開(kai)關(guan)電(dian)源(yuan)已(yi)經(jing)成(cheng)為(wei)了(le)我(wo)們(men)電(dian)路(lu)設(she)計(ji)當(dang)中(zhong)的(de)主(zhu)角(jiao)
，甚(shen)至(zhi)可(ke)以(yi)說(shuo)已(yi)經(jing)成(cheng)為(wei)了(le)與(yu)行(xing)業(ye)發(fa)展(zhan)密(mi)不(bu)可(ke)分(fen)的(de)一(yi)部(bu)分(fen)。與(yu)傳(chuan)統(tong)線(xian)性(xing)電(dian)源(yuan)相(xiang)比(bi)，在(zai)某(mou)一(yi)輸(shu)出(chu)功(gong)率(lv)點(dian)上(shang)線(xian)性(xing)電(dian)源(yuan)的(de)成(cheng)本(ben)要(yao)高(gao)於(yu)開(kai)關(guan)電(dian)源(yuan)，常(chang)見(jian)的(de)開(kai)關(guan)電(dian)源(yuan)可(ke)以(yi)分(fen)為(wei)兩(liang)種(zhong)，隔(ge)離(li)與(yu)非(fei)隔(ge)離(li)。

在zai本ben篇pian文wen章zhang當dang中zhong，我wo們men將jiang主zhu要yao對dui隔ge離li式shi開kai關guan電dian源yuan的de拓tuo撲pu形xing式shi進jin行xing探tan討tao。所suo以yi在zai下xia麵mian的de文wen章zhang當dang中zhong
，如ru果guo沒mei有you任ren何he特te殊shu的de說shuo明ming，文wen中zhong提ti及ji的de電dian源yuan將jiang均jun指zhi隔ge離li電dian源yuan。隔ge離li電dian源yuan按an照zhao結jie構gou形xing式shi不bu同tong，可ke分fen為wei兩liang大da類lei：正激式和反激式。反激式指在變壓器原(yuan)邊(bian)導(dao)通(tong)時(shi)副(fu)邊(bian)截(jie)止(zhi)，變(bian)壓(ya)器(qi)儲(chu)能(neng)。原(yuan)邊(bian)截(jie)止(zhi)時(shi)
，副(fu)邊(bian)導(dao)通(tong)
，能(neng)量(liang)釋(shi)放(fang)到(dao)負(fu)載(zai)的(de)工(gong)作(zuo)狀(zhuang)態(tai)
，一(yi)般(ban)常(chang)規(gui)反(fan)激(ji)式(shi)電(dian)源(yuan)單(dan)管(guan)多(duo)，雙(shuang)管(guan)的(de)不(bu)常(chang)見(jian)。正(zheng)激(ji)式(shi)指(zhi)在(zai)變(bian)壓(ya)器(qi)原(yuan)邊(bian)導(dao)通(tong)同(tong)時(shi)副(fu)邊(bian)感(gan)應(ying)出(chu)對(dui)應(ying)電(dian)壓(ya)輸(shu)出(chu)到(dao)負(fu)載(zai)，能(neng)量(liang)通(tong)過(guo)變(bian)壓(ya)器(qi)直(zhi)接(jie)傳(chuan)遞(di)。按(an)規(gui)格(ge)又(you)可(ke)分(fen)為(wei)常(chang)規(gui)正(zheng)激(ji)，包(bao)括(kuo)單(dan)管(guan)正(zheng)激(ji)，雙(shuang)管(guan)正(zheng)激(ji)。半(ban)橋(qiao)、橋式電路都屬於正激電路。

正(zheng)激(ji)和(he)反(fan)激(ji)電(dian)路(lu)各(ge)有(you)其(qi)特(te)點(dian)，在(zai)設(she)計(ji)電(dian)路(lu)的(de)過(guo)程(cheng)中(zhong)為(wei)達(da)到(dao)最(zui)優(you)性(xing)價(jia)比(bi)，可(ke)以(yi)靈(ling)活(huo)運(yun)用(yong)。一(yi)般(ban)在(zai)小(xiao)功(gong)率(lv)場(chang)合(he)可(ke)選(xuan)用(yong)反(fan)激(ji)式(shi)。稍(shao)微(wei)大(da)一(yi)些(xie)可(ke)采(cai)用(yong)單(dan)管(guan)正(zheng)激(ji)電(dian)路(lu)

