隨著油價的(de)(de)(de)不斷上漲和人們環(huan)保(bao)意識的(de)(de)(de)增(zeng)強，電(dian)動(dong)自行車以其價格低、綠色環(huan)保(bao)，使(shi)用(yong)安全方便等優點越(yue)來(lai)越(yue)受到消費者的(de)(de)(de)喜愛。評(ping)價電(dian)動(dong)自行車質量(liang)好(hao)壞的(de)(de)(de)重要參數之一是其蓄(xu)電(dian)池(chi)的(de)(de)(de)使(shi)用(yong)壽命(ming)。而蓄(xu)電(dian)池(chi)的(de)(de)(de)充(chong)電(dian)過程對其壽命(ming)影響(xiang)(xiang)最大。研究表明：過充(chong)電(dian)，可(ke)使(shi)蓄(xu)電(dian)池(chi)發(fa)熱(re)，電(dian)解液失水；而充(chong)電(dian)不足，則可(ke)使(shi)蓄(xu)電(dian)池(chi)內化學反應不充(chong)分，長期充(chong)電(dian)不足會導致(zhi)蓄(xu)電(dian)池(chi)容(rong)量(liang)下降(jiang)。由此可(ke)見，充(chong)電(dian)器性能的(de)(de)(de)好(hao)壞直接影響(xiang)(xiang)著蓄(xu)電(dian)池(chi)的(de)(de)(de)使(shi)用(yong)效果和使(shi)用(yong)壽命(ming)。

  目前市場上的充電器存在的主要不足，第一不是從副邊繞組直接獲得取樣信號，因而穩壓效果不理想；第二是輸出電流和電壓調節范圍窄，因而只適用于固定負載。為此，本文介紹了一種以單片機為控制器的通用智能充電器的(de)設計方案。該裝置能(neng)根據(ju)蓄(xu)電(dian)(dian)池(chi)的(de)充(chong)電(dian)(dian)特性或(huo)實(shi)時監(jian)測到(dao)的(de)充(chong)電(dian)(dian)狀態，來智(zhi)能(neng)化地調節充(chong)電(dian)(dian)電(dian)(dian)壓和充(chong)電(dian)(dian)電(dian)(dian)流(liu)，而且調節范圍寬，并具(ju)有(you)過流(liu)、過壓、過溫等保護功能(neng)。 1、系(xi)(xi)統結(jie)構 該系(xi)(xi)統主要由電(dian)(dian)源變換電(dian)(dian)路(lu)、采(cai)樣電(dian)(dian)路(lu)、微(wei)處理器(qi)，脈(mo)寬調制器(qi)、鍵(jian)盤(pan)、顯示器(qi)和溫度(du)傳感器(qi)等部分組成(cheng)，是一(yi)個閉(bi)環的(de)智(zhi)能(neng)充(chong)電(dian)(dian)系(xi)(xi)統。

   2、硬件電路 本智能充電器的(de)硬件電(dian)(dian)路分為(wei)(wei)(wei)開(kai)(kai)關電(dian)(dian)源(yuan)部分、以單片(pian)機為(wei)(wei)(wei)主(zhu)的(de)控(kong)制(zhi)電(dian)(dian)路和以UC3842為(wei)(wei)(wei)核心的(de)脈寬(kuan)調制(zhi)電(dian)(dian)路三部分。 2．1開(kai)(kai)關電(dian)(dian)源(yuan)設計 本設計采用電(dian)(dian)流控(kong)制(zhi)型脈寬(kuan)調制(zhi)方式。其整個工作過程是將(jiang)交流輸(shu)(shu)(shu)入經(jing)(jing)濾波、整流后(hou)變為(wei)(wei)(wei)直流高(gao)壓(ya)，再(zai)由(you)開(kai)(kai)關管斬波、高(gao)頻變壓(ya)器(qi)降壓(ya)后(hou)得到(dao)高(gao)頻矩(ju)形電(dian)(dian)壓(ya)，最(zui)后(hou)經(jing)(jing)過輸(shu)(shu)(shu)出(chu)整流濾波獲得所需(xu)要(yao)(yao)的(de)直流輸(shu)(shu)(shu)出(chu)電(dian)(dian)壓(ya)。系(xi)統對開(kai)(kai)關電(dian)(dian)源(yuan)的(de)要(yao)(yao)求是其交流輸(shu)(shu)(shu)入電(dian)(dian)壓(ya)范圍為(wei)(wei)(wei)90～270 V，能同(tong)時輸(shu)(shu)(shu)出(chu)+5V作為(wei)(wei)(wei)控(kong)制(zhi)部分電(dian)(dian)源(yuan)及12～60 V主(zhu)回路的(de)電(dian)(dian)壓(ya)。輸(shu)(shu)(shu)出(chu)電(dian)(dian)流為(wei)(wei)(wei)1～3 A。 2．2單片(pian)機控(kong)制(zhi)電(dian)(dian)路設計 單片(pian)機控(kong)制(zhi)電(dian)(dian)路主(zhu)要(yao)(yao)由(you)單片(pian)機AT89S52、ADCTLC0832、多路選擇開(kai)(kai)關CD4051、數字電(dian)(dian)位器(qi)X9C102、數字溫(wen)度傳感(gan)器(qi)DSl8820、取樣電(dian)(dian)阻Rs和Rw、2×4鍵盤(pan)、液晶顯示(shi)CONl6等(deng)組成。

