電(dian)(dian)(dian)(dian)動車充電(dian)(dian)(dian)(dian)器(qi)實際上(shang)就是一個開關電(dian)(dian)(dian)(dian)源加上(shang)一個檢(jian)測電(dian)(dian)(dian)(dian)路(lu),目前很多電(dian)(dian)(dian)(dian)動車的48V充電(dian)(dian)(dian)(dian)器(qi)都是采用KA3842和比較(jiao)器(qi)LM358來完(wan)成充電(dian)(dian)(dian)(dian)工(gong)作(zuo) 

工作原理

   220V交(jiao)流(liu)電(dian)(dian)(dian)(dian)經(jing)(jing)LF1雙向濾(lv)波.VD1－VD4整流(liu)為(wei)脈動直流(liu)電(dian)(dian)(dian)(dian)壓(ya),再(zai)經(jing)(jing)C3濾(lv)波后(hou)形成約(yue)300V的(de)(de)(de)直流(liu)電(dian)(dian)(dian)(dian)壓(ya),300V直流(liu)電(dian)(dian)(dian)(dian)壓(ya)經(jing)(jing)過啟(qi)動電(dian)(dian)(dian)(dian)阻R4為(wei)脈寬(kuan)調制集(ji)成電(dian)(dian)(dian)(dian)路(lu)IC1的(de)(de)(de)7腳提(ti)供啟(qi)動電(dian)(dian)(dian)(dian)壓(ya),IC1的(de)(de)(de)7腳得到(dao)啟(qi)動電(dian)(dian)(dian)(dian)壓(ya)后(hou),(7腳電(dian)(dian)(dian)(dian)壓(ya)高于14V時,集(ji)成電(dian)(dian)(dian)(dian)路(lu)開始工作),6腳輸出PWM脈沖(chong),驅動電(dian)(dian)(dian)(dian)源(yuan)開關(guan)管(場效應管)VT7工作在(zai)開關(guan)狀態,電(dian)(dian)(dian)(dian)流(liu)通過VT1的(de)(de)(de)S極(ji)-D極(ji)-R7-接(jie)地端(duan).此時開關(guan)變壓(ya)器(qi)T1的(de)(de)(de)8-9繞組產生(sheng)感應電(dian)(dian)(dian)(dian)壓(ya),經(jing)(jing)VD6，R2為(wei)IC1的(de)(de)(de)7腳提(ti)供穩定的(de)(de)(de)工作電(dian)(dian)(dian)(dian)壓(ya)，4腳外接(jie)振蕩電(dian)(dian)(dian)(dian)阻R10和(he)振蕩電(dian)(dian)(dian)(dian)容C7決定IC1的(de)(de)(de)振蕩頻(pin)率,

   IC2(TL431)為精密基準電壓(ya)(ya)源,IC4(光耦合器(qi)4N35)配合用來穩定充電電壓(ya)(ya),調(diao)(diao)整(zheng)RP1(510歐半可調(diao)(diao)電位(wei)器(qi))可以細調(diao)(diao)充電器(qi)的電壓(ya)(ya),LED1是電源指示燈.接通電源后該(gai)指示燈就會發(fa)出紅色的光。

   VT1開(kai)始工作后,變壓(ya)(ya)(ya)器的(de)次(ci)級6-5繞組(zu)輸出的(de)電(dian)(dian)(dian)壓(ya)(ya)(ya)經(jing)快速恢復二(er)極管VD60整流,C18濾波得到(dao)穩(wen)定的(de)電(dian)(dian)(dian)壓(ya)(ya)(ya)(約(yue)53V).此電(dian)(dian)(dian)壓(ya)(ya)(ya)一路經(jing)二(er)極管VD70(該二(er)極管起防止電(dian)(dian)(dian)池的(de)電(dian)(dian)(dian)流倒灌給(gei)(gei)充電(dian)(dian)(dian)器的(de)作用)給(gei)(gei)電(dian)(dian)(dian)池充電(dian)(dian)(dian),另一路經(jing)限流電(dian)(dian)(dian)阻R38,穩(wen)壓(ya)(ya)(ya)二(er)極管VZD1,濾波電(dian)(dian)(dian)容C60,為(wei)比較器IC3(LM358)提(ti)供12V工作電(dian)(dian)(dian)源(yuan),VD12為(wei)IC3提(ti)供基準電(dian)(dian)(dian)壓(ya)(ya)(ya),經(jing)R25,R26,R27分壓(ya)(ya)(ya)后送到(dao)IC3的(de)2腳和5腳。

