穩壓(ya)器(qi)(qi)由調壓(ya)電路(lu)(lu)、控制電路(lu)(lu)、及(ji)伺(si)服(fu)電機等組成。當(dang)輸(shu)入電壓(ya)或負載(zai)變化時，控制電路(lu)(lu)進行(xing)取樣、比較、放(fang)大，然后驅動(dong)伺(si)服(fu)電機轉動(dong)，使調壓(ya)器(qi)(qi)碳刷的(de)位(wei)置改變，通過自動(dong)調整線(xian)圈匝數比，從而保持輸(shu)出電壓(ya)的(de)穩定。

穩(wen)壓(ya)器是(shi)一種能自動調整(zheng)輸出電(dian)(dian)(dian)壓(ya)的供(gong)電(dian)(dian)(dian)電(dian)(dian)(dian)路或(huo)供(gong)電(dian)(dian)(dian)設(she)備(bei)，其(qi)作(zuo)用是(shi)將波動較大(da)和達(da)不到(dao)電(dian)(dian)(dian)器設(she)備(bei)要求的電(dian)(dian)(dian)源電(dian)(dian)(dian)壓(ya)穩(wen)定在它的設(she)定值(zhi)范(fan)圍內，使各種電(dian)(dian)(dian)路或(huo)電(dian)(dian)(dian)器設(she)備(bei)能在額定工作(zuo)電(dian)(dian)(dian)壓(ya)下正常工作(zuo)。

初的(de)電(dian)(dian)(dian)(dian)(dian)(dian)力穩(wen)壓(ya)(ya)器(qi)(qi)(qi)是靠繼(ji)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)的(de)跳動(dong)穩(wen)定(ding)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)的(de)。當電(dian)(dian)(dian)(dian)(dian)(dian)網(wang)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)出(chu)(chu)現波動(dong)時，電(dian)(dian)(dian)(dian)(dian)(dian)力穩(wen)壓(ya)(ya)器(qi)(qi)(qi)的(de)自動(dong)糾正電(dian)(dian)(dian)(dian)(dian)(dian)路啟動(dong)，使內部繼(ji)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)動(dong)作。迫(po)使輸出(chu)(chu)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)保持(chi)在(zai)設(she)定(ding)值附(fu)近(jin)，這(zhe)種電(dian)(dian)(dian)(dian)(dian)(dian)路優點是電(dian)(dian)(dian)(dian)(dian)(dian)路簡單，缺點是穩(wen)壓(ya)(ya)精度不高(gao)并(bing)且每一次繼(ji)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)跳動(dong)換擋，都(dou)會(hui)使供電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)源發(fa)生一次瞬時的(de)中斷并(bing)產(chan)生火花干擾(rao)。這(zhe)對電(dian)(dian)(dian)(dian)(dian)(dian)腦設(she)備的(de)讀(du)寫(xie)工作干擾(rao)很大(da)，容易造成電(dian)(dian)(dian)(dian)(dian)(dian)腦出(chu)(chu)現錯誤信號，嚴重時還會(hui)使硬盤損壞(huai)。

由于部分電(dian)器(qi)中含(han)有線(xian)圈組件，在通電(dian)初(chu)期(qi)會產生阻礙電(dian)流(liu)的(de)渦(wo)流(liu)，渦(wo)流(liu)的(de)產生既會削弱到電(dian)器(qi)啟動時(shi)(shi)的(de)瞬時(shi)(shi)電(dian)壓，導致啟動緩(huan)慢，又(you)會加強斷路后產生的(de)瞬時(shi)(shi)電(dian)壓，可(ke)能產生火花(hua)損壞(huai)電(dian)路。此(ci)時(shi)(shi)便(bian)需要一個(ge)穩(wen)壓器(qi)來保護電(dian)路的(de)正(zheng)常運行(xing)。

穩壓器(qi)由調(diao)壓電(dian)(dian)(dian)(dian)路(lu)、控(kong)制電(dian)(dian)(dian)(dian)路(lu)、及伺(si)服電(dian)(dian)(dian)(dian)機等組(zu)成，當輸(shu)入(ru)電(dian)(dian)(dian)(dian)壓或負載變化時，控(kong)制電(dian)(dian)(dian)(dian)路(lu)進(jin)行取樣、比較、放大，然后驅動伺(si)服電(dian)(dian)(dian)(dian)機轉(zhuan)動，使調(diao)壓器(qi)碳刷的位置改變，通過自動調(diao)整線圈匝數比，從而保持輸(shu)出電(dian)(dian)(dian)(dian)壓的穩定。容量較大的穩壓器(qi)，還采用電(dian)(dian)(dian)(dian)壓補(bu)償的原理工作。