開(kāi)關(guān)電源畢業(yè)設(shè)計(jì)的外文翻譯

1、<p>　　本科畢業(yè)設(shè)計(jì)(論文)</p><p>　　外文參考文獻(xiàn)譯文及原文</p><p>　　學(xué) 院 信息工程學(xué)院 </p><p>　　專 業(yè) 信息工程 </p><p>　　年級(jí)班別 </p>

2、<p>　　學(xué) 號(hào) </p><p>　　學(xué)生姓名 </p><p>　　指導(dǎo)教師 </p><p>　　2013年 # 月(僅供參考,請(qǐng)勿照搬)</p><p><b&g

3、t;　　目 錄</b></p><p><b>　　譯文1</b></p><p>　　基于單片機(jī)的開(kāi)關(guān)電源1</p><p><b>　　1、用途1</b></p><p><b>　　2、簡(jiǎn)介1</b></p><p><b

4、>　　3、分類2</b></p><p>　　4、開(kāi)關(guān)電源的分類3</p><p>　　5、技術(shù)發(fā)展動(dòng)向4</p><p><b>　　6、原理簡(jiǎn)介6</b></p><p><b>　　7、電路原理7</b></p><p>　　8、DC/DC變

5、換8</p><p>　　9、AC/DC變換8</p><p><b>　　原文10</b></p><p>　　The design Based onsingle chip switching power supply10</p><p><b>　　1、uses10</b></p

6、><p>　　2、Introduction10</p><p>　　3、classification11</p><p>　　4、the switching power supply.13</p><p>　　5、technology developments14</p><p>　　6、the principle

7、 of Introduction17</p><p>　　7、the circuit schematic18</p><p>　　8、the DC / DC conversion19</p><p>　　9, AC / DC conversion20</p><p><b>　　譯文</b></p>

8、<p>　　基于單片機(jī)的開(kāi)關(guān)電源</p><p><b>　　1、用途</b></p><p>　　開(kāi)關(guān)電源產(chǎn)品廣泛應(yīng)用于工業(yè)自動(dòng)化控制、軍工設(shè)備、科研設(shè)備、LED照明、工控設(shè)備、通訊設(shè)備、電力設(shè)備、儀器儀表、醫(yī)療設(shè)備、半導(dǎo)體制冷制熱、空氣凈化器，電子冰箱，液晶顯示器，LED燈具，通訊設(shè)備，視聽(tīng)產(chǎn)品，安防，電腦機(jī)箱，數(shù)碼產(chǎn)品和儀器類等領(lǐng)域。</p&g

9、t;<p><b>　　2、簡(jiǎn)介</b></p><p>　　隨著電力電子技術(shù)的高速發(fā)展，電力電子設(shè)備與人們的工作、生活的關(guān)系日益密切，而電子設(shè)備都離不開(kāi)可靠的電源，進(jìn)入80年代計(jì)算機(jī)電源全面實(shí)現(xiàn)了開(kāi)關(guān)電源化，率先完成計(jì)算機(jī)的電源換代，進(jìn)入90年代開(kāi)關(guān)電源相繼進(jìn)入各種電子、電器設(shè)備領(lǐng)域，程控交換機(jī)、通訊、電子檢測(cè)設(shè)備電源、控制設(shè)備電源等都已廣泛地使用了開(kāi)關(guān)電源，更促進(jìn)了開(kāi)關(guān)電源

10、技術(shù)的迅速發(fā)展。 　　</p><p>　　開(kāi)關(guān)電源是利用現(xiàn)代電力電子技術(shù)，控制開(kāi)關(guān)晶體管開(kāi)通和關(guān)斷的時(shí)間比率，維持穩(wěn)定輸出電壓的一種電源，開(kāi)關(guān)電源一般由脈沖寬度調(diào)制（PWM）控制IC和開(kāi)關(guān)器件（MOSFET、BJT等）構(gòu)成。開(kāi)關(guān)電源和線性電源相比，二者的成本都隨著輸出功率的增加而增長(zhǎng)，但二者增長(zhǎng)速率各異。線性電源成本在某一輸出功率點(diǎn)上，反而高于開(kāi)關(guān)電源。隨著電力電子技術(shù)的發(fā)展和創(chuàng)新，使得開(kāi)關(guān)電源技術(shù)在不斷地創(chuàng)新

11、，這一成本反轉(zhuǎn)點(diǎn)日益向低輸出電力端移動(dòng)，這為開(kāi)關(guān)電源提供了廣泛的發(fā)展空間。 　　</p><p>　　開(kāi)關(guān)電源高頻化是其發(fā)展的方向，高頻化使開(kāi)關(guān)電源小型化，并使開(kāi)關(guān)電源進(jìn)入更廣泛的應(yīng)用領(lǐng)域，特別是在高新技術(shù)領(lǐng)域的應(yīng)用，推動(dòng)了高新技術(shù)產(chǎn)品的小型化、輕便化。另外開(kāi)關(guān)電源的發(fā)展與應(yīng)用在節(jié)約能源、節(jié)約資源及保護(hù)環(huán)境方面都具有重要的意義。</p><p><b>　　3、分類</b&