   正常充電(dian)(dian)時(shi)，R33上端有0.18－0.2V的電(dian)(dian)壓，此(ci)電(dian)(dian)壓經R10加到IC3的3腳(jiao)，從1腳(jiao)輸(shu)(shu)出(chu)高(gao)電(dian)(dian)平(ping)。1腳(jiao)輸(shu)(shu)出(chu)的高(gao)電(dian)(dian)平(ping)信號分(fen)三路(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(gong)作(zuo)，第(di)二(er)路(lu)(lu)經過電(dian)(dian)阻(zu)R34點亮雙(shuang)色(se)二(er)極管(guan)(guan)LED2中(zhong)的紅色(se)發(fa)光(guang)(guang)二(er)極管(guan)(guan)，第(di)三路(lu)(lu)輸(shu)(shu)入到IC3的6腳(jiao)，此(ci)時(shi)7腳(jiao)輸(shu)(shu)出(chu)低電(dian)(dian)平(ping)，雙(shuang)色(se)發(fa)光(guang)(guang)二(er)極管(guan)(guan)LED2中(zhong)的綠色(se)發(fa)光(guang)(guang)二(er)極管(guan)(guan)熄滅，充電(dian)(dian)器進(jin)入恒流充電(dian)(dian)階段。

   當電池電壓升到44.2V左右時，充電器進(jin)入恒(heng)壓(ya)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)階(jie)段(duan)，電(dian)(dian)(dian)流(liu)逐漸減(jian)小。當(dang)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)減(jian)小到200MA－300MA時，R33上(shang)端的(de)(de)電(dian)(dian)(dian)壓(ya)下(xia)降，IC3的(de)(de)3腳(jiao)電(dian)(dian)(dian)壓(ya)低(di)于2腳(jiao)，1腳(jiao)輸出低(di)電(dian)(dian)(dian)平(ping)，雙色(se)發光二極(ji)(ji)管LED2中的(de)(de)紅(hong)色(se)發光二極(ji)(ji)管熄滅(mie)，三極(ji)(ji)管VT2截止(zhi)，風扇停止(zhi)運轉(zhuan)(zhuan)，同(tong)時IC3的(de)(de)7腳(jiao)輸出高(gao)電(dian)(dian)(dian)平(ping)，此高(gao)電(dian)(dian)(dian)平(ping)一(yi)(yi)路經過電(dian)(dian)(dian)阻R35點(dian)亮雙色(se)發光二極(ji)(ji)管LED2中的(de)(de)綠(lv)色(se)發光二極(ji)(ji)管（指示電(dian)(dian)(dian)瓶已(yi)經充(chong)(chong)(chong)(chong)滿(man)，此時并沒有真(zhen)正充(chong)(chong)(chong)(chong)滿(man)，實際上(shang)還得(de)一(yi)(yi)兩小時才能真(zhen)正充(chong)(chong)(chong)(chong)滿(man)），另一(yi)(yi)路經R52，VD18,R40,RP2到達IC2的(de)(de)1腳(jiao)，使輸出電(dian)(dian)(dian)壓(ya)降低(di)，充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)進(jin)入200MA-300MA的(de)(de)涓(juan)流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)階(jie)段(duan)（浮充(chong)(chong)(chong)(chong)），改(gai)變RP2的(de)(de)電(dian)(dian)(dian)阻值可以調整充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)由恒(heng)流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)狀態轉(zhuan)(zhuan)到涓(juan)流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)狀態的(de)(de)轉(zhuan)(zhuan)折電(dian)(dian)(dian)流(liu)（200－300MA）。

常見故障

   這種類型電(dian)動車充電(dian)器的常(chang)見(jian)故障有下面幾種情況：

1、高壓電路(lu)(lu)故障(zhang)：該部分電路(lu)(lu)出現(xian)問題的主要現(xian)象(xiang)是(shi)指示燈不(bu)(bu)亮。通常還伴有保(bao)險(xian)絲燒斷，此(ci)時應檢查整(zheng)流二(er)極管(guan)VD1-VD4是(shi)否(fou)擊穿，電容C3是(shi)否(fou)炸裂或(huo)者(zhe)鼓包，VT2是(shi)否(fou)擊穿，R7,R4是(shi)否(fou)開路(lu)(lu)，此(ci)時更(geng)換損(sun)壞的元(yuan)件即可排(pai)除(chu)故障(zhang)，若經(jing)常燒VT1,且VT1不(bu)(bu)燙手，則(ze)應重(zhong)點(dian)檢查R1,C4,VD5等元(yuan)器(qi)件，若VT1燙手，則(ze)重(zhong)點(dian)檢查開關變壓器(qi)次級電路(lu)(lu)中的元(yuan)器(qi)件有無短(duan)路(lu)(lu)或(huo)者(zhe)漏電。

   若紅色指示燈閃爍(shuo)，則故障多數是由R2或者(zhe)VD6開路(lu)，變壓器T1線(xian)腳虛(xu)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（充電器注明不可(ke)隨(sui)車(che)攜(xie)帶就是怕RP2因(yin)振動而改(gai)變阻值(zhi)），就會導致(zhi)輸出電(dian)(dian)(dian)壓漂移。若輸出電(dian)(dian)(dian)壓偏高，電(dian)(dian)(dian)瓶會過充，嚴重時會失水－發(fa)燙，最(zui)終導致(zhi)充爆(bao)，若輸出電(dian)(dian)(dian)壓偏低(di)，會導致(zhi)電(dian)(dian)(dian)瓶欠充，縮短其壽命。