穩(wen)壓二極管工作(zuo)在(zai)反向擊穿狀(zhuang)態時，其兩端的(de)電(dian)壓是基本不變(bian)的(de)。利用這(zhe)一性質，在(zai)電(dian)路里常用于構成穩(wen)壓電(dian)路。
穩壓二極管構(gou)成(cheng)的(de)穩壓電路，雖然(ran)穩定度不很高，但卻具有簡單(dan)、經(jing)濟實用(yong)的(de)優(you)點，因而應用(yong)非常廣泛。
在實際(ji)電路中，要使用(yong)好穩壓(ya)二極管，應(ying)注意如下幾個問題。
1、要(yao)注意(yi)一般(ban)二(er)(er)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)與(yu)穩(wen)(wen)壓(ya)(ya)(ya)二(er)(er)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)的(de)區別方法(fa)。不(bu)少的(de)一般(ban)二(er)(er)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)，特別是(shi)玻(bo)璃封裝的(de)管(guan)(guan)(guan)，外(wai)形(xing)顏色(se)等與(yu)穩(wen)(wen)壓(ya)(ya)(ya)二(er)(er)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)較相(xiang)似，如不(bu)細心區別，就(jiu)會使用(yong)(yong)錯(cuo)誤。區別方法(fa)是(shi)：看外(wai)形(xing)，不(bu)少穩(wen)(wen)壓(ya)(ya)(ya)二(er)(er)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)為園(yuan)柱(zhu)形(xing)，較短粗，而一般(ban)二(er)(er)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)若(ruo)為園(yuan)柱(zhu)形(xing)的(de)則較細長；看標志，穩(wen)(wen) 壓(ya)(ya)(ya)二(er)(er)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)的(de)外(wai)表面上都(dou)標有穩(wen)(wen)壓(ya)(ya)(ya)值(zhi)，如5V6，表示穩(wen)(wen)壓(ya)(ya)(ya)值(zhi)為5.6V；用(yong)(yong)萬(wan)用(yong)(yong)表進行測量，根據單向(xiang)(xiang)導電性，用(yong)(yong)X1K擋(dang)先把被測二(er)(er)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)的(de)正(zheng)負極(ji)(ji)(ji)(ji)性判斷出來，然后用(yong)(yong)X10K擋(dang)，黑表筆接二(er)(er)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)負極(ji)(ji)(ji)(ji)，紅表筆接二(er)(er)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)正(zheng)極(ji)(ji)(ji)(ji)，測的(de)阻(zu)值(zhi)與(yu)X1K擋(dang)時(shi)相(xiang)比(bi)，若(ruo)出現的(de)反(fan)向(xiang)(xiang)阻(zu)值(zhi)很大，為一般(ban)二(er)(er)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)的(de)可能性很大，若(ruo)出現的(de)反(fan)向(xiang)(xiang)阻(zu)值(zhi)變得很小，則為穩(wen)(wen)壓(ya)(ya)(ya)二(er)(er)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)。
2、注意穩(wen)(wen)(wen)壓(ya)(ya)二極管(guan)(guan)正向(xiang)(xiang)(xiang)使(shi)用(yong)與反向(xiang)(xiang)(xiang)使(shi)用(yong)的區別。穩(wen)(wen)(wen)壓(ya)(ya)二極管(guan)(guan)正向(xiang)(xiang)(xiang)導(dao)(dao)(dao)通(tong)(tong)使(shi)用(yong)時，與一(yi)(yi)般(ban)(ban)二極管(guan)(guan)正向(xiang)(xiang)(xiang)導(dao)(dao)(dao)通(tong)(tong)使(shi)用(yong)時基本相同(tong)，正向(xiang)(xiang)(xiang)導(dao)(dao)(dao)通(tong)(tong)后兩(liang)端電壓(ya)(ya)也是(shi)基本不(bu)變的，都(dou)約(yue)為0.7V。從理論上講(jiang)，穩(wen)(wen)(wen)壓(ya)(ya)二極管(guan)(guan)也可(ke)正向(xiang)(xiang)(xiang)使(shi)用(yong)做穩(wen)(wen)(wen)壓(ya)(ya)管(guan)(guan)用(yong)，但其穩(wen)(wen)(wen)壓(ya)(ya)值(zhi)將低于1V，且穩(wen)(wen)(wen)壓(ya)(ya)性能也不(bu)好，一(yi)(yi)般(ban)(ban)不(bu)單獨(du)用(yong)穩(wen)(wen)(wen)壓(ya)(ya)管(guan)(guan)的正向(xiang)(xiang)(xiang)導(dao)(dao)(dao)通(tong)(tong)特(te)性來穩(wen)(wen)(wen)壓(ya)(ya)，而是(shi)用(yong)反向(xiang)(xiang)(xiang)擊(ji)穿特(te)性來穩(wen)(wen)(wen)壓(ya)(ya)。反向(xiang)(xiang)(xiang)擊(ji)穿電壓(ya)(ya)值(zhi)即為穩(wen)(wen)(wen)壓(ya)(ya)值(zhi)。有(you)時將兩(liang)個穩(wen)(wen)(wen)壓(ya)(ya)管(guan)(guan)串聯使(shi)用(yong)，一(yi)(yi)個利(li)用(yong)它(ta)的正向(xiang)(xiang)(xiang)特(te)性，另一(yi)(yi)個利(li)用(yong)它(ta)的反向(xiang)(xiang)(xiang)特(te)性，則既能穩(wen)(wen)(wen)壓(ya)(ya)又可(ke)起溫度(du)補償作用(yong)，以提高穩(wen)(wen)(wen)壓(ya)(ya)效果。