    本部分(fen)設(she)(she)(she)(she)計(ji)時(shi)應先根據蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)型號(hao)(hao)參數，來通(tong)(tong)(tong)過(guo)(guo)(guo)(guo)(guo)鍵盤設(she)(she)(she)(she)計(ji)與之對應的(de)(de)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)、充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)以(yi)及(ji)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)間，當(dang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路接上(shang)蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)后(hou)，充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)過(guo)(guo)(guo)(guo)(guo)程(cheng)開(kai)始，此后(hou)由單(dan)(dan)(dan)片(pian)機(ji)(ji)通(tong)(tong)(tong)過(guo)(guo)(guo)(guo)(guo)取樣(yang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)RM檢(jian)(jian)測(ce)(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，若(ruo)檢(jian)(jian)測(ce)(ce)(ce)到蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)因過(guo)(guo)(guo)(guo)(guo)渡放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)而(er)(er)使(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)低(di)于正(zheng)常范圍。那(nei)么(me)，為了(le)避免充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)過(guo)(guo)(guo)(guo)(guo)大而(er)(er)造成蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)損(sun)壞，應先對蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)實(shi)行穩定的(de)(de)小(xiao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)本設(she)(she)(she)(she)計(ji)程(cheng)序中設(she)(she)(she)(she)為l／5的(de)(de)設(she)(she)(she)(she)定充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)，同(tong)時(shi)，單(dan)(dan)(dan)片(pian)機(ji)(ji)開(kai)始計(ji)時(shi)，之后(hou)單(dan)(dan)(dan)片(pian)機(ji)(ji)將(jiang)不(bu)斷(duan)檢(jian)(jian)測(ce)(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)和(he)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)并(bing)顯示在(zai)液晶屏(ping)上(shang)，隨著充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)進行，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)不(bu)斷(duan)上(shang)升(sheng)，當(dang)上(shang)升(sheng)到正(zheng)常范圍時(shi)，單(dan)(dan)(dan)片(pian)機(ji)(ji)可(ke)通(tong)(tong)(tong)過(guo)(guo)(guo)(guo)(guo)控制(zhi)數字(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)位(wei)器(qi)(qi)來調節輸(shu)出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，從而(er)(er)轉(zhuan)入(ru)大電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)恒(heng)流(liu)(liu)(liu)(liu)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)即設(she)(she)(she)(she)定電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)方式，此后(hou)，單(dan)(dan)(dan)片(pian)機(ji)(ji)一直(zhi)保持不(bu)停地檢(jian)(jian)測(ce)(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，當(dang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)達到設(she)(she)(she)(she)定值時(shi)，單(dan)(dan)(dan)片(pian)機(ji)(ji)發出(chu)指令，以(yi)增(zeng)大數字(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)位(wei)器(qi)(qi)的(de)(de)阻(zu)值，并(bing)通(tong)(tong)(tong)過(guo)(guo)(guo)(guo)(guo)脈寬(kuan)調制(zhi)減(jian)(jian)小(xiao)輸(shu)出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)。從而(er)(er)使(shi)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)減(jian)(jian)小(xiao)，當(dang)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)減(jian)(jian)小(xiao)到1／5的(de)(de)設(she)(she)(she)(she)定電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)時(shi)，再轉(zhuan)為涓流(liu)(liu)(liu)(liu)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，最后(hou)在(zai)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)間到時(shi)關閉電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源，這樣(yang)就避免了(le)因電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)溫升(sheng)過(guo)(guo)(guo)(guo)(guo)快或嚴(yan)重極化而(er)(er)影響充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)質量，提高蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)使(shi)用(yong)壽命。當(dang)檢(jian)(jian)測(ce)(ce)(ce)到電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)、充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)和(he)溫度超過(guo)(guo)(guo)(guo)(guo)設(she)(she)(she)(she)定值的(de)(de)1／10倍時(shi)由程(cheng)序設(she)(she)(she)(she)定，單(dan)(dan)(dan)片(pian)機(ji)(ji)立即輸(shu)出(chu)報警(jing)信(xin)號(hao)(hao)報警(jing)。同(tong)時(shi)使(shi)繼電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)動作并(bing)切斷(duan)總電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源，以(yi)提高充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)安全性和(he)可(ke)靠性。

