鑒于市場上鎳鎘電池和鋰電池共存的局面，本文設計的充電器可(ke)以對(dui)這(zhe)兩(liang)種電(dian)池進行充(chong)(chong)(chong)(chong)(chong)電(dian)，對(dui)鎳鎘(ge)電(dian)池組(zu)采用脈沖充(chong)(chong)(chong)(chong)(chong)電(dian)方(fang)式，對(dui)鋰電(dian)池組(zu)采用恒流充(chong)(chong)(chong)(chong)(chong)電(dian)方(fang)式，這(zhe)是(shi)依據電(dian)池的(de)(de)不同機(ji)理而(er)設計的(de)(de)，真正做到了一(yi)機(ji)兩(liang)用，此為該充(chong)(chong)(chong)(chong)(chong)電(dian)器(qi)(qi)的(de)(de)創新點(dian)(dian)，也(ye)是(shi)設計的(de)(de)難(nan)點(dian)(dian)。充(chong)(chong)(chong)(chong)(chong)電(dian)器(qi)(qi)的(de)(de)寬屏LCD可(ke)以同時顯示4組(zu)充(chong)(chong)(chong)(chong)(chong)電(dian)器(qi)(qi)的(de)(de)充(chong)(chong)(chong)(chong)(chong)電(dian)狀態，也(ye)可(ke)單(dan)獨顯示一(yi)組(zu)充(chong)(chong)(chong)(chong)(chong)電(dian)器(qi)(qi)上電(dian)池的(de)(de)各(ge)項參數，做到了對(dui)電(dian)池充(chong)(chong)(chong)(chong)(chong)電(dian)過(guo)程的(de)(de)實時監(jian)測。

　　系統整體設計

　　系統設(she)計目標是：

　　1．可同時對4組(zu)8.4V的鋰(li)離子電(dian)池或(huo)9.2V的鎳鎘電(dian)池進行(xing)充放(fang)電(dian)。

　　2．可與電(dian)池組中的(de)(de)芯(xin)片(pian)通(tong)信，判斷(duan)電(dian)池的(de)(de)化學(xue)性質。

　　3．對于不(bu)同化學性質(zhi)的(de)電池(chi)，將采用相(xiang)應的(de)充電方式。

　　4．可與電池組中的芯片通信(xin)，得(de)到該電池組的電壓、充電電流、容量等(deng)參數。

　　5．充電器帶有(you)LCD，可顯示電池的各(ge)項數(shu)據。

　　該充電器(qi)的功能框(kuang)圖如圖1所示(shi)。

　　
       系統(tong)硬件設計

　　總控單元的設計與實現

　　總(zong)控單元是由(you)微控制器PIC16F873和鍵盤控制芯片(pian)ZLG7289A構成(cheng)的。主要任務是負責與各

個充電(dian)單元(yuan)通(tong)信，并處理用(yong)戶輸(shu)入與(yu)LCD顯示(shi)信息。鍵(jian)盤控制芯片在這里負責6個按鍵(jian)和12個LED的控制。ZLG7289A與(yu)微控制器之間通(tong)過SPI總線進行雙向通(tong)信。主(zhu)控單元(yuan)每秒查詢一次各個充電(dian)單元(yuan)，獲取當前充電(dian)單元(yuan)的信息，如有(you)無電(dian)池(chi)、電(dian)池(chi)性質(zhi)、電(dian)池(chi)電(dian)壓(ya)等(deng)。之后由LCD模塊向用(yong)戶顯示(shi)。

　　充電單元的設計與實現

　　LTC4002鋰離子電池充電控制芯片

　　LTC4002是(shi)一款高(gao)效獨立(li)開關模式鋰離子電(dian)(dian)池充(chong)(chong)(chong)電(dian)(dian)控制(zhi)(zhi)器(qi)(qi)。該(gai)控制(zhi)(zhi)器(qi)(qi)有(you)(you)4.2V和(he)8.4V兩個(ge)版本。LTC4002-8.4具有(you)(you)500kHz開關頻(pin)率(lv)，是(shi)高(gao)效電(dian)(dian)流模式的(de)(de)PWM控制(zhi)(zhi)器(qi)(qi)。通過(guo)驅動一個(ge)外部(bu)P溝道MOSFET，它可以提(ti)供4A的(de)(de)充(chong)(chong)(chong)電(dian)(dian)電(dian)(dian)流，而效率(lv)可高(gao)達90％。輸出電(dian)(dian)壓(ya)設置為8.4V，最(zui)終浮動電(dian)(dian)壓(ya)并具1％的(de)(de)精(jing)度，而充(chong)(chong)(chong)電(dian)(dian)準(zhun)確度為5％。此(ci)外，該(gai)器(qi)(qi)件可在(zai)9V～22V范圍內的(de)(de)多種墻上(shang)適配(pei)器(qi)(qi)上(shang)運(yun)行。與(yu)遲滯(zhi)拓撲結構充(chong)(chong)(chong)電(dian)(dian)器(qi)(qi)相比，LTC4002-8.4的(de)(de)快速運(yun)行頻(pin)率(lv)與(yu)電(dian)(dian)流模式架構使之能(neng)夠使用小型電(dian)(dian)感器(qi)(qi)和(he)電(dian)(dian)容器(qi)(qi)。

