(guān)系，根據(jù)采樣電路電壓或者電流的變化將信號反饋給控制芯片UC3524，控制脈沖的輸圖49 間接取樣電路出，使電路工作穩(wěn)定。在圖45（B）中，VRS經(jīng)電壓比較器后輸出一個(gè)控制信號 到振蕩電路，通過減小振蕩電路的振蕩頻率，減小輸出電壓，從而減小輸出電流達(dá)到保護(hù)的目的。當(dāng)輸出過壓現(xiàn)象排除，可控硅的控制端觸發(fā)電壓通過R對地泄放，可控硅恢復(fù)斷開狀態(tài)。這個(gè)變壓器漏感的儲能必然消耗在緩沖電路或箝位電路，漏感越大，需要的緩沖電路越大，所產(chǎn)生的損耗越大，降低了開關(guān)電源的效率。三重絕緣漆包線繞制法（Triple Insulated）次級繞組的導(dǎo)線采用三重絕緣漆包線以便任意兩層結(jié)合都滿足電氣強(qiáng)度要求。因此，在兩個(gè)控制開關(guān)VT1和VT2分別處于導(dǎo)通和截止的過渡期間，兩個(gè)開關(guān)器件將會產(chǎn)生很大的功率損耗。 第3章 主電路設(shè)計(jì) 推挽式電路推挽式電路是一種放大電路，它按功放輸出級放大元件的數(shù)量，可以分為單端放大器和推挽放大器。 圖23 振蕩器的波形及輸出脈沖波形圖24 有正負(fù)偏壓的直接驅(qū)動電路 圖25 變壓器隔離驅(qū)動圖26 光耦合隔離驅(qū)動(1) 直接驅(qū)動法直接驅(qū)動法有兩種電路形式。此高平關(guān)斷特點(diǎn)既可用于電源OFF/ON人為控制，也可用于過電壓保護(hù)等電路。 電源中UC3524的各腳功能及外圍元件作用如下：1腳：內(nèi)部誤差檢測放大器A的差分放大器反相輸入端。第2章 控制及驅(qū)動電路分析電路的原理圖如下圖21所示： 圖21 逆變電路系統(tǒng)原理圖12V的直流電源經(jīng)逆變電路你變成電壓較小的頻率為50HZ的電能，經(jīng)變壓器變壓后升為稍大于220V的電壓，由于此時(shí)的電能中含有大量的諧波，故需經(jīng)LC濾波器濾波，此時(shí)電路的輸出為220V，50HZ的電能。IGBT經(jīng)常用于開關(guān)工作狀態(tài)，因此，它的安全工作區(qū)分為正向偏置安全工作區(qū)和反向偏置安全工作區(qū)。再經(jīng)過一段時(shí)間tir后，IC達(dá)到ICM= IL(IL為流經(jīng)感性負(fù)載的電流)。(2)轉(zhuǎn)移特性IGBT的轉(zhuǎn)移特性曲線如圖13所示。(1) 輸出伏安特性IGBT的輸出伏安特性曲線如圖12所示。下面就對絕緣柵雙極晶體管（IGBT）做詳細(xì)的介紹。由于其工作頻率低，關(guān)斷電路復(fù)雜，效率低，功耗大，因此在PWM調(diào)制中產(chǎn)生的正弦波不夠完善，并且噪聲大。現(xiàn)代逆變技術(shù)主要包括三個(gè)部分：半導(dǎo)體功率集成器件及其應(yīng)用、功率變換電路、逆變控制技術(shù)。洛陽理工學(xué)院畢業(yè)設(shè)計(jì)（論文） 500W 50HZ逆變電路摘 要現(xiàn)代逆變技術(shù)是研究現(xiàn)代逆變電路的理論和應(yīng)用設(shè)計(jì)方法的一門科學(xué)。逆變的目的就是為了獲得不同的穩(wěn)定的或變化的電能。目前，逆變器中已經(jīng)基本不再用SCR作為功率開關(guān)器件，SCR主要用做UPS的靜態(tài)開關(guān)。絕緣柵極雙極性晶體管 (Insulated Gate Bipolar Transistor，IGBT)是功率MOSFET和雙極型功率晶體管組合在一起的符合功率器件。它是表示以柵極發(fā)射極間電壓為變量的集電極電流和集電極發(fā)射極間電壓UGE的關(guān)系曲線。它表示在UGE不變的情況下，IC與UGE的關(guān)系曲線。tir稱為電流上升時(shí)間。正偏安全工作區(qū)FBSOA是指柵一射極間加正偏壓時(shí)的安全工作區(qū)，對應(yīng)IGBT的導(dǎo)通狀態(tài)。由于電路本身或外界的干擾：如溫度、干擾信號的影響，輸出可能會偏離規(guī)定值，電路通過采樣，將采樣電壓信號反饋給脈沖輸出電路即門極控制電路芯片UC3524的相應(yīng)引腳，引起脈沖輸出占空比的變化，通過控制晶閘管的導(dǎo)通時(shí)間，從而調(diào)節(jié)電壓的輸出?？