電(dian)動(dong)車充電(dian)器(qi)(qi)實(shi)際上就(jiu)是(shi)一個開關電(dian)源加上一個檢(jian)測電(dian)路,目前很多電(dian)動(dong)車的48V充電(dian)器(qi)(qi)都是(shi)采用KA3842和比較器(qi)(qi)LM358來完成充電(dian)工作 

工作原理

   220V交流(liu)電(dian)(dian)(dian)經(jing)LF1雙向濾(lv)波.VD1－VD4整流(liu)為脈(mo)動直流(liu)電(dian)(dian)(dian)壓(ya),再經(jing)C3濾(lv)波后形成(cheng)約300V的(de)直流(liu)電(dian)(dian)(dian)壓(ya),300V直流(liu)電(dian)(dian)(dian)壓(ya)經(jing)過(guo)啟動電(dian)(dian)(dian)阻R4為脈(mo)寬調(diao)制集(ji)成(cheng)電(dian)(dian)(dian)路IC1的(de)7腳(jiao)提供(gong)啟動電(dian)(dian)(dian)壓(ya),IC1的(de)7腳(jiao)得到(dao)啟動電(dian)(dian)(dian)壓(ya)后,(7腳(jiao)電(dian)(dian)(dian)壓(ya)高于14V時,集(ji)成(cheng)電(dian)(dian)(dian)路開(kai)(kai)始工(gong)作),6腳(jiao)輸(shu)出PWM脈(mo)沖,驅(qu)動電(dian)(dian)(dian)源(yuan)開(kai)(kai)關(guan)管(guan)(場效應管(guan))VT7工(gong)作在開(kai)(kai)關(guan)狀態,電(dian)(dian)(dian)流(liu)通(tong)過(guo)VT1的(de)S極-D極-R7-接地端.此(ci)時開(kai)(kai)關(guan)變(bian)壓(ya)器T1的(de)8-9繞組產生(sheng)感應電(dian)(dian)(dian)壓(ya),經(jing)VD6，R2為IC1的(de)7腳(jiao)提供(gong)穩定的(de)工(gong)作電(dian)(dian)(dian)壓(ya)，4腳(jiao)外接振(zhen)蕩(dang)電(dian)(dian)(dian)阻R10和振(zhen)蕩(dang)電(dian)(dian)(dian)容(rong)C7決定IC1的(de)振(zhen)蕩(dang)頻率,

   IC2(TL431)為(wei)精密基準電(dian)壓(ya)源(yuan),IC4(光耦合(he)器(qi)(qi)4N35)配合(he)用來(lai)穩(wen)定充電(dian)電(dian)壓(ya),調(diao)整(zheng)RP1(510歐半可(ke)調(diao)電(dian)位器(qi)(qi))可(ke)以細調(diao)充電(dian)器(qi)(qi)的(de)電(dian)壓(ya),LED1是電(dian)源(yuan)指示燈.接(jie)通電(dian)源(yuan)后該指示燈就會(hui)發出(chu)紅(hong)色(se)的(de)光。

   VT1開始工(gong)作后,變壓器的次級(ji)6-5繞組輸出的電(dian)(dian)(dian)(dian)壓經(jing)(jing)快速(su)恢復二極(ji)(ji)(ji)管VD60整流,C18濾波得到穩定(ding)的電(dian)(dian)(dian)(dian)壓(約53V).此電(dian)(dian)(dian)(dian)壓一(yi)路(lu)經(jing)(jing)二極(ji)(ji)(ji)管VD70(該二極(ji)(ji)(ji)管起防止電(dian)(dian)(dian)(dian)池(chi)的電(dian)(dian)(dian)(dian)流倒灌給(gei)充電(dian)(dian)(dian)(dian)器的作用)給(gei)電(dian)(dian)(dian)(dian)池(chi)充電(dian)(dian)(dian)(dian),另一(yi)路(lu)經(jing)(jing)限流電(dian)(dian)(dian)(dian)阻R38,穩壓二極(ji)(ji)(ji)管VZD1,濾波電(dian)(dian)(dian)(dian)容C60,為比較(jiao)器IC3(LM358)提供12V工(gong)作電(dian)(dian)(dian)(dian)源,VD12為IC3提供基準電(dian)(dian)(dian)(dian)壓,經(jing)(jing)R25,R26,R27分壓后送到IC3的2腳(jiao)和5腳(jiao)。