12、gt;</p><p>　　現(xiàn)代開(kāi)關(guān)電源有兩種：一種是直流開(kāi)關(guān)電源；另一種是交流開(kāi)關(guān)電源。這里主要介紹的只是直流開(kāi)關(guān)電源，其功能是將電能質(zhì)量較差的原生態(tài)電源（粗電），如市電電源或蓄電池電源，轉(zhuǎn)換成滿足設(shè)備要求的質(zhì)量較高的直流電壓（精電）。直流開(kāi)關(guān)電源的核心是DC/DC轉(zhuǎn)換器。因此直流開(kāi)關(guān) 電源的分類是依賴DC/DC轉(zhuǎn)換器分類的。也就是說(shuō)，直流開(kāi)關(guān)電源的分類與DC/DC轉(zhuǎn)換器的分類是基本相同的，DC/DC轉(zhuǎn)換器的分

13、類基本上就是直 流開(kāi)關(guān)電源的分類。 　　</p><p>　　直流DC/DC轉(zhuǎn)換器按輸入與輸出之間是否有電氣隔離可以分為兩類：一類是有隔離的稱為隔離式DC/DC轉(zhuǎn)換器；另一類是沒(méi)有隔離的稱為非隔離 式DC/DC轉(zhuǎn)換器。 　　</p><p>　　隔離式DC/DC轉(zhuǎn)換器也可以按有源功率器件的個(gè)數(shù)來(lái)分類。單管的DC/DC轉(zhuǎn)換器有正激式（Forward）和反激式（Feedback）兩種。雙管DC

14、/DC轉(zhuǎn)換器 有雙管正激式（Double Transistor Forward Converter），雙管反激式（Double Transistor Feedback Converter）、推挽式（Push-Pull Converter） 和半橋式（Half-Bridge Converter）四種。四管DC/DC轉(zhuǎn)換器就是全橋DC/DC轉(zhuǎn)換器（Full-Bridge Converter）。 　　</p><p>

15、　　非隔離式DC/DC轉(zhuǎn)換器，按有源功率器件的個(gè)數(shù)，可以分為單管、雙管和四管三類。單管DC/DC轉(zhuǎn)換器共有六種，即降壓式（Buck）DC/DC轉(zhuǎn)換器 ，升壓式（Boost）DC/DC轉(zhuǎn)換器、升壓降壓式（Buck Boost）DC/DC轉(zhuǎn)換器、Cuk DC/DC轉(zhuǎn)換器、Zeta DC/DC轉(zhuǎn)換器和SEPIC DC/DC轉(zhuǎn)換器。在這六種 單管DC/DC轉(zhuǎn)換器中，Buck和Boost式DC/DC轉(zhuǎn)換器是基本的，Buck-Boost、Cuk、Z

16、eta、SEPIC式DC/DC轉(zhuǎn)換器是從中派生出來(lái)的。雙管DC/DC轉(zhuǎn)換 器有雙管串接的升壓式（Buck-Boost）DC/DC轉(zhuǎn)換器。四管DC/DC轉(zhuǎn)換器常用的是全橋DC/DC轉(zhuǎn)換器（Full-Bridge Converter）。 　　</p><p>　　隔離式DC/DC轉(zhuǎn)換器在實(shí)現(xiàn)輸出與輸入電氣隔離時(shí)，通常采用變壓器來(lái)實(shí)現(xiàn)，由于變壓器具有變壓的功能，所以有利于擴(kuò)大轉(zhuǎn)換器的輸出應(yīng)用 范圍，也便于實(shí)現(xiàn)不同電壓的

17、多路輸出，或相同電壓的多種輸出。 　　</p><p>　　在功率開(kāi)關(guān)管的電壓和電流定額相同時(shí)，轉(zhuǎn)換器的輸出功率通常與所用開(kāi)關(guān)管的數(shù)量成正比。所以開(kāi)關(guān)管數(shù)越多，DC/DC轉(zhuǎn)換器的輸出功率越大，四管式比兩管式輸出功率大一倍，單管式輸出功率只有四管式的1/4。 　　</p><p>　　非隔離式轉(zhuǎn)換器與隔離式轉(zhuǎn)換器的組合，可以得到單個(gè)轉(zhuǎn)換器所不具各的一些特性。 　　</p>&l

18、t;p>　　按能量的傳輸來(lái)分，DC/DC轉(zhuǎn)換器有單向傳輸和雙向傳輸兩種。具有雙向傳輸功能的DC/DC轉(zhuǎn)換器，既可以從電源側(cè)向負(fù)載側(cè)傳輸功率，也可以從負(fù)載側(cè)向電源側(cè)傳輸功率。 　　</p><p>　　DC/DC轉(zhuǎn)換器也可以分為自激式和他控式。借助轉(zhuǎn)換器本身的正反饋信號(hào)實(shí)現(xiàn)開(kāi)關(guān)管自持周期性開(kāi)關(guān)的轉(zhuǎn)換器，叫做自激式轉(zhuǎn)換器，如洛耶爾 （Royer）轉(zhuǎn)換器就是一種典型的推挽自激式轉(zhuǎn)換器。他控式DC/DC轉(zhuǎn)換器中的開(kāi)

