穩(wen)壓(ya)二極管工作(zuo)在(zai)(zai)反向擊穿狀態時，其兩端的電(dian)(dian)壓(ya)是(shi)基本不變的。利(li)用(yong)這一性質，在(zai)(zai)電(dian)(dian)路里常用(yong)于構(gou)成穩(wen)壓(ya)電(dian)(dian)路。
穩(wen)壓(ya)二(er)極管構成的穩(wen)壓(ya)電(dian)路(lu)，雖(sui)然穩(wen)定(ding)度不很(hen)高，但卻具有簡單(dan)、經(jing)濟(ji)實用(yong)(yong)的優點，因(yin)而應用(yong)(yong)非常廣泛(fan)。
在實際電路中(zhong)，要使用好(hao)穩壓二極管，應注意如(ru)下(xia)幾個問題。
1、要(yao)注意一(yi)般二(er)(er)(er)極(ji)(ji)(ji)管(guan)(guan)與(yu)穩(wen)壓(ya)(ya)(ya)二(er)(er)(er)極(ji)(ji)(ji)管(guan)(guan)的(de)(de)區別(bie)方(fang)法(fa)。不少的(de)(de)一(yi)般二(er)(er)(er)極(ji)(ji)(ji)管(guan)(guan)，特別(bie)是(shi)玻(bo)璃封(feng)裝(zhuang)的(de)(de)管(guan)(guan)，外(wai)(wai)形(xing)顏色等與(yu)穩(wen)壓(ya)(ya)(ya)二(er)(er)(er)極(ji)(ji)(ji)管(guan)(guan)較(jiao)相似，如不細(xi)心區別(bie)，就(jiu)會(hui)使(shi)用(yong)錯誤。區別(bie)方(fang)法(fa)是(shi)：看(kan)外(wai)(wai)形(xing)，不少穩(wen)壓(ya)(ya)(ya)二(er)(er)(er)極(ji)(ji)(ji)管(guan)(guan)為(wei)園(yuan)(yuan)柱(zhu)形(xing)，較(jiao)短粗，而一(yi)般二(er)(er)(er)極(ji)(ji)(ji)管(guan)(guan)若(ruo)(ruo)為(wei)園(yuan)(yuan)柱(zhu)形(xing)的(de)(de)則較(jiao)細(xi)長；看(kan)標(biao)志(zhi)，穩(wen) 壓(ya)(ya)(ya)二(er)(er)(er)極(ji)(ji)(ji)管(guan)(guan)的(de)(de)外(wai)(wai)表(biao)面上都標(biao)有穩(wen)壓(ya)(ya)(ya)值(zhi)，如5V6，表(biao)示穩(wen)壓(ya)(ya)(ya)值(zhi)為(wei)5.6V；用(yong)萬用(yong)表(biao)進行測(ce)量(liang)，根據單向導電性(xing)，用(yong)X1K擋先把被測(ce)二(er)(er)(er)極(ji)(ji)(ji)管(guan)(guan)的(de)(de)正負極(ji)(ji)(ji)性(xing)判斷出(chu)來，然后用(yong)X10K擋，黑表(biao)筆接二(er)(er)(er)極(ji)(ji)(ji)管(guan)(guan)負極(ji)(ji)(ji)，紅(hong)表(biao)筆接二(er)(er)(er)極(ji)(ji)(ji)管(guan)(guan)正極(ji)(ji)(ji)，測(ce)的(de)(de)阻值(zhi)與(yu)X1K擋時相比(bi)，若(ruo)(ruo)出(chu)現(xian)的(de)(de)反向阻值(zhi)很大，為(wei)一(yi)般二(er)(er)(er)極(ji)(ji)(ji)管(guan)(guan)的(de)(de)可能性(xing)很大，若(ruo)(ruo)出(chu)現(xian)的(de)(de)反向阻值(zhi)變(bian)得很小，則為(wei)穩(wen)壓(ya)(ya)(ya)二(er)(er)(er)極(ji)(ji)(ji)管(guan)(guan)。
