隨著油(you)價的(de)(de)不(bu)斷上漲和人們(men)環保意(yi)識的(de)(de)增強，電(dian)(dian)(dian)動(dong)自行車(che)(che)以其價格低、綠色環保，使用(yong)安全方(fang)便等(deng)優點越來越受到(dao)消費者的(de)(de)喜愛(ai)。評價電(dian)(dian)(dian)動(dong)自行車(che)(che)質量(liang)好(hao)壞的(de)(de)重(zhong)要參數之一(yi)是其蓄(xu)(xu)(xu)電(dian)(dian)(dian)池(chi)的(de)(de)使用(yong)壽命(ming)。而蓄(xu)(xu)(xu)電(dian)(dian)(dian)池(chi)的(de)(de)充(chong)(chong)電(dian)(dian)(dian)過程(cheng)對其壽命(ming)影響最大。研(yan)究表明：過充(chong)(chong)電(dian)(dian)(dian)，可使蓄(xu)(xu)(xu)電(dian)(dian)(dian)池(chi)發熱，電(dian)(dian)(dian)解液失水(shui)；而充(chong)(chong)電(dian)(dian)(dian)不(bu)足，則可使蓄(xu)(xu)(xu)電(dian)(dian)(dian)池(chi)內化學反應不(bu)充(chong)(chong)分(fen)，長(chang)期充(chong)(chong)電(dian)(dian)(dian)不(bu)足會導致蓄(xu)(xu)(xu)電(dian)(dian)(dian)池(chi)容量(liang)下降(jiang)。由(you)此可見，充(chong)(chong)電(dian)(dian)(dian)器性能的(de)(de)好(hao)壞直接影響著蓄(xu)(xu)(xu)電(dian)(dian)(dian)池(chi)的(de)(de)使用(yong)效果和使用(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)(de)設(she)計方案。該(gai)裝置能根據蓄電(dian)(dian)池的(de)(de)充(chong)電(dian)(dian)特性或實時監測(ce)到的(de)(de)充(chong)電(dian)(dian)狀態(tai)，來智能化(hua)地(di)調節(jie)充(chong)電(dian)(dian)電(dian)(dian)壓(ya)(ya)和(he)充(chong)電(dian)(dian)電(dian)(dian)流，而(er)且調節(jie)范圍寬(kuan)，并具有過(guo)(guo)流、過(guo)(guo)壓(ya)(ya)、過(guo)(guo)溫(wen)等(deng)(deng)保護功(gong)能。 1、系統(tong)結構 該(gai)系統(tong)主(zhu)要由電(dian)(dian)源(yuan)變換電(dian)(dian)路(lu)、采樣電(dian)(dian)路(lu)、微處理器(qi)(qi)，脈寬(kuan)調制器(qi)(qi)、鍵盤、顯(xian)示器(qi)(qi)和(he)溫(wen)度傳感器(qi)(qi)等(deng)(deng)部分(fen)組成，是一個閉(bi)環的(de)(de)智能充(chong)電(dian)(dian)系統(tong)。

   2、硬件電路 本智能充電器的(de)硬件(jian)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)分(fen)(fen)為開(kai)關(guan)電(dian)(dian)(dian)(dian)源(yuan)(yuan)部(bu)分(fen)(fen)、以單片(pian)機(ji)為主的(de)控(kong)制電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)和以UC3842為核心的(de)脈(mo)寬(kuan)調制電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)三部(bu)分(fen)(fen)。 2．1開(kai)關(guan)電(dian)(dian)(dian)(dian)源(yuan)(yuan)設(she)計 本設(she)計采用電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)控(kong)制型脈(mo)寬(kuan)調制方式。其整個(ge)工作(zuo)過程是(shi)將(jiang)交流(liu)(liu)(liu)(liu)輸(shu)入(ru)經(jing)濾(lv)波(bo)(bo)、整流(liu)(liu)(liu)(liu)后變為直流(liu)(liu)(liu)(liu)高(gao)壓(ya)(ya)，再(zai)由開(kai)關(guan)管(guan)斬波(bo)(bo)、高(gao)頻(pin)變壓(ya)(ya)器降壓(ya)(ya)后得(de)到高(gao)頻(pin)矩形電(dian)(dian)(dian)(dian)壓(ya)(ya)，最(zui)后經(jing)過輸(shu)出整流(liu)(liu)(liu)(liu)濾(lv)波(bo)(bo)獲得(de)所(suo)需(xu)要的(de)直流(liu)(liu)(liu)(liu)輸(shu)出電(dian)(dian)(dian)(dian)壓(ya)(ya)。系統對開(kai)關(guan)電(dian)(dian)(dian)(dian)源(yuan)(yuan)的(de)要求是(shi)其交流(liu)(liu)(liu)(liu)輸(shu)入(ru)電(dian)(dian)(dian)(dian)壓(ya)(ya)范圍為90～270 V，能同(tong)時輸(shu)出+5V作(zuo)為控(kong)制部(bu)分(fen)(fen)電(dian)(dian)(dian)(dian)源(yuan)(yuan)及12～60 V主回路(lu)(lu)(lu)的(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)。