隨著(zhu)油價(jia)(jia)的(de)(de)不(bu)斷上漲和人(ren)們環(huan)保(bao)意(yi)識的(de)(de)增強，電(dian)(dian)(dian)動(dong)自行車(che)以其(qi)(qi)價(jia)(jia)格(ge)低、綠色環(huan)保(bao)，使(shi)用(yong)(yong)安全方便等優(you)點(dian)越(yue)來越(yue)受到消費者的(de)(de)喜愛。評價(jia)(jia)電(dian)(dian)(dian)動(dong)自行車(che)質(zhi)量好壞的(de)(de)重(zhong)要參數(shu)之(zhi)一是(shi)其(qi)(qi)蓄(xu)電(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)使(shi)用(yong)(yong)壽(shou)命。而蓄(xu)電(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)充(chong)電(dian)(dian)(dian)過程對其(qi)(qi)壽(shou)命影(ying)響(xiang)最大。研究(jiu)表(biao)明：過充(chong)電(dian)(dian)(dian)，可使(shi)蓄(xu)電(dian)(dian)(dian)池(chi)(chi)(chi)發熱(re)，電(dian)(dian)(dian)解液失水；而充(chong)電(dian)(dian)(dian)不(bu)足，則可使(shi)蓄(xu)電(dian)(dian)(dian)池(chi)(chi)(chi)內(nei)化(hua)學反(fan)應(ying)不(bu)充(chong)分，長(chang)期充(chong)電(dian)(dian)(dian)不(bu)足會導致(zhi)蓄(xu)電(dian)(dian)(dian)池(chi)(chi)(chi)容量下降。由此可見，充(chong)電(dian)(dian)(dian)器(qi)性能(neng)的(de)(de)好壞直接影(ying)響(xiang)著(zhu)蓄(xu)電(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)使(shi)用(yong)(yong)效果和使(shi)用(yong)(yong)壽(shou)命。

  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設計方案。該(gai)裝(zhuang)置(zhi)能根(gen)據蓄電(dian)(dian)(dian)(dian)(dian)池的充(chong)電(dian)(dian)(dian)(dian)(dian)特性或實時監(jian)測到(dao)的充(chong)電(dian)(dian)(dian)(dian)(dian)狀(zhuang)態，來智(zhi)能化地調(diao)節充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓和充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)，而且(qie)調(diao)節范圍寬(kuan)，并具有(you)過流(liu)(liu)、過壓、過溫(wen)等(deng)(deng)保護功能。 1、系統(tong)結構 該(gai)系統(tong)主要(yao)由電(dian)(dian)(dian)(dian)(dian)源變換電(dian)(dian)(dian)(dian)(dian)路、采(cai)樣電(dian)(dian)(dian)(dian)(dian)路、微處理器，脈寬(kuan)調(diao)制器、鍵盤(pan)、顯(xian)示器和溫(wen)度傳感器等(deng)(deng)部分(fen)組成，是一個(ge)閉環的智(zhi)能充(chong)電(dian)(dian)(dian)(dian)(dian)系統(tong)。

   2、硬件電路 本智能充電器的(de)(de)硬件電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)分(fen)為開關電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)部分(fen)、以(yi)單(dan)片(pian)機為主(zhu)的(de)(de)控(kong)(kong)制(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)和以(yi)UC3842為核心的(de)(de)脈(mo)寬(kuan)調制(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)三(san)部分(fen)。 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)控(kong)(kong)制(zhi)型脈(mo)寬(kuan)調制(zhi)方式。其整(zheng)個工作過程是(shi)將交(jiao)流(liu)輸(shu)入經濾波、整(zheng)流(liu)后變為直(zhi)流(liu)高壓(ya)(ya)(ya)，再由開關管斬波、高頻變壓(ya)(ya)(ya)器降(jiang)壓(ya)(ya)(ya)后得到高頻矩形電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)，最后經過輸(shu)出(chu)(chu)整(zheng)流(liu)濾波獲得所需(xu)要的(de)(de)直(zhi)流(liu)輸(shu)出(chu)(chu)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)。系統對(dui)開關電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)的(de)(de)要求是(shi)其交(jiao)流(liu)輸(shu)入電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)范圍為90～270 V，能同時輸(shu)出(chu)(chu)+5V作為控(kong)(kong)制(zhi)部分(fen)電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)及(ji)12～60 V主(zhu)回路(lu)(lu)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)。輸(shu)出(chu)(chu)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)為1～3 A。 2．2單(dan)片(pian)機控(kong)(kong)制(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)設計 單(dan)片(pian)機控(kong)(kong)制(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)主(zhu)要由單(dan)片(pian)機AT89S52、ADCTLC0832、多路(lu)(lu)選擇開關CD4051、數字(zi)電(dian)(dian)(dian)(dian)(dian)(dian)位器X9C102、數字(zi)溫度傳感(gan)器DSl8820、取樣電(dian)(dian)(dian)(dian)(dian)(dian)阻Rs和Rw、2×4鍵(jian)盤(pan)、液晶(jing)顯(xian)示CONl6等組成。

