電動車以其出行便捷、低碳環保的優勢已進入我們的生活，但它的充電器故障率較高很令人頭疼。出于這個緣故，本人根據多年酌維修經驗，總結了電動車充電器的(de)常見故障的(de)維(wei)修方法，供(gong)大家參考。由于電(dian)動車充電(dian)器的(de)輸(shu)入(ru)電(dian)路工作在(zai)高電(dian)壓、太電(dian)流(liu)的(de)狀態下，因此，故障率(lv)最(zui)高。如高壓大電(dian)流(liu)整流(liu)三極管(guan)、濾波電(dian)容、開關功率(lv)管(guan)等;其次較易損壞的(de)就是(shi)輸(shu)出整流(liu)部分的(de)整流(liu)二極管(guan)、保(bao)護(hu)二極管(guan)、濾波電(dian)容、限流(liu)電(dian)阻等;再就是(shi)脈寬調制控(kong)制器的(de)反饋部分和保(bao)護(hu)電(dian)路部分。

1.保險絲管熔斷

一般情(qing)況下(xia)，保險絲管熔斷(duan)說明充(chong)電(dian)(dian)(dian)器(qi)的內部(bu)電(dian)(dian)(dian)路(lu)存在(zai)(zai)短路(lu)或過流(liu)(liu)的故障。這是由(you)于充(chong)電(dian)(dian)(dian)器(qi)長時間工(gong)作在(zai)(zai)高電(dian)(dian)(dian)壓、大電(dian)(dian)(dian)流(liu)(liu)的狀態下(xia)，內部(bu)器(qi)件的故障率(lv)較高所致(zhi)。另(ling)外(wai)，電(dian)(dian)(dian)網電(dian)(dian)(dian)壓的波動，浪涌都(dou)會引(yin)起充(chong)電(dian)(dian)(dian)器(qi)內電(dian)(dian)(dian)流(liu)(liu)瞬間增(zeng)大而使保險絲熔斷(duan)。

維修方(fang)法∶首(shou)先仔細查(cha)看電(dian)路板(ban)上(shang)(shang)面的(de)各個元(yuan)件，看這(zhe)(zhe)些(xie)元(yuan)件的(de)外表是(shi)否(fou)(fou)被燒(shao)(shao)糊(hu)或(huo)有(you)電(dian)解(jie)液(ye)溢出，聞―聞有(you)無(wu)異昧(mei)。再(zai)測(ce)量電(dian)源(yuan)輸(shu)入端(duan)的(de)電(dian)阻值，若小于20OkΩ ，則(ze)說明(ming)后端(duan)有(you)局部短路現象，然后分別測(ce)量4只整流(liu)二極管(guan)(guan)正，反電(dian)阻值和兩個限(xian)流(liu)電(dian)阻的(de)阻值，看有(you)無(wu)短路或(huo)燒(shao)(shao)壞(huai)的(de);最后再(zai)測(ce)量電(dian)源(yuan)濾波電(dian)容是(shi)否(fou)(fou)能(neng)進(jin)行正常(chang)充放電(dian)、開關功(gong)率管(guan)(guan)是(shi)否(fou)(fou)擊穿(chuan)損(sun)壞(huai)、UC3842及(ji)周圍元(yuan)件是(shi)否(fou)(fou)擊穿(chuan)，燒(shao)(shao)壞(huai)等。需(xu)要說明(ming)的(de)是(shi)，因(yin)是(shi)在路測(ce)量，有(you)可(ke)能(neng)會使測(ce)量結(jie)果(guo)有(you)誤或(huo)造成(cheng)誤判，因(yin)此必要時可(ke)把(ba)元(yuan)器(qi)件焊(han)下來測(ce)量。如果(guo)仍然沒(mei)有(you)上(shang)(shang)述(shu)情(qing)況，則(ze)測(ce)量一下輸(shu)入電(dian)源(yuan)線及(ji)輸(shu)出電(dian)源(yuan)線是(shi)否(fou)(fou)內部短路。一般情(qing)況上(shang)(shang)，在熔斷(duan)器(qi)熔斷(duan)故(gu)障中，整流(liu)二極管(guan)(guan)，電(dian)源(yuan)濾波電(dian)容、開關功(gong)率管(guan)(guan)、UC3842是(shi)易損(sun)件，損(sun)壞(huai)的(de)概率可(ke)達(da)95%以上(shang)(shang)，要著重檢查(cha)這(zhe)(zhe)些(xie)元(yuan)器(qi)件，就很容易排除故(gu)障。