   顯(xian)示器(qi)可(ke)用于顯(xian)示單片(pian)機(ji)(ji)實時采樣到(dao)的(de)蓄電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓、充(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)、已充(chong)(chong)(chong)電(dian)(dian)(dian)時間和蓄電(dian)(dian)(dian)池(chi)的(de)溫度，鍵盤則用于設(she)定(ding)充(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓充(chong)(chong)(chong)電(dian)(dian)(dian)極限電(dian)(dian)(dian)壓、恒流(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)極限充(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)和充(chong)(chong)(chong)電(dian)(dian)(dian)時間。電(dian)(dian)(dian)路中的(de)單片(pian)機(ji)(ji)可(ke)通過串口RS232和上(shang)位機(ji)(ji)相連，以用于存儲(chu)數據和虛擬顯(xian)示充(chong)(chong)(chong)電(dian)(dian)(dian)參(can)數的(de)設(she)定(ding)。當(dang)檢測(ce)到(dao)充(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)為(wei)(wei)零時，單片(pian)機(ji)(ji)轉入休眠狀態。而當(dang)檢測(ce)到(dao)充(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)不(bu)為(wei)(wei)零時，單片(pian)機(ji)(ji)被激活。

   2．3 PWM控制器設計 PW M控制器部分是以UC3842為核心。UC3842芯片內含有5.0 V基準電壓穩壓器、高增益誤差放大器和脈沖寬度比較器，它可以控制芯片內的驅動器。而驅動器則可提供25 mA的輸出電流．可直接驅動NOSFET調整管，從而調整充電器的(de)輸出電壓和電流。由(you)(you)于(yu)該驅動(dong)(dong)器(qi)(qi)同(tong)時具有過流、過壓保護，工作電源電壓可以在8～40 V，而啟動(dong)(dong)電流小于(yu)1 mA，工作溫(wen)度為(wei)O～70℃，因而是(shi)目前較理想的(de)新型脈寬調制器(qi)(qi)。 PWM控制器(qi)(qi)在啟動(dong)(dong)時，是(shi)由(you)(you)R1、Rw。

   為(wei)UC3842提供(gong)啟動電(dian)(dian)(dian)(dian)壓(ya)，待其(qi)工作后，其(qi)輔助(zhu)繞組(zu)3、4端(duan)的(de)電(dian)(dian)(dian)(dian)壓(ya)經D1整流(liu)、C4、C5濾波、DW1穩(wen)(wen)壓(ya)后得到的(de)16 V直流(liu)電(dian)(dian)(dian)(dian)壓(ya)，一路加(jia)到UC38427的(de)7腳為(wei)其(qi)供(gong)電(dian)(dian)(dian)(dian)，另一路經R3和數(shu)(shu)字(zi)電(dian)(dian)(dian)(dian)位(wei)(wei)器X9C102分(fen)壓(ya)后加(jia)到UC3842的(de)2腳。以作為(wei)脈寬調制(zhi)(zhi)的(de)輸入(ru)信號。一般在這類(lei)電(dian)(dian)(dian)(dian)源的(de)設計中(zhong)，輸出(chu)電(dian)(dian)(dian)(dian)壓(ya)取樣(yang)可(ke)與(yu)UC3842的(de)供(gong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓(ya)相(xiang)連。為(wei)了反映輸出(chu)電(dian)(dian)(dian)(dian)壓(ya)變化，本(ben)設計沒有(you)(you)加(jia)穩(wen)(wen)壓(ya)管，但這會使UC3842的(de)工作電(dian)(dian)(dian)(dian)壓(ya)不(bu)穩(wen)(wen)，輸出(chu)諧波成分(fen)增多(duo)，為(wei)了克服此不(bu)足(zu)，本(ben)設計中(zhong)UC3842的(de)供(gong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓(ya)采用(yong)由3、4繞組(zu)端(duan)壓(ya)單(dan)獨整流(liu)、濾波、穩(wen)(wen)壓(ya)后，提供(gong)給UC3842芯片16 V的(de)穩(wen)(wen)定電(dian)(dian)(dian)(dian)壓(ya)。充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓(ya)的(de)調節是將電(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)壓(ya)經外環電(dian)(dian)(dian)(dian)壓(ya)取樣(yang)電(dian)(dian)(dian)(dian)路R12、RM取樣(yang)，再經多(duo)路電(dian)(dian)(dian)(dian)子開(kai)關選擇(ze)、MD變換，單(dan)片機處(chu)理后，送入(ru)數(shu)(shu)字(zi)電(dian)(dian)(dian)(dian)位(wei)(wei)器，以控制(zhi)(zhi)數(shu)(shu)字(zi)電(dian)(dian)(dian)(dian)位(wei)(wei)器的(de)有(you)(you)效電(dian)(dian)(dian)(dian)阻。

