目前市場上出售的(de)各種(zhong)型(xing)號的(de)充電(dian)(dian)器要求外接電(dian)(dian)源時(shi)(shi)正(zheng)、負極(ji)(ji)性(xing)絕對不能(neng)有誤，否則充電(dian)(dian)時(shi)(shi)將燒(shao)壞電(dian)(dian)池或電(dian)(dian)器，這里介紹一(yi)種(zhong)安(an)全(quan)型(xing)充電(dian)(dian)器電(dian)(dian)路(lu)，使用時(shi)(shi)可不用校(xiao)正(zheng)正(zheng)負極(ji)(ji)性(xing)，直接接入電(dian)(dian)池的(de)極(ji)(ji)性(xing)，即能(neng)安(an)全(quan)充電(dian)(dian)，使用起來(lai)很得(de)心(xin)順手(shou)。該無極(ji)(ji)性(xing)充電(dian)(dian)器電(dian)(dian)路(lu)見附圖所(suo)示。

　　該電路(lu)由二只雙向(xiang)可控硅“VT1、VT2’、兩只整流(liu)二極管“VD1、VD2’以(yi)及雙向(xiang)可控硅柵(zha)極觸發電路(lu)“R1、VD3、R2、VD4”等組成(cheng)。

　　若電(dian)路不(bu)連接(jie)蓄電(dian)池，兩只可(ke)控硅“VT1、VT2’均無柵電(dian)流(liu)，不(bu)導通，因此即使有交流(liu)輸入也沒有輸出電(dian)壓。確保安全。

　　當電(dian)(dian)路中(zhong)輸(shu)出(+)端(duan)(duan)連接電(dian)(dian)池(chi)(chi)正極(ji)(ji)(ji)(ji)、輸(shu)出(-)端(duan)(duan)接負極(ji)(ji)(ji)(ji)時，由于蓄(xu)(xu)(xu)電(dian)(dian)池(chi)(chi)存(cun)在(zai)剩(sheng)余電(dian)(dian)壓，將(jiang)使VT1出柵極(ji)(ji)(ji)(ji)電(dian)(dian)流“經VT1、G極(ji)(ji)(ji)(ji)-VD3-R1”使VT1導通。在(zai)交(jiao)流電(dian)(dian)正半周(zhou)經VT1和VT2對蓄(xu)(xu)(xu)電(dian)(dian)池(chi)(chi)進行充電(dian)(dian)：相反(fan)，若蓄(xu)(xu)(xu)電(dian)(dian)池(chi)(chi)正極(ji)(ji)(ji)(ji)連(-)端(duan)(duan)、負極(ji)(ji)(ji)(ji)連(+)端(duan)(duan)，則VT2有(you)柵極(ji)(ji)(ji)(ji)電(dian)(dian)流而導通，通過VT2和VT1給蓄(xu)(xu)(xu)電(dian)(dian)池(chi)(chi)充電(dian)(dian)。

　　綜上所述：不(bu)論是(shi)電(dian)(dian)(dian)(dian)(dian)(dian)池正(zheng)極、負極輸出，(+、-)、(-、+)端連接均能(neng)正(zheng)常充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)。如果(guo)蓄電(dian)(dian)(dian)(dian)(dian)(dian)池剩余電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)過小(xiao)不(bu)能(neng)觸(chu)(chu)發VT1或VT2導通，就(jiu)不(bu)能(neng)進(jin)行充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)。對于(yu)(yu)這種情(qing)(qing)況，可用(yong)晶體管代替VD3和(he)VD4來減小(xiao)晶閘管的(de)(de)觸(chu)(chu)發電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)。而對于(yu)(yu)VT1、VT2和(he)VD1、VD2器件的(de)(de)要求耐(nai)壓(ya)大(da)于(yu)(yu)100V、連續工(gong)作電(dian)(dian)(dian)(dian)(dian)(dian)流為20A以上。VD3、VD4只(zhi)需(xu)耐(nai)壓(ya)大(da)于(yu)(yu)50V、工(gong)作電(dian)(dian)(dian)(dian)(dian)(dian)流100mA左(zuo)右就(jiu)行了(le)。具體情(qing)(qing)況根(gen)據蓄電(dian)(dian)(dian)(dian)(dian)(dian)池的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)及充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流實際(ji)需(xu)要而確定，靈(ling)活(huo)掌(zhang)握選(xuan)用(yong)這些電(dian)(dian)(dian)(dian)(dian)(dian)子(zi)元器件。

　　例(li)如：要(yao)對48V蓄電(dian)(dian)(dian)池充電(dian)(dian)(dian)，限流電(dian)(dian)(dian)阻R1、R2功率(lv)需要(yao)2W以上的電(dian)(dian)(dian)阻。但(dan)注意,T電(dian)(dian)(dian)源變壓器(qi)次級有(you)直流成(cheng)分(fen)電(dian)(dian)(dian)流通過(guo)，磁(ci)化電(dian)(dian)(dian)流增大，因此變壓器(qi)的設計容量要(yao)大些，次級輸出電(dian)(dian)(dian)壓分(fen)別為7V、14V、28V、42V、56V，S選(xuan)用(yong)五擋(dang)轉換開(kai)關。其他元器(qi)件(jian)無特殊要(yao)求，按圖中所標的參數為準。而(er)輸出的正負極(ji)分(fen)別為：6V、12V、24V、36V、48V。