電源適配器幾大常用電子元器件基礎知識學習
關于從(cong)事電子(zi)行業的工程師(shi)來說，是(shi)每(mei)天都需求去接觸，每(mei)天都需求用(yong)到的，但其(qi)實里邊的門(men)門(men)道(dao)道(dao)許多工程師(shi)未必了解。這(zhe)兒列舉出(chu)工程師(shi)門(men)常用(yong)的電源(yuan)適配(pei)器幾大電子(zi)元器材，及相關的基礎(chu)概念和(he)知識，和(he)大家一同溫習一遍。
一、電阻
作為(wei)電子行業的(de)工(gong)作者(zhe)，電阻是無人(ren)不知無人(ren)不曉的(de)。它的(de)重要(yao)性，毋庸置疑(yi)。人(ren)們都(dou)說(shuo)“電阻是所有電子電路(lu)中使用最多的(de)元件。
電(dian)(dian)阻(zu)(zu)，因(yin)為(wei)物(wu)(wu)質(zhi)(zhi)對(dui)電(dian)(dian)流產生的阻(zu)(zu)止效果，所以稱(cheng)其(qi)該效果下的電(dian)(dian)阻(zu)(zu)物(wu)(wu)質(zhi)(zhi)。電(dian)(dian)阻(zu)(zu)將會導(dao)致(zhi)電(dian)(dian)子(zi)流通(tong)量(liang)的變化，電(dian)(dian)阻(zu)(zu)越小(xiao)(xiao)，電(dian)(dian)子(zi)流通(tong)量(liang)越大(da)，反(fan)之亦然。沒有電(dian)(dian)阻(zu)(zu)或電(dian)(dian)阻(zu)(zu)很(hen)小(xiao)(xiao)的物(wu)(wu)質(zhi)(zhi)稱(cheng)其(qi)為(wei)電(dian)(dian)導(dao)體，簡稱(cheng)導(dao)體。不能形成(cheng)電(dian)(dian)流傳輸的物(wu)(wu)質(zhi)(zhi)稱(cheng)為(wei)電(dian)(dian)絕緣(yuan)體，簡稱(cheng)絕緣(yuan)體。
在物理學中，用(yong)電阻(zu)(zu)來表(biao)明導體(ti)(ti)對電流(liu)阻(zu)(zu)止(zhi)效果(guo)(guo)的(de)(de)(de)(de)巨細(xi)。導體(ti)(ti)的(de)(de)(de)(de)電阻(zu)(zu)越大，表(biao)明導體(ti)(ti)對電流(liu)的(de)(de)(de)(de)阻(zu)(zu)止(zhi)效果(guo)(guo)越大。不(bu)同的(de)(de)(de)(de)導體(ti)(ti)，電阻(zu)(zu)一般不(bu)同，電阻(zu)(zu)是導體(ti)(ti)自身的(de)(de)(de)(de)一種特性。電阻(zu)(zu)元件是對電流(liu)出現阻(zu)(zu)止(zhi)效果(guo)(guo)的(de)(de)(de)(de)耗能元件。
電阻元件的電阻值巨細(xi)一般與溫度(du)有關，衡量電阻受溫度(du)影(ying)響巨細(xi)的物理(li)量是(shi)溫度(du)系(xi)數(shu)，其定義(yi)為溫度(du)每升(sheng)高1℃時電阻值產生變(bian)化的百分數(shu)。
電阻在(zai)電路頂用“R”加(jia)數字表明，如：R1表明編號為1 的電阻。電阻在(zai)電路中的首要(yao)效(xiao)果(guo)為分流、限流、分壓、偏置等。
二、電容
電容(rong)指的(de)是在給定電位差下(xia)的(de)電荷儲藏量;記為C，國際單位是法拉(F)。一般來(lai)說，電荷在電場中會受力而(er)移(yi)動，當導(dao)體之間有了(le)介(jie)質(zhi)，則阻止(zhi)了(le)電荷移(yi)動而(er)使得(de)電荷累(lei)積在導(dao)體上;形成電荷的(de)累(lei)積儲存，最常見的(de)比(bi)如便是兩片平行金屬(shu)板。也是電容(rong)器的(de)俗(su)稱(cheng)。
1、電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)在(zai)電(dian)(dian)(dian)(dian)路中(zhong)一般用“C”加(jia)數(shu)字表明(ming)(ming)(如(ru)C13表明(ming)(ming)編號(hao)為(wei)13 的(de)電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong))。電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)是由兩片(pian)金屬(shu)膜緊靠，中(zhong)間(jian)用絕緣資料隔開而(er)組成(cheng)的(de)元件。電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)的(de)特性首要(yao)是隔直(zhi)流通(tong)溝通(tong)。