19、關(guān)器件控制信號(hào)，是由外部專門的控制電路產(chǎn)生的。 　</p><p><b>　　4、開(kāi)關(guān)電源的分類</b></p><p>　　人們?cè)陂_(kāi)關(guān)電源技術(shù)領(lǐng)域是邊開(kāi)發(fā)相關(guān)電力電子器件，邊開(kāi)發(fā)開(kāi)關(guān)變頻技術(shù)，兩者相互促進(jìn)推動(dòng)著開(kāi)關(guān)電源每年以超過(guò)兩位數(shù)字的增長(zhǎng)率向著輕、小、薄、低噪聲、高可靠、抗干擾的方向發(fā)展。開(kāi)關(guān)電源可分為AC/DC和DC/DC兩大類，也有AC/AC DC/AC

20、如逆變器 DC/DC變換器現(xiàn)已實(shí)現(xiàn)模塊化，且設(shè)計(jì)技術(shù)及生產(chǎn)工藝在國(guó)內(nèi)外均已成熟和標(biāo)準(zhǔn)化，并已得到用戶的認(rèn)可，但AC/DC的模塊化，因其自身的特性使得在模塊化的進(jìn)程中，遇到較為復(fù)雜的技術(shù)和工藝制造問(wèn)題。以下分別對(duì)兩類開(kāi)關(guān)電源的結(jié)構(gòu)和特性作以闡述。</p><p>　　自激式：是無(wú)須外加信號(hào)源能自行振蕩，自激式完全可以把它看作是一個(gè)變壓器反饋式振蕩電路。</p><p>　　它激式：則完全依賴

21、于外部維持振蕩，在實(shí)際應(yīng)用中它激式應(yīng)用比較廣泛。根據(jù)激勵(lì)信號(hào)結(jié)構(gòu)分類；可分為脈沖調(diào)寬和脈沖調(diào)幅兩種，脈沖調(diào)寬是控制信號(hào)的寬度，也就是頻率，脈沖調(diào)幅控制信號(hào)的幅度，兩者的作用相同都是使振蕩頻率維持在某一范圍內(nèi)，達(dá)到穩(wěn)定電壓的效果。變壓器的繞組一般可以分成三種類型，一組是參與振蕩的初級(jí)繞組，一組是維持振蕩的反饋繞組，還有一組是負(fù)載繞組。比如在家用電器中使用的上海正藝科技生產(chǎn)的開(kāi)關(guān)電源，將220V的交流電經(jīng)過(guò)橋式整流，變換成300V左右的直流

22、電，濾波后進(jìn)入變壓器后加到開(kāi)關(guān)管的集電極進(jìn)行高頻振蕩，反饋繞組反饋到基極維持電路振蕩，負(fù)載繞組感應(yīng)的電信號(hào)，經(jīng)整流、濾波、穩(wěn)壓得到的直流電壓給負(fù)載提供電能。負(fù)載繞組在提供電能的同時(shí)，也肩負(fù)起穩(wěn)定電壓的能力，其原理是在電壓輸出電路接一個(gè)電壓取樣裝置，監(jiān)測(cè)輸出電壓的變化情況，及時(shí)反饋給振蕩電路調(diào)整振蕩頻率，從而達(dá)到穩(wěn)定電壓的目的，為了避免電路的干擾，反饋回振蕩電路的電壓會(huì)用光電耦合器隔離。</p><p><b

23、>　　5、技術(shù)發(fā)展動(dòng)向</b></p><p>　　開(kāi)關(guān)電源高頻化是其發(fā)展的方向，高頻化使開(kāi)關(guān)電源小型化，并使開(kāi)關(guān)電源進(jìn)入更廣泛的應(yīng)用領(lǐng)域，特別是在高新技術(shù)領(lǐng)域的應(yīng)用，推動(dòng)了開(kāi)關(guān)電源的發(fā)展前進(jìn)，每年以超過(guò)兩位數(shù)字的增長(zhǎng)率向著輕、小、薄、低噪聲、高可靠、抗干擾的方向發(fā)展。開(kāi)關(guān)電源可分為AC/DC和DC/DC兩大類，DC/DC變換器現(xiàn)已實(shí)現(xiàn)模塊化，且設(shè)計(jì)技術(shù)及生產(chǎn)工藝在國(guó)內(nèi)外均已成熟和標(biāo)準(zhǔn)化，并已得

24、到用戶的認(rèn)可，但AC/DC的模塊化，因其自身的特性使得在模塊化的進(jìn)程中，遇到較為復(fù)雜的技術(shù)和工藝制造問(wèn)題。另外，開(kāi)關(guān)電源的發(fā)展與應(yīng)用在節(jié)約能源、節(jié)約資源及保護(hù)環(huán)境方面都具有重要的意義。 　　</p><p>　　開(kāi)關(guān)電源中應(yīng)用的電力電子器件主要為二極管、IGBT和MOSFET。 　　</p><p>　　SCR在開(kāi)關(guān)電源輸入整流電路及軟啟動(dòng)電路中有少量應(yīng)用，GTR驅(qū)動(dòng)困難，開(kāi)關(guān)頻率低，逐漸