輸(shu)出電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)為1～3 A。 2．2單片(pian)機(ji)控(kong)制電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)設(she)計 單片(pian)機(ji)控(kong)制電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)主要由單片(pian)機(ji)AT89S52、ADCTLC0832、多路(lu)(lu)(lu)選(xuan)擇開(kai)關(guan)CD4051、數字電(dian)(dian)(dian)(dian)位(wei)器X9C102、數字溫度傳感器DSl8820、取樣電(dian)(dian)(dian)(dian)阻(zu)Rs和Rw、2×4鍵盤、液晶顯示(shi)CONl6等(deng)組成。

    本(ben)部(bu)分設(she)(she)(she)計(ji)時(shi)(shi)應先(xian)根據蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)型號參數(shu)(shu)，來通過(guo)鍵盤設(she)(she)(she)計(ji)與之對應的(de)充(chong)(chong)(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)、充(chong)(chong)(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)以及充(chong)(chong)(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi)間，當(dang)(dang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路接上蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)后(hou)，充(chong)(chong)(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)過(guo)程(cheng)(cheng)開始，此后(hou)由(you)單片(pian)機(ji)通過(guo)取樣(yang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻RM檢測(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)，若(ruo)檢測(ce)到(dao)蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)因過(guo)渡放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)而使電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)低于正常范圍。那么，為(wei)了避免充(chong)(chong)(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)過(guo)大而造成蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)損壞，應先(xian)對蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)實行穩定(ding)(ding)的(de)小(xiao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)充(chong)(chong)(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)本(ben)設(she)(she)(she)計(ji)程(cheng)(cheng)序(xu)中設(she)(she)(she)為(wei)l／5的(de)設(she)(she)(she)定(ding)(ding)充(chong)(chong)(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)，同時(shi)(shi)，單片(pian)機(ji)開始計(ji)時(shi)(shi)，之后(hou)單片(pian)機(ji)將(jiang)不(bu)斷(duan)檢測(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)和(he)充(chong)(chong)(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)并(bing)顯示在液晶屏(ping)上，隨著充(chong)(chong)(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)進(jin)行，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)不(bu)斷(duan)上升，當(dang)(dang)上升到(dao)正常范圍時(shi)(shi)，單片(pian)機(ji)可(ke)(ke)通過(guo)控制數(shu)(shu)字電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)位器(qi)(qi)來調節輸出電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)，從而轉入大電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)恒(heng)流(liu)(liu)(liu)充(chong)(chong)(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)即(ji)設(she)(she)(she)定(ding)(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)方式，此后(hou)，單片(pian)機(ji)一直(zhi)保(bao)持不(bu)停地檢測(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)，當(dang)(dang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)達到(dao)設(she)(she)(she)定(ding)(ding)值時(shi)(shi)，單片(pian)機(ji)發出指令，以增大數(shu)(shu)字電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)位器(qi)(qi)的(de)阻值，并(bing)通過(guo)脈(mo)寬調制減(jian)小(xiao)輸出電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)。從而使充(chong)(chong)(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)減(jian)小(xiao)，當(dang)(dang)充(chong)(chong)(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)減(jian)小(xiao)到(dao)1／5的(de)設(she)(she)(she)定(ding)(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)時(shi)(shi)，再轉為(wei)涓流(liu)(liu)(liu)充(chong)(chong)(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，最(zui)后(hou)在充(chong)(chong)(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi)間到(dao)時(shi)(shi)關閉電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源，這樣(yang)就避免了因電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)溫升過(guo)快或嚴重(zhong)極化(hua)而影響充(chong)(chong)(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)質量，提(ti)高蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)使用壽(shou)命。當(dang)(dang)檢測(ce)到(dao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)、充(chong)(chong)(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)和(he)溫度(du)超過(guo)設(she)(she)(she)定(ding)(ding)值的(de)1／10倍時(shi)(shi)由(you)程(cheng)(cheng)序(xu)設(she)(she)(she)定(ding)(ding)，單片(pian)機(ji)立即(ji)輸出報警(jing)信(xin)號報警(jing)。同時(shi)(shi)使繼電(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)源，以提(ti)高充(chong)(chong)(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)安全性和(he)可(ke)(ke)靠性。

   顯示(shi)器可(ke)用(yong)于(yu)顯示(shi)單片(pian)機(ji)(ji)實時(shi)采樣到(dao)的(de)蓄電(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)壓(ya)、充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流、已充(chong)電(dian)(dian)(dian)(dian)(dian)時(shi)間(jian)和(he)(he)蓄電(dian)(dian)(dian)(dian)(dian)池的(de)溫度，鍵盤則用(yong)于(yu)設定(ding)充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓(ya)充(chong)電(dian)(dian)(dian)(dian)(dian)極限(xian)電(dian)(dian)(dian)(dian)(dian)壓(ya)、恒(heng)流充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流極限(xian)充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流和(he)(he)充(chong)電(dian)(dian)(dian)(dian)(dian)時(shi)間(jian)。電(dian)(dian)(dian)(dian)(dian)路中的(de)單片(pian)機(ji)(ji)可(ke)通過(guo)串口RS232和(he)(he)上位機(ji)(ji)相(xiang)連，以用(yong)于(yu)存儲數據(ju)和(he)(he)虛擬(ni)顯示(shi)充(chong)電(dian)(dian)(dian)(dian)(dian)參數的(de)設定(ding)。