開關電源(yuan)的(de)(de)前身是線性穩壓電(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)，各種(zhong)電(dian)(dian)(dian)(dian)子(zi)裝置、許多(duo)電(dian)(dian)(dian)(dian)氣(qi)控制設備(bei)的(de)(de)工(gong)作(zuo)電(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)都是直流電(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)。在開關電(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)出(chu)現之(zhi)前，這些裝置的(de)(de)工(gong)作(zuo)電(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)都采(cai)用(yong)線性穩壓電(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)。由(you)于計(ji)算(suan)機等(deng)電(dian)(dian)(dian)(dian)子(zi)裝置的(de)(de)集成度不斷增(zeng)加，功能越(yue)來(lai)越(yue)強(qiang)，它們的(de)(de)體積越(yue)來(lai)越(yue)小，迫切需要體積小、重量輕、效率高、性能好的(de)(de)新(xin)型(xing)電(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)，這就(jiu)成了開關電(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)發展的(de)(de)強(qiang)大動力。

20世(shi)紀60末，由于(yu)微電(dian)子技術(shu)的(de)快速發展，高反壓、大電(dian)流的(de)功率(lv)(lv)(lv)開(kai)(kai)(kai)關(guan)(guan)晶體(ti)管的(de)出現，使(shi)得采(cai)用高工作頻(pin)(pin)(pin)率(lv)(lv)(lv)的(de)開(kai)(kai)(kai)關(guan)(guan)電(dian)源(yuan)得以問世(shi)，那(nei)時(shi)確(que)定的(de)開(kai)(kai)(kai)關(guan)(guan)電(dian)源(yuan)基(ji)本機構一(yi)(yi)(yi)直沿用至今。開(kai)(kai)(kai)關(guan)(guan)頻(pin)(pin)(pin)率(lv)(lv)(lv)的(de)提(ti)高有(you)助于(yu)開(kai)(kai)(kai)關(guan)(guan)電(dian)源(yuan)的(de)體(ti)積減(jian)小、重(zhong)量(liang)減(jian)輕(qing)。早期的(de)開(kai)(kai)(kai)關(guan)(guan)電(dian)源(yuan)的(de)開(kai)(kai)(kai)關(guan)(guan)頻(pin)(pin)(pin)率(lv)(lv)(lv)僅為KHz，隨著(zhu)電(dian)力MOS管的(de)應用，開(kai)(kai)(kai)關(guan)(guan)電(dian)源(yuan)的(de)開(kai)(kai)(kai)關(guan)(guan)頻(pin)(pin)(pin)率(lv)(lv)(lv)進一(yi)(yi)(yi)步提(ti)高，使(shi)得電(dian)源(yuan)體(ti)積更小，重(zhong)量(liang)更輕(qing)，效(xiao)率(lv)(lv)(lv)更進一(yi)(yi)(yi)步提(ti)高。

由于和穩壓(ya)(ya)電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)相比(bi)，開(kai)關電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)在絕大(da)多(duo)數性(xing)能電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)指標(biao)上都具有很大(da)的(de)優勢。因此，目前除了對直流(liu)輸出電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)的(de)紋波(bo)要求不(bu)高的(de)場合以外(wai)，開(kai)關電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)已經全面取代了線性(xing)穩壓(ya)(ya)電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)。作為電(dian)(dian)(dian)(dian)(dian)子裝置(zhi)的(de)供電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)，線性(xing)穩壓(ya)(ya)電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)主要用(yong)于小(xiao)功(gong)率范圍。因此，在20世紀80年代以前，作為線性(xing)穩壓(ya)(ya)電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)的(de)更新換代產品，開(kai)關電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)也主要用(yong)于小(xiao)功(gong)率的(de)場合。那時，中、大(da)功(gong)率直流(liu)電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)仍以晶閘管(guan)相控整流(liu)電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)為主。

但是，20世紀80年代起，由于絕(jue)緣柵雙極型晶體管IGBT的(de)(de)出現(xian)(xian)，打破了這一格(ge)局。使得開關(guan)電(dian)源(yuan)(yuan)(yuan)的(de)(de)容(rong)量不斷增大，在(zai)許多中等(deng)容(rong)量的(de)(de)范(fan)圍內，迅速取(qu)代了線性(xing)電(dian)源(yuan)(yuan)(yuan)，在(zai)通信領域(yu)，早期的(de)(de)48V基(ji)礎(chu)電(dian)源(yuan)(yuan)(yuan)幾乎都是采(cai)用(yong)晶閘(zha)(zha)管相控(kong)電(dian)源(yuan)(yuan)(yuan)，現(xian)(xian)在(zai)已逐(zhu)步被開關(guan)電(dian)源(yuan)(yuan)(yuan)所取(qu)代。電(dian)力(li)系統的(de)(de)操(cao)作用(yong)直流(liu)(liu)電(dian)源(yuan)(yuan)(yuan)，以前也是采(cai)用(yong)晶閘(zha)(zha)管相控(kong)電(dian)源(yuan)(yuan)(yuan)，目(mu)前開關(guan)電(dian)源(yuan)(yuan)(yuan)已成為其主(zhu)流(liu)(liu)電(dian)源(yuan)(yuan)(yuan)，開關(guan)電(dian)源(yuan)(yuan)(yuan)的(de)(de)應用(yong)范(fan)圍正(zheng)在(zai)不斷擴大。

如前所訴，開(kai)關(guan)(guan)(guan)頻(pin)(pin)率(lv)(lv)的提高(gao)可以使(shi)(shi)(shi)電源的體(ti)(ti)積減(jian)(jian)小、重量(liang)減(jian)(jian)輕(qing)，但卻(que)使(shi)(shi)(shi)得開(kai)關(guan)(guan)(guan)損耗(hao)增大，電源效(xiao)率(lv)(lv)降低(di)。另(ling)外，開(kai)關(guan)(guan)(guan)電源頻(pin)(pin)率(lv)(lv)的提高(gao)也使(shi)(shi)(shi)得電源的電磁(ci)干(gan)擾問題變得突出起來。為(wei)了(le)解決這一(yi)問題，20世紀80年代，出現了(le)采用軟開(kai)關(guan)(guan)(guan)技術。在理想情(qing)況下，可使(shi)(shi)(shi)開(kai)關(guan)(guan)(guan)損耗(hao)降為(wei)零，提高(gao)效(xiao)率(lv)(lv)，同時也使(shi)(shi)(shi)電磁(ci)干(gan)擾大大減(jian)(jian)小，因而(er)也有助于進(jin)一(yi)步(bu)提高(gao)開(kai)關(guan)(guan)(guan)頻(pin)(pin)率(lv)(lv)，使(shi)(shi)(shi)得電源進(jin)一(yi)步(bu)向(xiang)體(ti)(ti)積小、重量(liang)輕(qing)、效(xiao)率(lv)(lv)高(gao)的方向(xiang)發展。