25、被IGBT和MOSFET取代。</p><p>　　開(kāi)關(guān)電源的發(fā)展方向是高頻、高可靠、低耗、低噪聲、抗干擾和模塊化。由于開(kāi)關(guān)電源輕、小、薄的關(guān)鍵技術(shù)是高頻化，因此國(guó)外各大開(kāi)關(guān)電源制造商都致力于同步開(kāi)發(fā)新型高智能化的元器件，特別是改善二次整流器件的損耗，并在功率鐵氧體材料上加大科技創(chuàng)新，以提高在高頻率和較大磁通密度（Bs)下獲得高的磁性能，而電容器的小型化也是一項(xiàng)關(guān)鍵技術(shù)。SMT技術(shù)的應(yīng)用使得開(kāi)關(guān)電源取得了長(zhǎng)足的進(jìn)

26、展，在電路板兩面布置元器件，以確保開(kāi)關(guān)電源的輕、小、薄。開(kāi)關(guān)電源的高頻化就必然對(duì)傳統(tǒng)的PWM開(kāi)關(guān)技術(shù)進(jìn)行創(chuàng)新，實(shí)現(xiàn)ZVS、ZCS的軟開(kāi)關(guān)技術(shù)已成為開(kāi)關(guān)電源的主流技術(shù)，并大幅提高了開(kāi)關(guān)電源的工作效率。對(duì)于高可靠性指標(biāo)，美國(guó)的開(kāi)關(guān)電源生產(chǎn)商通過(guò)降低運(yùn)行電流，降低結(jié)溫等措施以減少器件的應(yīng)力，使得產(chǎn)品的可靠性大大提高。 　　</p><p>　　模塊化是開(kāi)關(guān)電源發(fā)展的總體趨勢(shì)，可以采用模塊化電源組成分布式電源系統(tǒng)，可以設(shè)

27、計(jì)成N+1冗余電源系統(tǒng)，并實(shí)現(xiàn)并聯(lián)方式的容量擴(kuò)展。針對(duì)開(kāi)關(guān)電源運(yùn)行噪聲大這一缺點(diǎn)，若單獨(dú)追求高頻化其噪聲也必將隨著增大，而采用部分諧振轉(zhuǎn)換電路技術(shù)，在理論上即可實(shí)現(xiàn)高頻化又可降低噪聲，但部分諧振轉(zhuǎn)換技術(shù)的實(shí)際應(yīng)用仍存在著技術(shù)問(wèn)題，故仍需在這一領(lǐng)域開(kāi)展大量的工作，以使得該項(xiàng)技術(shù)得以實(shí)用化。 　　</p><p>　　電力電子技術(shù)的不斷創(chuàng)新，使開(kāi)關(guān)電源產(chǎn)業(yè)有著廣闊的發(fā)展前景。要加快我國(guó)開(kāi)關(guān)電源產(chǎn)業(yè)的發(fā)展速度，就必須走

28、技術(shù)創(chuàng)新之路，走出有中國(guó)特色的產(chǎn)學(xué)研聯(lián)合發(fā)展之路，為我國(guó)國(guó)民經(jīng)濟(jì)的高速發(fā)展做出貢獻(xiàn)。</p><p>　　開(kāi)關(guān)電源的發(fā)展和趨勢(shì)</p><p>　　1955年美國(guó)羅耶（Roger)發(fā)明的自激振蕩推挽晶體管單變壓器直流變換器，是實(shí)現(xiàn)高頻轉(zhuǎn)換控制電路的開(kāi)端，1957年美國(guó)查賽（Jen Sen)發(fā)明了自激式推挽雙變壓器，1964年美國(guó)科學(xué)家們提出取消工頻變壓器的串聯(lián)開(kāi)關(guān)電源的設(shè)想，這對(duì)電源向體積

29、和重量的下降獲得了一條根本的途徑。到了1969年由于大功率硅晶體管的耐壓提高，二極管反向恢復(fù)時(shí)間的縮短等元器件改善，終于做成了25千赫的開(kāi)關(guān)電源。 　　</p><p>　　目前，開(kāi)關(guān)電源以小型、輕量和高效率的特點(diǎn)被廣泛應(yīng)用于以電子計(jì)算機(jī)為主導(dǎo)的各種終端設(shè)備、通信設(shè)備等幾乎所有的電子設(shè)備，是當(dāng)今電子信息產(chǎn)業(yè)飛速發(fā)展不可缺少的一種電源方式。目前市場(chǎng)上出售的開(kāi)關(guān)電源中采用雙極性晶體管制成的100kHz、用MOS－FE