　　鋰離(li)子／鎳鎘電池兩(liang)用充電單元的總體(ti)設計

　　從前(qian)面對(dui)(dui)LTC4002的(de)分(fen)析可(ke)知(zhi)，該芯片是針對(dui)(dui)鋰(li)(li)離子(zi)電(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)充(chong)(chong)電(dian)(dian)(dian)控制(zhi)器，要(yao)實(shi)現(xian)對(dui)(dui)鎳(nie)(nie)鎘(ge)(ge)電(dian)(dian)(dian)池(chi)(chi)(chi)(chi)充(chong)(chong)電(dian)(dian)(dian)需要(yao)解決以(yi)(yi)(yi)下問題(ti)：首(shou)先，LTC4002對(dui)(dui)電(dian)(dian)(dian)池(chi)(chi)(chi)(chi)電(dian)(dian)(dian)壓(ya)(ya)進行(xing)(xing)監測，保證電(dian)(dian)(dian)池(chi)(chi)(chi)(chi)電(dian)(dian)(dian)壓(ya)(ya)不(bu)(bu)(bu)超過8.4V。但對(dui)(dui)于鎳(nie)(nie)鎘(ge)(ge)電(dian)(dian)(dian)池(chi)(chi)(chi)(chi)組(zu)，充(chong)(chong)電(dian)(dian)(dian)截(jie)止電(dian)(dian)(dian)壓(ya)(ya)可(ke)以(yi)(yi)(yi)達到(dao)9.2V。其(qi)(qi)次，鎳(nie)(nie)鎘(ge)(ge)電(dian)(dian)(dian)池(chi)(chi)(chi)(chi)充(chong)(chong)電(dian)(dian)(dian)即(ji)將結(jie)束時，需要(yao)對(dui)(dui)電(dian)(dian)(dian)池(chi)(chi)(chi)(chi)進行(xing)(xing)以(yi)(yi)(yi)正常電(dian)(dian)(dian)流30％和10％的(de)涓流充(chong)(chong)電(dian)(dian)(dian)。所以(yi)(yi)(yi)，第二(er)個需要(yao)解決的(de)問題(ti)是如(ru)何控制(zhi)恒流充(chong)(chong)電(dian)(dian)(dian)的(de)電(dian)(dian)(dian)流大小。此外，對(dui)(dui)鎳(nie)(nie)鎘(ge)(ge)電(dian)(dian)(dian)池(chi)(chi)(chi)(chi)充(chong)(chong)電(dian)(dian)(dian)應使用脈沖(chong)充(chong)(chong)電(dian)(dian)(dian)方(fang)式。即(ji)以(yi)(yi)(yi)1s為(wei)周期，95％的(de)時間用來充(chong)(chong)電(dian)(dian)(dian)，1％的(de)時間用來放電(dian)(dian)(dian)，其(qi)(qi)余時間不(bu)(bu)(bu)充(chong)(chong)電(dian)(dian)(dian)也(ye)不(bu)(bu)(bu)放電(dian)(dian)(dian)。最(zui)后，如(ru)何判斷(duan)某一個電(dian)(dian)(dian)池(chi)(chi)(chi)(chi)是鋰(li)(li)離子(zi)電(dian)(dian)(dian)池(chi)(chi)(chi)(chi)還(huan)是鎳(nie)(nie)鎘(ge)(ge)電(dian)(dian)(dian)池(chi)(chi)(chi)(chi)，因(yin)為(wei)若把鋰(li)(li)離子(zi)電(dian)(dian)(dian)池(chi)(chi)(chi)(chi)誤(wu)判為(wei)鎳(nie)(nie)鎘(ge)(ge)電(dian)(dian)(dian)池(chi)(chi)(chi)(chi)，會使充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)(ya)高(gao)于8.4V，這對(dui)(dui)鋰(li)(li)離子(zi)電(dian)(dian)(dian)池(chi)(chi)(chi)(chi)是十分(fen)危險的(de)，而(er)將鎳(nie)(nie)鎘(ge)(ge)電(dian)(dian)(dian)池(chi)(chi)(chi)(chi)誤(wu)判為(wei)鋰(li)(li)離子(zi)電(dian)(dian)(dian)池(chi)(chi)(chi)(chi)，則可(ke)能造成電(dian)(dian)(dian)池(chi)(chi)(chi)(chi)充(chong)(chong)電(dian)(dian)(dian)不(bu)(bu)(bu)足。因(yin)此，必(bi)須保證極低的(de)誤(wu)判率。