   從而間接控制UC3842的2腳電壓，進而控制脈沖占空比，以改變充電電壓。 充電器輸出電(dian)(dian)(dian)(dian)(dian)壓(ya)偏高時，反饋回UC3842的(de)2腳電(dian)(dian)(dian)(dian)(dian)壓(ya)也(ye)升高超過(guo)參考(kao)電(dian)(dian)(dian)(dian)(dian)壓(ya)2.5 V之(zhi)后(hou)，驅動信號(hao)的(de)脈沖占空比減(jian)小，使輸出電(dian)(dian)(dian)(dian)(dian)壓(ya)下降，從而達到(dao)穩壓(ya)的(de)目的(de)。充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)的(de)調節主要(yao)是先(xian)將(jiang)充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)經(jing)外環(huan)電(dian)(dian)(dian)(dian)(dian)流(liu)取(qu)樣電(dian)(dian)(dian)(dian)(dian)阻Rs取(qu)樣和(he)LM358放大可用R1調節放大倍數、多路(lu)電(dian)(dian)(dian)(dian)(dian)子開關(guan)選擇、MD變換，再送單片機處理(li)，然(ran)后(hou)調節數字電(dian)(dian)(dian)(dian)(dian)位器的(de)阻值。其調節過(guo)程與電(dian)(dian)(dian)(dian)(dian)壓(ya)調節相似，實際上，電(dian)(dian)(dian)(dian)(dian)流(liu)調節也(ye)是通過(guo)電(dian)(dian)(dian)(dian)(dian)壓(ya)調節實現的(de)。

    2．4．保(bao)(bao)護(hu)電(dian)(dian)(dian)(dian)(dian)路設計(ji) 當(dang)(dang)過流(liu)(liu)或短路時，內(nei)環(huan)(huan)取(qu)(qu)(qu)樣電(dian)(dian)(dian)(dian)(dian)阻R10兩端的(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)升高。當(dang)(dang)3腳(jiao)(jiao)電(dian)(dian)(dian)(dian)(dian)壓(ya)超過1伏(fu)時，通過UC3842的(de)內(nei)部調制可使其停止脈寬輸(shu)出，開關(guan)管截止，輸(shu)出電(dian)(dian)(dian)(dian)(dian)壓(ya)和電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)均為0，從而(er)保(bao)(bao)護(hu)電(dian)(dian)(dian)(dian)(dian)源。過壓(ya)時，DW1和DW2會擊穿(chuan)而(er)短路，也會造成(cheng)過流(liu)(liu)保(bao)(bao)護(hu)，DW2可用以保(bao)(bao)護(hu)場效應(ying)管和UC3842。而(er)當(dang)(dang)發生(sheng)欠壓(ya)時，即當(dang)(dang)UC3842的(de)7腳(jiao)(jiao)電(dian)(dian)(dian)(dian)(dian)壓(ya)降(jiang)至10 V以下時，UC3842將啟動(dong)欠壓(ya)鎖(suo)定(ding)電(dian)(dian)(dian)(dian)(dian)路而(er)關(guan)閉開關(guan)控(kong)制器(qi)。內(nei)環(huan)(huan)的(de)這種(zhong)反饋調整是(shi)(shi)(shi)在輸(shu)出電(dian)(dian)(dian)(dian)(dian)壓(ya)尚未發生(sheng)變化時，通過檢測(ce)內(nei)環(huan)(huan)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)使脈寬提前得到調整，前饋控(kong)制，從而(er)加快(kuai)了變換器(qi)對異(yi)常情況的(de)動(dong)態響應(ying)速(su)度(du)。以便更加快(kuai)速(su)有效地(di)起到保(bao)(bao)護(hu)作用。當(dang)(dang)然，外(wai)環(huan)(huan)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)、電(dian)(dian)(dian)(dian)(dian)壓(ya)的(de)取(qu)(qu)(qu)樣Rs、Rw亦可通過單片機的(de)調節作用來達(da)到對異(yi)常情況的(de)保(bao)(bao)護(hu)，但(dan)響應(ying)速(su)度(du)比內(nei)環(huan)(huan)慢5～10個(ge)工頻(pin)周期，因此(ci)，外(wai)環(huan)(huan)取(qu)(qu)(qu)樣主要是(shi)(shi)(shi)調節充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)和充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓(ya)，兼(jian)作二次(ci)保(bao)(bao)護(hu)，而(er)內(nei)環(huan)(huan)取(qu)(qu)(qu)樣則是(shi)(shi)(shi)主要的(de)，它是(shi)(shi)(shi)一次(ci)的(de)保(bao)(bao)護(hu)，這種(zhong)雙環(huan)(huan)保(bao)(bao)護(hu)方式會更加安全(quan)可靠。

