電(dian)(dian)動車充電(dian)(dian)器(qi)(qi)實際上(shang)就是一個開關(guan)電(dian)(dian)源加(jia)上(shang)一個檢測電(dian)(dian)路,目(mu)前很多(duo)電(dian)(dian)動車的48V充電(dian)(dian)器(qi)(qi)都(dou)是采用KA3842和比(bi)較(jiao)器(qi)(qi)LM358來(lai)完成充電(dian)(dian)工作 

工作原理

   220V交流電(dian)(dian)(dian)(dian)經(jing)(jing)LF1雙(shuang)向(xiang)濾(lv)波.VD1－VD4整流為(wei)(wei)脈動(dong)(dong)(dong)(dong)直流電(dian)(dian)(dian)(dian)壓,再經(jing)(jing)C3濾(lv)波后形成約300V的(de)直流電(dian)(dian)(dian)(dian)壓,300V直流電(dian)(dian)(dian)(dian)壓經(jing)(jing)過啟動(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)阻(zu)(zu)R4為(wei)(wei)脈寬(kuan)調制(zhi)集成電(dian)(dian)(dian)(dian)路(lu)IC1的(de)7腳(jiao)提供啟動(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)壓,IC1的(de)7腳(jiao)得(de)到啟動(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)壓后,(7腳(jiao)電(dian)(dian)(dian)(dian)壓高于14V時(shi),集成電(dian)(dian)(dian)(dian)路(lu)開始工(gong)作),6腳(jiao)輸出PWM脈沖,驅動(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)源開關(guan)管(guan)(場效應管(guan))VT7工(gong)作在開關(guan)狀(zhuang)態(tai),電(dian)(dian)(dian)(dian)流通過VT1的(de)S極-D極-R7-接地端.此時(shi)開關(guan)變壓器T1的(de)8-9繞組產生感應電(dian)(dian)(dian)(dian)壓,經(jing)(jing)VD6，R2為(wei)(wei)IC1的(de)7腳(jiao)提供穩定的(de)工(gong)作電(dian)(dian)(dian)(dian)壓，4腳(jiao)外接振(zhen)蕩(dang)電(dian)(dian)(dian)(dian)阻(zu)(zu)R10和(he)振(zhen)蕩(dang)電(dian)(dian)(dian)(dian)容C7決定IC1的(de)振(zhen)蕩(dang)頻率,

   IC2(TL431)為精密基準電(dian)壓(ya)源,IC4(光(guang)耦合(he)器(qi)4N35)配合(he)用來(lai)穩定充(chong)電(dian)電(dian)壓(ya),調整RP1(510歐半(ban)可調電(dian)位器(qi))可以(yi)細調充(chong)電(dian)器(qi)的(de)電(dian)壓(ya),LED1是電(dian)源指示燈(deng).接通電(dian)源后該(gai)指示燈(deng)就會發(fa)出紅色的(de)光(guang)。

   VT1開始工(gong)(gong)作(zuo)后,變壓(ya)器的(de)次級6-5繞組輸(shu)出的(de)電(dian)壓(ya)經快(kuai)速恢復二(er)(er)極管VD60整流,C18濾(lv)波(bo)得到穩(wen)定的(de)電(dian)壓(ya)(約53V).此電(dian)壓(ya)一(yi)路(lu)經二(er)(er)極管VD70(該(gai)二(er)(er)極管起防止電(dian)池的(de)電(dian)流倒灌給充電(dian)器的(de)作(zuo)用)給電(dian)池充電(dian),另(ling)一(yi)路(lu)經限流電(dian)阻(zu)R38,穩(wen)壓(ya)二(er)(er)極管VZD1,濾(lv)波(bo)電(dian)容(rong)C60,為比較器IC3(LM358)提(ti)(ti)供12V工(gong)(gong)作(zuo)電(dian)源,VD12為IC3提(ti)(ti)供基(ji)準(zhun)電(dian)壓(ya),經R25,R26,R27分壓(ya)后送到IC3的(de)2腳和5腳。

   正常充電(dian)(dian)時，R33上端有0.18－0.2V的(de)(de)電(dian)(dian)壓(ya)，此電(dian)(dian)壓(ya)經R10加(jia)到IC3的(de)(de)3腳，從1腳輸(shu)(shu)出(chu)高(gao)電(dian)(dian)平。1腳輸(shu)(shu)出(chu)的(de)(de)高(gao)電(dian)(dian)平信號(hao)分三(san)路(lu)(lu)輸(shu)(shu)出(chu)，第(di)一(yi)路(lu)(lu)驅動VT2導通，散熱風(feng)扇得電(dian)(dian)開始工作，第(di)二(er)路(lu)(lu)經過電(dian)(dian)阻R34點亮雙色(se)二(er)極(ji)管(guan)LED2中的(de)(de)紅色(se)發(fa)光二(er)極(ji)管(guan)，第(di)三(san)路(lu)(lu)輸(shu)(shu)入到IC3的(de)(de)6腳，此時7腳輸(shu)(shu)出(chu)低電(dian)(dian)平，雙色(se)發(fa)光二(er)極(ji)管(guan)LED2中的(de)(de)綠色(se)發(fa)光二(er)極(ji)管(guan)熄滅，充電(dian)(dian)器進入恒流充電(dian)(dian)階段(duan)。