   正(zheng)常充(chong)電(dian)(dian)(dian)時，R33上(shang)端有(you)0.18－0.2V的(de)電(dian)(dian)(dian)壓，此電(dian)(dian)(dian)壓經R10加到IC3的(de)3腳，從1腳輸出(chu)(chu)高(gao)電(dian)(dian)(dian)平。1腳輸出(chu)(chu)的(de)高(gao)電(dian)(dian)(dian)平信號(hao)分三(san)路(lu)(lu)輸出(chu)(chu)，第(di)(di)一路(lu)(lu)驅動(dong)VT2導(dao)通，散熱風扇得電(dian)(dian)(dian)開始工作，第(di)(di)二(er)路(lu)(lu)經過電(dian)(dian)(dian)阻(zu)R34點亮雙(shuang)色(se)二(er)極(ji)管(guan)(guan)LED2中(zhong)的(de)紅色(se)發(fa)(fa)光二(er)極(ji)管(guan)(guan)，第(di)(di)三(san)路(lu)(lu)輸入到IC3的(de)6腳，此時7腳輸出(chu)(chu)低電(dian)(dian)(dian)平，雙(shuang)色(se)發(fa)(fa)光二(er)極(ji)管(guan)(guan)LED2中(zhong)的(de)綠色(se)發(fa)(fa)光二(er)極(ji)管(guan)(guan)熄(xi)滅，充(chong)電(dian)(dian)(dian)器進入恒流充(chong)電(dian)(dian)(dian)階段。

   當電池電壓升到44.2V左右時，充電器進入恒壓充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)階段，電(dian)(dian)(dian)(dian)流(liu)逐漸減小(xiao)。當(dang)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)減小(xiao)到200MA－300MA時(shi)，R33上端的(de)(de)(de)電(dian)(dian)(dian)(dian)壓下降，IC3的(de)(de)(de)3腳電(dian)(dian)(dian)(dian)壓低于(yu)2腳，1腳輸(shu)出(chu)低電(dian)(dian)(dian)(dian)平(ping)，雙色發光二(er)(er)極管LED2中的(de)(de)(de)紅(hong)色發光二(er)(er)極管熄滅(mie)，三極管VT2截止，風扇(shan)停止運轉(zhuan)，同時(shi)IC3的(de)(de)(de)7腳輸(shu)出(chu)高電(dian)(dian)(dian)(dian)平(ping)，此高電(dian)(dian)(dian)(dian)平(ping)一(yi)路經(jing)(jing)過電(dian)(dian)(dian)(dian)阻R35點亮雙色發光二(er)(er)極管LED2中的(de)(de)(de)綠(lv)色發光二(er)(er)極管（指示電(dian)(dian)(dian)(dian)瓶已經(jing)(jing)充(chong)(chong)(chong)滿(man)，此時(shi)并沒有真正(zheng)充(chong)(chong)(chong)滿(man)，實際上還得一(yi)兩小(xiao)時(shi)才(cai)能真正(zheng)充(chong)(chong)(chong)滿(man)），另一(yi)路經(jing)(jing)R52，VD18,R40,RP2到達IC2的(de)(de)(de)1腳，使輸(shu)出(chu)電(dian)(dian)(dian)(dian)壓降低，充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)進入200MA-300MA的(de)(de)(de)涓流(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)階段（浮充(chong)(chong)(chong)），改(gai)變RP2的(de)(de)(de)電(dian)(dian)(dian)(dian)阻值可以調整充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)由(you)恒流(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)狀(zhuang)態(tai)轉(zhuan)到涓流(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)狀(zhuang)態(tai)的(de)(de)(de)轉(zhuan)折電(dian)(dian)(dian)(dian)流(liu)（200－300MA）。

常見故障

   這種(zhong)(zhong)類型電動車充(chong)電器的常見故(gu)障有下面幾種(zhong)(zhong)情況：

1、高壓電(dian)路故障(zhang)：該部分電(dian)路出現(xian)問(wen)題的主要(yao)現(xian)象是(shi)(shi)指示燈不亮。通常還伴有(you)保險(xian)絲燒(shao)斷，此時(shi)應檢查整流(liu)二極管VD1-VD4是(shi)(shi)否(fou)擊穿，電(dian)容C3是(shi)(shi)否(fou)炸裂或者(zhe)鼓(gu)包，VT2是(shi)(shi)否(fou)擊穿，R7,R4是(shi)(shi)否(fou)開(kai)路，此時(shi)更換損(sun)壞的元(yuan)件即可排除故障(zhang)，若經常燒(shao)VT1,且VT1不燙手，則應重點檢查R1,C4,VD5等元(yuan)器件，若VT1燙手，則重點檢查開(kai)關變壓器次級電(dian)路中的元(yuan)器件有(you)無短路或者(zhe)漏電(dian)。

   若紅色(se)指示燈閃爍，則(ze)故障(zhang)多(duo)數是(shi)由R2或者VD6開(kai)路，變壓(ya)器T1線(xian)腳虛(xu)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(zhu)明不可隨車攜帶就是(shi)怕RP2因(yin)振(zhen)動而改(gai)變阻值），就會導致輸(shu)出(chu)電(dian)壓漂移。若輸(shu)出(chu)電(dian)壓偏高，電(dian)瓶會過充(chong)(chong)，嚴重時(shi)會失水－發燙，最終(zhong)導致充(chong)(chong)爆(bao)，若輸(shu)出(chu)電(dian)壓偏低，會導致電(dian)瓶欠充(chong)(chong)，縮短其壽(shou)命(ming)。