，中(zhong)等(deng)功(gong)率(lv)可(ke)采(cai)用(yong)雙(shuang)管(guan)正(zheng)激(ji)電(dian)路(lu)或(huo)半(ban)橋(qiao)電(dian)路(lu)

，低(di)電(dian)壓(ya)時(shi)采(cai)用(yong)推(tui)挽(wan)電(dian)路(lu)
，與(yu)半(ban)橋(qiao)工(gong)作(zuo)狀(zhuang)態(tai)相(xiang)同(tong)。大(da)功(gong)率(lv)輸(shu)出(chu)，一(yi)般(ban)采(cai)用(yong)橋(qiao)式(shi)電(dian)路(lu)
，低(di)壓(ya)也(ye)可(ke)采(cai)用(yong)推(tui)挽(wan)電(dian)路(lu)。

反(fan)激(ji)式(shi)電(dian)源(yuan)因(yin)其(qi)結(jie)構(gou)簡(jian)單(dan)，省(sheng)掉(diao)了(le)一(yi)個(ge)和(he)變(bian)壓(ya)器(qi)體(ti)積(ji)大(da)小(xiao)差(cha)不(bu)多(duo)的(de)電(dian)感(gan)
，而(er)在(zai)中(zhong)小(xiao)功(gong)率(lv)電(dian)源(yuan)中(zhong)得(de)到(dao)廣(guang)泛(fan)的(de)應(ying)用(yong)。在(zai)有(you)些(xie)介(jie)紹(shao)中(zhong)講(jiang)到(dao)反(fan)激(ji)式(shi)電(dian)源(yuan)功(gong)率(lv)隻(zhi)能(neng)做(zuo)到(dao)幾(ji)十(shi)瓦(wa)，輸(shu)出(chu)功(gong)率(lv)超(chao)過(guo)100瓦就沒有優勢，實現起來有難度。本人認為一般情況下是這樣的，但也不能一概而論
，PI公司的TOP芯片就可做到300瓦

，有文章介紹反激電源可做到上千瓦，但沒見過實物。輸出功率大小與輸出電壓高低有關。

反fan激ji電dian源yuan變bian壓ya器qi漏lou感gan是shi一yi個ge非fei常chang關guan鍵jian的de參can數shu，由you於yu反fan激ji電dian源yuan需xu要yao變bian壓ya器qi儲chu存cun能neng量liang


，要yao使shi變bian壓ya器qi鐵tie芯xin得de到dao充chong分fen利li用yong
，一yi般ban都dou要yao在zai磁ci路lu中zhong開kai氣qi隙xi，其qi目mu的de是shi改gai變bian鐵tie芯xin磁ci滯zhi回hui線xian的de斜xie率lv，使shi變bian壓ya器qi能neng夠gou承cheng受shou大da的de脈mai衝chong電dian流liu衝chong擊ji，而er不bu至zhi於yu鐵tie芯xin進jin入ru飽bao和he非fei線xian形xing狀zhuang態tai
，磁ci路lu中zhong氣qi隙xi處chu於yu高gao磁ci阻zu狀zhuang態tai，在zai磁ci路lu中zhong產chan生sheng漏lou磁ci遠yuan大da於yu完wan全quan閉bi合he磁ci路lu。

maichongdianyalianxianjinkenengduan
，qizhongshurukaiguanguandaobianyaqilianxian，shuchubianyaqidaozhengliuguanlianjiexian。maichongdianliuhuanlujinkenengxiaorushurulvbodianrongzhengdaobianyaqidaokaiguanguanfanhuidianrongfu。shuchubufenbianyaqichuduandaozhengliuguandaoshuchudiangandaoshuchudianrongfanhuibianyaqidianluzhongX電容要盡量接近開關電源輸入端，輸入線應避免與其他電路平行
，應避開。Y電容應放置在機殼接地端子或FG連接端。共摸電感應與變壓器保持一定距離，以避免磁偶合。

