隨著(zhu)油價的(de)(de)不(bu)(bu)斷上漲和(he)人們環保(bao)意識的(de)(de)增強，電(dian)(dian)(dian)動自(zi)行車以其(qi)價格低、綠色環保(bao)，使用(yong)(yong)安(an)全(quan)方便(bian)等優點越來越受到消費(fei)者的(de)(de)喜愛。評價電(dian)(dian)(dian)動自(zi)行車質量好(hao)壞(huai)的(de)(de)重要參(can)數之(zhi)一是其(qi)蓄(xu)(xu)電(dian)(dian)(dian)池的(de)(de)使用(yong)(yong)壽命(ming)。而(er)蓄(xu)(xu)電(dian)(dian)(dian)池的(de)(de)充電(dian)(dian)(dian)過程對其(qi)壽命(ming)影響最大。研(yan)究(jiu)表明：過充電(dian)(dian)(dian)，可(ke)使蓄(xu)(xu)電(dian)(dian)(dian)池發熱，電(dian)(dian)(dian)解液失(shi)水；而(er)充電(dian)(dian)(dian)不(bu)(bu)足，則可(ke)使蓄(xu)(xu)電(dian)(dian)(dian)池內化(hua)學反應(ying)不(bu)(bu)充分，長期(qi)充電(dian)(dian)(dian)不(bu)(bu)足會導致蓄(xu)(xu)電(dian)(dian)(dian)池容量下降。由(you)此可(ke)見，充電(dian)(dian)(dian)器(qi)性能的(de)(de)好(hao)壞(huai)直接(jie)影響著(zhu)蓄(xu)(xu)電(dian)(dian)(dian)池的(de)(de)使用(yong)(yong)效(xiao)果和(he)使用(yong)(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(she)計方案。該(gai)裝置能根據(ju)蓄電池的(de)充電特性(xing)或實時監(jian)測(ce)到的(de)充電狀態，來智能化(hua)地調(diao)(diao)節充電電壓和(he)(he)充電電流，而且(qie)調(diao)(diao)節范圍(wei)寬(kuan)，并具有過(guo)流、過(guo)壓、過(guo)溫(wen)等保護(hu)功(gong)能。 1、系(xi)統(tong)結構(gou) 該(gai)系(xi)統(tong)主要(yao)由電源變換(huan)電路、采樣電路、微處理器(qi)(qi)，脈寬(kuan)調(diao)(diao)制器(qi)(qi)、鍵盤、顯示器(qi)(qi)和(he)(he)溫(wen)度傳感器(qi)(qi)等部分組成，是一個閉環的(de)智能充電系(xi)統(tong)。

   2、硬件電路 本智能充電器的硬件電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)分為(wei)(wei)開關電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)部(bu)分、以單片(pian)機(ji)為(wei)(wei)主(zhu)的控(kong)制(zhi)(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)和以UC3842為(wei)(wei)核心的脈寬調(diao)制(zhi)(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)三(san)部(bu)分。 2．1開關電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)設計 本設計采用電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)控(kong)制(zhi)(zhi)型脈寬調(diao)制(zhi)(zhi)方式。其整(zheng)個工作過(guo)程是將交流(liu)(liu)輸(shu)入經濾(lv)波、整(zheng)流(liu)(liu)后(hou)變為(wei)(wei)直流(liu)(liu)高壓(ya)，再(zai)由(you)(you)開關管斬(zhan)波、高頻(pin)變壓(ya)器降壓(ya)后(hou)得到高頻(pin)矩(ju)形電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，最后(hou)經過(guo)輸(shu)出(chu)(chu)(chu)整(zheng)流(liu)(liu)濾(lv)波獲得所需要(yao)(yao)的直流(liu)(liu)輸(shu)出(chu)(chu)(chu)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)。系統對開關電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)的要(yao)(yao)求(qiu)是其交流(liu)(liu)輸(shu)入電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)范(fan)圍(wei)為(wei)(wei)90～270 V，能(neng)同時輸(shu)出(chu)(chu)(chu)+5V作為(wei)(wei)控(kong)制(zhi)(zhi)部(bu)分電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)及(ji)12～60 V主(zhu)回路(lu)的電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)。輸(shu)出(chu)(chu)(chu)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)為(wei)(wei)1～3 A。 2．2單片(pian)機(ji)控(kong)制(zhi)(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)設計 單片(pian)機(ji)控(kong)制(zhi)(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)主(zhu)要(yao)(yao)由(you)(you)單片(pian)機(ji)AT89S52、ADCTLC0832、多路(lu)選擇開關CD4051、數字電(dian)(dian)(dian)(dian)(dian)(dian)位器X9C102、數字溫度傳感器DSl8820、取樣電(dian)(dian)(dian)(dian)(dian)(dian)阻Rs和Rw、2×4鍵盤、液晶顯(xian)示(shi)CONl6等組成(cheng)。