當檢測到(dao)充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流為零(ling)時(shi)，單片(pian)機(ji)(ji)轉入休眠狀態。而(er)當檢測到(dao)充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流不(bu)為零(ling)時(shi)，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，從而調整充電器的輸出電(dian)壓(ya)和電(dian)流(liu)(liu)。由(you)于該驅動器(qi)同(tong)時(shi)具有(you)過流(liu)(liu)、過壓(ya)保護(hu)，工作電(dian)源電(dian)壓(ya)可以在8～40 V，而(er)啟動電(dian)流(liu)(liu)小于1 mA，工作溫度為O～70℃，因而(er)是目(mu)前較理(li)想的新型脈寬調制(zhi)器(qi)。 PWM控制(zhi)器(qi)在啟動時(shi)，是由(you)R1、Rw。

   為(wei)UC3842提供啟動電(dian)(dian)(dian)壓(ya)(ya)，待其工(gong)作后(hou)，其輔助繞組3、4端(duan)的(de)電(dian)(dian)(dian)壓(ya)(ya)經(jing)D1整流、C4、C5濾波(bo)、DW1穩(wen)(wen)壓(ya)(ya)后(hou)得到(dao)的(de)16 V直流電(dian)(dian)(dian)壓(ya)(ya)，一路加(jia)(jia)到(dao)UC38427的(de)7腳為(wei)其供電(dian)(dian)(dian)，另一路經(jing)R3和數(shu)字(zi)電(dian)(dian)(dian)位器X9C102分壓(ya)(ya)后(hou)加(jia)(jia)到(dao)UC3842的(de)2腳。以作為(wei)脈寬調制(zhi)的(de)輸(shu)入(ru)信號。一般在這(zhe)類(lei)電(dian)(dian)(dian)源的(de)設計(ji)中，輸(shu)出(chu)電(dian)(dian)(dian)壓(ya)(ya)取樣(yang)(yang)可與(yu)UC3842的(de)供電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)(ya)相連(lian)。為(wei)了反映輸(shu)出(chu)電(dian)(dian)(dian)壓(ya)(ya)變化，本設計(ji)沒有加(jia)(jia)穩(wen)(wen)壓(ya)(ya)管，但這(zhe)會使UC3842的(de)工(gong)作電(dian)(dian)(dian)壓(ya)(ya)不(bu)穩(wen)(wen)，輸(shu)出(chu)諧波(bo)成(cheng)分增多(duo)，為(wei)了克服此(ci)不(bu)足，本設計(ji)中UC3842的(de)供電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)(ya)采用由3、4繞組端(duan)壓(ya)(ya)單(dan)獨(du)整流、濾波(bo)、穩(wen)(wen)壓(ya)(ya)后(hou)，提供給UC3842芯(xin)片(pian)16 V的(de)穩(wen)(wen)定電(dian)(dian)(dian)壓(ya)(ya)。充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)(ya)的(de)調節(jie)是將電(dian)(dian)(dian)池電(dian)(dian)(dian)壓(ya)(ya)經(jing)外環電(dian)(dian)(dian)壓(ya)(ya)取樣(yang)(yang)電(dian)(dian)(dian)路R12、RM取樣(yang)(yang)，再經(jing)多(duo)路電(dian)(dian)(dian)子開(kai)關(guan)選擇、MD變換(huan)，單(dan)片(pian)機處理(li)后(hou)，送入(ru)數(shu)字(zi)電(dian)(dian)(dian)位器，以控制(zhi)數(shu)字(zi)電(dian)(dian)(dian)位器的(de)有效電(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(shu)出電(dian)(dian)(dian)壓(ya)(ya)(ya)偏(pian)高(gao)時，反(fan)饋(kui)回UC3842的(de)(de)2腳電(dian)(dian)(dian)壓(ya)(ya)(ya)也升高(gao)超過(guo)參考(kao)電(dian)(dian)(dian)壓(ya)(ya)(ya)2.5 V之后，驅動信號的(de)(de)脈沖占空比(bi)減(jian)小，使輸(shu)出電(dian)(dian)(dian)壓(ya)(ya)(ya)下降(jiang)，從而達到穩壓(ya)(ya)(ya)的(de)(de)目的(de)(de)。充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)的(de)(de)調(diao)(diao)節(jie)(jie)(jie)(jie)主要是(shi)先(xian)將充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)經外(wai)環電(dian)(dian)(dian)流(liu)(liu)取樣電(dian)(dian)(dian)阻(zu)Rs取樣和LM358放大可用R1調(diao)(diao)節(jie)(jie)(jie)(jie)放大倍數、多路(lu)電(dian)(dian)(dian)子(zi)開(kai)關(guan)選擇(ze)、MD變(bian)換，再送單片機處理，然(ran)后調(diao)(diao)節(jie)(jie)(jie)(jie)數字電(dian)(dian)(dian)位器的(de)(de)阻(zu)值。其(qi)調(diao)(diao)節(jie)(jie)(jie)(jie)過(guo)程與電(dian)(dian)(dian)壓(ya)(ya)(ya)調(diao)(diao)節(jie)(jie)(jie)(jie)相似(si)，實(shi)際上，電(dian)(dian)(dian)流(liu)(liu)調(diao)(diao)節(jie)(jie)(jie)(jie)也是(shi)通過(guo)電(dian)(dian)(dian)壓(ya)(ya)(ya)調(diao)(diao)節(jie)(jie)(jie)(jie)實(shi)現(xian)的(de)(de)。