　　本部分根據(ju)LTC4002的(de)(de)工(gong)作(zuo)原理，設計了既(ji)可以對(dui)(dui)鋰(li)離子電(dian)(dian)(dian)池(chi)進行恒(heng)流-恒(heng)壓充(chong)(chong)電(dian)(dian)(dian)，又可以對(dui)(dui)鎳鎘電(dian)(dian)(dian)池(chi)進行脈沖(chong)式充(chong)(chong)電(dian)(dian)(dian)的(de)(de)電(dian)(dian)(dian)路。充(chong)(chong)電(dian)(dian)(dian)單元的(de)(de)總體(ti)功能(neng)框圖如圖2所示。其中，信(xin)號(hao)調理電(dian)(dian)(dian)路使充(chong)(chong)電(dian)(dian)(dian)器(qi)既(ji)可以對(dui)(dui)8.4V的(de)(de)鋰(li)電(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)，又可以對(dui)(dui)9.2V的(de)(de)鎳鎘電(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)，同時也起到(dao)控制充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流大小的(de)(de)作(zuo)用。

　　利用(yong)微控(kong)制(zhi)(zhi)器控(kong)制(zhi)(zhi)LTC4002的工作狀態，配合放(fang)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)路使充電(dian)(dian)(dian)(dian)器可以(yi)對(dui)鎳鎘電(dian)(dian)(dian)(dian)池進(jin)行脈(mo)沖方式充電(dian)(dian)(dian)(dian)。

　　微控制器通(tong)(tong)過一定的通(tong)(tong)信協議(HDQ16)與(yu)智能電(dian)池通(tong)(tong)信，確定其(qi)容(rong)量、化學(xue)性(xing)質等關鍵(jian)參數(shu)。

　　信號調理電路(lu)的設計(ji)

　　為(wei)了使LTC4002可對(dui)高于8.4V的(de)(de)(de)電(dian)(dian)池進行恒流充電(dian)(dian)，并可調(diao)(diao)節(jie)充電(dian)(dian)電(dian)(dian)流，在LTC4002的(de)(de)(de)BAT和SENSE端與采樣(yang)(yang)電(dian)(dian)阻之間(jian)加入一級信號調(diao)(diao)理電(dian)(dian)路(lu)(lu)。該(gai)電(dian)(dian)路(lu)(lu)的(de)(de)(de)主要功能(neng)是對(dui)采樣(yang)(yang)電(dian)(dian)阻兩端的(de)(de)(de)信號進行運算，針對(dui)不(bu)同化學性質(zhi)的(de)(de)(de)電(dian)(dian)池，將相應的(de)(de)(de)信號送給LTC4002。該(gai)信號調(diao)(diao)理電(dian)(dian)路(lu)(lu)如圖3所(suo)示(shi)。

這里(li)定義采樣電(dian)(dian)(dian)阻(zu)兩端的電(dian)(dian)(dian)壓(ya)值是VBAT和Vsense，那么(me)充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流在(zai)采樣電(dian)(dian)(dian)阻(zu)上的壓(ya)降VRS為(wei)：VRS=Vsense-VBAT，該信(xin)號(hao)為(wei)減法(fa)器(qi)的輸出。設乘法(fa)器(qi)的乘系數為(wei)K，那么(me)乘法(fa)器(qi)的輸出為(wei)KVRS。對于鋰子電(dian)(dian)(dian)池(chi)，二選(xuan)(xuan)一開(kai)(kai)關將選(xuan)(xuan)通(tong)電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓(ya)VBAT；對于鎳(nie)鎘電(dian)(dian)(dian)池(chi)，二選(xuan)(xuan)一開(kai)(kai)關將選(xuan)(xuan)通(tong)7V恒(heng)定電(dian)(dian)(dian)壓(ya)。這里(li)設二選(xuan)(xuan)一模擬(ni)開(kai)(kai)關的輸出為(wei)V1，那么(me)加法(fa)器(qi)的輸出Vs應(ying)為(wei)：Vs=KVRS+V1，這樣一來，送到LTC4002的BAT和SENSE兩端的電(dian)(dian)(dian)壓(ya)之差(cha)應(ying)為(wei)KVRS。只(zhi)要正(zheng)確控制K值，就可以使充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流為(wei)正(zheng)常(chang)充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流的1／K。因此，可以通(tong)過二選(xuan)(xuan)一開(kai)(kai)關控制電(dian)(dian)(dian)流為(wei)恒(heng)流充(chong)(chong)電(dian)(dian)(dian)時(shi)的10％或30％。

