快速充(chong)(chong)電(dian)(dian)(dian)是指能在(zai)(zai)1～5h內(nei)使蓄(xu)電(dian)(dian)(dian)池(chi)達到或接近完(wan)(wan)全(quan)充(chong)(chong)電(dian)(dian)(dian)狀態的(de)(de)一種(zhong)充(chong)(chong)電(dian)(dian)(dian)方法。常用于牽引用蓄(xu)電(dian)(dian)(dian)池(chi)需要在(zai)(zai)較短時間內(nei)恢復完(wan)(wan)全(quan)充(chong)(chong)電(dian)(dian)(dian)狀態時的(de)(de)充(chong)(chong)電(dian)(dian)(dian)。快速充(chong)(chong)電(dian)(dian)(dian)對蓄(xu)電(dian)(dian)(dian)池(chi)的(de)(de)性(xing)能和壽(shou)命有損。蓄(xu)電(dian)(dian)(dian)池(chi)的(de)(de)正常充(chong)(chong)電(dian)(dian)(dian)耗時約10～20h，如何能快速充(chong)(chong)電(dian)(dian)(dian)而(er)不損害蓄(xu)電(dian)(dian)(dian)池(chi)的(de)(de)性(xing)能和壽(shou)命，是人們關注的(de)(de)熱門研(yan)究課題(ti)。

快速充電電路特點
　　1、輸出電壓設定好后(例如36V)，若被充電瓶極板脫落斷開，造成某組電池不通，或出現短路，則電瓶端電壓即降低或為零，這時充電器將無輸出電流。
　　2、若被充電瓶電壓偏離設定電壓，如設定電壓為36V，誤接24V、12V、6V電瓶等，充電器也無輸出電流，若設定為24V誤接為36V電瓶，由于充電器輸出電壓低于電瓶電壓，因而也不能向電瓶充電。 　　
　　3、充電器兩輸出端若短路時，由于充電器中可控硅SCR的觸發電路不能工作，因而可控硅不導通，輸出電流為零。 　　
　　4、若使用時誤將電瓶正負極接反，則可控硅觸發電路反向截止，無觸發信號，可控硅不導通，輸出電流為零。 　　
　　5、采用脈沖充電，有利于延長電瓶壽命。由于低壓交流電經全波整流后是脈動直流，只有當其波峰電壓大于電瓶電壓時，可控硅才會導通，而當脈動直流電壓處于波谷區時，可控硅反偏截止，停止向電瓶充電，因而流過電瓶的是脈動直流電。 　　
　　6、快速充電，充滿自停。由于剛開始充電時電瓶兩端電壓較低，因而充電電流較大。當電瓶即將充足時(36V電瓶端電壓可達44V)，由于充電電壓越來越接近脈動直流輸出電壓的波峰值，則充電電流也會越來越小，自動變為涓流充電。當電瓶兩端電壓被充到整流輸出的波峰最大值時，充電過程停止。經試驗，三節電動車蓄電池36V(12V／12Ah三節串聯)，用該充電器只需幾個小時即可充滿。 　　
　　7、電路簡單、易于制作(zuo)，幾乎不用維(wei)護(hu)及維(wei)修。

　　快速充電電路原理
　　AC220V市電(dian)(dian)(dian)(dian)(dian)經變壓(ya)器T1降壓(ya)，經D1-D4全(quan)波整(zheng)(zheng)流(liu)后，供給充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)路工作(zuo)。當輸(shu)出(chu)端按(an)正確(que)極(ji)性接入(ru)設定的被(bei)充電(dian)(dian)(dian)(dian)(dian)瓶(ping)后，若整(zheng)(zheng)流(liu)輸(shu)出(chu)脈動電(dian)(dian)(dian)(dian)(dian)壓(ya)的每個半波峰值超過電(dian)(dian)(dian)(dian)(dian)瓶(ping)的輸(shu)出(chu)電(dian)(dian)(dian)(dian)(dian)壓(ya)，則可(ke)(ke)控(kong)(kong)硅SCR經Q的集電(dian)(dian)(dian)(dian)(dian)極(ji)電(dian)(dian)(dian)(dian)(dian)流(liu)觸(chu)發(fa)導(dao)(dao)通(tong)，電(dian)(dian)(dian)(dian)(dian)流(liu)經可(ke)(ke)控(kong)(kong)硅給電(dian)(dian)(dian)(dian)(dian)瓶(ping)充電(dian)(dian)(dian)(dian)(dian)。脈動電(dian)(dian)(dian)(dian)(dian)壓(ya)接近電(dian)(dian)(dian)(dian)(dian)瓶(ping)電(dian)(dian)(dian)(dian)(dian)壓(ya)時，可(ke)(ke)控(kong)(kong)硅關斷(duan)，停止充電(dian)(dian)(dian)(dian)(dian)。調(diao)節R4，可(ke)(ke)調(diao)節晶體管Q的導(dao)(dao)通(tong)電(dian)(dian)(dian)(dian)(dian)壓(ya)，一(yi)般(ban)可(ke)(ke)將R4由大到(dao)(dao)小調(diao)整(zheng)(zheng)到(dao)(dao)Q導(dao)(dao)通(tong)能觸(chu)發(fa)可(ke)(ke)控(kong)(kong)硅(導(dao)(dao)通(tong))即可(ke)(ke)。圖中(zhong)發(fa)光管D5用(yong)作(zuo)電(dian)(dian)(dian)(dian)(dian)源指示(shi)(shi)，而D6用(yong)作(zuo)充電(dian)(dian)(dian)(dian)(dian)指示(shi)(shi)。