電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)容(rong)(rong)(rong)(rong)(rong)(rong)量的(de)巨(ju)細便(bian)是表明(ming)(ming)能(neng)貯存電(dian)(dian)(dian)(dian)能(neng)的(de)巨(ju)細，電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)對溝通(tong)信(xin)號(hao)的(de)阻止效果稱(cheng)為(wei)容(rong)(rong)(rong)(rong)(rong)(rong)抗，它與溝通(tong)信(xin)號(hao)的(de)頻率和電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)量有關。容(rong)(rong)(rong)(rong)(rong)(rong)抗XC=1/2πfc(f表明(ming)(ming)溝通(tong)信(xin)號(hao)的(de)頻率，C 表明(ming)(ming)電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)容(rong)(rong)(rong)(rong)(rong)(rong)量)電(dian)(dian)(dian)(dian)話機中(zhong)常用電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)的(de)品種有電(dian)(dian)(dian)(dian)解電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)、瓷片(pian)電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)、貼(tie)片(pian)電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)、獨石電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)、鉭電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)和滌(di)綸電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)等(deng)。
2、辨認(ren)(ren)方(fang)法(fa)(fa)：電(dian)容(rong)的辨認(ren)(ren)方(fang)法(fa)(fa)與(yu)電(dian)阻的辨認(ren)(ren)方(fang)法(fa)(fa)根本相(xiang)同(tong)，分直標法(fa)(fa)、色標法(fa)(fa)和數標法(fa)(fa)3 種。電(dian)容(rong)的根本單位用法(fa)(fa)拉(F)表明，其它單位還有：毫(hao)法(fa)(fa)(mF)、微法(fa)(fa)(uF)、納法(fa)(fa)(nF)、皮法(fa)(fa)(pF)。
三、晶體二極管
晶(jing)體(ti)二極管(guan)(guan)(crystaldiode)固態電子器材中的(de)半導(dao)體(ti)兩頭器材。這(zhe)些器材首(shou)要(yao)的(de)特(te)征(zheng)是具(ju)有非線性(xing)的(de)電流-電壓特(te)性(xing)。此(ci)后跟(gen)著半導(dao)體(ti)資料(liao)和工藝技(ji)術(shu)的(de)開展(zhan)，利用(yong)不同的(de)半導(dao)體(ti)資料(liao)、摻雜(za)分(fen)布、幾何(he)結構(gou)，研制(zhi)出(chu)結構(gou)品種繁(fan)多(duo)(duo)、功能用(yong)處各異的(de)多(duo)(duo)種晶(jing)體(ti)二極管(guan)(guan)。制(zhi)造資料(liao)有鍺、硅(gui)及(ji)化合物半導(dao)體(ti)。晶(jing)體(ti)二極管(guan)(guan)可用(yong)來產生(sheng)、操控、接納、變換、擴大信號和進(jin)行能量(liang)轉化等。
晶體(ti)二極管在電路(lu)中常用“D”加(jia)數(shu)字表(biao)明(ming)，如：D5表(biao)明(ming)編號為(wei)5的二極管。
1、效果(guo)：二(er)極管(guan)(guan)(guan)的(de)首要特性是(shi)單向導(dao)電(dian)(dian)性，也便是(shi)在(zai)正(zheng)向電(dian)(dian)壓(ya)(ya)的(de)效果(guo)下，導(dao)通電(dian)(dian)阻(zu)很小(xiao);而在(zai)反向電(dian)(dian)壓(ya)(ya)效果(guo)下導(dao)通電(dian)(dian)阻(zu)極大或(huo)無窮大。正(zheng)因為二(er)極管(guan)(guan)(guan)具(ju)有上(shang)述特性，無繩電(dian)(dian)話機(ji)中常(chang)把它用在(zai)整流、阻(zu)隔、穩壓(ya)(ya)、極性維護、編碼操(cao)控(kong)、調頻調制(zhi)和靜噪等電(dian)(dian)路中。電(dian)(dian)話機(ji)里使用的(de)晶體二(er)極管(guan)(guan)(guan)按(an)效果(guo)可分為：整流二(er)極管(guan)(guan)(guan)、阻(zu)隔二(er)極管(guan)(guan)(guan)、肖特基二(er)極管(guan)(guan)(guan)、發光二(er)極管(guan)(guan)(guan)、穩壓(ya)(ya)二(er)極管(guan)(guan)(guan)等。