    本部分(fen)設(she)(she)(she)計(ji)時(shi)(shi)(shi)應先根據(ju)蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)型號參數，來通(tong)過(guo)(guo)(guo)鍵盤設(she)(she)(she)計(ji)與之對應的(de)(de)充(chong)(chong)(chong)電(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)流(liu)(liu)(liu)(liu)(liu)、充(chong)(chong)(chong)電(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)壓以(yi)及充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi)(shi)間，當電(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)池(chi)后(hou)，充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)過(guo)(guo)(guo)程開始，此后(hou)由單(dan)片(pian)(pian)機(ji)通(tong)過(guo)(guo)(guo)取(qu)樣(yang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻RM檢(jian)測電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓，若檢(jian)測到蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)因(yin)(yin)過(guo)(guo)(guo)渡放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)而使電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓低于(yu)正(zheng)常范圍。那(nei)么，為(wei)了(le)避(bi)免(mian)充(chong)(chong)(chong)電(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)流(liu)(liu)(liu)(liu)(liu)過(guo)(guo)(guo)大而造成蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)損(sun)壞，應先對蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)實(shi)行(xing)穩(wen)定(ding)(ding)(ding)(ding)的(de)(de)小(xiao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)本設(she)(she)(she)計(ji)程序中設(she)(she)(she)為(wei)l／5的(de)(de)設(she)(she)(she)定(ding)(ding)(ding)(ding)充(chong)(chong)(chong)電(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)流(liu)(liu)(liu)(liu)(liu)，同時(shi)(shi)(shi)，單(dan)片(pian)(pian)機(ji)開始計(ji)時(shi)(shi)(shi)，之后(hou)單(dan)片(pian)(pian)機(ji)將不(bu)斷(duan)檢(jian)測電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓和(he)充(chong)(chong)(chong)電(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)流(liu)(liu)(liu)(liu)(liu)并(bing)(bing)顯示在(zai)液晶(jing)屏上(shang)，隨著充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)進行(xing)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓不(bu)斷(duan)上(shang)升，當上(shang)升到正(zheng)常范圍時(shi)(shi)(shi)，單(dan)片(pian)(pian)機(ji)可通(tong)過(guo)(guo)(guo)控制數字電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)位(wei)器(qi)來調節輸(shu)(shu)出(chu)(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓，從而轉入(ru)大電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)恒(heng)流(liu)(liu)(liu)(liu)(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)即(ji)設(she)(she)(she)定(ding