目前市(shi)場上出售的(de)各種型(xing)號(hao)的(de)充(chong)電(dian)(dian)器(qi)要求外接電(dian)(dian)源時(shi)正(zheng)(zheng)、負極(ji)性(xing)絕對不(bu)能(neng)(neng)有誤，否則(ze)充(chong)電(dian)(dian)時(shi)將(jiang)燒壞電(dian)(dian)池(chi)或電(dian)(dian)器(qi)，這里介紹一(yi)種安全型(xing)充(chong)電(dian)(dian)器(qi)電(dian)(dian)路，使(shi)用(yong)時(shi)可不(bu)用(yong)校正(zheng)(zheng)正(zheng)(zheng)負極(ji)性(xing)，直接接入電(dian)(dian)池(chi)的(de)極(ji)性(xing)，即能(neng)(neng)安全充(chong)電(dian)(dian)，使(shi)用(yong)起來(lai)很得心順手。該無(wu)極(ji)性(xing)充(chong)電(dian)(dian)器(qi)電(dian)(dian)路見附(fu)圖所(suo)示。

　　該電(dian)路由二只雙向可控硅“VT1、VT2’、兩只整(zheng)流二極管“VD1、VD2’以及雙向可控硅柵極觸發(fa)電(dian)路“R1、VD3、R2、VD4”等組成。

　　若電路不(bu)連接蓄電池，兩只可控硅“VT1、VT2’均(jun)無柵電流，不(bu)導通，因(yin)此即使有交(jiao)流輸入(ru)也沒(mei)有輸出電壓。確保安全(quan)。

　　當(dang)電(dian)(dian)(dian)路(lu)中(zhong)輸出(chu)(+)端(duan)連接電(dian)(dian)(dian)池(chi)正(zheng)(zheng)極(ji)、輸出(chu)(-)端(duan)接負極(ji)時，由(you)于蓄電(dian)(dian)(dian)池(chi)存在剩余電(dian)(dian)(dian)壓，將使VT1出(chu)柵(zha)極(ji)電(dian)(dian)(dian)流(liu)(liu)“經VT1、G極(ji)-VD3-R1”使VT1導通(tong)。在交流(liu)(liu)電(dian)(dian)(dian)正(zheng)(zheng)半周經VT1和(he)VT2對蓄電(dian)(dian)(dian)池(chi)進行充電(dian)(dian)(dian)：相反，若蓄電(dian)(dian)(dian)池(chi)正(zheng)(zheng)極(ji)連(-)端(duan)、負極(ji)連(+)端(duan)，則VT2有柵(zha)極(ji)電(dian)(dian)(dian)流(liu)(liu)而導通(tong)，通(tong)過(guo)VT2和(he)VT1給蓄電(dian)(dian)(dian)池(chi)充電(dian)(dian)(dian)。

　　綜上所(suo)述(shu)：不論是電(dian)池(chi)(chi)正(zheng)極、負極輸出(chu)，(+、-)、(-、+)端連接(jie)均(jun)能(neng)正(zheng)常充(chong)電(dian)。如果蓄電(dian)池(chi)(chi)剩余電(dian)壓過小不能(neng)觸發(fa)(fa)VT1或VT2導(dao)通，就(jiu)(jiu)不能(neng)進行(xing)充(chong)電(dian)。對于(yu)這種情況(kuang)，可用(yong)晶體管代替VD3和(he)VD4來減小晶閘管的觸發(fa)(fa)電(dian)壓。而(er)對于(yu)VT1、VT2和(he)VD1、VD2器(qi)件(jian)的要(yao)求耐壓大于(yu)100V、連續工(gong)作電(dian)流為20A以上。VD3、VD4只(zhi)需耐壓大于(yu)50V、工(gong)作電(dian)流100mA左右就(jiu)(jiu)行(xing)了。具(ju)體情況(kuang)根據蓄電(dian)池(chi)(chi)的電(dian)壓及充(chong)電(dian)電(dian)流實(shi)際(ji)需要(yao)而(er)確定，靈活掌握(wo)選(xuan)用(yong)這些電(dian)子元器(qi)件(jian)。

　　例如：要對48V蓄電(dian)池充電(dian)，限流(liu)電(dian)阻R1、R2功率需要2W以上(shang)的(de)(de)電(dian)阻。但注意,T電(dian)源變壓(ya)(ya)器次(ci)級(ji)有直(zhi)流(liu)成分(fen)電(dian)流(liu)通過(guo)，磁化電(dian)流(liu)增大(da)，因此變壓(ya)(ya)器的(de)(de)設計(ji)容量要大(da)些，次(ci)級(ji)輸出電(dian)壓(ya)(ya)分(fen)別(bie)為(wei)7V、14V、28V、42V、56V，S選用五(wu)擋轉換開關(guan)。其(qi)他元(yuan)器件無(wu)特殊要求，按圖(tu)中所標的(de)(de)參數為(wei)準。而輸出的(de)(de)正負極分(fen)別(bie)為(wei)：6V、12V、24V、36V、48V。