輸shu出chu電dian容rong一yi般ban可ke采cai用yong兩liang隻zhi一yi隻zhi靠kao近jin整zheng流liu管guan另ling一yi隻zhi應ying靠kao近jin輸shu出chu端duan子zi，可ke影ying響xiang電dian源yuan輸shu出chu紋wen波bo指zhi標biao
，兩liang隻zhi小xiao容rong量liang電dian容rong並bing聯lian效xiao果guo應ying優you於yu用yong一yi隻zhi大da容rong量liang電dian容rong。發fa熱re器qi件jian要yao和he電dian解jie電dian容rong保bao持chi一yi定ding距ju離li，以yi延yan長chang整zheng機ji壽shou命ming

，電dian解jie電dian容rong是shi開kai關guan電dian源yuan壽shou命ming的de瓶ping勁jin，如ru變bian壓ya器qi、功率管、大功率電阻要和電解保持距離，電解之間也須留出散熱空間
，條件允許可將其放置在進風口。
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PCBbuxiandeyixieyuanzeyinzhibanshejishi
，yaokaolvdaoganraoduixitongdeyingxiang，jiangdianludemonibufenheshuzibufendedianluyangefenkai
，duihexindianluzhongdianfanghu，jiangxitongdixianhuanrao，bingbuxianjinkenengcu，dianyuanzengjialvbodianlu
，caiyongDC-DC隔離，信號采用光電隔離，設計隔離電源，分析容易產生幹擾的部分(如時鍾電路、通訊電路等)和容易被幹擾的部分(如模擬采樣電路等)
，duizheliangzhongleixingdedianlufenbiecaiqucuoshi。duiyuganraoyuanjiancaiquyizhicuoshi，duiminganyuanjiancaiqugelihebaohucuoshi
，bingqiejiangtamenzaikongjianhedianqishanglakaijuli。zaibanjishejishi，haiyaozhuyiyuanqijianfangzhiyaoyuanliyinzhibanbianyan，zheduifanghukongqifangdianshiyoulide。

隨著印製線路板製造工藝的不斷完善和提高，一般加工廠製造出線間距等於甚至小於0.1mm已經不存在什麼問題
，完全能夠滿足大多數應用場合。考慮到開關電源所采用的元器件及生產工藝
，一般雙麵板最小線間距設為0.3mm，單麵板最小線間距設為0.5mm，焊盤與焊盤
、焊盤與過孔或過孔與過孔，最小間距設為 0.5mm，可避免在焊接操作過程中出現“橋接”現(xian)象(xiang)。，這(zhe)樣(yang)大(da)多(duo)數(shu)製(zhi)板(ban)廠(chang)都(dou)能(neng)夠(gou)很(hen)輕(qing)鬆(song)滿(man)足(zu)生(sheng)產(chan)要(yao)求(qiu)，並(bing)可(ke)以(yi)把(ba)成(cheng)品(pin)率(lv)控(kong)製(zhi)得(de)非(fei)常(chang)高(gao)，亦(yi)可(ke)實(shi)現(xian)合(he)理(li)的(de)布(bu)線(xian)密(mi)度(du)及(ji)有(you)一(yi)個(ge)較(jiao)經(jing)濟(ji)的(de)成(cheng)本(ben)。

