二極(ji)管的主要特性是單向導(dao)電(dian)(dian)性，也就是在正(zheng)向電(dian)(dian)壓(ya)的作(zuo)用(yong)下，導(dao)通(tong)電(dian)(dian)阻很(hen)小(xiao);而在反向電(dian)(dian)壓(ya)作(zuo)用(yong)下導(dao)通(tong)電(dian)(dian)阻極(ji)大或無(wu)窮大。正(zheng)因為二極(ji)管具有(you)上述特性，電(dian)(dian)路(lu)中(zhong)常(chang)把它用(yong)在整流、 穩壓(ya)電(dian)(dian)路(lu)里。

　　穩(wen)壓(ya)(ya)(ya)二(er)(er)極(ji)管(guan)(guan)的(de)(de)穩(wen)壓(ya)(ya)(ya)原理(li)：穩(wen)壓(ya)(ya)(ya)二(er)(er)極(ji)管(guan)(guan)的(de)(de)特點就是加(jia)反向(xiang)(xiang)電(dian)(dian)壓(ya)(ya)(ya)擊穿后(hou)，其兩端的(de)(de)電(dian)(dian)壓(ya)(ya)(ya)基(ji)本(ben) 保持(chi)不變。而整流(liu)二(er)(er)極(ji)管(guan)(guan)反向(xiang)(xiang)擊穿后(hou)就損壞(huai)了.這樣，當(dang)把穩(wen)壓(ya)(ya)(ya)管(guan)(guan)接入電(dian)(dian)路(lu)以后(hou)，若由于(yu)電(dian)(dian)源電(dian)(dian)壓(ya)(ya)(ya)發生波動， 或(huo)其它原因造(zao)成電(dian)(dian)路(lu)中各點電(dian)(dian)壓(ya)(ya)(ya)變動時，負載兩端的(de)(de)電(dian)(dian)壓(ya)(ya)(ya)將基(ji)本(ben)保持(chi)不變。 穩(wen)壓(ya)(ya)(ya)二(er)(er)極(ji)管(guan)(guan)用來穩(wen)壓(ya)(ya)(ya)或(huo)在串(chuan)聯電(dian)(dian)路(lu)中作基(ji)準電(dian)(dian)壓(ya)(ya)(ya)

　　整流二(er)極管(guan)(guan)和穩(wen)壓(ya)二(er)極管(guan)(guan)都是PN半導(dao)體(ti)器件(jian).所不同的是整流二(er)極管(guan)(guan)用的是單向導(dao)電性.穩(wen)壓(ya)二(er)極管(guan)(guan)是利用了其反向特性.在(zai)電路中反向聯接.