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以對這兩種電(dian)(dian)(dian)池(chi)(chi)進行充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)，對鎳鎘(ge)電(dian)(dian)(dian)池(chi)(chi)組(zu)(zu)采用(yong)脈(mo)沖充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)方式，對鋰電(dian)(dian)(dian)池(chi)(chi)組(zu)(zu)采用(yong)恒流充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)方式，這是(shi)依據電(dian)(dian)(dian)池(chi)(chi)的(de)(de)(de)(de)不(bu)同機理(li)而設(she)計(ji)的(de)(de)(de)(de)，真正做(zuo)到(dao)了一(yi)機兩用(yong)，此為該(gai)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)的(de)(de)(de)(de)創新點，也(ye)是(shi)設(she)計(ji)的(de)(de)(de)(de)難(nan)點。充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)的(de)(de)(de)(de)寬(kuan)屏LCD可以同時(shi)顯(xian)示4組(zu)(zu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)的(de)(de)(de)(de)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)狀態，也(ye)可單獨顯(xian)示一(yi)組(zu)(zu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)上電(dian)(dian)(dian)池(chi)(chi)的(de)(de)(de)(de)各項參(can)數，做(zuo)到(dao)了對電(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)過程的(de)(de)(de)(de)實時(shi)監(jian)測。

　　系統整體設計

　　系統設計目(mu)標是：

　　1．可同(tong)時對4組8.4V的鋰離子電池或9.2V的鎳鎘(ge)電池進(jin)行充(chong)放電。

　　2．可與電(dian)(dian)池(chi)組中的芯片通(tong)信(xin)，判斷(duan)電(dian)(dian)池(chi)的化學(xue)性質。

　　3．對于不同化學性質(zhi)的(de)(de)電池，將采(cai)用相應的(de)(de)充電方式(shi)。

　　4．可(ke)與電池組中的芯片(pian)通信，得到(dao)該電池組的電壓、充電電流、容量(liang)等參數。

　　5．充電器帶有LCD，可顯(xian)示電池的(de)各項數據。

　　該充電器的功能框圖(tu)如圖(tu)1所示。

　　
       系統硬件設計

　　總控單元的設計與實(shi)現

　　總控單(dan)元是由微控制(zhi)器(qi)PIC16F873和(he)鍵盤控制(zhi)芯片ZLG7289A構成的。主(zhu)要任務(wu)是負責與各

個充(chong)電(dian)(dian)單(dan)元(yuan)通(tong)信(xin)(xin)，并處理(li)用戶輸(shu)入與LCD顯示(shi)(shi)信(xin)(xin)息。鍵盤控(kong)制芯片在這里(li)負責6個按鍵和(he)12個LED的(de)控(kong)制。ZLG7289A與微控(kong)制器之間(jian)通(tong)過SPI總線進行雙向(xiang)通(tong)信(xin)(xin)。主控(kong)單(dan)元(yuan)每(mei)秒查(cha)詢一次各個充(chong)電(dian)(dian)單(dan)元(yuan)，獲取(qu)當前充(chong)電(dian)(dian)單(dan)元(yuan)的(de)信(xin)(xin)息，如有(you)無電(dian)(dian)池(chi)、電(dian)(dian)池(chi)性質(zhi)、電(dian)(dian)池(chi)電(dian)(dian)壓等。之后由(you)LCD模(mo)塊向(xiang)用戶顯示(shi)(shi)。