　　對于LTC4002的(de)BAT端輸入值(zhi)，當開(kai)關選(xuan)通(tong)鋰離(li)子電(dian)池(chi)時，BAT的(de)輸入即是(shi)電(dian)池(chi)電(dian)壓。此時，LTC4002可(ke)以控(kong)制整(zheng)個(ge)鋰離(li)子的(de)充電(dian)過程。不需任何外界的(de)干預。

　　當開關選通了7V恒定(ding)(ding)電(dian)(dian)(dian)壓(ya)(ya)后，BAT端的輸入恒定(ding)(ding)為7V，此時，LTC4002無法知道電(dian)(dian)(dian)池(chi)(chi)的真實電(dian)(dian)(dian)壓(ya)(ya)，只認為電(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)壓(ya)(ya)為7V。所以(yi)(yi)，盡管電(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)壓(ya)(ya)高于8.4V，仍會以(yi)(yi)恒定(ding)(ding)電(dian)(dian)(dian)流(liu)對電(dian)(dian)(dian)池(chi)(chi)進行(xing)充(chong)電(dian)(dian)(dian)。在這種情況下，需(xu)要(yao)微控(kong)制器的干(gan)預，否則，會造(zao)成電(dian)(dian)(dian)池(chi)(chi)的過充(chong)。由于微控(kong)制器內部帶有ADC，可(ke)以(yi)(yi)監測(ce)電(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)壓(ya)(ya)的變化。當電(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)壓(ya)(ya)達(da)到指(zhi)定(ding)(ding)值時，減(jian)小充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)，直至電(dian)(dian)(dian)池(chi)(chi)充(chong)滿。這樣就(jiu)可(ke)以(yi)(yi)對9.2V的鎳(nie)鎘(ge)電(dian)(dian)(dian)池(chi)(chi)進行(xing)充(chong)電(dian)(dian)(dian)了。

　　脈沖(chong)充放電(dian)電(dian)路的(de)設計

　　由于(yu)LTC4002是(shi)恒流充電(dian)(dian)(dian)控(kong)制(zhi)(zhi)芯片，因此，必(bi)須使用微(wei)控(kong)制(zhi)(zhi)器控(kong)制(zhi)(zhi)其充電(dian)(dian)(dian)使能引(yin)腳COMP。當需要LTC4002輸(shu)出充電(dian)(dian)(dian)脈(mo)沖時(shi)，使控(kong)制(zhi)(zhi)COMP引(yin)腳的端口變為(wei)高(gao)阻態，使COMP引(yin)腳自(zi)行升至360mV以上時(shi)，便有充電(dian)(dian)(dian)電(dian)(dian)(dian)流輸(shu)出。放電(dian)(dian)(dian)時(shi)，必(bi)須將(jiang)COMP引(yin)腳拉低(di)，使LTC4002關斷充電(dian)(dian)(dian)電(dian)(dian)(dian)流。之后，再打開放電(dian)(dian)(dian)電(dian)(dian)(dian)路。微(wei)控(kong)制(zhi)(zhi)器選用PIC16F873，它是(shi)一款(kuan)基于(yu)Fla

