目前(qian)市場(chang)上出售的(de)各種(zhong)型(xing)號(hao)的(de)充電(dian)(dian)器(qi)要(yao)求(qiu)外接電(dian)(dian)源(yuan)時(shi)(shi)正、負極性(xing)絕(jue)對不(bu)能(neng)有(you)誤，否(fou)則(ze)充電(dian)(dian)時(shi)(shi)將燒(shao)壞電(dian)(dian)池(chi)或電(dian)(dian)器(qi)，這(zhe)里介紹一種(zhong)安全(quan)型(xing)充電(dian)(dian)器(qi)電(dian)(dian)路，使(shi)用時(shi)(shi)可不(bu)用校(xiao)正正負極性(xing)，直(zhi)接接入電(dian)(dian)池(chi)的(de)極性(xing)，即能(neng)安全(quan)充電(dian)(dian)，使(shi)用起來(lai)很得心順手。該無極性(xing)充電(dian)(dian)器(qi)電(dian)(dian)路見附圖所示。

　　該電路由二(er)只雙向可控硅“VT1、VT2’、兩只整流二(er)極管“VD1、VD2’以及雙向可控硅柵極觸發電路“R1、VD3、R2、VD4”等組成(cheng)。

　　若電(dian)(dian)(dian)(dian)路(lu)不連接蓄電(dian)(dian)(dian)(dian)池，兩只可(ke)控硅“VT1、VT2’均無柵(zha)電(dian)(dian)(dian)(dian)流(liu)，不導(dao)通(tong)，因此即(ji)使有交流(liu)輸(shu)入也沒有輸(shu)出(chu)電(dian)(dian)(dian)(dian)壓。確(que)保安全。

　　當電(dian)路中輸(shu)出(+)端(duan)連接電(dian)池(chi)正(zheng)極、輸(shu)出(-)端(duan)接負(fu)極時，由于蓄(xu)電(dian)池(chi)存在剩(sheng)余電(dian)壓(ya)，將使VT1出柵極電(dian)流“經VT1、G極-VD3-R1”使VT1導通。在交流電(dian)正(zheng)半(ban)周經VT1和(he)(he)VT2對蓄(xu)電(dian)池(chi)進行充電(dian)：相(xiang)反，若蓄(xu)電(dian)池(chi)正(zheng)極連(-)端(duan)、負(fu)極連(+)端(duan)，則VT2有柵極電(dian)流而(er)導通，通過VT2和(he)(he)VT1給(gei)蓄(xu)電(dian)池(chi)充電(dian)。

　　綜(zong)上所述(shu)：不(bu)論是電(dian)(dian)(dian)(dian)池(chi)正極、負極輸出，(+、-)、(-、+)端連接均能正常充電(dian)(dian)(dian)(dian)。如果(guo)蓄電(dian)(dian)(dian)(dian)池(chi)剩余電(dian)(dian)(dian)(dian)壓(ya)過(guo)小不(bu)能觸發(fa)VT1或VT2導(dao)通，就(jiu)不(bu)能進(jin)行充電(dian)(dian)(dian)(dian)。對于(yu)這種情(qing)況(kuang)，可用晶體管(guan)代替(ti)VD3和(he)VD4來減小晶閘管(guan)的(de)觸發(fa)電(dian)(dian)(dian)(dian)壓(ya)。而對于(yu)VT1、VT2和(he)VD1、VD2器(qi)(qi)件的(de)要求(qiu)耐壓(ya)大于(yu)100V、連續(xu)工作電(dian)(dian)(dian)(dian)流為20A以上。VD3、VD4只需耐壓(ya)大于(yu)50V、工作電(dian)(dian)(dian)(dian)流100mA左右就(jiu)行了。具體情(qing)況(kuang)根據(ju)蓄電(dian)(dian)(dian)(dian)池(chi)的(de)電(dian)(dian)(dian)(dian)壓(ya)及充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流實際需要而確(que)定，靈活掌(zhang)握(wo)選(xuan)用這些電(dian)(dian)(dian)(dian)子(zi)元器(qi)(qi)件。

　　例如(ru)：要對48V蓄電(dian)池充(chong)電(dian)，限(xian)流(liu)(liu)(liu)電(dian)阻R1、R2功率需(xu)要2W以(yi)上的(de)(de)電(dian)阻。但注意,T電(dian)源變(bian)壓(ya)器(qi)次級(ji)有直流(liu)(liu)(liu)成分(fen)電(dian)流(liu)(liu)(liu)通過，磁化(hua)電(dian)流(liu)(liu)(liu)增(zeng)大，因此(ci)變(bian)壓(ya)器(qi)的(de)(de)設計(ji)容(rong)量要大些，次級(ji)輸(shu)出(chu)電(dian)壓(ya)分(fen)別(bie)為(wei)7V、14V、28V、42V、56V，S選用五擋(dang)轉換開(kai)關。其他元器(qi)件(jian)無(wu)特殊(shu)要求，按圖中所標的(de)(de)參數(shu)為(wei)準。而輸(shu)出(chu)的(de)(de)正負(fu)極分(fen)別(bie)為(wei)：6V、12V、24V、36V、48V。