    本部分設計(ji)時應(ying)先(xian)根據蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)的(de)(de)(de)型號(hao)參數，來通過(guo)(guo)(guo)鍵盤設計(ji)與之(zhi)對應(ying)的(de)(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)、充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)以(yi)(yi)及充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時間，當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路接(jie)上(shang)蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)后(hou)，充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)過(guo)(guo)(guo)程(cheng)開(kai)始，此后(hou)由(you)單(dan)(dan)(dan)片(pian)機(ji)(ji)通過(guo)(guo)(guo)取樣電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)RM檢(jian)(jian)測電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，若檢(jian)(jian)測到(dao)蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)因(yin)過(guo)(guo)(guo)渡(du)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)而(er)(er)使(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)低(di)于正常范圍(wei)。那么，為了避免充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)過(guo)(guo)(guo)大(da)而(er)(er)造成蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)損壞，應(ying)先(xian)對蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)實行(xing)穩定(ding)(ding)的(de)(de)(de)小(xiao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)本設計(ji)程(cheng)序中設為l／5的(de)(de)(de)設定(ding)(ding)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)，同時，單(dan)(dan)(dan)片(pian)機(ji)(ji)開(kai)始計(ji)時，之(zhi)后(hou)單(dan)(dan)(dan)片(pian)機(ji)(ji)將不斷檢(jian)(jian)測電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)和(he)(he)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)并(bing)顯示在(zai)液(ye)晶屏上(shang)，隨著充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)進行(xing)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)不斷上(shang)升，當上(shang)升到(dao)正常范圍(wei)時，單(dan)(dan)(dan)片(pian)機(ji)(ji)可通過(guo)(guo)(guo)控制(zhi)數字(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)位器來調(diao)節(jie)輸出(chu)(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，從而(er)(er)轉入大(da)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)即設定(ding)(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)方式，此后(hou)，單(dan)(dan)(dan)片(pian)機(ji)(ji)一直保持(chi)不停地檢(jian)(jian)測電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)達到(dao)設定(ding)(ding)值(zhi)時，單(dan)(dan)(dan)片(pian)機(ji)(ji)發(fa)出(chu)(chu)指令，以(yi)(yi)增(zeng)大(da)數字(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)位器的(de)(de)(de)阻(zu)值(zhi)，并(bing)通過(guo)(guo)(guo)脈寬調(diao)制(zhi)減小(xiao)輸出(chu)(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)。從而(er)(er)使(shi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)減小(xiao)，當充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)減小(xiao)到(dao)1／5的(de)(de)(de)設定(ding)(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)時，再轉為涓流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，最后(hou)在(zai)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時間到(dao)時關閉電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)，這樣就(jiu)避免了因(yin)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)溫升過(guo)(guo)(guo)快或嚴重極化而(er)(er)影響充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)質量，提高蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)的(de)(de)(de)使(shi)用壽命。當檢(jian)(jian)測到(dao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)、充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)和(he)(he)溫度超過(guo)(guo)(guo)設定(ding)(ding)值(zhi)的(de)(de)(de)1／10倍時由(you)程(cheng)序設定(ding)(ding)，單(dan)(dan)(dan)片(pian)機(ji)(ji)立即輸出(chu)(chu)報警信號(hao)報警。同時使(shi)繼電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器動作并(bing)切斷總電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)，以(yi)(yi)提高充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)安全性和(he)(he)可靠性。