30、T制成的500kHz電源，雖已實(shí)用化，但其頻率有待進(jìn)一步提高。要提高開(kāi)關(guān)頻率，就要減少開(kāi)關(guān)損耗，而要減少開(kāi)關(guān)損耗，就需要有高速開(kāi)關(guān)元器件。然而，開(kāi)關(guān)速度提高后，會(huì)受電路中分布電感和電容或二極管中存儲(chǔ)電荷的影響而產(chǎn)生浪涌或噪聲。這樣，不僅會(huì)影響周圍電子設(shè)備，還會(huì)大大降低電源本身的可靠性。其中，為防止隨開(kāi)關(guān)啟-閉所發(fā)生的電壓浪涌，可采用R-C或L-C緩沖器，而對(duì)由二極管存儲(chǔ)電荷所致的電流浪涌可采用非晶態(tài)等磁芯制成的磁緩沖器。不過(guò)，對(duì)1MHz

31、以上的高頻，要采用諧振電路，以使開(kāi)關(guān)上的電壓或通過(guò)開(kāi)關(guān)的電流呈正弦波，這樣既可減少開(kāi)關(guān)損耗，同時(shí)也可控制浪涌的發(fā)生。這種開(kāi)關(guān)方式稱為諧振式開(kāi)關(guān)。目前對(duì)這種開(kāi)關(guān)電源的研究很活躍，因?yàn)椴捎眠@種方式不需要大幅度提高開(kāi)關(guān)速度就可以在理論上把開(kāi)關(guān)損耗降到零，而且噪聲也小，可望成為開(kāi)關(guān)電源高頻化的一種主要方式。當(dāng)前，世界上許多國(guó)</p><p><b>　　6、原理簡(jiǎn)介</b></p>&

32、lt;p>　　開(kāi)關(guān)電源的工作過(guò)程相當(dāng)容易理解，在線性電源中，讓功率晶體管工作在線性模式，與線性電源不同的是，PWM開(kāi)關(guān)電源是讓功率晶體管工作在導(dǎo)通和關(guān)斷的狀態(tài)，在這兩種狀態(tài)中，加在功率晶體管上的伏-安乘積是很小的（在導(dǎo)通時(shí)，電壓低，電流大；關(guān)斷時(shí)，電壓高，電流?。?功率器件上的伏安乘積就是功率半導(dǎo)體器件上所產(chǎn)生的損耗。 　　</p><p>　　與線性電源相比，PWM開(kāi)關(guān)電源更為有效的工作過(guò)程是通過(guò)“斬波”

33、，即把輸入的直流電壓斬成幅值等于輸入電壓幅值的脈沖電壓來(lái)實(shí)現(xiàn)的。脈沖的占空比由開(kāi)關(guān)電源的控制器來(lái)調(diào)節(jié)。一旦輸入電壓被斬成交流方波，其幅值就可以通過(guò)變壓器來(lái)升高或降低。通過(guò)增加變壓器的二次繞組數(shù)就可以增加輸出的電壓組數(shù)。最后這些交流波形經(jīng)過(guò)整流濾波后就得到直流輸出電壓。 　　</p><p>　　控制器的主要目的是保持輸出電壓穩(wěn)定，其工作過(guò)程與線性形式的控制器很類似。也就是說(shuō)控制器的功能塊、電壓參考和誤差放大器，可

34、以設(shè)計(jì)成與線性調(diào)節(jié)器相同。他們的不同之處在于，誤差放大器的輸出（誤差電壓）在驅(qū)動(dòng)功率管之前要經(jīng)過(guò)一個(gè)電壓/脈沖寬度轉(zhuǎn)換單元。 　　</p><p>　　開(kāi)關(guān)電源有兩種主要的工作方式：正激式變換和升壓式變換。盡管它們各部分的布置差別很小，但是工作過(guò)程相差很大，在特定的應(yīng)用場(chǎng)合下各有優(yōu)點(diǎn)。</p><p><b>　　7、電路原理</b></p><p

35、>　　所謂開(kāi)關(guān)電源，顧名思義，就是這里有一扇門，一開(kāi)門電源就通過(guò)，一關(guān)門電源就停止通過(guò)，那么什么是門呢，開(kāi)關(guān)電源里有的采用可控硅，有的采用開(kāi)關(guān)管，這兩個(gè)元器件性能差不多，都是靠基極、（開(kāi)關(guān)管）控制極（可控硅）上加上脈沖信號(hào)來(lái)完成導(dǎo)通和截止的，脈沖信號(hào)正半周到來(lái)，控制極上電壓升高，開(kāi)關(guān)管或可控硅就導(dǎo)通，由220V整流、濾波后輸出的300V電壓就導(dǎo)通，通過(guò)開(kāi)關(guān)變壓器傳到次級(jí)，再通過(guò)變壓比將電壓升高或降低，供各個(gè)電路工作。振蕩脈沖負(fù)半周