    2．4．保(bao)(bao)(bao)護(hu)(hu)(hu)電(dian)(dian)路(lu)設(she)計 當(dang)過(guo)流(liu)(liu)或短(duan)路(lu)時，內環(huan)取(qu)(qu)樣(yang)電(dian)(dian)阻(zu)R10兩(liang)端的(de)電(dian)(dian)壓(ya)升高。當(dang)3腳(jiao)(jiao)電(dian)(dian)壓(ya)超過(guo)1伏時，通過(guo)UC3842的(de)內部調(diao)制(zhi)(zhi)可(ke)使其(qi)停止(zhi)脈寬(kuan)輸出(chu)，開關(guan)管(guan)截(jie)止(zhi)，輸出(chu)電(dian)(dian)壓(ya)和電(dian)(dian)流(liu)(liu)均為0，從而保(bao)(bao)(bao)護(hu)(hu)(hu)電(dian)(dian)源。過(guo)壓(ya)時，DW1和DW2會(hui)(hui)擊(ji)穿(chuan)而短(duan)路(lu)，也會(hui)(hui)造成(cheng)過(guo)流(liu)(liu)保(bao)(bao)(bao)護(hu)(hu)(hu)，DW2可(ke)用(yong)(yong)以保(bao)(bao)(bao)護(hu)(hu)(hu)場(chang)效應管(guan)和UC3842。而當(dang)發生(sheng)欠壓(ya)時，即當(dang)UC3842的(de)7腳(jiao)(jiao)電(dian)(dian)壓(ya)降至10 V以下(xia)時，UC3842將(jiang)啟動欠壓(ya)鎖(suo)定電(dian)(dian)路(lu)而關(guan)閉開關(guan)控(kong)制(zhi)(zhi)器。內環(huan)的(de)這種反(fan)饋調(diao)整是在(zai)輸出(chu)電(dian)(dian)壓(ya)尚(shang)未發生(sheng)變化時，通過(guo)檢(jian)測內環(huan)電(dian)(dian)流(liu)(liu)使脈寬(kuan)提前(qian)得到調(diao)整，前(qian)饋控(kong)制(zhi)(zhi)，從而加(jia)快了變換器對(dui)異常情(qing)況的(de)動態響應速(su)度。以便更加(jia)快速(su)有效地起到保(bao)(bao)(bao)護(hu)(hu)(hu)作用(yong)(yong)。當(dang)然，外環(huan)電(dian)(dian)流(liu)(liu)、電(dian)(dian)壓(ya)的(de)取(qu)(qu)樣(yang)Rs、Rw亦可(ke)通過(guo)單片機的(de)調(diao)節作用(yong)(yong)來達(da)到對(dui)異常情(qing)況的(de)保(bao)(bao)(bao)護(hu)(hu)(hu)，但響應速(su)度比內環(huan)慢5～10個工頻周期，因此，外環(huan)取(qu)(qu)樣(yang)主要是調(diao)節充電(dian)(dian)電(dian)(dian)流(liu)(liu)和充電(dian)(dian)電(dian)(dian)壓(ya)，兼作二(er)次(ci)保(bao)(bao)(bao)護(hu)(hu)(hu)，而內環(huan)取(qu)(qu)樣(yang)則(ze)是主要的(de)，它是一次(ci)的(de)保(bao)(bao)(bao)護(hu)(hu)(hu)，這種雙(shuang)環(huan)保(bao)(bao)(bao)護(hu)(hu)(hu)方(fang)式會(hui)(hui)更加(jia)安(an)全可(ke)靠。

    3、軟件設(she)計 在程序的(de)初始階段，首先是(shi)(shi)(shi)對單片機進行(xing)初始化，即(ji)根(gen)據(ju)不(bu)(bu)同(tong)的(de)電(dian)(dian)(dian)(dian)池(chi)設(she)定(ding)不(bu)(bu)同(tong)的(de)充(chong)(chong)電(dian)(dian)(dian)(dian)參數，選擇不(bu)(bu)同(tong)的(de)充(chong)(chong)電(dian)(dian)(dian)(dian)策略。其后是(shi)(shi)(shi)判斷電(dian)(dian)(dian)(dian)池(chi)是(shi)(shi)(shi)否連接(jie)正(zheng)確(que)，根(gen)據(ju)電(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)壓(ya)(ya)值(zhi)判斷應該進入哪一個(ge)充(chong)(chong)電(dian)(dian)(dian)(dian)階段即(ji)小(xiao)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)預充(chong)(chong)電(dian)(dian)(dian)(dian)，大電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)恒(heng)(heng)流(liu)(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)或恒(heng)(heng)壓(ya)(ya)涓(juan)流(liu)(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)方(fang)式(shi)。