2.無直流電壓輸出或電壓輸出不穩定

如(ru)果保(bao)險絲(si)是完好的，在有負(fu)載的惰況下。這類故障(zhang)要原(yuan)因有：過(guo)壓、過(guo)流(liu)保(bao)護(hu)電(dian)(dian)路(lu)出現開路(lu)，短(duan)路(lu)現象(xiang);振(zhen)癆電(dian)(dian)路(lu)沒有工作;電(dian)(dian)源負(fu)載過(guo)重，高(gao)頻(pin)整(zheng)流(liu)濾波電(dian)(dian)路(lu)中整(zheng)流(liu)二極管被擊穿：濾波電(dian)(dian)容(rong)漏電(dian)(dian)等。

維修方法：首先，用萬用表測量高頻脈沖變壓器的各個元器件是否有損壞：排除了高頻整流二極管擊穿、負載短路的情況后，再測量各輸出端的直流電壓，如果這時輸出仍為零，則可以肯定是電源的控(kong)制電(dian)路出(chu)了故(gu)障，最后用萬用表靜(jing)態測量高(gao)頻濾波(bo)電(dian)路中整(zheng)流(liu)二極管及低壓(ya)濾波(bo)電(dian)容(rong)是否損壞，如果上述元器件(jian)有損壞，更換(huan)好新(xin)元器件(jian)，一般故(gu)障即可排(pai)除(chu)。但要注意(yi)：輸出(chu)線(xian)斷線(xian)或開焊、虛焊也會(hui)造成這種故(gu)障，在維修時應注意(yi)這種情況。

3.無直流電壓輸出，但保險絲絲完好

這種現象說明充電(dian)器未工(gong)作(zuo)，或是工(gong)作(zuo)后(hou)進入了保(bao)護狀(zhuang)態(tai)。

維修方法(fa)：首先(xian)應判(pan)(pan)斷一下(xia)充電(dian)(dian)器(qi)的變控芯(xin)片(pian)UC3842是(shi)(shi)否處在王作狀(zhuang)態或(huo)(huo)已經損壞。具體判(pan)(pan)斷方法(fa)是(shi)(shi)：加電(dian)(dian)測UC3842的7腳(jiao)對(dui)地(di)(di)電(dian)(dian)壓，若7腳(jiao)電(dian)(dian)壓正(zheng)常(chang)(chang)并且8腳(jiao)有(you)+5∨電(dian)(dian)壓，1、2、4、6腳(jiao)也會有(you)不(bu)同的電(dian)(dian)壓，則說(shuo)明(ming)電(dian)(dian)路已啟振，UC3842基(ji)本正(zheng)常(chang)(chang)。若7腳(jiao)電(dian)(dian)壓低(di)，其余管(guan)腳(jiao)無電(dian)(dian)壓，則說(shuo)明(ming)UC3842已損壞。最常(chang)(chang)見的損壞是(shi)(shi)7腳(jiao)對(dui)地(di)(di)擊(ji)(ji)穿，6、7腳(jiao)對(dui)地(di)(di)擊(ji)(ji)穿和1、7腳(jiao)對(dui)地(di)(di)擊(ji)(ji)穿。如果(guo)這幾(ji)只腳(jiao)都未擊(ji)(ji)穿，而充電(dian)(dian)器(qi)還(huan)是(shi)(shi)不(bu)能(neng)正(zheng)常(chang)(chang)啟動，也說(shuo)明(ming)UC3842已損壞，應直接(jie)更換。若判(pan)(pan)斷芯(xin)片(pian)沒(mei)有(you)壞，則著檢查開(kai)關(guan)這柵(zha)極的限流電(dian)(dian)阻是(shi)(shi)否開(kai)焊、虛焊或(huo)(huo)變值以(yi)及開(kai)關(guan)功(gong)率管(guan)本身(shen)是(shi)(shi)否性能(neng)不(bu)良。除(chu)此(ci)(ci)之處，電(dian)(dian)源輸出(chu)線斷線或(huo)(huo)接(jie)觸(chu)不(bu)良也會造成這種(zhong)故障，因此(ci)(ci)在維修時也應注(zhu)意。