36、到來(lái)，電源調(diào)整管的基極、或可控硅的控制極電壓低于原來(lái)的設(shè)置電壓，電源調(diào)整管截止，300V電源被關(guān)斷，開(kāi)關(guān)變壓器次級(jí)沒(méi)電壓，這時(shí)各電路所需的工作電壓，就靠次級(jí)本路整流后的濾波電容放電來(lái)維持。待到下一個(gè)脈沖的周期正半周信號(hào)到來(lái)時(shí)，重復(fù)上一個(gè)過(guò)程。這個(gè)開(kāi)關(guān)變壓器就叫高頻變壓器，因?yàn)樗墓ぷ黝l率高于50HZ低頻。那么推動(dòng)開(kāi)關(guān)管或可控硅的脈沖如何獲得呢，這就需要有個(gè)振蕩電路產(chǎn)生，我們知道，晶體三極管有個(gè)特性，就是基極對(duì)發(fā)射極電壓是0.65-0.7

37、V是放大狀態(tài)，0.7V以上就是飽和導(dǎo)通狀態(tài)， -0.1V- -0.3V就工作在振蕩狀態(tài)，那么其工作點(diǎn)調(diào)好后，就靠較深的負(fù)反饋來(lái)產(chǎn)生負(fù)</p><p><b>　　8、DC/DC變換</b></p><p>　　DC/DC變換是將固定的直流電壓變換成可變的直流電壓，也稱為直流斬波。斬波器的工作方式有兩種，一是脈寬調(diào)制方式Ts不變，改變ton(通用)，二是頻率調(diào)制方式，t

38、on不變，改變Ts（易產(chǎn)生干擾）。其具體的電路由以下幾類：</p><p>　　Buck電路——降壓斬波器，其輸出平均電壓U0小于輸入電壓Ui，極性相同。</p><p>　　Boost電路——升壓斬波器，其輸出平均電壓 開(kāi)關(guān)電源及電路圖U0大于輸入電壓Ui，極性相同。</p><p>　　Buck－Boost電路——降壓或升壓斬波器，其輸出平均電壓U0大于或小于

39、輸入電壓Ui，極性相反，電感傳輸。</p><p>　　Cuk電路——降壓或升壓斬波器，其輸出平均電 　　壓U0大于或小于輸入電壓Ui，極性相反，電容傳輸。</p><p>　　上述為非隔離型電路，隔離型電路有正激電路、反激電路、半橋電路、全橋電路、推挽電路。 　　當(dāng)今軟開(kāi)關(guān)技術(shù)使得DC/DC發(fā)生了質(zhì)的飛躍，美國(guó)VICOR公司設(shè)計(jì)制造的多種ECI軟開(kāi)關(guān)DC/DC變換器，其最大輸出功率有30

40、0W、600W、800W等，相應(yīng)的功率密度為(6.2、10、17)W/cm3，效率為（80～90）%。日本Nemic Lambda公司最新推出的一種采用軟開(kāi)關(guān)技術(shù)的高頻開(kāi)關(guān)電源模塊RM系列，其開(kāi)關(guān)頻率為（200～300)kHz，功率密度已達(dá)到27W/cm3，采用同步整流器（MOSFET代替肖特基二極管），使整個(gè)電路效率提高到90%。</p><p><b>　　9、AC/DC變換</b>&l

41、t;/p><p>　　AC/DC變換是將交流變換為直流，其功率流向可以是雙向的，功率流由電源流向負(fù)載的稱為“整流”，功率流由負(fù)載返回電源的稱為“有源逆變”。AC/DC變換器輸入為50/60Hz的交流電，因必須經(jīng)整流、濾波，因此體積相對(duì)較大的濾波電容器是必不可少的，同時(shí)因遇到安全標(biāo)準(zhǔn)（如UL、CCEE等）及EMC指令的限制（如IEC、、FCC、CSA），交流輸入側(cè)必須加EMC濾波及使用符合安全標(biāo)準(zhǔn)的元件，這樣就限制AC

42、/DC電源體積的小型化，另外，由于內(nèi)部的高頻、高壓、大電流開(kāi)關(guān)動(dòng)作，使得解決EMC電磁兼容問(wèn)題難度加大，也就對(duì)內(nèi)部高密度安裝電路設(shè)計(jì)提出了很高的要求，由于同樣的原因，高電壓、大電流開(kāi)關(guān)使得電源工作損耗增大，限制了AC/DC變換器模塊化的進(jìn)程，因此必須采用電源系統(tǒng)優(yōu)化設(shè)計(jì)方法才能使其工作效率達(dá)到一定的滿意程度。 　　</p><p>　　AC/DC變換按電路的接線方式可分為，半波電路、全波電路。按電源相數(shù)可分為，單

43、相、三相、多相。按電路工作象限又可分為一象限、二象限、三象限、四象限。 　　</p><p>　　開(kāi)關(guān)電源的選用 　　</p><p>　　開(kāi)關(guān)電源在輸入抗干擾性能上，由于其自身電路結(jié)構(gòu)的特點(diǎn)（多級(jí)串聯(lián)），一般的輸入干擾如浪涌電壓很難通過(guò)，在輸出電壓穩(wěn)定度這一技術(shù)指標(biāo)上與線性電源相比具有較大的優(yōu)勢(shì)，其輸出電壓穩(wěn)定度可達(dá)(0.5～1）%。開(kāi)關(guān)電源模塊作為一種電力電子集成器件，要注意選擇。&l

