很(hen)多人其實(shi)并(bing)不知道開關電源適(shi)配(pei)器(qi)是(shi)什么，甚至很(hen)多人把它單純理解(jie)為“開(kai)(kai)關(guan)”。其實官(guan)方對(dui)開(kai)(kai)關(guan)電(dian)(dian)(dian)(dian)源的解(jie)釋是(shi)利用電(dian)(dian)(dian)(dian)子開(kai)(kai)關(guan)器件（如(ru)晶狀體、場(chang)效應管(guan)、可(ke)控(kong)(kong)硅閘流管(guan)等），通(tong)過(guo)控(kong)(kong)制(zhi)電(dian)(dian)(dian)(dian)路,使電(dian)(dian)(dian)(dian)子開(kai)(kai)關(guan)器件不停地“接通(tong)”和(he)“關(guan)斷”，讓電(dian)(dian)(dian)(dian)子開(kai)(kai)關(guan)器件對(dui)輸(shu)入電(dian)(dian)(dian)(dian)壓進行脈沖(chong)調(diao)制(zhi)，從(cong)而實現(xian)DC/AC、DC/DC電(dian)(dian)(dian)(dian)壓變換，以及輸(shu)出電(dian)(dian)(dian)(dian)壓可(ke)調(diao)和(he)自動穩壓。那(nei)么開(kai)(kai)關(guan)電(dian)(dian)(dian)(dian)源都(dou)有(you)哪(na)些特點呢？

開關電(dian)源一般有三種工作模(mo)式：頻(pin)率、脈沖(chong)寬(kuan)度固定模(mo)式，頻(pin)率固定、脈沖(chong)寬(kuan)度可變模(mo)式，頻(pin)率、脈沖(chong)寬(kuan)度可變模(mo)式。前一種工作模(mo)式多(duo)(duo)用(yong)于(yu)DC/AC逆變電(dian)源，或DC/DC電(dian)壓(ya)變換(huan)；后兩(liang)種工作模(mo)式多(duo)(duo)用(yong)于(yu)開關穩壓(ya)電(dian)源。

根據開(kai)(kai)(kai)關(guan)(guan)(guan)器件在電(dian)(dian)路中(zhong)連接(jie)的方式(shi)(shi)(shi)(shi)，開(kai)(kai)(kai)關(guan)(guan)(guan)電(dian)(dian)源(yuan)大體上可(ke)分(fen)(fen)為：串聯(lian)(lian)式(shi)(shi)(shi)(shi)開(kai)(kai)(kai)關(guan)(guan)(guan)電(dian)(dian)源(yuan)、并聯(lian)(lian)式(shi)(shi)(shi)(shi)開(kai)(kai)(kai)關(guan)(guan)(guan)電(dian)(dian)源(yuan)、變壓器式(shi)(shi)(shi)(shi)開(kai)(kai)(kai)關(guan)(guan)(guan)電(dian)(dian)源(yuan)等三(san)大類。其中(zhong)，變壓器式(shi)(shi)(shi)(shi)開(kai)(kai)(kai)關(guan)(guan)(guan)電(dian)(dian)源(yuan)（后面簡稱(cheng)變壓器開(kai)(kai)(kai)關(guan)(guan)(guan)電(dian)(dian)源(yuan)）還可(ke)以(yi)(yi)進一(yi)步分(fen)(fen)成：推挽式(shi)(shi)(shi)(shi)、半橋式(shi)(shi)(shi)(shi)、全橋式(shi)(shi)(shi)(shi)等多種(zhong)；根據變壓器的激(ji)勵和輸出電(dian)(dian)壓的相位，又可(ke)以(yi)(yi)分(fen)(fen)成：正激(ji)式(shi)(shi)(shi)(shi)、反激(ji)式(shi)(shi)(shi)(shi)、單激(ji)式(shi)(shi)(shi)(shi)和雙激(ji)式(shi)(shi)(shi)(shi)等多種(zhong)。

另外開關電(dian)源和其他電(dian)源相比，還有兩個優點。

1、體(ti)積小、重量輕：由于沒有(you)工頻(pin)變壓器，所以體(ti)積和重量只(zhi)有(you)線性電(dian)源的20～30%。

2、功耗小、效(xiao)率(lv)高：功率(lv)晶體(ti)管工(gong)作在開關(guan)狀態，所(suo)以晶體(ti)管上的(de)功耗小，轉(zhuan) 化(hua)效(xiao)率(lv)高，一般為60～70%，而線性電電源只有30～40%。