　　充電單元的設(she)計與實(shi)現

　　LTC4002鋰離子電池充電控制芯片

　　LTC4002是一款高效(xiao)(xiao)獨(du)立開關模式(shi)鋰離子電(dian)池(chi)充(chong)電(dian)控(kong)制器(qi)。該(gai)控(kong)制器(qi)有4.2V和8.4V兩個(ge)版本。LTC4002-8.4具(ju)有500kHz開關頻率，是高效(xiao)(xiao)電(dian)流(liu)模式(shi)的(de)PWM控(kong)制器(qi)。通過驅(qu)動(dong)一個(ge)外部P溝道MOSFET，它可(ke)以提供4A的(de)充(chong)電(dian)電(dian)流(liu)，而(er)(er)效(xiao)(xiao)率可(ke)高達90％。輸出電(dian)壓(ya)設置為8.4V，最終(zhong)浮動(dong)電(dian)壓(ya)并具(ju)1％的(de)精度，而(er)(er)充(chong)電(dian)準(zhun)確度為5％。此外，該(gai)器(qi)件可(ke)在9V～22V范圍內的(de)多種墻上適配器(qi)上運行(xing)。與(yu)(yu)遲滯拓撲結構充(chong)電(dian)器(qi)相比，LTC4002-8.4的(de)快速運行(xing)頻率與(yu)(yu)電(dian)流(liu)模式(shi)架構使之(zhi)能夠使用小型電(dian)感器(qi)和電(dian)容器(qi)。

　　鋰離子／鎳鎘電池(chi)兩用充電單元(yuan)的總體設計

　　從前面對(dui)LTC4002的(de)(de)(de)(de)分(fen)析可知，該芯片是針對(dui)鋰(li)離(li)(li)(li)子(zi)(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)(de)(de)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)控(kong)制器(qi)，要實現對(dui)鎳(nie)(nie)鎘(ge)(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)需要解決以(yi)下問題：首(shou)先(xian)，LTC4002對(dui)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓進行監測(ce)，保(bao)證(zheng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓不超過8.4V。但對(dui)于鎳(nie)(nie)鎘(ge)(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)組(zu)，充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)截止電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓可以(yi)達到9.2V。其(qi)次，鎳(nie)(nie)鎘(ge)(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)即將(jiang)結(jie)束時(shi)，需要對(dui)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)進行以(yi)正常電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流30％和10％的(de)(de)(de)(de)涓流充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)。所以(yi)，第二(er)個需要解決的(de)(de)(de)(de)問題是如(ru)何控(kong)制恒流充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流大(da)小。此(ci)外，對(dui)鎳(nie)(nie)鎘(ge)(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)應使(shi)用(yong)脈沖充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)方式。即以(yi)1s為周期，95％的(de)(de)(de)(de)時(shi)間用(yong)來充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，1％的(de)(de)(de)(de)時(shi)間用(yong)來放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，其(qi)余時(shi)間不充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)也(ye)不放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)。最后，如(ru)何判斷某一個電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)是鋰(li)離(li)(li)(li)子(zi)(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)還是鎳(nie)(nie)鎘(ge)(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)，因為若把鋰(li)離(li)(li)(li)子(zi)(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)誤(wu)判為鎳(nie)(nie)鎘(ge)(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)，會使(shi)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓高于8.4V，這對(dui)鋰(li)離(li)(li)(li)子(zi)(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)是十分(fen)危險的(de)(de)(de)(de)，而(er)將(jiang)鎳(nie)(nie)鎘(ge)(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)誤(wu)判為鋰(li)離(li)(li)(li)子(zi)(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)，則可能造成電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)不足。因此(ci)，必須保(bao)證(zheng)極低的(de)(de)(de)(de)誤(wu)判率。

　　本部分根據LTC4002的(de)(de)工作原理(li)，設計(ji)了既可(ke)以對(dui)(dui)鋰離(li)子電(dian)(dian)(dian)(dian)(dian)池進(jin)行(xing)恒(heng)(heng)流(liu)-恒(heng)(heng)壓(ya)充(chong)電(dian)(dian)(dian)(dian)(dian)，又可(ke)以對(dui)(dui)鎳鎘電(dian)(dian)(dian)(dian)(dian)池進(jin)行(xing)脈沖式充(chong)電(dian)(dian)(dian)(dian)(dian)的(de)(de)電(dian)(dian)(dian)(dian)(dian)路。充(chong)電(dian)(dian)(dian)(dian)(dian)單元(yuan)的(de)(de)總體功能框圖如圖2所示。其(qi)中，信號調理(li)電(dian)(dian)(dian)(dian)(dian)路使充(chong)電(dian)(dian)(dian)(dian)(dian)器既可(ke)以對(dui)(dui)8.4V的(de)(de)鋰電(dian)(dian)(dian)(dian)(dian)池充(chong)電(dian)(dian)(dian)(dian)(dian)，又可(ke)以對(dui)(dui)9.2V的(de)(de)鎳鎘電(dian)(dian)(dian)(dian)(dian)池充(chong)電(dian)(dian)(dian)(dian)(dian)，同時也起到控制充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)大小的(de)(de)作用(yong)。