)(ding)(ding)(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)方(fang)式，此后(hou)，單(dan)片(pian)(pian)機(ji)一直保持(chi)不(bu)停地檢(jian)測電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓，當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓達到設(she)(she)(she)定(ding)(ding)(ding)(ding)值時(shi)(shi)(shi)，單(dan)片(pian)(pian)機(ji)發出(chu)(chu)指令，以(yi)增大數字電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)位(wei)器(qi)的(de)(de)阻值，并(bing)(bing)通(tong)過(guo)(guo)(guo)脈(mo)寬調制減小(xiao)輸(shu)(shu)出(chu)(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓。從而使充(chong)(chong)(chong)電(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)流(liu)(liu)(liu)(liu)(liu)減小(xiao)，當充(chong)(chong)(chong)電(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)流(liu)(liu)(liu)(liu)(liu)減小(xiao)到1／5的(de)(de)設(she)(she)(she)定(ding)(ding)(ding)(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)時(shi)(shi)(shi)，再轉為(wei)涓流(liu)(liu)(liu)(liu)(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，最后(hou)在(zai)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi)(shi)間到時(shi)(shi)(shi)關閉電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)，這樣(yang)就(jiu)避(bi)免(mian)了(le)因(yin)(yin)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)溫(wen)升過(guo)(guo)(guo)快或嚴(yan)重極化(hua)而影響充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)質(zhi)量，提高蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)使用(yong)壽命(ming)。當檢(jian)測到電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓、充(chong)(chong)(chong)電(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)流(liu)(liu)(liu)(liu)(liu)和(he)溫(wen)度超過(guo)(guo)(guo)設(she)(she)(she)定(ding)(ding)(ding)(ding)值的(de)(de)1／10倍(bei)時(shi)(shi)(shi)由程序設(she)(she)(she)定(ding)(ding)(ding)(ding)，單(dan)片(pian)(pian)機(ji)立即(ji)輸(shu)(shu)出(chu)(chu)報警信(xin)號報警。同時(shi)(shi)(shi)使繼電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)動作(zuo)并(bing)(bing)切(qie)斷(duan)總電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)，以(yi)提高充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)安全性和(he)可靠性。

   顯示(shi)器可用于(yu)顯示(shi)單片機(ji)實時(shi)采樣到(dao)(dao)的蓄電(dian)(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)、充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)、已(yi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)間和(he)(he)蓄電(dian)(dian)(dian)(dian)(dian)(dian)池的溫度，鍵盤則用于(yu)設定充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)極限電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)、恒流(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)極限充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)和(he)(he)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)間。電(dian)(dian)(dian)(dian)(dian)(dian)路中的單片機(ji)可通過串口(kou)RS232和(he)(he)上位機(ji)相連(lian)，以用于(yu)存儲數據(ju)和(he)(he)虛擬顯示(shi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)參(can)數的設定。