電(dian)(dian)動車充電(dian)(dian)器(qi)實際上就是(shi)一個開(kai)關電(dian)(dian)源加上一個檢測(ce)電(dian)(dian)路,目前很多電(dian)(dian)動車的48V充電(dian)(dian)器(qi)都(dou)是(shi)采用KA3842和(he)比(bi)較器(qi)LM358來完成充電(dian)(dian)工作 

工作原理

   220V交流(liu)電(dian)(dian)(dian)(dian)(dian)經LF1雙向(xiang)濾波.VD1－VD4整(zheng)流(liu)為脈(mo)動(dong)直(zhi)流(liu)電(dian)(dian)(dian)(dian)(dian)壓,再經C3濾波后形成(cheng)約300V的直(zhi)流(liu)電(dian)(dian)(dian)(dian)(dian)壓,300V直(zhi)流(liu)電(dian)(dian)(dian)(dian)(dian)壓經過啟(qi)動(dong)電(dian)(dian)(dian)(dian)(dian)阻R4為脈(mo)寬調制集成(cheng)電(dian)(dian)(dian)(dian)(dian)路(lu)IC1的7腳(jiao)提供(gong)啟(qi)動(dong)電(dian)(dian)(dian)(dian)(dian)壓,IC1的7腳(jiao)得到啟(qi)動(dong)電(dian)(dian)(dian)(dian)(dian)壓后,(7腳(jiao)電(dian)(dian)(dian)(dian)(dian)壓高(gao)于14V時(shi),集成(cheng)電(dian)(dian)(dian)(dian)(dian)路(lu)開(kai)始工作),6腳(jiao)輸出PWM脈(mo)沖(chong),驅動(dong)電(dian)(dian)(dian)(dian)(dian)源開(kai)關管(場效應管)VT7工作在開(kai)關狀(zhuang)態,電(dian)(dian)(dian)(dian)(dian)流(liu)通過VT1的S極-D極-R7-接(jie)地端.此時(shi)開(kai)關變壓器T1的8-9繞組產生感應電(dian)(dian)(dian)(dian)(dian)壓,經VD6，R2為IC1的7腳(jiao)提供(gong)穩定(ding)(ding)的工作電(dian)(dian)(dian)(dian)(dian)壓，4腳(jiao)外接(jie)振(zhen)(zhen)蕩(dang)(dang)電(dian)(dian)(dian)(dian)(dian)阻R10和(he)振(zhen)(zhen)蕩(dang)(dang)電(dian)(dian)(dian)(dian)(dian)容C7決定(ding)(ding)IC1的振(zhen)(zhen)蕩(dang)(dang)頻率,

   IC2(TL431)為精密(mi)基準電(dian)壓源,IC4(光(guang)(guang)耦合器(qi)(qi)4N35)配合用來穩定充電(dian)電(dian)壓,調整RP1(510歐半可調電(dian)位(wei)器(qi)(qi))可以細調充電(dian)器(qi)(qi)的(de)電(dian)壓,LED1是(shi)電(dian)源指示(shi)(shi)燈.接通電(dian)源后該(gai)指示(shi)(shi)燈就(jiu)會發出紅色(se)的(de)光(guang)(guang)。

   VT1開始(shi)工(gong)作(zuo)后,變壓器的次級6-5繞組輸出的電(dian)(dian)壓經(jing)快速(su)恢復二(er)極(ji)管(guan)(guan)VD60整流(liu),C18濾波(bo)(bo)得(de)到(dao)(dao)穩(wen)定的電(dian)(dian)壓(約53V).此電(dian)(dian)壓一路經(jing)二(er)極(ji)管(guan)(guan)VD70(該二(er)極(ji)管(guan)(guan)起(qi)防止電(dian)(dian)池的電(dian)(dian)流(liu)倒灌給充電(dian)(dian)器的作(zuo)用)給電(dian)(dian)池充電(dian)(dian),另一路經(jing)限流(liu)電(dian)(dian)阻R38,穩(wen)壓二(er)極(ji)管(guan)(guan)VZD1,濾波(bo)(bo)電(dian)(dian)容C60,為比(bi)較器IC3(LM358)提供12V工(gong)作(zuo)電(dian)(dian)源,VD12為IC3提供基準電(dian)(dian)壓,經(jing)R25,R26,R27分壓后送到(dao)(dao)IC3的2腳和5腳。

   正常充電時(shi)(shi)，R33上端有0.18－0.2V的(de)電壓，此電壓經(jing)R10加到IC3的(de)3腳，從1腳輸(shu)(shu)出高電平(ping)。1腳輸(shu)(shu)出的(de)高電平(ping)信號(hao)分三路(lu)輸(shu)(shu)出，第(di)一路(lu)驅動VT2導通(tong)，散熱(re)風扇得電開始工(gong)作，第(di)二路(lu)經(jing)過電阻R34點亮(liang)雙色(se)二極(ji)(ji)管(guan)LED2中(zhong)的(de)紅色(se)發光(guang)二極(ji)(ji)管(guan)，第(di)三路(lu)輸(shu)(shu)入(ru)到IC3的(de)6腳，此時(shi)(shi)7腳輸(shu)(shu)出低(di)電平(ping)，雙色(se)發光(guang)二極(ji)(ji)管(guan)LED2中(zhong)的(de)綠(lv)色(se)發光(guang)二極(ji)(ji)管(guan)熄滅(mie)，充電器進入(ru)恒(heng)流充電階段(duan)。

