各種移動設備的飛速發展，也加快了充電電池的發展，為了滿足現今移動設備的需要，充電電池的容量也越來越大，其中鎳氫充電電池是大容量電池的主要品種，在電力電子、交通以及通信領域有了較多的應用，在很多智能儀器儀表中，鎳氫電池常用來作為備用電池，充電器是充電電池的必備品，這篇文章就來講述一種基于分立元件構成的電池自動恒流充電電路(lu)，著重講(jiang)述了充(chong)電電路(lu)的組(zu)成(cheng)、結構特(te)點(dian)、工作原(yuan)理及電路(lu)的調節。

1 電路(lu)總體設計思路(lu)

簡易電(dian)(dian)池自動恒流(liu)(liu)充電(dian)(dian)電(dian)(dian)路的總體框圖如圖1所(suo)示(shi)。它是由變壓器整流(liu)(liu)電(dian)(dian)路、恒流(liu)(liu)產(chan)生電(dian)(dian)路、自動斷電(dian)(dian)電(dian)(dian)路、顯示(shi)電(dian)(dian)路和電(dian)(dian)源電(dian)(dian)路5部(bu)分構成。

變壓(ya)(ya)(ya)(ya)器整流(liu)電(dian)(dian)路(lu)(lu)的(de)(de)(de)功(gong)(gong)能(neng)是(shi)將(jiang)公共電(dian)(dian)網(wang)中(zhong)的(de)(de)(de)220V交流(liu)電(dian)(dian)轉換為合適(shi)的(de)(de)(de)電(dian)(dian)流(liu)和(he)電(dian)(dian)壓(ya)(ya)(ya)(ya)信號(hao)，從(cong)而為后續(xu)電(dian)(dian)路(lu)(lu)提供信號(hao)。恒流(liu)產生電(dian)(dian)路(lu)(lu)的(de)(de)(de)功(gong)(gong)能(neng)是(shi)利用晶體(ti)管(guan)電(dian)(dian)流(liu)源為電(dian)(dian)路(lu)(lu)產生恒定的(de)(de)(de)充電(dian)(dian)電(dian)(dian)流(liu)。自動斷(duan)電(dian)(dian)電(dian)(dian)路(lu)(lu)的(de)(de)(de)功(gong)(gong)能(neng)是(shi)利用三(san)極管(guan)飽和(he)導通時的(de)(de)(de)電(dian)(dian)壓(ya)(ya)(ya)(ya)特性，從(cong)而實(shi)現電(dian)(dian)路(lu)(lu)當電(dian)(dian)池充滿電(dian)(dian)時能(neng)夠自動切斷(duan)電(dian)(dian)源。顯示電(dian)(dian)路(lu)(lu)的(de)(de)(de)功(gong)(gong)能(neng)是(shi)利用發光二極管(guan)將(jiang)電(dian)(dian)路(lu)(lu)開(kai)始充電(dian)(dian)和(he)結束(shu)充電(dian)(dian)的(de)(de)(de)狀態顯示出來。穩壓(ya)(ya)(ya)(ya)電(dian)(dian)源電(dian)(dian)路(lu)(lu)的(de)(de)(de)功(gong)(gong)能(neng)是(shi)為上述所有電(dian)(dian)路(lu)(lu)提供直流(liu)電(dian)(dian)壓(ya)(ya)(ya)(ya)。

1.1 變壓(ya)器(qi)整流電路(lu)及電源電路(lu)的(de)設計(ji)

變(bian)壓器整(zheng)流(liu)電(dian)(dian)路和穩壓電(dian)(dian)源電(dian)(dian)路(如圖2虛線左(zuo)邊所(suo)示(shi))，其主(zhu)要由變(bian)壓器、二(er)極(ji)管橋式電(dian)(dian)路、電(dian)(dian)容(rong)構成。其中(zhong)變(bian)壓器采用(yong)常規的鐵心變(bian)壓器，并將公共電(dian)(dian)網(wang)中(zhong)的220 V交流(liu)電(dian)(dian)變(bian)為(wei)12 V交流(liu)電(dian)(dian)，再通過二(er)極(ji)管橋式電(dian)(dian)路進行整(zheng)流(liu)和電(dian)(dian)容(rong)C1濾(lv)波。整(zheng)流(liu)信號由VC1引出。在此(ci)基礎(chu)上再接三端穩壓器CW7812及電(dian)(dian)容(rong)C3、C4(如圖2虛線右邊所(suo)示(shi))，這樣整(zheng)個電(dian)(dian)路就構成穩壓電(dian)(dian)源電(dian)(dian)路。由B點提供(gong)+12 V的直流(liu)電(dian)(dian)壓。