    3、軟件設計 在程(cheng)序的初始(shi)階段(duan)，首先是(shi)對單片機進(jin)(jin)(jin)行初始(shi)化，即根(gen)據(ju)不(bu)同的電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)設定(ding)不(bu)同的充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)參數(shu)，選擇(ze)不(bu)同的充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)策略。其(qi)后(hou)是(shi)判(pan)斷電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)是(shi)否連接正確，根(gen)據(ju)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)值判(pan)斷應該進(jin)(jin)(jin)入(ru)(ru)哪一(yi)個充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)階段(duan)即小(xiao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)預充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，大電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)恒流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)或(huo)恒壓(ya)涓(juan)流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)方(fang)式。在預充(chong)(chong)階段(duan)，應降(jiang)低充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，而在恒流(liu)方(fang)式時(shi)，應不(bu)斷檢測充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)是(shi)否達(da)到(dao)恒定(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)如(ru)1.8 A，如(ru)果(guo)小(xiao)于1.8 A，則抬高電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)兩(liang)端的電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，使之達(da)到(dao)1.8 A，以(yi)上調節過程(cheng)均可采用比例控(kong)制(zhi)。在電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)兩(liang)端電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)達(da)到(dao)設定(ding)值后(hou)，系統再進(jin)(jin)(jin)入(ru)(ru)涓(juan)流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)模式。該充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)的程(cheng)序流(liu)程(cheng)如(ru)圖3所(suo)示。圖3中，Is為(wei)設定(ding)的充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)即恒流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)，Umin為(wei)蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極限(xian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，Umax為(wei)蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極限(xian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)。

   應用試驗 本設計選用了電動自行車常用的36 V／12 Ah鉛酸蓄電池作為測試對象，其恒壓充電電壓設定為43 V，恒流充電電流Is為1.8 A，起始時，隨著充電的進行，充電電流幾乎維持1.8 A不變，但電池電壓不斷升高，當充電3小時后。電壓上升減慢；當充電到4小時后，充電電壓接近43 V；之后電壓上升更加緩慢。而且充電下降較快。當充到43 V時，充電器自(zi)動(dong)停(ting)止。從測(ce)(ce)試數(shu)據來(lai)看，該設計達到(dao)了(le)恒流快充(chong)(chong)(chong)(chong)，恒壓(ya)涓充(chong)(chong)(chong)(chong)，充(chong)(chong)(chong)(chong)滿自(zi)行(xing)關斷的設計要求。 5、結束語 本文設計的過度放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)預充(chong)(chong)(chong)(chong)、恒流快充(chong)(chong)(chong)(chong)、恒壓(ya)涓充(chong)(chong)(chong)(chong)、智能(neng)(neng)(neng)控(kong)制的充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)方(fang)案，能(neng)(neng)(neng)很好地解(jie)決電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)自(zi)行(xing)車(che)用電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)在(zai)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)過程中存在(zai)的過充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)、充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)不(bu)足和發(fa)熱(re)等(deng)問題(ti)，并能(neng)(neng)(neng)根據不(bu)同(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)選擇不(bu)同(tong)(tong)的充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)方(fang)案。而且具有通用性。能(neng)(neng)(neng)實(shi)時檢測(ce)(ce)并顯示(shi)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流、充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)、充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)時間和蓄電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)溫度等(deng)參數(shu)。由于電(dian)(dian)(dian)(dian)(dian)(dian)路具有內(nei)外(wai)環控(kong)制，符(fu)合最(zui)優控(kong)制規(gui)律。最(zui)具有過流、過壓(ya)和超溫保護功能(neng)(neng)(neng)，同(tong)(tong)時由于

   UC3842采用穩壓供電，因此，不但諧波污染(ran)程度(du)低，原副邊電氣隔離安全可(ke)靠，同時(shi)還可(ke)根據負載情況通過(guo)單片機來進行控制，并可(ke)實現跳周(zhou)期模式工作。故可(ke)提高電源(yuan)的效率。