   當電池電壓升到44.2V左右時，充電器進入恒(heng)壓(ya)充(chong)電(dian)(dian)(dian)(dian)階段(duan)(duan)，電(dian)(dian)(dian)(dian)流逐(zhu)漸減小(xiao)。當充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流減小(xiao)到(dao)(dao)200MA－300MA時(shi)(shi)，R33上端的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)壓(ya)下降(jiang)，IC3的(de)(de)(de)(de)3腳(jiao)電(dian)(dian)(dian)(dian)壓(ya)低(di)(di)于2腳(jiao)，1腳(jiao)輸(shu)出低(di)(di)電(dian)(dian)(dian)(dian)平，雙(shuang)色發(fa)光二(er)(er)極管(guan)LED2中的(de)(de)(de)(de)紅色發(fa)光二(er)(er)極管(guan)熄滅(mie)，三極管(guan)VT2截止(zhi)，風扇停(ting)止(zhi)運轉(zhuan)，同(tong)時(shi)(shi)IC3的(de)(de)(de)(de)7腳(jiao)輸(shu)出高電(dian)(dian)(dian)(dian)平，此高電(dian)(dian)(dian)(dian)平一路經(jing)過(guo)電(dian)(dian)(dian)(dian)阻R35點亮雙(shuang)色發(fa)光二(er)(er)極管(guan)LED2中的(de)(de)(de)(de)綠色發(fa)光二(er)(er)極管(guan)（指示(shi)電(dian)(dian)(dian)(dian)瓶(ping)已經(jing)充(chong)滿(man)，此時(shi)(shi)并沒有真正(zheng)充(chong)滿(man)，實際上還得(de)一兩小(xiao)時(shi)(shi)才能真正(zheng)充(chong)滿(man)），另一路經(jing)R52，VD18,R40,RP2到(dao)(dao)達IC2的(de)(de)(de)(de)1腳(jiao)，使(shi)輸(shu)出電(dian)(dian)(dian)(dian)壓(ya)降(jiang)低(di)(di)，充(chong)電(dian)(dian)(dian)(dian)器(qi)進入200MA-300MA的(de)(de)(de)(de)涓流充(chong)電(dian)(dian)(dian)(dian)階段(duan)(duan)（浮充(chong)），改變RP2的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)阻值(zhi)可以(yi)調整充(chong)電(dian)(dian)(dian)(dian)器(qi)由恒(heng)流充(chong)電(dian)(dian)(dian)(dian)狀(zhuang)態(tai)轉(zhuan)到(dao)(dao)涓流充(chong)電(dian)(dian)(dian)(dian)狀(zhuang)態(tai)的(de)(de)(de)(de)轉(zhuan)折電(dian)(dian)(dian)(dian)流（200－300MA）。

常見故障

   這種(zhong)類型電動車(che)充電器的常見故障有(you)下面幾(ji)種(zhong)情況：

1、高壓(ya)電路(lu)故(gu)障：該(gai)部(bu)分電路(lu)出現問題的主要現象是(shi)指示燈不(bu)亮。通(tong)常(chang)還(huan)伴有保險絲燒(shao)(shao)斷(duan)，此時應(ying)檢查(cha)整流(liu)二(er)極管VD1-VD4是(shi)否擊(ji)穿，電容(rong)C3是(shi)否炸(zha)裂或者鼓包，VT2是(shi)否擊(ji)穿，R7,R4是(shi)否開路(lu)，此時更換損壞的元件即(ji)可排除故(gu)障，若經常(chang)燒(shao)(shao)VT1,且VT1不(bu)燙手，則(ze)應(ying)重點(dian)檢查(cha)R1,C4,VD5等(deng)元器件，若VT1燙手，則(ze)重點(dian)檢查(cha)開關(guan)變壓(ya)器次級(ji)電路(lu)中(zhong)的元器件有無短路(lu)或者漏電。

   若紅(hong)色指(zhi)示燈閃爍(shuo)，則故障多數(shu)是由R2或者(zhe)VD6開路，變壓器T1線腳虛焊(han)引起。

2、低壓電路故障：低壓電路中最常見的故障就是電流檢測電阻R33燒斷，此時的故障現象是紅燈一直亮，綠燈不亮，輸出電壓低，電瓶始終充不進電，另外，若RP2接觸不良或者因振動導致阻值變化（充電器注(zhu)明(ming)不可(ke)隨車攜帶(dai)就是怕RP2因振(zhen)動而改變阻值），就會(hui)導致(zhi)輸出電(dian)壓(ya)漂移(yi)。若輸出電(dian)壓(ya)偏高，電(dian)瓶(ping)(ping)會(hui)過充，嚴重時會(hui)失水－發燙，最終導致(zhi)充爆，若輸出電(dian)壓(ya)偏低，會(hui)導致(zhi)電(dian)瓶(ping)(ping)欠充，縮(suo)短其壽命。