1.2 恒(heng)流電(dian)路的(de)設計

如圖3所示，由穩壓(ya)管(guan)VZ1、晶體管(guan)VT1、電阻(zu)R1、電容(rong)C2構成(cheng)的晶體管(guan)電流源提供(gong)恒定電流，

取(qu)穩壓管(guan)電(dian)(dian)壓為(wei)(wei)5 V，R1為(wei)(wei)51 Ω，此時(shi)IC≈1OO mA，作為(wei)(wei)電(dian)(dian)路的充(chong)電(dian)(dian)電(dian)(dian)流。

1.3 自動(dong)充電(dian)(dian)檢測電(dian)(dian)路和(he)指(zhi)示電(dian)(dian)路的設(she)計

如圖4電(dian)(dian)(dian)路所示，自動斷電(dian)(dian)(dian)電(dian)(dian)(dian)路是由三極(ji)管VT2、電(dian)(dian)(dian)壓(ya)跟隨器A1、電(dian)(dian)(dian)壓(ya)比較器A2電(dian)(dian)(dian)阻R4、R5、R6、R7、R8、R11和可變(bian)電(dian)(dian)(dian)阻RP1構成。當(dang)充(chong)電(dian)(dian)(dian)開始時(shi)(shi)，電(dian)(dian)(dian)壓(ya)比較器輸出高電(dian)(dian)(dian)平，VT2導通，VT1也導通，指示燈(deng)發光二(er)極(ji)管亮，給(gei)(gei)電(dian)(dian)(dian)池(chi)(chi)充(chong)電(dian)(dian)(dian)。可以先設定(ding)轉換開關(guan)為1時(shi)(shi)給(gei)(gei)一節電(dian)(dian)(dian)池(chi)(chi)充(chong)電(dian)(dian)(dian)，轉換開關(guan)為2時(shi)(shi)給(gei)(gei)二(er)節電(dian)(dian)(dian)池(chi)(chi)充(chong)電(dian)(dian)(dian)，依(yi)次類推，實現對(dui)1-4節電(dian)(dian)(dian)池(chi)(chi)充(chong)電(dian)(dian)(dian)。當(dang)電(dian)(dian)(dian)充(chong)滿(man)時(shi)(shi)，電(dian)(dian)(dian)壓(ya)比較器輸出低(di)電(dian)(dian)(dian)平，VT2截止，VT1不(bu)導通，發光二(er)極(ji)管熄滅，充(chong)電(dian)(dian)(dian)完畢(bi)。

 2 簡易充(chong)電器總(zong)電路原理圖(tu)及元器件(jian)清單

2.1 簡易充電器(qi)總電路原理圖

簡易電(dian)(dian)池(chi)自動恒(heng)(heng)流充電(dian)(dian)電(dian)(dian)路的(de)(de)總電(dian)(dian)路圖(tu)如圖(tu)5所示(shi)。它是由(you)變壓器(qi)整流電(dian)(dian)路、恒(heng)(heng)流產生電(dian)(dian)路、充電(dian)(dian)檢測電(dian)(dian)路、顯示(shi)電(dian)(dian)路和電(dian)(dian)源電(dian)(dian)路5部分構成。總電(dian)(dian)路圖(tu)中需要(yao)注(zhu)意的(de)(de)是各個單元電(dian)(dian)路之(zhi)間(jian)的(de)(de)連接一(yi)定要(yao)準確(que)，同時各部分的(de)(de)布局要(yao)合理。

2.2 元器(qi)件清單(dan)

本設計(ji)用的元件清單如表1。

3 結束語

通過以上(shang)的講解我們發現簡易(yi)電池自動恒流充電電路具(ju)有很(hen)多優點，電路結構簡單(dan)、功能(neng)完善(shan)、調節方便(bian)等，適合(he)無線電愛(ai)好者自行制作及高職學生(sheng)電子實訓(xun)。

                                                                                                         本文摘自于中國充電器網