初的(de)電(dian)(dian)力穩(wen)壓(ya)器是(shi)靠繼電(dian)(dian)器的(de)跳(tiao)動(dong)穩(wen)定電(dian)(dian)壓(ya)的(de)。當電(dian)(dian)網(wang)電(dian)(dian)壓(ya)出(chu)現波動(dong)時，電(dian)(dian)力穩(wen)壓(ya)器的(de)自動(dong)糾(jiu)正電(dian)(dian)路啟動(dong)，使內部(bu)繼電(dian)(dian)器動(dong)作。迫使輸(shu)出(chu)電(dian)(dian)壓(ya)保持在(zai)設定值附近(jin)，這(zhe)種(zhong)電(dian)(dian)路優點是(shi)電(dian)(dian)路簡單，缺點是(shi)穩(wen)壓(ya)精度不(bu)高并且(qie)每一(yi)次繼電(dian)(dian)器跳(tiao)動(dong)換擋，都會使供電(dian)(dian)電(dian)(dian)源(yuan)發生(sheng)一(yi)次瞬時的(de)中(zhong)斷并產(chan)生(sheng)火花(hua)干(gan)擾。

后期(qi)也(ye)是(shi)(shi)現在的穩壓(ya)器(qi)一(yi)般(ban)是(shi)(shi)工(gong)業級穩壓(ya)器(qi)，工(gong)業級穩壓(ya)器(qi)是(shi)(shi)利(li)用感應原理(li)來做電(dian)壓(ya)調(diao)整(zheng)(zheng)、無接點(dian)于負載中呈線性升(sheng)降壓(ya)調(diao)整(zheng)(zheng)，電(dian)壓(ya)調(diao)整(zheng)(zheng)中，不會產生頻率偏移及電(dian)涌(yong)，致(zhi)負載電(dian)力品質(zhi)與輸入端(duan)相同。采用高效率和(he)寬大的安全范圍工(gong)業級零件組合而成，可以承受惡劣的溫度(du)、濕度(du)、震(zhen)動及污穢環境。

穩壓(ya)器主要由調(diao)(diao)壓(ya)電(dian)路(lu)、控制電(dian)路(lu)、及(ji)伺(si)(si)服(fu)電(dian)機等組成，當(dang)輸入電(dian)壓(ya)或(huo)負載變(bian)化(hua)時，控制電(dian)路(lu)進行取(qu)樣(yang)、比較、放大，然后驅動(dong)伺(si)(si)服(fu)電(dian)機轉動(dong)，使調(diao)(diao)壓(ya)器碳刷的(de)位置(zhi)改變(bian)，通過自動(dong)調(diao)(diao)整(zheng)線圈(quan)匝數(shu)比，從而保持輸出電(dian)壓(ya)的(de)穩定。容(rong)量(liang)較大的(de)穩壓(ya)器，還(huan)采用電(dian)壓(ya)補(bu)償的(de)原(yuan)理工作。