2、注意穩(wen)(wen)(wen)(wen)(wen)壓二(er)極管(guan)(guan)正(zheng)(zheng)(zheng)向(xiang)(xiang)使(shi)用(yong)與反向(xiang)(xiang)使(shi)用(yong)的(de)區別。穩(wen)(wen)(wen)(wen)(wen)壓二(er)極管(guan)(guan)正(zheng)(zheng)(zheng)向(xiang)(xiang)導通(tong)(tong)使(shi)用(yong)時(shi)，與一般(ban)(ban)二(er)極管(guan)(guan)正(zheng)(zheng)(zheng)向(xiang)(xiang)導通(tong)(tong)使(shi)用(yong)時(shi)基本(ben)相同(tong)，正(zheng)(zheng)(zheng)向(xiang)(xiang)導通(tong)(tong)后兩(liang)端電壓也是基本(ben)不(bu)變的(de)，都(dou)約為0.7V。從(cong)理(li)論(lun)上講，穩(wen)(wen)(wen)(wen)(wen)壓二(er)極管(guan)(guan)也可正(zheng)(zheng)(zheng)向(xiang)(xiang)使(shi)用(yong)做穩(wen)(wen)(wen)(wen)(wen)壓管(guan)(guan)用(yong)，但其穩(wen)(wen)(wen)(wen)(wen)壓值將(jiang)低于(yu)1V，且穩(wen)(wen)(wen)(wen)(wen)壓性能(neng)也不(bu)好，一般(ban)(ban)不(bu)單(dan)獨用(yong)穩(wen)(wen)(wen)(wen)(wen)壓管(guan)(guan)的(de)正(zheng)(zheng)(zheng)向(xiang)(xiang)導通(tong)(tong)特(te)性來(lai)穩(wen)(wen)(wen)(wen)(wen)壓，而(er)是用(yong)反向(xiang)(xiang)擊穿特(te)性來(lai)穩(wen)(wen)(wen)(wen)(wen)壓。反向(xiang)(xiang)擊穿電壓值即為穩(wen)(wen)(wen)(wen)(wen)壓值。有時(shi)將(jiang)兩(liang)個穩(wen)(wen)(wen)(wen)(wen)壓管(guan)(guan)串聯使(shi)用(yong)，一個利用(yong)它(ta)(ta)的(de)正(zheng)(zheng)(zheng)向(xiang)(xiang)特(te)性，另一個利用(yong)它(ta)(ta)的(de)反向(xiang)(xiang)特(te)性，則既能(neng)穩(wen)(wen)(wen)(wen)(wen)壓又可起溫度補償(chang)作用(yong)，以提高穩(wen)(wen)(wen)(wen)(wen)壓效果。
3、要(yao)注意限(xian)流電(dian)(dian)阻(zu)的作用(yong)及(ji)阻(zu)值大(da)(da)小(xiao)的影響。在穩(wen)(wen)壓(ya)(ya)二極管(guan)穩(wen)(wen)壓(ya)(ya)電(dian)(dian)路(lu)中，一(yi)般都要(yao)串接一(yi)個電(dian)(dian)阻(zu)R，如圖(tu)1或2示(shi)。該電(dian)(dian)阻(zu)在電(dian)(dian)路(lu)中起限(xian)流和提高(gao)穩(wen)(wen)壓(ya)(ya)效(xiao)果的作用(yong)。若不加該電(dian)(dian)阻(zu)即當(dang)R=0時，容易(yi)燒壞(huai)穩(wen)(wen)壓(ya)(ya)管(guan)，穩(wen)(wen)壓(ya)(ya)效(xiao)果也會極差(cha)。限(xian)流電(dian)(dian)阻(zu)的阻(zu)值越大(da)(da)，電(dian)(dian)路(lu)穩(wen)(wen)壓(ya)(ya)性能越好，但輸入與(yu)輸出(chu)壓(ya)(ya)差(cha)也會過大(da)(da)，耗(hao)電(dian)(dian)也就越多。