3、要(yao)注(zhu)意限流(liu)電(dian)(dian)阻(zu)的(de)作(zuo)用及(ji)阻(zu)值大(da)小的(de)影響。在穩(wen)(wen)壓(ya)二(er)極管穩(wen)(wen)壓(ya)電(dian)(dian)路中，一般都要(yao)串接(jie)一個電(dian)(dian)阻(zu)R，如圖(tu)1或2示。該(gai)電(dian)(dian)阻(zu)在電(dian)(dian)路中起限流(liu)和提高(gao)穩(wen)(wen)壓(ya)效果的(de)作(zuo)用。若不加(jia)該(gai)電(dian)(dian)阻(zu)即當R=0時，容(rong)易燒壞(huai)穩(wen)(wen)壓(ya)管，穩(wen)(wen)壓(ya)效果也(ye)會(hui)極差(cha)。限流(liu)電(dian)(dian)阻(zu)的(de)阻(zu)值越大(da)，電(dian)(dian)路穩(wen)(wen)壓(ya)性(xing)能越好，但輸(shu)入與輸(shu)出壓(ya)差(cha)也(ye)會(hui)過大(da)，耗電(dian)(dian)也(ye)就越多(duo)。
4、要(yao)注意(yi)輸(shu)(shu)入(ru)與輸(shu)(shu)出的(de)壓(ya)(ya)(ya)差。正常使用(yong)時(shi)，穩(wen)壓(ya)(ya)(ya)二極管穩(wen)壓(ya)(ya)(ya)電(dian)路的(de)輸(shu)(shu)出電(dian)壓(ya)(ya)(ya)等(deng)于穩(wen)壓(ya)(ya)(ya)管反(fan)向擊穿后兩端的(de)穩(wen)壓(ya)(ya)(ya)值，若輸(shu)(shu)入(ru)到穩(wen)壓(ya)(ya)(ya)電(dian)路中的(de)電(dian)壓(ya)(ya)(ya)值小于穩(wen)壓(ya)(ya)(ya)管的(de)穩(wen)壓(ya)(ya)(ya)值，則(ze)電(dian)路將失去穩(wen)壓(ya)(ya)(ya)作(zuo)用(yong)，只有(you)是大(da)于關(guan)系時(shi)，才有(you)穩(wen)壓(ya)(ya)(ya)作(zuo)用(yong)，并且壓(ya)(ya)(ya)差越大(da)，限流電(dian)阻(zu)的(de)阻(zu)值也應越大(da)，否則(ze)會損壞穩(wen)壓(ya)(ya)(ya)管。
5、穩(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)管(guan)可(ke)串(chuan)聯使用(yong)。幾(ji)個(ge)(ge)(ge)穩(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)管(guan)串(chuan)聯后，可(ke)獲(huo)得多個(ge)(ge)(ge)不同的穩(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)值(zhi)，故串(chuan)聯使用(yong)較常見。下面(mian)舉(ju)例說明兩(liang)個(ge)(ge)(ge)穩(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)管(guan)串(chuan)聯使用(yong)后，如(ru)(ru)何(he)求得穩(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)值(zhi)。若一(yi)個(ge)(ge)(ge)穩(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)管(guan)的穩(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)值(zhi)為5.6V，另一(yi)個(ge)(ge)(ge)穩(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)值(zhi)為3.6V，設穩(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)管(guan)正向(xiang)導通(tong)時電壓(ya)(ya)均為0.7V，則串(chuan)聯后共有四種不同的穩(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)值(zhi)，如(ru)(ru)圖1示。
6、穩壓(ya)(ya)管(guan)一般不(bu)并(bing)聯(lian)(lian)使用(yong)。幾個穩壓(ya)(ya)管(guan)并(bing)聯(lian)(lian)后(hou)(hou)，穩壓(ya)(ya)值將由最低(包括正向導通后(hou)(hou)的(de)電壓(ya)(ya)值)的(de)一個來(lai)決定。還是以(yi)上述兩個穩壓(ya)(ya)管(guan)為例，來(lai)說(shuo)明穩壓(ya)(ya)值的(de)計算方(fang)法(fa)。兩個并(bing)聯(lian)(lian)后(hou)(hou)共有四種情況(kuang)，穩壓(ya)(ya)值只(zhi)有兩個。除非(fei)特殊情況(kuang)，穩壓(ya)(ya)二極(ji)管(guan)都不(bu)并(bing)聯(lian)(lian)使用(yong)。