sh的8位微控(kong)制(zhi)器。內部有定時器、看門(men)狗電路、10位ADC等(deng)模(mo)塊。

　　微(wei)控制器以1s為周期對鎳(nie)鎘電(dian)(dian)池進行脈沖充放(fang)電(dian)(dian)。

　　系統軟件設計

　　系統軟件(jian)總(zong)體設計

　　充(chong)(chong)(chong)電(dian)(dian)(dian)單(dan)(dan)(dan)元(yuan)中的(de)(de)(de)微控(kong)制(zhi)器主要(yao)負責充(chong)(chong)(chong)電(dian)(dian)(dian)過程的(de)(de)(de)控(kong)制(zhi)和與(yu)總(zong)控(kong)板的(de)(de)(de)通信，程序流程如圖4所示(shi)。充(chong)(chong)(chong)電(dian)(dian)(dian)單(dan)(dan)(dan)元(yuan)首(shou)先判(pan)斷是否有電(dian)(dian)(dian)池(chi)(chi)(chi)，如果有電(dian)(dian)(dian)池(chi)(chi)(chi)放入，則判(pan)斷充(chong)(chong)(chong)放電(dian)(dian)(dian)狀(zhuang)態(tai)(tai)(tai)，默認是充(chong)(chong)(chong)電(dian)(dian)(dian)狀(zhuang)態(tai)(tai)(tai)，該狀(zhuang)態(tai)(tai)(tai)可由總(zong)控(kong)單(dan)(dan)(dan)元(yuan)改變。若充(chong)(chong)(chong)電(dian)(dian)(dian)單(dan)(dan)(dan)元(yuan)處于充(chong)(chong)(chong)電(dian)(dian)(dian)狀(zhuang)態(tai)(tai)(tai)，則繼續(xu)判(pan)斷電(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)(de)化學性質(zhi)，針對不同(tong)的(de)(de)(de)電(dian)(dian)(dian)池(chi)(chi)(chi)采用不同(tong)的(de)(de)(de)充(chong)(chong)(chong)電(dian)(dian)(dian)方式。若處于放電(dian)(dian)(dian)狀(zhuang)態(tai)(tai)(tai)，則對電(dian)(dian)(dian)池(chi)(chi)(chi)組(zu)進行放電(dian)(dian)(dian)，直到電(dian)(dian)(dian)池(chi)(chi)(chi)電(dian)(dian)(dian)壓低于閾(yu)值電(dian)(dian)(dian)壓后，轉(zhuan)為充(chong)(chong)(chong)電(dian)(dian)(dian)狀(zhuang)態(tai)(tai)(tai)。

　　除(chu)主程序外，總控(kong)單(dan)元(yuan)(yuan)(yuan)與充(chong)(chong)(chong)電(dian)單(dan)元(yuan)(yuan)(yuan)的通信(xin)是(shi)在中斷服務程序中實現的。當充(chong)(chong)(chong)電(dian)單(dan)元(yuan)(yuan)(yuan)收到(dao)總控(kong)單(dan)元(yuan)(yuan)(yuan)的指令(ling)后，進入中斷。若(ruo)指令(ling)是(shi)查(cha)詢數據指令(ling)，則(ze)向(xiang)總控(kong)單(dan)元(yuan)(yuan)(yuan)發(fa)送需要的數據。若(ruo)是(shi)充(chong)(chong)(chong)電(dian)狀態(tai)(tai)設(she)置指令(ling)，則(ze)依據指令(ling)設(she)置充(chong)(chong)(chong)電(dian)單(dan)元(yuan)(yuan)(yuan)的充(chong)(chong)(chong)電(dian)狀態(tai)(tai)。

　　通信協議的實現

　　通過與電池組中電能計量芯片通信的方法來判斷電池的性質。本系統可以與遵循HDQ16接口協議的智能電池組進行通信，除了電池組的化學性質外，還可以將電池組的容量、電壓、充電電流、編號等數據一并讀取，供充電器顯示之用。

　　充電(dian)單元可以(yi)通過HDQ總線對智(zhi)能(neng)(neng)電(dian)池(chi)進行讀操(cao)作。HDQ16接口協(xie)議是基于指(zhi)(zhi)(zhi)令的(de)協(xie)議。一(yi)個處理器(qi)發(fa)送8位(wei)指(zhi)(zhi)(zhi)令碼給(gei)智(zhi)能(neng)(neng)電(dian)池(chi)，這(zhe)個8位(wei)的(de)指(zhi)(zhi)(zhi)令碼由兩部分組成，7位(wei)HDQ16指(zhi)(zhi)(zhi)令碼(位(wei)0～6)和1位(wei)讀／寫指(zhi)(zhi)(zhi)令。讀／寫指(zhi)(zhi)(zhi)令指(zhi)(zhi)(zhi)示(shi)智(zhi)能(neng)(neng) 電(dian)池(chi)存(cun)儲(chu)接下(xia)來的(de)16位(wei)數(shu)據到一(yi)個指(zhi)(zhi)(zhi)定的(de)寄存(cun)器(qi)，或者從指(zhi)(zhi)(zhi)定的(de)寄存(cun)器(qi)輸出16位(wei)數(shu)據。在HDQ16里，數(shu)據字節(jie)(指(zhi)(zhi)(zhi)令)或者字(數(shu)據)的(de)最不重(zhong)要的(de)位(wei)會優(you)先(xian)傳輸。