最小線間距隻適合信號控製電路和電壓低於63V的低壓電路

，當線間電壓大於該值時一般可按照500V/1mm經驗值取線間距。

方法一：上shang文wen提ti到dao的de線xian路lu板ban開kai槽cao的de方fang法fa適shi用yong於yu一yi些xie間jian距ju不bu夠gou的de場chang合he，順shun便bian提ti一yi下xia
，該gai法fa也ye常chang用yong來lai作zuo為wei保bao護hu放fang電dian間jian隙xi，常chang見jian於yu電dian視shi機ji顯xian象xiang管guan尾wei板ban和he電dian源yuan交jiao流liu輸shu入ru處chu。該gai法fa在zai模mo塊kuai電dian源yuan中zhong得de到dao了le廣guang泛fan的de應ying用yong
，在zai灌guan封feng的de條tiao件jian下xia可ke獲huo得de很hen好hao的de效xiao果guo。

方法二：墊絕緣紙

，可采用青殼紙、聚脂膜、聚(ju)四(si)氟(fu)乙(yi)烯(xi)定(ding)向(xiang)膜(mo)等(deng)絕(jue)緣(yuan)材(cai)料(liao)。一(yi)般(ban)通(tong)用(yong)電(dian)源(yuan)用(yong)青(qing)殼(ke)紙(zhi)或(huo)聚(ju)脂(zhi)膜(mo)墊(dian)在(zai)線(xian)路(lu)板(ban)於(yu)金(jin)屬(shu)機(ji)殼(ke)間(jian)
，這(zhe)種(zhong)材(cai)料(liao)有(you)機(ji)械(xie)強(qiang)度(du)高(gao)，有(you)一(yi)定(ding)抗(kang)潮(chao)濕(shi)的(de)能(neng)力(li)。聚(ju)四(si)氟(fu)乙(yi)烯(xi)定(ding)向(xiang)膜(mo)由(you)於(yu)具(ju)有(you)耐(nai)高(gao)溫(wen)的(de)特(te)性(xing)在(zai)模(mo)塊(kuai)電(dian)源(yuan)中(zhong)得(de)到(dao)廣(guang)泛(fan)的(de)應(ying)用(yong)。在(zai)元(yuan)件(jian)和(he)周(zhou)圍(wei)導(dao)體(ti)間(jian)也(ye)可(ke)墊(dian)絕(jue)緣(yuan)薄(bo)膜(mo)來(lai)提(ti)高(gao)絕(jue)緣(yuan)抗(kang)電(dian)性(xing)能(neng)。

zuijinjinian
，suizheduocengxianlubanzaikaiguandianyuandianluzhongyingyong，shideyinzhixianlubianyaqichengweikeneng，youyuduocengban，cengjianjujiaoxiao
，yekeyichongfenliyongbianyaqichuangkoujiemian，kezaizhuxianlubanshangzaijiayidaoliangpianyouduocengbanzuchengdeyinzhixianquandadaoliyongchuangkou
，jiangdixianludianliumidudemude，youyucaiyongyinzhixianquan，jianshaolerengongganyu，bianyaqiyizhixinghao，pingmianjiegou，lougandi，ouhehao。kaiqishicixin
，lianghaodesanretiaojian。youyuqijuyouzhuduodeyoushi

，youliyudapiliangshengchan
，suoyidedaoguangfandeyingyong。danyanzhikaifachuqitourujiaoda，bushihexiaoguimoshengchan。

fanjidianyuanfanshedianyahaiyouyigequedingyinsujunyongkaiguandianyuandefanshedianyahaiyuyigecanshuyouguan
，najiushishuchudianya
，shuchudianyayuedizebianyaqizashubiyueda，bianyaqilouganyueda
，kaiguanguanchengshoudianyayuegao，youkenengjichuankaiguanguan、xishoudianluxiaohaogonglvyueda，youkenengshixishouhuilugonglvqijianyongjiushixiao。zaishejidiyashuchuxiaogonglvfanjidianyuandeyouhuaguochengzhongbixuxiaoxinchuli
，qichulifangfayoujige：