在預充(chong)(chong)階段，應降(jiang)低(di)充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓(ya)(ya)，而(er)在恒(heng)(heng)流(liu)(liu)(liu)方(fang)式(shi)時，應不(bu)(bu)斷檢測充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)是(shi)(shi)(shi)否達(da)到(dao)恒(heng)(heng)定(ding)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)如(ru)1.8 A，如(ru)果小(xiao)于1.8 A，則抬高電(dian)(dian)(dian)(dian)池(chi)兩端的(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)，使之(zhi)達(da)到(dao)1.8 A，以上調節過程均(jun)可(ke)采(cai)用比例控制。在電(dian)(dian)(dian)(dian)池(chi)兩端電(dian)(dian)(dian)(dian)壓(ya)(ya)達(da)到(dao)設(she)定(ding)值(zhi)后，系(xi)統再進入涓(juan)流(liu)(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)模式(shi)。該充(chong)(chong)電(dian)(dian)(dian)(dian)器的(de)程序流(liu)(liu)(liu)程如(ru)圖3所(suo)示。圖3中，Is為設(she)定(ding)的(de)充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)即(ji)恒(heng)(heng)流(liu)(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)，Umin為蓄(xu)電(dian)(dian)(dian)(dian)池(chi)的(de)放(fang)電(dian)(dian)(dian)(dian)極(ji)限(xian)電(dian)(dian)(dian)(dian)壓(ya)(ya)，Umax為蓄(xu)電(dian)(dian)(dian)(dian)池(chi)的(de)充(chong)(chong)電(dian)(dian)(dian)(dian)極(ji)限(xian)電(dian)(dian)(dian)(dian)壓(ya)(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)動停止。從(cong)測試數據來看，該設計(ji)達到了(le)恒(heng)(heng)流(liu)(liu)(liu)快充(chong)(chong)，恒(heng)(heng)壓涓充(chong)(chong)，充(chong)(chong)滿自(zi)行(xing)關斷的設計(ji)要求。 5、結束語 本文設計(ji)的過(guo)度放電(dian)(dian)(dian)(dian)預充(chong)(chong)、恒(heng)(heng)流(liu)(liu)(liu)快充(chong)(chong)、恒(heng)(heng)壓涓充(chong)(chong)、智能(neng)(neng)(neng)(neng)控制(zhi)(zhi)的充(chong)(chong)電(dian)(dian)(dian)(dian)方(fang)(fang)案，能(neng)(neng)(neng)(neng)很好(hao)地解決電(dian)(dian)(dian)(dian)動自(zi)行(xing)車(che)用電(dian)(dian)(dian)(dian)池在(zai)充(chong)(chong)電(dian)(dian)(dian)(dian)過(guo)程中(zhong)存在(zai)的過(guo)充(chong)(chong)電(dian)(dian)(dian)(dian)、充(chong)(chong)電(dian)(dian)(dian)(dian)不足和發熱(re)等問題，并能(neng)(neng)(neng)(neng)根據不同電(dian)(dian)(dian)(dian)池選擇不同的充(chong)(chong)電(dian)(dian)(dian)(dian)方(fang)(fang)案。而(er)且具有通用性。能(neng)(neng)(neng)(neng)實時檢測并顯示充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)、充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓、充(chong)(chong)電(dian)(dian)(dian)(dian)時間和蓄(xu)電(dian)(dian)(dian)(dian)池溫度等參數。由于(yu)電(dian)(dian)(dian)(dian)路具有內外環(huan)控制(zhi)(zhi)，符合最優控制(zhi)(zhi)規律。最具有過(guo)流(liu)(liu)(liu)、過(guo)壓和超溫保護功能(neng)(neng)(neng)(neng)，同時由于(yu)

   UC3842采用穩壓供電，因此，不但諧波污染程度(du)低(di)，原副邊電氣(qi)隔離安全可(ke)靠，同時還可(ke)根據負載情(qing)況(kuang)通過(guo)單片機來進行(xing)控制，并可(ke)實現跳周期模式工作。故可(ke)提高電源(yuan)的效率。