44、t;/p><p><b>　　原文</b></p><p>　　The design Based onsingle chip switching power supply</p><p><b>　　1、uses</b></p><p>　　The switching power supply prod

45、ucts are widely used in industrial automation and control, military equipment, scientific equipment, LED lighting, industrial equipment,communications equipment,electrical equipment,instrumentation, medical equipment, se

46、miconductor cooling and heating, air purifiers, electronic refrigerator, LCD monitor, LED lighting, communications equipment, audio-visual products, security, computer chassis, digital products and equipment and other fi

47、elds.</p><p>　　2、Introduction</p><p>　　With the rapid development of power electronics technology, power electronics equipment and people's work, the relationship of life become increasingly

48、 close, and electronic equipment without reliable power, into the 1980s, computer power and the full realization of the switching power supply, the first to complete the computer Power new generation to enter the switchi

49、ng power supply in the 1990s have entered into a variety of electronic, electrical devices, program-controlled switchboards, comm</p><p>　　Switching power supply is the use of modern power electronics techno

50、logy to control the ratio of the switching transistor to turn on and off to maintain a stable output voltage power supply, switching power supply is generally controlled by pulse width modulation (PWM) ICs and switching

51、devices (MOSFET, BJT) composition. Switching power supply and linear power compared to both the cost and growth with the increase of output power, but the two different growth rates. A power point, linear power s</p&g

52、t;<p>　　The direction of its development is the high-frequency switching power supply, high frequency switching power supply miniaturization, and switching power supply into a wider range of application areas, es

53、pecially in high-tech fields, and promote the miniaturization of high-tech products, light of. In addition, the development and application of the switching power supply in terms of energy conservation, resource conserva

54、tion and environmental protection are of great significance.</p><p>　　3、classification</p><p>　　Modern switching power supply, there are two: one is the DC switching power supply; the other is t

55、he AC switching power supply. Introduces only DC switching power supply and its function is poor power quality of the original eco-power (coarse) - such as mains power or battery power, converted to meet the equipment re

56、quirements of high-quality DC voltage (Varitronix) . The core of the DC switching power supply DC / DC converter. DC switching power supply classification is dependent on the classif</p><p>　　DC /DC converte

57、r between the input and output electrical isolation can be divided into two categories: one is isolated called isolated DC/DC converter; the other is not isolated as non-isolated DC / DC converter.</p><p>　　

58、Isolated DC / DC converter can also be classified by the number of active power devices. The single tube of DC / DC converter Forward (Forward), Feedback (Feedback) two. The double-barreled double-barreled DC/ DC convert

59、er Forward (Double Transistor Forward Converter), twin-tube feedback (Double Transistor Feedback Converter), Push-Pull (Push the Pull Converter) and half-bridge (Half-Bridge Converter) four. Four DC / DC converter is the

60、 full-bridge DC / DC converter (Full-Bridge Converter).</p><p>　　Non-isolated DC / DC converter, according to the number of active power devices can be divided into single-tube, double pipe, and four three c

61、ategories. Single tube to a total of six of the DC / DC converter, step-down (Buck) DC / DC converter, step-up (Boost) DC / DC converters, DC / DC converter, boost buck (Buck Boost) device of Cuk the DC / DC converter, t

62、he Zeta DC / DC converter and SEPIC, the DC / DC converter. DC / DC converters, the Buck and Boost type DC / DC converter is the basic buc</p><p>　　Isolated DC / DC converter input and output electrical isol

63、ation is usually transformer to achieve the function of the transformer has a transformer, so conducive to the expansion of the converter output range of applications, but also easy to achieve different voltage output ,

64、or a variety of the same voltage output.</p><p>　　Power switch voltage and current rating, the converter's output power is usually proportional to the number of switch. The more the number of switch, the

65、 greater the output power of the DC / DC converter, four type than the two output power is twice as large, single-tube output power of only four 1/4.</p><p>　　A combination of non-isolated converters and iso

66、lated converters can be a single converter does not have their own characteristics. Energy transmission points, one-way transmission and two-way transmission of two DC / DC converter. DC / DC converter with bi-directiona

67、l transmission function, either side of the transmission power from the power of lateral load power from the load-lateral side of the transmission power.</p><p>　　DC / DC converter can be divided into self-e

68、xcited and separately controlled. With the positive feedback signal converter to switch to self-sustaining periodic switching converter, called self-excited converter, such as the the Luo Yeer (Royer,) converter is a typ

69、ical push-pull self-oscillating converter. Controlled DC / DC converter switching device control signal is generated by specialized external control circuit.</p><p>　　4、the switching power supply.</p>

70、<p>　　People in the field of switching power supply technology side of the development of power electronic devices, while the development of the switching inverter technology, the two promote each other to promote

71、the switching power supply annual growth rate of more than two digits toward the light, small, thin, low-noise, high reliability, the direction of development of anti-jamming. Switching power supply can be divided into A