   顯示(shi)器可用于顯示(shi)單(dan)片(pian)機(ji)(ji)實時(shi)采樣(yang)到的(de)蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)、充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)、已充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)間和(he)蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池的(de)溫度，鍵盤則(ze)用于設定充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極限(xian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)、恒流(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)極限(xian)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)和(he)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)間。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路中的(de)單(dan)片(pian)機(ji)(ji)可通過串(chuan)口RS232和(he)上(shang)位機(ji)(ji)相(xiang)連，以用于存儲數據和(he)虛擬顯示(shi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)參(can)數的(de)設定。當檢測到充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)為(wei)零時(shi)，單(dan)片(pian)機(ji)(ji)轉(zhuan)入(ru)休眠狀態。而當檢測到充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)不為(wei)零時(shi)，單(dan)片(pian)機(ji)(ji)被(bei)激活(huo)。

   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(liu)。由于該驅動(dong)器(qi)同時具(ju)有過流(liu)、過壓保(bao)護，工作(zuo)電源電壓可以(yi)在(zai)8～40 V，而啟動(dong)電流(liu)小(xiao)于1 mA，工作(zuo)溫度為O～70℃，因而是目前較(jiao)理想的(de)新型(xing)脈寬調(diao)制器(qi)。 PWM控制器(qi)在(zai)啟動(dong)時，是由R1、Rw。

   為(wei)UC3842提供啟動電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，待其(qi)工作(zuo)后(hou)，其(qi)輔助繞組3、4端的(de)(de)(de)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)經(jing)D1整(zheng)流、C4、C5濾波(bo)(bo)、DW1穩(wen)壓(ya)(ya)(ya)(ya)后(hou)得到(dao)的(de)(de)(de)16 V直流電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，一(yi)路加到(dao)UC38427的(de)(de)(de)7腳為(wei)其(qi)供電(dian)(dian)(dian)，另一(yi)路經(jing)R3和數字(zi)電(dian)(dian)(dian)位(wei)器(qi)X9C102分壓(ya)(ya)(ya)(ya)后(hou)加到(dao)UC3842的(de)(de)(de)2腳。以作(zuo)為(wei)脈寬(kuan)調制(zhi)的(de)(de)(de)輸(shu)入信號。一(yi)般在這類電(dian)(dian)(dian)源的(de)(de)(de)設計中，輸(shu)出電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)取(qu)樣可與(yu)UC3842的(de)(de)(de)供電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)相連。為(wei)了反映輸(shu)出電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)變化(hua)，本(ben)(ben)設計沒有加穩(wen)壓(ya)(ya)(ya)(ya)管，但這會使UC3842的(de)(de)(de)工作(zuo)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)不(bu)穩(wen)，輸(shu)出諧波(bo)(bo)成分增多，為(wei)了克服此不(bu)足(zu)，本(ben)(ben)設計中UC3842的(de)(de)(de)供電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)采用由3、4繞組端壓(ya)(ya)(ya)(ya)單獨(du)整(zheng)流、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)(de)穩(wen)定電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)。充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)的(de)(de)(de)調節(jie)是將(jiang)電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)經(jing)外(wai)環電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)取(qu)樣電(dian)(dian)(dian)路R12、RM取(qu)樣，再經(jing)多路電(dian)(dian)(dian)子(zi)開關選擇、MD變換，單片機(ji)處理后(hou)，送入數字(zi)電(dian)(dian)(dian)位(wei)器(qi)，以控制(zhi)數字(zi)電(dian)(dian)(dian)位(wei)器(qi)的(de)(de)(de)有效(xiao)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。 充電器輸出(chu)電(dian)壓偏高時，反(fan)饋回(hui)UC3842的(de)2腳電(dian)壓也升(sheng)高超過參考電(dian)壓2.5 V之后(hou)，驅動信號的(de)脈沖(chong)占空比減小(xiao)，使輸出(chu)電(dian)壓下降，從而(er)達到穩壓的(de)目的(de)。充電(dian)電(dian)流的(de)調(diao)節主要是(shi)先將充電(dian)電(dian)流經外環(huan)電(dian)流取(qu)(qu)樣(yang)電(dian)阻Rs取(qu)(qu)樣(yang)和LM358放大(da)可用R1調(diao)節放大(da)倍數、多路(lu)電(dian)子開(kai)關(guan)選擇、MD變(bian)換，再送單片機(ji)處理，然后(hou)調(diao)節數字電(dian)位(wei)器的(de)阻值(zhi)。其調(diao)節過程(cheng)與電(dian)壓調(diao)節相似，實(shi)際上，電(dian)流調(diao)節也是(shi)通過電(dian)壓調(diao)節實(shi)現的(de)。