　　利用微(wei)控制(zhi)器控制(zhi)LTC4002的工作(zuo)狀(zhuang)態(tai)，配合(he)放電(dian)電(dian)路使充(chong)(chong)電(dian)器可以對鎳鎘電(dian)池進(jin)行脈沖方式(shi)充(chong)(chong)電(dian)。

　　微控制器通(tong)過一(yi)定(ding)(ding)的(de)通(tong)信協議(HDQ16)與智能電池通(tong)信，確定(ding)(ding)其容量、化學性質等關鍵(jian)參數。

　　信號調理電路的(de)設計

　　為了使LTC4002可(ke)對高于8.4V的(de)(de)電(dian)池進(jin)行恒流充電(dian)，并可(ke)調(diao)節充電(dian)電(dian)流，在LTC4002的(de)(de)BAT和SENSE端與采(cai)樣電(dian)阻之間加入一級(ji)信號調(diao)理電(dian)路(lu)。該(gai)電(dian)路(lu)的(de)(de)主(zhu)要功能是(shi)對采(cai)樣電(dian)阻兩端的(de)(de)信號進(jin)行運(yun)算(suan)，針對不同(tong)化學性質的(de)(de)電(dian)池，將(jiang)相應(ying)的(de)(de)信號送給LTC4002。該(gai)信號調(diao)理電(dian)路(lu)如圖3所示。

這(zhe)里(li)定(ding)義(yi)采樣電(dian)(dian)(dian)阻兩(liang)端(duan)的(de)(de)電(dian)(dian)(dian)壓值是VBAT和(he)Vsense，那么充電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)在采樣電(dian)(dian)(dian)阻上的(de)(de)壓降VRS為：VRS=Vsense-VBAT，該信號為減(jian)法(fa)器(qi)的(de)(de)輸(shu)出。設乘(cheng)法(fa)器(qi)的(de)(de)乘(cheng)系數為K，那么乘(cheng)法(fa)器(qi)的(de)(de)輸(shu)出為KVRS。對(dui)于(yu)鋰子電(dian)(dian)(dian)池(chi)，二(er)選一開(kai)關將選通電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓VBAT；對(dui)于(yu)鎳鎘電(dian)(dian)(dian)池(chi)，二(er)選一開(kai)關將選通7V恒定(ding)電(dian)(dian)(dian)壓。這(zhe)里(li)設二(er)選一模擬開(kai)關的(de)(de)輸(shu)出為V1，那么加法(fa)器(qi)的(de)(de)輸(shu)出Vs應(ying)為：Vs=KVRS+V1，這(zhe)樣一來，送到(dao)LTC4002的(de)(de)BAT和(he)SENSE兩(liang)端(duan)的(de)(de)電(dian)(dian)(dian)壓之(zhi)差應(ying)為KVRS。只要正(zheng)確控制(zhi)K值，就(jiu)可(ke)以使充電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)為正(zheng)常(chang)充電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)的(de)(de)1／K。因此，可(ke)以通過二(er)選一開(kai)關控制(zhi)電(dian)(dian)(dian)流(liu)(liu)為恒流(liu)(liu)充電(dian)(dian)(dian)時的(de)(de)10％或30％。