當檢測到(dao)(dao)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)為(wei)零時(shi)，單片機(ji)轉入(ru)休眠狀(zhuang)態。而當檢測到(dao)(dao)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)不(bu)為(wei)零時(shi)，單片機(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(dian)壓和電(dian)流(liu)(liu)。由(you)于該(gai)驅(qu)動(dong)器(qi)同(tong)時(shi)(shi)具有過流(liu)(liu)、過壓保護，工作電(dian)源(yuan)電(dian)壓可以在8～40 V，而(er)啟(qi)動(dong)電(dian)流(liu)(liu)小于1 mA，工作溫度為O～70℃，因而(er)是目(mu)前較(jiao)理想的(de)新型脈寬調制(zhi)器(qi)。 PWM控制(zhi)器(qi)在啟(qi)動(dong)時(shi)(shi)，是由(you)R1、Rw。

   為UC3842提供啟(qi)動電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，待其(qi)工作后(hou)，其(qi)輔(fu)助繞組3、4端的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)經(jing)(jing)D1整(zheng)流(liu)、C4、C5濾波(bo)(bo)、DW1穩(wen)壓(ya)(ya)(ya)(ya)后(hou)得到的(de)(de)16 V直流(liu)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，一(yi)路加到UC38427的(de)(de)7腳為其(qi)供電(dian)(dian)(dian)(dian)(dian)(dian)，另一(yi)路經(jing)(jing)R3和數(shu)字(zi)電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)器X9C102分壓(ya)(ya)(ya)(ya)后(hou)加到UC3842的(de)(de)2腳。以作為脈寬調制的(de)(de)輸(shu)(shu)入信號。一(yi)般在這(zhe)類(lei)電(dian)(dian)(dian)(dian)(dian)(dian)源的(de)(de)設計(ji)中，輸(shu)(shu)出電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)取樣(yang)可與(yu)UC3842的(de)(de)供電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)相連。為了反(fan)映輸(shu)(shu)出電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)變(bian)化，本(ben)設計(ji)沒有(you)加穩(wen)壓(ya)(ya)(ya)(ya)管，但這(zhe)會使UC3842的(de)(de)工作電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)不穩(wen)，輸(shu)(shu)出諧(xie)波(bo)(bo)成分增多(duo)，為了克(ke)服此不足，本(ben)設計(ji)中UC3842的(de)(de)供電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)采用(yong)由3、4繞組端壓(ya)(ya)(ya)(ya)單獨整(zheng)流(liu)、濾波(bo)(bo)、穩(wen)壓(ya)(ya)(ya)(ya)后(hou)，提供給UC3842芯(xin)片16 V的(de)(de)穩(wen)定電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)。充電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)的(de)(de)調節是(shi)將電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)經(jing)(jing)外環電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)取樣(yang)電(dian)(dian)(dian)(dian)(dian)(dian)路R12、RM取樣(yang)，再經(jing)(jing)多(duo)路電(dian)(dian)(dian)(dian)(dian)(dian)子開關選擇、MD變(bian)換，單片機處(chu)理(li)后(hou)，送入數(shu)字(zi)電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)器，以控制數(shu)字(zi)電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)器的(de)(de)有(you)效電(dian)(dian)(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(shu)出電(dian)(dian)(dian)壓偏高(gao)時(shi)，反(fan)饋回UC3842的(de)(de)2腳電(dian)(dian)(dian)壓也升高(gao)超(chao)過參考(kao)電(dian)(dian)(dian)壓2.5 V之(zhi)后(hou)，驅動(dong)信號的(de)(de)脈沖占空比減小，使輸(shu)出電(dian)(dian)(dian)壓下降，從而達(da)到(dao)穩壓的(de)(de)目的(de)(de)。