    2．4．保(bao)(bao)護(hu)(hu)(hu)(hu)電(dian)路(lu)設計 當(dang)(dang)過(guo)流(liu)或短路(lu)時(shi)(shi)(shi)，內(nei)環(huan)(huan)(huan)(huan)取樣電(dian)阻R10兩端的(de)電(dian)壓(ya)(ya)(ya)(ya)升(sheng)高。當(dang)(dang)3腳電(dian)壓(ya)(ya)(ya)(ya)超過(guo)1伏(fu)時(shi)(shi)(shi)，通(tong)(tong)過(guo)UC3842的(de)內(nei)部調(diao)(diao)制(zhi)可(ke)(ke)使其停止脈(mo)寬輸(shu)出(chu)，開關管截止，輸(shu)出(chu)電(dian)壓(ya)(ya)(ya)(ya)和(he)(he)電(dian)流(liu)均為(wei)0，從而(er)(er)保(bao)(bao)護(hu)(hu)(hu)(hu)電(dian)源。過(guo)壓(ya)(ya)(ya)(ya)時(shi)(shi)(shi)，DW1和(he)(he)DW2會(hui)擊穿而(er)(er)短路(lu)，也(ye)會(hui)造成過(guo)流(liu)保(bao)(bao)護(hu)(hu)(hu)(hu)，DW2可(ke)(ke)用(yong)(yong)以保(bao)(bao)護(hu)(hu)(hu)(hu)場效應管和(he)(he)UC3842。而(er)(er)當(dang)(dang)發生(sheng)欠(qian)(qian)壓(ya)(ya)(ya)(ya)時(shi)(shi)(shi)，即當(dang)(dang)UC3842的(de)7腳電(dian)壓(ya)(ya)(ya)(ya)降至10 V以下時(shi)(shi)(shi)，UC3842將啟動欠(qian)(qian)壓(ya)(ya)(ya)(ya)鎖定電(dian)路(lu)而(er)(er)關閉開關控制(zhi)器。內(nei)環(huan)(huan)(huan)(huan)的(de)這(zhe)種反饋調(diao)(diao)整(zheng)是在輸(shu)出(chu)電(dian)壓(ya)(ya)(ya)(ya)尚未發生(sheng)變化時(shi)(shi)(shi)，通(tong)(tong)過(guo)檢測內(nei)環(huan)(huan)(huan)(huan)電(dian)流(liu)使脈(mo)寬提前得到調(diao)(diao)整(zheng)，前饋控制(zhi)，從而(er)(er)加快了變換器對異常情(qing)(qing)況的(de)動態響應速(su)(su)度。以便更加快速(su)(su)有效地起到保(bao)(bao)護(hu)(hu)(hu)(hu)作用(yong)(yong)。當(dang)(dang)然，外(wai)環(huan)(huan)(huan)(huan)電(dian)流(liu)、電(dian)壓(ya)(ya)(ya)(ya)的(de)取樣Rs、Rw亦可(ke)(ke)通(tong)(tong)過(guo)單片機的(de)調(diao)(diao)節(jie)作用(yong)(yong)來達到對異常情(qing)(qing)況的(de)保(bao)(bao)護(hu)(hu)(hu)(hu)，但響應速(su)(su)度比內(nei)環(huan)(huan)(huan)(huan)慢5～10個(ge)工頻周(zhou)期，因(yin)此，外(wai)環(huan)(huan)(huan)(huan)取樣主要是調(diao)(diao)節(jie)充(chong)(chong)電(dian)電(dian)流(liu)和(he)(he)充(chong)(chong)電(dian)電(dian)壓(ya)(ya)(ya)(ya)，兼作二次保(bao)(bao)護(hu)(hu)(hu)(hu)，而(er)(er)內(nei)環(huan)(huan)(huan)(huan)取樣則是主要的(de)，它(ta)是一次的(de)保(bao)(bao)護(hu)(hu)(hu)(hu)，這(zhe)種雙環(huan)(huan)(huan)(huan)保(bao)(bao)護(hu)(hu)(hu)(hu)方(fang)式(shi)會(hui)更加安全可(ke)(ke)靠。