A、采cai用yong大da一yi個ge功gong率lv等deng級ji的de磁ci芯xin降jiang低di漏lou感gan，這zhe樣yang可ke提ti高gao低di壓ya反fan激ji電dian源yuan的de轉zhuan換huan效xiao率lv，降jiang低di損sun耗hao，減jian小xiao輸shu出chu紋wen波bo，提ti高gao多duo路lu輸shu出chu電dian源yuan的de交jiao差cha調tiao整zheng率lv，一yi般ban常chang見jian於yu家jia電dian用yong開kai關guan電dian源yuan，如ru光guang碟die機ji
、DVB機頂盒等。

B
、如ru果guo條tiao件jian不bu允yun許xu加jia大da磁ci芯xin，隻zhi能neng降jiang低di反fan射she電dian壓ya
，減jian小xiao占zhan空kong比bi。降jiang低di反fan射she電dian壓ya可ke減jian小xiao漏lou感gan但dan有you可ke能neng使shi電dian源yuan轉zhuan換huan效xiao率lv降jiang低di
，這zhe兩liang者zhe是shi一yi個ge矛mao盾dun
，必bi須xu要yao有you一yi個ge替ti代dai過guo程cheng才cai能neng找zhao到dao一yi個ge合he適shi的de點dian，在zai變bian壓ya器qi替ti代dai實shi驗yan過guo程cheng中zhong，可ke以yi檢jian測ce變bian壓ya器qi原yuan邊bian的de反fan峰feng電dian壓ya，盡jin量liang降jiang低di反fan峰feng電dian壓ya脈mai衝chong的de寬kuan度du，和he幅fu度du，可ke增zeng加jia變bian換huan器qi的de工gong作zuo安an全quan裕yu度du。一yi般ban反fan射she電dian壓ya在zai110V時比較合適。

C、增強耦合，降低損耗，采用新的技術
，和繞線工藝，變壓器為滿足安全規範會在原邊和副邊間采取絕緣措施，如墊絕緣膠帶、加jia絕jue緣yuan端duan空kong膠jiao帶dai。這zhe些xie將jiang影ying響xiang變bian壓ya器qi漏lou感gan性xing能neng，現xian實shi生sheng產chan中zhong可ke采cai用yong初chu級ji繞rao組zu包bao繞rao次ci級ji的de繞rao法fa。或huo者zhe次ci級ji用yong三san重zhong絕jue緣yuan線xian繞rao製zhi，取qu消xiao初chu次ci級ji間jian的de絕jue緣yuan物wu，可ke以yi增zeng強qiang耦ou合he
，甚shen至zhi可ke采cai用yong寬kuan銅tong皮pi繞rao製zhi。
[page]

fanjidianyuanbianyaqicixinzaigongzuozaidanxiangcihuazhuangtai，suoyiciluxuyaokaiqixi，leisiyumaidongzhiliudianganqi。bufencilutongguokongqifengxiouhe。weishenmekaiqixideyuanlibenrenlijiewei：由於功率鐵氧體也具有近似於矩形的工作特性曲線(磁滯回線)，在工作特性曲線上Y軸表示磁感應強度(B)，現在的生產工藝一般飽和點在400mT以上，一般此值在設計中取值應該在200-300mT比較合適、X軸表示磁場強度(H)此值與磁化電流強度成比例關係。磁路開氣隙相當於把磁體磁滯回線向X軸zhou向xiang傾qing斜xie
，在zai同tong樣yang的de磁ci感gan應ying強qiang度du下xia


，可ke承cheng受shou更geng大da的de磁ci化hua電dian流liu，則ze相xiang當dang於yu磁ci心xin儲chu存cun更geng多duo的de能neng量liang，此ci能neng量liang在zai開kai關guan管guan截jie止zhi時shi通tong過guo變bian壓ya器qi次ci級ji瀉xie放fang到dao負fu載zai電dian路lu
，反fan激ji電dian源yuan磁ci芯xin開kai氣qi隙xi有you兩liang個ge作zuo用yong。

