目(mu)前(qian)市場上出售(shou)的各種型號的充電(dian)(dian)(dian)器(qi)要求外接(jie)電(dian)(dian)(dian)源時(shi)正、負(fu)極性絕對不能有誤，否則(ze)充電(dian)(dian)(dian)時(shi)將(jiang)燒壞電(dian)(dian)(dian)池或電(dian)(dian)(dian)器(qi)，這里(li)介紹一種安全型充電(dian)(dian)(dian)器(qi)電(dian)(dian)(dian)路(lu)，使(shi)用時(shi)可(ke)不用校正正負(fu)極性，直接(jie)接(jie)入電(dian)(dian)(dian)池的極性，即(ji)能安全充電(dian)(dian)(dian)，使(shi)用起來很(hen)得心順(shun)手(shou)。該無極性充電(dian)(dian)(dian)器(qi)電(dian)(dian)(dian)路(lu)見附(fu)圖所(suo)示(shi)。

　　該(gai)電(dian)路(lu)由二(er)只雙向可(ke)控硅“VT1、VT2’、兩(liang)只整流二(er)極管“VD1、VD2’以(yi)及雙向可(ke)控硅柵極觸發(fa)電(dian)路(lu)“R1、VD3、R2、VD4”等組(zu)成。

　　若電(dian)路不(bu)連(lian)接蓄電(dian)池，兩(liang)只可控硅“VT1、VT2’均無柵(zha)電(dian)流，不(bu)導通，因此即使有交流輸入也沒有輸出電(dian)壓。確保安全。

　　當電(dian)路中輸(shu)出(chu)(+)端(duan)連(lian)接電(dian)池(chi)正極(ji)(ji)(ji)、輸(shu)出(chu)(-)端(duan)接負(fu)極(ji)(ji)(ji)時(shi)，由(you)于蓄(xu)(xu)電(dian)池(chi)存(cun)在剩余電(dian)壓，將使VT1出(chu)柵極(ji)(ji)(ji)電(dian)流“經VT1、G極(ji)(ji)(ji)-VD3-R1”使VT1導通。在交流電(dian)正半周(zhou)經VT1和VT2對蓄(xu)(xu)電(dian)池(chi)進行(xing)充電(dian)：相(xiang)反(fan)，若蓄(xu)(xu)電(dian)池(chi)正極(ji)(ji)(ji)連(lian)(-)端(duan)、負(fu)極(ji)(ji)(ji)連(lian)(+)端(duan)，則VT2有柵極(ji)(ji)(ji)電(dian)流而導通，通過(guo)VT2和VT1給(gei)蓄(xu)(xu)電(dian)池(chi)充電(dian)。

　　綜(zong)上(shang)所述：不(bu)論是電(dian)(dian)(dian)池(chi)正極、負極輸出，(+、-)、(-、+)端連(lian)接均能正常充(chong)電(dian)(dian)(dian)。如果蓄(xu)電(dian)(dian)(dian)池(chi)剩余電(dian)(dian)(dian)壓過小不(bu)能觸發VT1或VT2導通，就不(bu)能進行充(chong)電(dian)(dian)(dian)。對(dui)于(yu)(yu)(yu)這(zhe)種(zhong)情況，可用晶(jing)體管(guan)代替VD3和VD4來減小晶(jing)閘(zha)管(guan)的觸發電(dian)(dian)(dian)壓。而(er)(er)對(dui)于(yu)(yu)(yu)VT1、VT2和VD1、VD2器件(jian)的要求耐壓大于(yu)(yu)(yu)100V、連(lian)續工(gong)作(zuo)電(dian)(dian)(dian)流為20A以上(shang)。VD3、VD4只需(xu)耐壓大于(yu)(yu)(yu)50V、工(gong)作(zuo)電(dian)(dian)(dian)流100mA左右就行了。具體情況根據蓄(xu)電(dian)(dian)(dian)池(chi)的電(dian)(dian)(dian)壓及充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流實際需(xu)要而(er)(er)確定，靈活掌握選用這(zhe)些(xie)電(dian)(dian)(dian)子元器件(jian)。

　　例如：要(yao)對48V蓄電池(chi)充電，限流(liu)電阻(zu)R1、R2功(gong)率需要(yao)2W以(yi)上的電阻(zu)。但(dan)注意,T電源變壓器(qi)次級有直流(liu)成分(fen)電流(liu)通(tong)過，磁化電流(liu)增大，因(yin)此(ci)變壓器(qi)的設計(ji)容量要(yao)大些，次級輸(shu)(shu)出電壓分(fen)別為7V、14V、28V、42V、56V，S選(xuan)用(yong)五(wu)擋轉換開關。其他元(yuan)器(qi)件無特(te)殊要(yao)求，按圖中(zhong)所標的參數為準。而(er)輸(shu)(shu)出的正負極(ji)分(fen)別為：6V、12V、24V、36V、48V。