4、要注意(yi)輸入(ru)與輸出的(de)(de)壓(ya)(ya)(ya)差(cha)。正常(chang)使(shi)用(yong)時(shi)，穩(wen)(wen)(wen)壓(ya)(ya)(ya)二(er)極(ji)管(guan)(guan)穩(wen)(wen)(wen)壓(ya)(ya)(ya)電路的(de)(de)輸出電壓(ya)(ya)(ya)等于(yu)穩(wen)(wen)(wen)壓(ya)(ya)(ya)管(guan)(guan)反向(xiang)擊穿(chuan)后兩端的(de)(de)穩(wen)(wen)(wen)壓(ya)(ya)(ya)值(zhi)，若輸入(ru)到穩(wen)(wen)(wen)壓(ya)(ya)(ya)電路中的(de)(de)電壓(ya)(ya)(ya)值(zhi)小于(yu)穩(wen)(wen)(wen)壓(ya)(ya)(ya)管(guan)(guan)的(de)(de)穩(wen)(wen)(wen)壓(ya)(ya)(ya)值(zhi)，則(ze)電路將(jiang)失去(qu)穩(wen)(wen)(wen)壓(ya)(ya)(ya)作用(yong)，只有是大于(yu)關系時(shi)，才有穩(wen)(wen)(wen)壓(ya)(ya)(ya)作用(yong)，并(bing)且壓(ya)(ya)(ya)差(cha)越(yue)大，限流(liu)電阻的(de)(de)阻值(zhi)也應越(yue)大，否則(ze)會損壞穩(wen)(wen)(wen)壓(ya)(ya)(ya)管(guan)(guan)。
5、穩(wen)(wen)壓(ya)管可串(chuan)聯(lian)使用(yong)。幾個(ge)穩(wen)(wen)壓(ya)管串(chuan)聯(lian)后，可獲得多個(ge)不同的(de)穩(wen)(wen)壓(ya)值(zhi)，故串(chuan)聯(lian)使用(yong)較常見。下(xia)面舉例說明(ming)兩個(ge)穩(wen)(wen)壓(ya)管串(chuan)聯(lian)使用(yong)后，如何求得穩(wen)(wen)壓(ya)值(zhi)。若一(yi)個(ge)穩(wen)(wen)壓(ya)管的(de)穩(wen)(wen)壓(ya)值(zhi)為5.6V，另一(yi)個(ge)穩(wen)(wen)壓(ya)值(zhi)為3.6V，設穩(wen)(wen)壓(ya)管正向(xiang)導通時電(dian)壓(ya)均為0.7V，則(ze)串(chuan)聯(lian)后共有四(si)種不同的(de)穩(wen)(wen)壓(ya)值(zhi)，如圖1示。
6、穩(wen)壓管(guan)一般不并(bing)(bing)聯(lian)(lian)使用。幾個(ge)穩(wen)壓管(guan)并(bing)(bing)聯(lian)(lian)后，穩(wen)壓值(zhi)將由最低(包括正向導通后的(de)電(dian)壓值(zhi))的(de)一個(ge)來決定。還是以上述(shu)兩(liang)(liang)個(ge)穩(wen)壓管(guan)為例，來說明(ming)穩(wen)壓值(zhi)的(de)計算方法。兩(liang)(liang)個(ge)并(bing)(bing)聯(lian)(lian)后共(gong)有(you)四(si)種情況(kuang)，穩(wen)壓值(zhi)只有(you)兩(liang)(liang)個(ge)。除(chu)非特殊(shu)情況(kuang)，穩(wen)壓二(er)極管(guan)都不并(bing)(bing)聯(lian)(lian)使用。