　　對(dui)于LTC4002的(de)BAT端輸入值，當(dang)開關(guan)選(xuan)通鋰離子電池時(shi)(shi)，BAT的(de)輸入即是電池電壓。此(ci)時(shi)(shi)，LTC4002可以控制整個(ge)鋰離子的(de)充(chong)電過程。不需(xu)任何外界(jie)的(de)干預。

　　當開(kai)關選通了7V恒(heng)(heng)定(ding)(ding)電(dian)壓(ya)(ya)(ya)后(hou)，BAT端的(de)輸(shu)入恒(heng)(heng)定(ding)(ding)為7V，此時，LTC4002無法知(zhi)道(dao)電(dian)池(chi)(chi)(chi)(chi)的(de)真實電(dian)壓(ya)(ya)(ya)，只認為電(dian)池(chi)(chi)(chi)(chi)電(dian)壓(ya)(ya)(ya)為7V。所以，盡管電(dian)池(chi)(chi)(chi)(chi)電(dian)壓(ya)(ya)(ya)高于8.4V，仍會(hui)以恒(heng)(heng)定(ding)(ding)電(dian)流對(dui)電(dian)池(chi)(chi)(chi)(chi)進行充電(dian)。在(zai)這種(zhong)情況下，需要(yao)微(wei)控(kong)制器的(de)干預，否則，會(hui)造成電(dian)池(chi)(chi)(chi)(chi)的(de)過充。由于微(wei)控(kong)制器內部帶有ADC，可以監測電(dian)池(chi)(chi)(chi)(chi)電(dian)壓(ya)(ya)(ya)的(de)變化。當電(dian)池(chi)(chi)(chi)(chi)電(dian)壓(ya)(ya)(ya)達到指定(ding)(ding)值時，減(jian)小充電(dian)電(dian)流，直至(zhi)電(dian)池(chi)(chi)(chi)(chi)充滿。這樣(yang)就可以對(dui)9.2V的(de)鎳鎘電(dian)池(chi)(chi)(chi)(chi)進行充電(dian)了。

　　脈沖充放電電路的設計

　　由于(yu)LTC4002是恒流充(chong)電(dian)(dian)(dian)控制(zhi)(zhi)芯片，因此，必須使用微控制(zhi)(zhi)器控制(zhi)(zhi)其(qi)充(chong)電(dian)(dian)(dian)使能引(yin)腳COMP。當需要LTC4002輸出(chu)充(chong)電(dian)(dian)(dian)脈沖時，使控制(zhi)(zhi)COMP引(yin)腳的端口(kou)變為高阻態，使COMP引(yin)腳自(zi)行升至(zhi)360mV以(yi)上時，便(bian)有充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流輸出(chu)。放(fang)電(dian)(dian)(dian)時，必須將(jiang)COMP引(yin)腳拉低(di)，使LTC4002關斷(duan)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流。之后，再打開(kai)放(fang)電(dian)(dian)(dian)電(dian)(dian)(dian)路(lu)。微控制(zhi)(zhi)器選用PIC16F873，它(ta)是一款基(ji)于(yu)Fla