4.直流電壓輸出過高

這種故障(zhang)往往是(shi)由穩壓(ya)取(qu)樣和(he)穩壓(ya)控(kong)(kong)制(zhi)電(dian)(dian)路異常所(suo)至，在充電(dian)(dian)器(qi)中，直流輸出(chu)、取(qu)樣電(dian)(dian)阻、誤差取(qu)樣放大器(qi)、光(guang)耦合器(qi)、電(dian)(dian)源控(kong)(kong)制(zhi)芯片等共同構成了一個閉(bi)合的(de)控(kong)(kong)制(zhi)環路，任何一處出(chu)問題會導致電(dian)(dian)壓(ya)升(sheng)高。

維修方法：由于充電(dian)(dian)(dian)(dian)(dian)(dian)器有過壓(ya)(ya)(ya)保護電(dian)(dian)(dian)(dian)(dian)(dian)路，輸出電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)過高首先會使過壓(ya)(ya)(ya)保護電(dian)(dian)(dian)(dian)(dian)(dian)路動作。因(yin)此(ci)(ci)遇到這(zhe)種故障，我(wo)們可以(yi)斷開過壓(ya)(ya)(ya)保護電(dian)(dian)(dian)(dian)(dian)(dian)路，使這(zhe)壓(ya)(ya)(ya)保護電(dian)(dian)(dian)(dian)(dian)(dian)路不起(qi)作用(yong)，然后測(ce)(ce)量開機(ji)瞬間的電(dian)(dian)(dian)(dian)(dian)(dian)源主電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)。如果(guo)測(ce)(ce)量值比正常值高出1V以(yi)上，說(shuo)明輸出電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)過高的原因(yin)確實(shi)在控(kong)制(zhi)環路中。此(ci)(ci)時應著(zhu)重檢查取樣電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)是(shi)否變值或損(sun)壞(huai)(huai)，精(jing)密(mi)基(ji)準(zhun)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)源（TL431）或光耦器（PC817）是(shi)否性(xing)能(neng)不良(liang)、變質(zhi)或損(sun)壞(huai)(huai)。其(qi)中精(jing)密(mi)基(ji)準(zhun)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)源（TL431）極(ji)易損(sun)壞(huai)(huai)，我(wo)們可用(yong)下述(shu)方法對精(jing)密(mi)穩壓(ya)(ya)(ya)放大器進行判別(bie)：將TL431 的參考端（Ref）與它的陰(yin)極(ji)（Cathode）相連(lian)，串1OkΩ的電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)，接入5∨電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)。若陽極(ji)（Anode）與陰(yin)極(ji)之間為(wei)2.5V，并且(qie)等(deng)侍片刻還仍為(wei)2.5∨，則為(wei)好管(guan)，否則為(wei)壞(huai)(huai)管(guan)。

5.直流電壓輸出過低

根(gen)據維修(xiu)經驗(yan)，除穩壓控制電路會(hui)引起輸出(chu)電壓過低外，還有(you)以下(xia)幾點原因：

（1）輸(shu)出電壓端整流三(san)極(ji)莒(ju)、濾波電容失效(xiao)，可(ke)以(yi)通過代換法進(jin)行判斷。

（2）開(kai)關(guan)功率管(guan)的(de)性(xing)能(neng)下降(jiang)，導(dao)致開(kai)關(guan)管(guan)不能(neng)正(zheng)常導(dao)通，使電源的(de)內(nei)阻增加，帶負(fu)載能(neng)力下降(jiang)。