赏ㄟ^外部取樣電壓對其進(jìn)行供電。114腳：內(nèi)部兩路驅(qū)動級NPN雙極型三極管的發(fā)射極引出端。如圖24所示，為了使IGBT穩(wěn)定工作，一般要求雙電源供電方式，即驅(qū)動電路要求采用正、負(fù)偏壓的兩電源方式，輸入信號經(jīng)整形器整形后進(jìn)入放大級，放大級采用有源負(fù)載方式以提供足夠的門極電流。單端放大器的輸出級由一只放大元件（或多只元件但并聯(lián)成一組）完成對信號正負(fù)兩個(gè)半周的放大。而推挽電路則不會存在這種損耗。圖33給出三重絕緣法結(jié)構(gòu)。因此，應(yīng)該選擇 變壓器漏感比較小的繞制方法。光電耦合保護(hù)電路：如圖42所示，當(dāng)UO有過壓現(xiàn)象時(shí)，穩(wěn)壓管擊穿導(dǎo)通，經(jīng)光耦(OT2)R6到地產(chǎn)生電流流過，光電耦合器的發(fā)光二極管發(fā)光，從而使光電耦合器的光敏三極管導(dǎo)通。圖45（B）的精度要比圖45（A）的精度高，因?yàn)?5（B）設(shè)計(jì)了誤差比較和誤差放大電路。本設(shè)計(jì)所采用的取樣電路為間接取樣電路，它的優(yōu)點(diǎn)是可以減小主電路的復(fù)雜程度，排除采樣電路對主電路的干擾，又可靈敏地對主電路的變化做出快速的反應(yīng)，可根據(jù)電路的實(shí)際需要改變采樣繞組的匝數(shù)來改變?nèi)与妷狠敵鲋?。在本次畢業(yè)設(shè)計(jì)中，通過對逆變電源主電路、控制電路等電氣控制電路環(huán)節(jié)的設(shè)計(jì)以及對電路元件參數(shù)的計(jì)算與選擇，了解了逆變電源設(shè)計(jì)的全過程，鞏固和加強(qiáng)了本專業(yè)的專業(yè)理論知識，同時(shí)設(shè)計(jì)也滿足了現(xiàn)代工程設(shè)計(jì)的要求，達(dá)到了預(yù)期的目標(biāo)。 the reality can be used in production around the primary winding secondary wrapping method. Or subsystem with a triple insulated wire wound to remove the insulation between the initial levels, can enhance the coupling, and even use wide copper winding. 開關(guān)電源的設(shè)計(jì)開關(guān)電源分為兩個(gè)獨(dú)立形式的隔離和非孤立這里主要談?wù)勯_關(guān)電源拓?fù)浣Y(jié)構(gòu)形式下，非指定的隔離電源。s TOP chips can do 300 watts, an article describes the flyback power supply can be on the KW, but not seen in kind. Power output and the output voltage level. Flyback power transformer leakage inductance is a critical parameter, because the power needs of the flyback transformer stored energy, to make full use of transformer core, the general must be open in the magnetic circuit air gap, the aim is to change the core hysteresis back line of the slope, so that transformers can withstand the impact of a large pulse current, which is not core into saturation nonlinear stat