反fan激ji電dian源yuan的de變bian壓ya器qi工gong作zuo在zai單dan向xiang磁ci化hua狀zhuang態tai，不bu僅jin要yao通tong過guo磁ci耦ou合he傳chuan遞di能neng量liang，還hai擔dan負fu電dian壓ya變bian換huan輸shu入ru輸shu出chu隔ge離li的de多duo重zhong作zuo用yong。所suo以yi氣qi隙xi的de處chu理li需xu要yao非fei常chang小xiao心xin
，氣qi隙xi太tai大da可ke使shi漏lou感gan變bian大da，磁ci滯zhi損sun耗hao增zeng加jia，鐵tie損sun、銅損增大，影響電源的整機性能。氣隙太小有可能使變壓器磁芯飽和，導致電源損壞。

suoweifanjidianyuandelianxuyuduanxumoshishizhibianyaqidegongzuozhuangtai，zaimanzaizhuangtaibianyaqigongzuoyunengliangwanquanchuandi
，huobuwanquanchuandidegongzuomoshi。yibanyaogenjugongzuohuanjingjinxingsheji，changguifanjidianyuanyinggaigongzuozailianxumoshi，zheyangkaiguanguan、線xian路lu的de損sun耗hao都dou比bi較jiao小xiao，而er且qie可ke以yi減jian輕qing輸shu入ru輸shu出chu電dian容rong的de工gong作zuo應ying力li，但dan是shi這zhe也ye有you一yi些xie例li外wai。由you於yu製zhi造zao工gong藝yi特te點dian，高gao反fan壓ya二er極ji管guan
，反fan向xiang恢hui複fu時shi間jian長chang
，速su度du低di，在zai電dian流liu連lian續xu狀zhuang態tai，二er極ji管guan是shi在zai有you正zheng向xiang偏pian壓ya時shi恢hui複fu，反fan向xiang恢hui複fu時shi的de能neng量liang損sun耗hao非fei常chang大da

，不bu利li於yu變bian換huan器qi性xing能neng的de提ti高gao，輕qing則ze降jiang低di轉zhuan換huan效xiao率lv，整zheng流liu管guan嚴yan重zhong發fa熱re，重zhong則ze甚shen至zhi燒shao毀hui整zheng流liu管guan。由you於yu在zai斷duan續xu模mo式shi下xia
，二er極ji管guan是shi在zai零ling偏pian壓ya情qing況kuang下xia反fan向xiang偏pian置zhi，損sun耗hao可ke以yi降jiang到dao一yi個ge比bi較jiao低di的de水shui平ping。

fanjikaiguandianyuanbianyaqiyinggongzuozailianxumoshi，najiuyaoqiubijiaodaderaozudianganliang

，dangranlianxuyeshiyouyidingchengdude，guofenzhuiqiujueduilianxushibuxianshide
，youkenengxuyaohendadecixin
，feichangduodexianquanzashu
，tongshibansuizhedadelouganhefenbudianrong
，kenengdebuchangshi。nameruhequedingzhegecanshune，tongguoduocishijian
，jifenxitongxingdesheji，benrenrenwei


，zaibiaochengdianyashurushi，shuchudadao50%~60%變壓器從斷續，過渡到連續狀態比較合適。

本ben篇pian文wen章zhang從cong結jie構gou到dao電dian路lu板ban的de設she計ji，一yi路lu介jie紹shao了le如ru何he將jiang開kai關guan電dian源yuan進jin行xing合he理li的de設she計ji。並bing給gei出chu了le了le一yi些xie問wen題ti的de解jie決jue方fang法fa。可ke以yi說shuo包bao含han了le一yi個ge開kai關guan電dian源yuan設she計ji的de全quan部bu過guo程cheng
，從cong設she計ji和he實shi際ji生sheng產chan都dou進jin行xing了le詳xiang細xi的de介jie紹shao

，對dui新xin手shou來lai說shuo是shi不bu可ke多duo得de的de寶bao貴gui知zhi識shi
，希xi望wang大da家jia能neng從cong本ben篇pian文wen章zhang當dang中zhong學xue習xi到dao合he理li設she計ji開kai關guan電dian源yuan的de方fang法fa，並bing加jia以yi靈ling活huo運yun用yong。