（3）開(kai)關功率管的(de)源極通常接一個阻(zu)(zu)值很(hen)小但功率很(hen)大(da)的(de)電(dian)阻(zu)(zu)，作為過(guo)流吳護(hu)檢測(ce)電(dian)阻(zu)(zu)。該電(dian)阻(zu)(zu)的(de)阻(zu)(zu)值―般在0.2～O.8Ω。如該電(dian)阻(zu)(zu)變值或(huo)開(kai)焊(han)、接觸不良(liang)也(ye)會造成輸出電(dian)壓(ya)過(guo)低。

（4）高頻脈(mo)沖變壓器不(bu)良，不(bu)但造成輸出(chu)黽壓下降，還(huan)會造成開關功率管激勵(li)不(bu)足從而屢損(sun)開關管。

（5）高壓直流濾波電容(rong)不良，造成電源帶負載(zai)能力差。

（6）電(dian)源輸出(chu)線接觸(chu)不良，有―定的(de)接觸(chu)電(dian)阻，造(zao)成(cheng)輸出(chu)電(dian)壓過低。

（7）電(dian)(dian)(dian)(dian)網(wang)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)過低(di)。雖然充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)在低(di)玉下(xia)仍然可以輸出額定的充(chong)(chong)咆電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)，但(dan)當電(dian)(dian)(dian)(dian)網(wang)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)低(di)于充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)的最(zui)低(di)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)限定值時，也會使輸出電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)過低(di)。

維修方法∶首先用萬用表檢查―下高壓直流濾波電容是否變質、容量是否下降、能否正常充放電。如無以上問題，則測量一下開關功率管的電極的限流電阻以及源極的過流保護殮測電阻是否變值、變質或開焊、接觸不良。若無問題，再檢查―下高頻變壓器的鐵(tie)芯(xin)是否完好無損。除此z外還有(you)可能就是輸出(chu)濾波電(dian)容容量(liang)降低，或開焊、虛接(jie);電(dian)源輸出(chu)限流電(dian)阻變值或虛接(jie);電(dian)源輸出(chu)線虛接(jie)等。

這(zhe)些困素(su)都(dou)不要放過，都(dou)應(ying)仔細檢查，確(que)保萬無(wu)―失(shi)。

6.散熱風扇不轉

這(zhe)種故障原(yuan)困主要(yao)是(shi)控制(zhi)風(feng)扇的(de)三極管(guan)（一般為8550或(huo)(huo)8050）損壞(huai)，或(huo)(huo)者風(feng)扇本身損壞(huai)或(huo)(huo)風(feng)葉(xie)被雜(za)物(wu)卡住(zhu)。但(dan)有些充(chong)電(dian)器申采(cai)用(yong)(yong)的(de)是(shi)智能散熱，對于采(cai)用(yong)(yong)這(zhe)種方式(shi)散熱的(de)充(chong)電(dian)器，熱敏電(dian)阻損壞(huai)的(de)概率是(shi)很大的(de)。

扇本身損壞(huai)，可以把風(feng)(feng)扇從電(dian)路板上拔(ba)下來，另外接上一個(ge)12V的(de)直流電(dian)（注意正、負極），看是(shi)否(fou)轉(zhuan)動(dong)，還要看有無異物卡住。若擺動(dong)凡(fan)下風(feng)(feng)扇的(de)電(dian)線(xian)，風(feng)(feng)扇就轉(zhuan)動(dong)，則說(shuo)明電(dian)線(xian)內部有斷(duan)線(xian)或(huo)接頭接觸不良(liang)。若仍不轉(zhuan)動(dong)，則風(feng)(feng)扇必壞(huai)。對于采用智能散熱(re)的(de)充(chong)電(dian)器來說(shuo)，除按(an)上述(shu)檢(jian)查外，還應檢(jian)查一下熱(re)敏電(dian)阻是(shi)否(fou)接觸不良(liang)或(huo)損壞(huai)、開焊等。但要注意此(ci)熱(re)敏電(dian)阻為(wei)負溫度(du)系數，更換時應注意。