72、C / DC and DC / DC two categories, AC / AC DC / AC, such as inverters, D</p><p>　　Self-excited: no external signal source can be self-oscillation, completely self-excited to see it as feedback oscillation ci

73、rcuit of a transformer.</p><p>　　Separate excitation: entirely dependent on external sustain oscillations, excited used widely in practical applications. According to the excitation signal structure classifi

74、cation; can be divided into pulse-width-modulated and pulse amplitude modulated two pulse width modulated control the width of the signal is frequency, pulse amplitude modulation control signal amplitude between the same

75、 effect are the oscillation frequency to maintain within a certain range to achieve the effect of voltage </p><p>　　5、technology developments</p><p>　　The high-frequency switching power supply i

76、s the direction of its development, high-frequency switching power supply miniaturization, and switching power supply into the broader field of application, especially in high-tech fields, and promote the development and

77、 advancement of the switching power supply, an annual more than two-digit growth rate toward the light, small, thin, low noise, high reliability, the direction of the anti-jamming. Switching power supply can be divided i

78、nto AC / DC and D</p><p>　　The switching power supply applications in power electronic devices as diodes, IGBT and MOSFET.</p><p>　　SCR switching power supply input rectifier circuit and soft st

79、art circuit, a small amount of applications, the GTR drive difficult, low switching frequency, gradually replace the IGBT and MOSFET.</p><p>　　Direction of development of the switching power supply is a high

80、-frequency, high reliability, low power, low noise, jamming and modular. Small, thin, and the key technology is the high frequency switching power supply light, so foreign major switching power supply manufacturers have

81、committed to synchronize the development of new intelligent components, in particular, is to improve the secondary rectifier loss, and the power of iron Oxygen materials to increase scientific and technological innov<

82、/p><p>　　Modularity is the overall trend of switching power supply, distributed power systems can be composed of modular power supply, can be designed to N +1 redundant power system, and the parallel capacity e

83、xpansion. For this shortcoming of the switching power supply running noise, separate the pursuit of high frequency noise will also increase, while the use of part of the resonant converter circuit technology to achieve h

84、igh frequency, in theory, but also reduce noise, but some The practical applica</p><p>　　Power electronics technology innovation, switching power supply industry has broad prospects for development. To accel

85、erate the pace of development of the switching power supply industry in China, it must take the road of technological innovation, out of joint production and research development path with Chinese characteristics and con

86、tribute to the rapid development of China's national economy.</p><p>　　Developments and trends of the switching power supply</p><p>　　1955 U.S. Royer (Roger) invented the self-oscillating pu

87、sh-pull transistor single-transformer DC-DC converter is the beginning of the high-frequency conversion control circuit 1957 check race Jen, Sen, invented a self-oscillating push-pull dual transformers, 1964, U.S. scient

88、ists canceled frequency transformer in series the idea of ??switching power supply, the power supply to the size and weight of the decline in a fundamental way. 1969 increased due to the pressure of the high-power silico

89、n tr</p><p>　　At present, the switching power supply to the small, lightweight and high efficiency characteristics are widely used in a variety of computer-oriented terminal equipment, communications equipme

90、nt, etc. Almost all electronic equipment is indispensable for a rapid development of today's electronic information industry power mode. Bipolar transistor made of 100kHz, 500kHz power MOS-FET made, though already th

91、e practical switching power supply is currently available on the market, but its frequency </p><p>　　6、the principle of Introduction</p><p>　　The switching power supply of the process is quite e

92、asy to understand, linear power supplies, power transistors operating in the linear mode and linear power, the PWM switching power supply to the power transistor turns on and off state, in both states, on the power trans

93、istor V - security product is very small (conduction, low voltage, large current; shutdown, voltage, current) Voltammetric product / power device is power semiconductor devices on the loss.</p><p>　　Compared

94、 with the linear power supply, the PWM switching power supply more efficient process is achieved by "chopping", that is cut into the amplitude of the input DC voltage equal to the input voltage amplitude of the

95、 pulse voltage. The pulse duty cycle is adjusted by the switching power supply controller. Once the input voltage is cut into the AC square wave, its amplitude through the transformer to raise or lower. Number of groups

96、of output voltage can be increased by increasing the number of</p><p>　　The main purpose of the controller is to maintain the stability of the output voltage, the course of their work is very similar to the

97、linear form of the controller. That is the function blocks of the controller, the voltage reference and error amplifier can be designed the same as the linear regulator. Their difference lies in the error amplifier outpu

98、t (error voltage) in the drive before the power tube to go through a voltage / pulse-width conversion unit.</p><p>　　Switching power supply There are two main ways of working: Forward transform and boost tra

99、nsformation. Although they are all part of the layout difference is small, but the course of their work vary greatly, have advantages in specific applications.</p><p>　　7、the circuit schematic</p><

100、;p>　　The so-called switching power supply, as the name implies, is a door, a door power through a closed power to stop by, then what is the door, the switching power supply using SCR, some switch, these two component

101、performance is similar, are relying on the base switch control pole (SCR), coupled with the pulse signal to complete the on and off, the pulse signal is half attentive to control the pole voltage increases, the switch or