充電(dian)(dian)(dian)電(dian)(dian)(dian)流的(de)(de)調(diao)(diao)節(jie)(jie)主要是先將充電(dian)(dian)(dian)電(dian)(dian)(dian)流經(jing)外環電(dian)(dian)(dian)流取樣電(dian)(dian)(dian)阻(zu)Rs取樣和LM358放(fang)大(da)可用R1調(diao)(diao)節(jie)(jie)放(fang)大(da)倍(bei)數(shu)、多路(lu)電(dian)(dian)(dian)子開關選擇(ze)、MD變(bian)換(huan)，再送單片機處理，然后(hou)調(diao)(diao)節(jie)(jie)數(shu)字電(dian)(dian)(dian)位器(qi)的(de)(de)阻(zu)值。其調(diao)(diao)節(jie)(jie)過程與電(dian)(dian)(dian)壓調(diao)(diao)節(jie)(jie)相(xiang)似，實際(ji)上，電(dian)(dian)(dian)流調(diao)(diao)節(jie)(jie)也是通(tong)過電(dian)(dian)(dian)壓調(diao)(diao)節(jie)(jie)實現的(de)(de)。

    2．4．保(bao)(bao)護(hu)電(dian)(dian)(dian)路(lu)(lu)設(she)計 當過(guo)流(liu)或短路(lu)(lu)時(shi)(shi)，內(nei)(nei)環(huan)取(qu)樣電(dian)(dian)(dian)阻R10兩端的(de)電(dian)(dian)(dian)壓(ya)(ya)(ya)升高。當3腳(jiao)電(dian)(dian)(dian)壓(ya)(ya)(ya)超過(guo)1伏(fu)時(shi)(shi)，通過(guo)UC3842的(de)內(nei)(nei)部調(diao)(diao)(diao)制可使其停止脈寬輸出(chu)，開關管(guan)截止，輸出(chu)電(dian)(dian)(dian)壓(ya)(ya)(ya)和(he)電(dian)(dian)(dian)流(liu)均為(wei)0，從而(er)(er)保(bao)(bao)護(hu)電(dian)(dian)(dian)源。過(guo)壓(ya)(ya)(ya)時(shi)(shi)，DW1和(he)DW2會(hui)(hui)擊穿而(er)(er)短路(lu)(lu)，也會(hui)(hui)造成過(guo)流(liu)保(bao)(bao)護(hu)，DW2可用以保(bao)(bao)護(hu)場效應管(guan)和(he)UC3842。而(er)(er)當發生欠(qian)壓(ya)(ya)(ya)時(shi)(shi)，即當UC3842的(de)7腳(jiao)電(dian)(dian)(dian)壓(ya)(ya)(ya)降至10 V以下時(shi)(shi)，UC3842將(jiang)啟動(dong)欠(qian)壓(ya)(ya)(ya)鎖(suo)定電(dian)(dian)(dian)路(lu)(lu)而(er)(er)關閉開關控制器(qi)。內(nei)(nei)環(huan)的(de)這(zhe)種反饋調(diao)(diao)(diao)整(zheng)是在輸出(chu)電(dian)(dian)(dian)壓(ya)(ya)(ya)尚未發生變(bian)化時(shi)(shi)，通過(guo)檢(jian)測內(nei)(nei)環(huan)電(dian)(dian)(dian)流(liu)使脈寬提前得(de)到(dao)調(diao)(diao)(diao)整(zheng)，前饋控制，從而(er)(er)加快(kuai)了變(bian)換器(qi)對異(yi)常情(qing)況的(de)動(dong)態響應速(su)度。以便更(geng)加快(kuai)速(su)有效地(di)起到(dao)保(bao)(bao)護(hu)作用。當然，外(wai)環(huan)電(dian)(dian)(dian)流(liu)、電(dian)(dian)(dian)壓(ya)(ya)(ya)的(de)取(qu)樣Rs、Rw亦可通過(guo)單(dan)片機的(de)調(diao)(diao)(diao)節作用來達到(dao)對異(yi)常情(qing)況的(de)保(bao)(bao)護(hu)，但響應速(su)度比內(nei)(nei)環(huan)慢5～10個工頻周期(qi)，因此，外(wai)環(huan)取(qu)樣主要是調(diao)(diao)(diao)節充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)和(he)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)(ya)(ya)，兼作二次(ci)保(bao)(bao)護(hu)，而(er)(er)內(nei)(nei)環(huan)取(qu)樣則(ze)是主要的(de)，它是一次(ci)的(de)保(bao)(bao)護(hu)，這(zhe)種雙環(huan)保(bao)(bao)護(hu)方式會(hui)(hui)更(geng)加安全(quan)可靠。

    3、軟(ruan)件設計 在(zai)程(cheng)序的(de)初始(shi)(shi)階段，首先(xian)是對單(dan)片機進行初始(shi)(shi)化，即根據(ju)(ju)不(bu)同(tong)的(de)電(dian)(dian)(dian)(dian)(dian)池設定不(bu)同(tong)的(de)充(chong)電(dian)(dian)(dian)(dian)(dian)參數，選擇不(bu)同(tong)的(de)充(chong)電(dian)(dian)(dian)(dian)(dian)策略。