   當電池電壓升到44.2V左右時，充電器進入恒(heng)(heng)壓充(chong)(chong)電(dian)(dian)(dian)階(jie)段，電(dian)(dian)(dian)流(liu)逐漸減(jian)小。當(dang)充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)減(jian)小到200MA－300MA時，R33上端的(de)(de)(de)電(dian)(dian)(dian)壓下降，IC3的(de)(de)(de)3腳(jiao)電(dian)(dian)(dian)壓低(di)于2腳(jiao)，1腳(jiao)輸(shu)出低(di)電(dian)(dian)(dian)平，雙色發光(guang)二(er)極管LED2中的(de)(de)(de)紅色發光(guang)二(er)極管熄滅，三極管VT2截止，風扇(shan)停(ting)止運轉，同時IC3的(de)(de)(de)7腳(jiao)輸(shu)出高(gao)電(dian)(dian)(dian)平，此高(gao)電(dian)(dian)(dian)平一路(lu)經(jing)過電(dian)(dian)(dian)阻(zu)R35點亮雙色發光(guang)二(er)極管LED2中的(de)(de)(de)綠色發光(guang)二(er)極管（指(zhi)示電(dian)(dian)(dian)瓶已經(jing)充(chong)(chong)滿(man)，此時并沒有真正充(chong)(chong)滿(man)，實際(ji)上還得一兩小時才能真正充(chong)(chong)滿(man)），另一路(lu)經(jing)R52，VD18,R40,RP2到達IC2的(de)(de)(de)1腳(jiao)，使輸(shu)出電(dian)(dian)(dian)壓降低(di)，充(chong)(chong)電(dian)(dian)(dian)器進入200MA-300MA的(de)(de)(de)涓流(liu)充(chong)(chong)電(dian)(dian)(dian)階(jie)段（浮充(chong)(chong)），改變RP2的(de)(de)(de)電(dian)(dian)(dian)阻(zu)值可(ke)以(yi)調整充(chong)(chong)電(dian)(dian)(dian)器由(you)恒(heng)(heng)流(liu)充(chong)(chong)電(dian)(dian)(dian)狀態(tai)轉到涓流(liu)充(chong)(chong)電(dian)(dian)(dian)狀態(tai)的(de)(de)(de)轉折電(dian)(dian)(dian)流(liu)（200－300MA）。

常見故障

   這種類(lei)型電動(dong)車充電器的常見故(gu)障有下面幾種情況：

1、高壓電(dian)路(lu)故障：該(gai)部分電(dian)路(lu)出現(xian)問題(ti)的主要現(xian)象是(shi)(shi)指示(shi)燈不亮(liang)。通(tong)常(chang)還伴有(you)保險絲燒斷，此時應(ying)檢(jian)查(cha)整流二極管VD1-VD4是(shi)(shi)否(fou)擊穿，電(dian)容C3是(shi)(shi)否(fou)炸(zha)裂或者(zhe)鼓包，VT2是(shi)(shi)否(fou)擊穿，R7,R4是(shi)(shi)否(fou)開路(lu)，此時更換損壞的元(yuan)件(jian)(jian)即可(ke)排除(chu)故障，若經(jing)常(chang)燒VT1,且VT1不燙手，則應(ying)重(zhong)(zhong)點(dian)檢(jian)查(cha)R1,C4,VD5等(deng)元(yuan)器件(jian)(jian)，若VT1燙手，則重(zhong)(zhong)點(dian)檢(jian)查(cha)開關(guan)變壓器次級電(dian)路(lu)中的元(yuan)器件(jian)(jian)有(you)無短(duan)路(lu)或者(zhe)漏電(dian)。

   若紅色指示(shi)燈(deng)閃爍，則(ze)故(gu)障多數(shu)是由R2或者VD6開路，變壓器T1線腳虛焊引起。

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（充電器注明不(bu)可(ke)隨車攜帶就是怕RP2因振(zhen)動而(er)改變阻值(zhi)），就會(hui)導(dao)致(zhi)輸(shu)出電(dian)壓漂移(yi)。若輸(shu)出電(dian)壓偏(pian)高，電(dian)瓶會(hui)過充，嚴重時會(hui)失水(shui)－發(fa)燙，最終導(dao)致(zhi)充爆，若輸(shu)出電(dian)壓偏(pian)低，會(hui)導(dao)致(zhi)電(dian)瓶欠充，縮短其壽(shou)命。