　　一個(ge)塊的(de)(de)(de)傳輸(shu)包括(kuo)三個(ge)不同的(de)(de)(de)部分。第一部分經由主(zhu)機或(huo)者智能電(dian)池(chi)把HDQ16引腳置邏(luo)輯低狀態一個(ge)tSTRH：B時(shi)間(jian)(jian)后(hou)開始發送(song)。接(jie)下來的(de)(de)(de)部分是(shi)真正的(de)(de)(de)數(shu)(shu)據(ju)傳輸(shu)，數(shu)(shu)據(ju)位在tDSU:B時(shi)間(jian)(jian)間(jian)(jian)隔里是(shi)有效的(de)(de)(de)，負邊界(jie)用來開始通信。數(shu)(shu)據(ju)位被保持一個(ge)tDH:DV時(shi)間(jian)(jian)間(jian)(jian)隔，以便允許主(zhu)機或(huo)智能電(dian)池(chi)采樣數(shu)(shu)據(ju)位。

　　在負邊界開始通(tong)信后，最后一(yi)部分通(tong)過返回給HDQ16引腳一(yi)個邏輯高狀(zhuang)態，至(zhi)少保(bao)持(chi)tSSU:B時間(jian)間(jian)隔(ge)來(lai)停止傳輸(shu)(shu)。最后一(yi)個邏輯高狀(zhuang)態必(bi)須(xu)保(bao)持(chi)一(yi)個tCYCH:B時間(jian)間(jian)隔(ge)，以(yi)便有(you)時間(jian)讓塊傳輸(shu)(shu)完(wan)全(quan)停止。

　　如果發生通信錯誤(wu)(e.g.，tCYCB>250μs)，主機就(jiu)發送給智能電池一(yi)個BREAK信號，讓其控制(zhi)串行接(jie)口。當HDQ16引腳在一(yi)個時(shi)間(jian)(jian)間(jian)(jian)隔(ge)，或者(zhe)更長時(shi)間(jian)(jian)里(li)為邏輯(ji)低狀(zhuang)態(tai)時(shi)，智能電池就(jiu)會偵測BREAK。然(ran)后，HDQ16引腳回到其正常(chang)預設高邏輯(ji)狀(zhuang)態(tai)一(yi)個tBR時(shi)間(jian)(jian)間(jian)(jian)隔(ge)。然(ran)后，智能電池就(jiu)準(zhun)備從主機那(nei)里(li)接(jie)收(shou)指(zhi)令。

　　HDQ16引腳(jiao)是開(kai)漏的(de)，需要(yao)一個外部的(de)上拉電(dian)阻。

　　圖5是用邏輯分析(xi)儀顯(xian)示的(de)(de)一次(ci)HDQ總(zong)線上的(de)(de)通(tong)信波(bo)形。

　　本文提(ti)出的充(chong)(chong)電(dian)(dian)系(xi)統(tong)從技(ji)(ji)術上(shang)很好(hao)地解決了(le)上(shang)述(shu)問題，通過LCD顯示屏可(ke)以清晰便(bian)捷地讀出電(dian)(dian)源(yuan)(yuan)的剩余容量(liang)、已有充(chong)(chong)放電(dian)(dian)次數(shu)、充(chong)(chong)電(dian)(dian)及放電(dian)(dian)電(dian)(dian)流、電(dian)(dian)池(chi)電(dian)(dian)壓、容量(liang)統(tong)計和電(dian)(dian)池(chi)特性(xing)等重要(yao)內容，并且通過設定，可(ke)以判斷電(dian)(dian)源(yuan)(yuan)是(shi)否達(da)到報廢標準(zhun)，及時提(ti)醒操作者(zhe)更新電(dian)(dian)源(yuan)(yuan)。為電(dian)(dian)源(yuan)(yuan)維護保(bao)養工作提(ti)供明確的參考數(shu)據，降低了(le)對(dui)操作人員專(zhuan)業技(ji)(ji)術水平的要(yao)求，保(bao)證(zheng)了(le)列車尾部電(dian)(dian)源(yuan)(yuan)的安全使用。