2、辨認方法：二極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)的辨認很簡單，小功率二極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)的N 極(ji)(ji)(ji)(ji)(負極(ji)(ji)(ji)(ji))，在二極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)外表(biao)大多(duo)選(xuan)用一種(zhong)色圈標(biao)出來(lai)，有(you)些(xie)二極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)也用二極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)專(zhuan)用符(fu)號來(lai)表(biao)明P 極(ji)(ji)(ji)(ji)(正(zheng)極(ji)(ji)(ji)(ji))或N 極(ji)(ji)(ji)(ji)(負極(ji)(ji)(ji)(ji))，也有(you)選(xuan)用符(fu)號標(biao)志(zhi)為“P”、“N”來(lai)確定二極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)極(ji)(ji)(ji)(ji)性的。發光二極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)的正(zheng)負極(ji)(ji)(ji)(ji)可從引腳(jiao)長短來(lai)辨認，長腳(jiao)為正(zheng)，短腳(jiao)為負。
3、測試注意事項：用(yong)數字式(shi)(shi)萬用(yong)表(biao)去測二(er)(er)極(ji)(ji)(ji)管(guan)(guan)(guan)時，紅(hong)表(biao)筆接(jie)二(er)(er)極(ji)(ji)(ji)管(guan)(guan)(guan)的正(zheng)極(ji)(ji)(ji)，黑表(biao)筆接(jie)二(er)(er)極(ji)(ji)(ji)管(guan)(guan)(guan)的負極(ji)(ji)(ji)，此時測得的阻(zu)值(zhi)才是二(er)(er)極(ji)(ji)(ji)管(guan)(guan)(guan)的正(zheng)向導通阻(zu)值(zhi)，這與指針式(shi)(shi)萬用(yong)表(biao)的表(biao)筆接(jie)法(fa)剛好相反。
四、穩壓二極管
穩壓二(er)極(ji)(ji)管(guan)(又名齊納(na)二(er)極(ji)(ji)管(guan)),此二(er)極(ji)(ji)管(guan)是一(yi)種(zhong)直到(dao)臨界反向擊穿電(dian)(dian)壓前都具有很高電(dian)(dian)阻的(de)半導體(ti)器材.穩壓二(er)極(ji)(ji)管(guan)在電(dian)(dian)路中(zhong)常(chang)用“ZD”加數字表明。
1、穩壓(ya)二極管的(de)穩壓(ya)原(yuan)(yuan)理：穩壓(ya)二極管的(de)特色便是(shi)擊穿后，其兩(liang)頭(tou)(tou)的(de)電(dian)(dian)(dian)壓(ya)根本堅持(chi)不變。這樣，當把穩壓(ya)管接入電(dian)(dian)(dian)路(lu)今后，若因(yin)(yin)為電(dian)(dian)(dian)源電(dian)(dian)(dian)壓(ya)產生波動，或其它原(yuan)(yuan)因(yin)(yin)形成電(dian)(dian)(dian)路(lu)中各點(dian)電(dian)(dian)(dian)壓(ya)變化(hua)時(shi)，負載兩(liang)頭(tou)(tou)的(de)電(dian)(dian)(dian)壓(ya)將根本堅持(chi)不變。
2、毛(mao)(mao)病特色：穩壓二極管(guan)的毛(mao)(mao)病首要表(biao)現在開(kai)路(lu)、短路(lu)和(he)穩壓值不(bu)穩定(ding)。在這3種毛(mao)(mao)病中，前(qian)一種毛(mao)(mao)病表(biao)現出電源(yuan)電壓升高;后(hou)2種毛(mao)(mao)病表(biao)現為電源(yuan)電壓變低到零伏或輸出不(bu)穩定(ding)。
| 【上一個】 常見的脈沖電源電路有什么主要特點？ | 【下一個】 維護大功率電源適配器有好方法 |
| ^ 電源適配器幾大常用電子元器件基礎知識學習 |