其后是判斷(duan)電(dian)(dian)(dian)(dian)(dian)池是否(fou)連接正確，根據(ju)(ju)電(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)壓(ya)值(zhi)判斷(duan)應該進入(ru)哪一個(ge)充(chong)電(dian)(dian)(dian)(dian)(dian)階段即小(xiao)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)預充(chong)電(dian)(dian)(dian)(dian)(dian)，大電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)恒(heng)(heng)流(liu)(liu)充(chong)電(dian)(dian)(dian)(dian)(dian)或恒(heng)(heng)壓(ya)涓(juan)流(liu)(liu)充(chong)電(dian)(dian)(dian)(dian)(dian)方(fang)式。在(zai)預充(chong)階段，應降低充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓(ya)，而在(zai)恒(heng)(heng)流(liu)(liu)方(fang)式時，應不(bu)斷(duan)檢測(ce)充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)是否(fou)達到恒(heng)(heng)定電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)如1.8 A，如果小(xiao)于(yu)1.8 A，則抬高電(dian)(dian)(dian)(dian)(dian)池兩(liang)端(duan)的(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)，使之達到1.8 A，以上調節(jie)過程(cheng)均可采用比例(li)控(kong)制(zhi)。在(zai)電(dian)(dian)(dian)(dian)(dian)池兩(liang)端(duan)電(dian)(dian)(dian)(dian)(dian)壓(ya)達到設定值(zhi)后，系統再進入(ru)涓(juan)流(liu)(liu)充(chong)電(dian)(dian)(dian)(dian)(dian)模式。該充(chong)電(dian)(dian)(dian)(dian)(dian)器的(de)程(cheng)序流(liu)(liu)程(cheng)如圖3所示。圖3中，Is為(wei)(wei)設定的(de)充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)即恒(heng)(heng)流(liu)(liu)充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)，Umin為(wei)(wei)蓄電(dian)(dian)(dian)(dian)(dian)池的(de)放電(dian)(dian)(dian)(dian)(dian)極限(xian)電(dian)(dian)(dian)(dian)(dian)壓(ya)，Umax為(wei)(wei)蓄電(dian)(dian)(dian)(dian)(dian)池的(de)充(chong)電(dian)(dian)(dian)(dian)(dian)極限(xian)電(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)(zi)動停止。從測試數據(ju)來看，該設(she)(she)計(ji)達到了恒(heng)流快充(chong)，恒(heng)壓(ya)涓充(chong)，充(chong)滿自(zi)(zi)行關斷的設(she)(she)計(ji)要求。 5、結束語 本文設(she)(she)計(ji)的過(guo)度放電(dian)(dian)(dian)(dian)預充(chong)、恒(heng)流快充(chong)、恒(heng)壓(ya)涓充(chong)、智能(neng)控制的充(chong)電(dian)(dian)(dian)(dian)方(fang)案，能(neng)很好地解決電(dian)(dian)(dian)(dian)動自(zi)(zi)行車用電(dian)(dian)(dian)(dian)池(chi)在充(chong)電(dian)(dian)(dian)(dian)過(guo)程中存在的過(guo)充(chong)電(dian)(dian)(dian)(dian)、充(chong)電(dian)(dian)(dian)(dian)不(bu)足和發熱(re)等問題，并能(neng)根據(ju)不(bu)同(tong)電(dian)(dian)(dian)(dian)池(chi)選擇不(bu)同(tong)的充(chong)電(dian)(dian)(dian)(dian)方(fang)案。而且(qie)具(ju)(ju)有通用性。能(neng)實(shi)時檢(jian)測并顯示充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流、充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓(ya)、充(chong)電(dian)(dian)(dian)(dian)時間(jian)和蓄電(dian)(dian)(dian)(dian)池(chi)溫度等參數。由于電(dian)(dian)(dian)(dian)路具(ju)(ju)有內(nei)外環控制，符合最(zui)優(you)控制規律。最(zui)具(ju)(ju)有過(guo)流、過(guo)壓(ya)和超(chao)溫保護(hu)功(gong)能(neng)，同(tong)時由于

   UC3842采(cai)用穩壓(ya)供電(dian)(dian)，因此，不(bu)但(dan)諧波(bo)污染程(cheng)度(du)低，原副邊(bian)電(dian)(dian)氣(qi)隔離(li)安全可(ke)(ke)靠，同時(shi)還可(ke)(ke)根據負載情況通過單片機來(lai)進行控制(zhi)，并可(ke)(ke)實(shi)現跳(tiao)周期模(mo)式工作(zuo)。故可(ke)(ke)提高電(dian)(dian)源的(de)效率。