穩(wen)(wen)壓(ya)器是一種能(neng)自動調整輸出電(dian)(dian)壓(ya)的(de)(de)供(gong)電(dian)(dian)電(dian)(dian)路(lu)或供(gong)電(dian)(dian)設(she)備，其作(zuo)用是將波動較大和達不到(dao)電(dian)(dian)器設(she)備要求的(de)(de)電(dian)(dian)源電(dian)(dian)壓(ya)穩(wen)(wen)定在(zai)它的(de)(de)設(she)定值(zhi)范圍(wei)內(nei)，使各種電(dian)(dian)路(lu)或電(dian)(dian)器設(she)備能(neng)在(zai)額定工(gong)(gong)作(zuo)電(dian)(dian)壓(ya)下正常(chang)工(gong)(gong)作(zuo)。

最初的電(dian)(dian)(dian)(dian)(dian)力(li)穩(wen)壓(ya)(ya)器(qi)是靠繼(ji)(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)的跳動(dong)穩(wen)定電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)的。當電(dian)(dian)(dian)(dian)(dian)網(wang)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)出(chu)現(xian)波動(dong)時，電(dian)(dian)(dian)(dian)(dian)力(li)穩(wen)壓(ya)(ya)器(qi)的自動(dong)糾正電(dian)(dian)(dian)(dian)(dian)路啟動(dong)，使(shi)(shi)內部繼(ji)(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)動(dong)作。迫使(shi)(shi)輸出(chu)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)保持(chi)在(zai)設定值附近，這種電(dian)(dian)(dian)(dian)(dian)路優(you)點是電(dian)(dian)(dian)(dian)(dian)路簡(jian)單，缺點是穩(wen)壓(ya)(ya)精度不高并且每一次繼(ji)(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)跳動(dong)換擋，都會使(shi)(shi)供電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)源發(fa)生一次瞬時的中斷并產(chan)生火花干擾(rao)。

這對電(dian)腦設(she)備的讀寫工(gong)作干(gan)擾很大，容易(yi)造成(cheng)電(dian)腦出現錯誤(wu)信(xin)號，嚴重時還會使硬盤(pan)損壞。

高(gao)質(zhi)量的(de)小(xiao)型穩壓(ya)器(qi)(qi)，大多采用電機(ji)拖動(dong)碳刷(shua)的(de)方法(fa)穩定電壓(ya)，這種穩壓(ya)器(qi)(qi)對電器(qi)(qi)設備(bei)產生(sheng)的(de)干擾很小(xiao)穩壓(ya)精度相對較(jiao)高(gao)。