    3、軟(ruan)件設計 在(zai)程(cheng)序(xu)的(de)(de)初始(shi)階(jie)段，首先是(shi)(shi)對單片機進(jin)行初始(shi)化，即(ji)(ji)(ji)根據(ju)不同的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池設定不同的(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)參數，選擇不同的(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)策略。其后是(shi)(shi)判(pan)斷電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池是(shi)(shi)否(fou)連接正(zheng)確，根據(ju)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓值判(pan)斷應(ying)該進(jin)入(ru)哪(na)一個充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)階(jie)段即(ji)(ji)(ji)小電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)預充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，大(da)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)恒流(liu)(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)或恒壓涓流(liu)(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)方(fang)式。在(zai)預充(chong)(chong)階(jie)段，應(ying)降低充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓，而在(zai)恒流(liu)(liu)(liu)方(fang)式時，應(ying)不斷檢測充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)是(shi)(shi)否(fou)達(da)到(dao)恒定電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)如1.8 A，如果小于1.8 A，則抬高電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池兩端的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓，使(shi)之達(da)到(dao)1.8 A，以上調節(jie)過程(cheng)均可采用比例控制。在(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池兩端電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓達(da)到(dao)設定值后，系(xi)統再進(jin)入(ru)涓流(liu)(liu)(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)器的(de)(de)程(cheng)序(xu)流(liu)(liu)(liu)程(cheng)如圖3所(suo)示。圖3中(zhong)，Is為設定的(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)即(ji)(ji)(ji)恒流(liu)(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)，Umin為蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池的(de)(de)放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)限(xian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓，Umax為蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池的(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)限(xian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓。

   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，充電器自動停(ting)止。從測試數據(ju)來看，該設計(ji)達到了恒(heng)(heng)流(liu)快(kuai)(kuai)充，恒(heng)(heng)壓涓充，充滿自行關斷的(de)設計(ji)要(yao)求。 5、結束語(yu) 本文設計(ji)的(de)過(guo)度放電(dian)(dian)(dian)預充、恒(heng)(heng)流(liu)快(kuai)(kuai)充、恒(heng)(heng)壓涓充、智(zhi)能(neng)控制(zhi)(zhi)的(de)充電(dian)(dian)(dian)方案，能(neng)很(hen)好地解決電(dian)(dian)(dian)動自行車用電(dian)(dian)(dian)池在充電(dian)(dian)(dian)過(guo)程中存在的(de)過(guo)充電(dian)(dian)(dian)、充電(dian)(dian)(dian)不足和發熱(re)等(deng)問題，并能(neng)根據(ju)不同(tong)電(dian)(dian)(dian)池選(xuan)擇不同(tong)的(de)充電(dian)(dian)(dian)方案。而且具(ju)有通用性。能(neng)實時(shi)檢測并顯示(shi)充電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)、充電(dian)(dian)(dian)電(dian)(dian)(dian)壓、充電(dian)(dian)(dian)時(shi)間和蓄電(dian)(dian)(dian)池溫度等(deng)參(can)數。由(you)于(yu)電(dian)(dian)(dian)路具(ju)有內(nei)外環控制(zhi)(zhi)，符(fu)合最(zui)優控制(zhi)(zhi)規(gui)律。最(zui)具(ju)有過(guo)流(liu)、過(guo)壓和超溫保(bao)護功能(neng)，同(tong)時(shi)由(you)于(yu)

   UC3842采用(yong)穩壓供(gong)電，因此，不但諧波(bo)污染程度低，原副邊電氣隔離安全可靠，同時還可根據負載情況通過單(dan)片機來進行控制，并可實現跳周期模式工作(zuo)。故可提(ti)高電源的效率。