sh的(de)8位微(wei)控制器(qi)。內部有定時器(qi)、看門狗電路、10位ADC等模塊。

　　微(wei)控制(zhi)器(qi)以(yi)1s為周期對鎳鎘電池進行脈沖充(chong)放電。

　　系統軟件設計

　　系統軟(ruan)件總體設計

　　充(chong)電(dian)(dian)單(dan)元中的微控(kong)(kong)制(zhi)器主要負責(ze)充(chong)電(dian)(dian)過程(cheng)的控(kong)(kong)制(zhi)和與(yu)總(zong)控(kong)(kong)板的通信，程(cheng)序流程(cheng)如(ru)圖4所示(shi)。充(chong)電(dian)(dian)單(dan)元首先判(pan)斷是否有電(dian)(dian)池(chi)(chi)，如(ru)果有電(dian)(dian)池(chi)(chi)放(fang)入，則判(pan)斷充(chong)放(fang)電(dian)(dian)狀(zhuang)態(tai)(tai)，默認是充(chong)電(dian)(dian)狀(zhuang)態(tai)(tai)，該狀(zhuang)態(tai)(tai)可(ke)由總(zong)控(kong)(kong)單(dan)元改變。若充(chong)電(dian)(dian)單(dan)元處于充(chong)電(dian)(dian)狀(zhuang)態(tai)(tai)，則繼續判(pan)斷電(dian)(dian)池(chi)(chi)的化(hua)學性質，針對(dui)不(bu)同的電(dian)(dian)池(chi)(chi)采用不(bu)同的充(chong)電(dian)(dian)方式。若處于放(fang)電(dian)(dian)狀(zhuang)態(tai)(tai)，則對(dui)電(dian)(dian)池(chi)(chi)組進行(xing)放(fang)電(dian)(dian)，直到電(dian)(dian)池(chi)(chi)電(dian)(dian)壓(ya)低于閾值電(dian)(dian)壓(ya)后，轉為充(chong)電(dian)(dian)狀(zhuang)態(tai)(tai)。

　　除主程(cheng)序外，總(zong)(zong)控單(dan)元與充電(dian)單(dan)元的(de)通信(xin)是(shi)在中斷服務程(cheng)序中實(shi)現的(de)。當充電(dian)單(dan)元收(shou)到總(zong)(zong)控單(dan)元的(de)指(zhi)令(ling)(ling)后(hou)，進入中斷。若指(zhi)令(ling)(ling)是(shi)查(cha)詢(xun)數據指(zhi)令(ling)(ling)，則向總(zong)(zong)控單(dan)元發送需要(yao)的(de)數據。若是(shi)充電(dian)狀態(tai)設置(zhi)指(zhi)令(ling)(ling)，則依據指(zhi)令(ling)(ling)設置(zhi)充電(dian)單(dan)元的(de)充電(dian)狀態(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)(dian)單元可以通過HDQ總(zong)線對智(zhi)能(neng)電(dian)(dian)池進行讀操作(zuo)。HDQ16接(jie)口協議是基于(yu)指(zhi)(zhi)令(ling)的(de)協議。一個處理器(qi)發送8位(wei)指(zhi)(zhi)令(ling)碼(ma)給智(zhi)能(neng)電(dian)(dian)池，這個8位(wei)的(de)指(zhi)(zhi)令(ling)碼(ma)由兩部分組成，7位(wei)HDQ16指(zhi)(zhi)令(ling)碼(ma)(位(wei)0～6)和1位(wei)讀／寫指(zhi)(zhi)令(ling)。讀／寫指(zhi)(zhi)令(ling)指(zhi)(zhi)示智(zhi)能(neng) 電(dian)(dian)池存儲接(jie)下來的(de)16位(wei)數(shu)據(ju)到一個指(zhi)(zhi)定的(de)寄(ji)存器(qi)，或者從指(zhi)(zhi)定的(de)寄(ji)存器(qi)輸出16位(wei)數(shu)據(ju)。在HDQ16里，數(shu)據(ju)字(zi)節(指(zhi)(zhi)令(ling))或者字(zi)(數(shu)據(ju))的(de)最(zui)不重(zhong)要的(de)位(wei)會優先傳輸。

　　一(yi)(yi)個(ge)(ge)塊的傳輸包括三個(ge)(ge)不同的部(bu)分。第(di)一(yi)(yi)部(bu)分經由主機或者(zhe)智(zhi)能(neng)電池把HDQ16引腳(jiao)置(zhi)邏輯低狀(zhuang)態一(yi)(yi)個(ge)(ge)tSTRH：B時間后開(kai)始(shi)發(fa)送(song)。接下來(lai)的部(bu)分是真(zhen)正的數(shu)據傳輸，數(shu)據位(wei)(wei)在tDSU:B時間間隔里是有效(xiao)的，負邊界用來(lai)開(kai)始(shi)通(tong)信。數(shu)據位(wei)(wei)被(bei)保持一(yi)(yi)個(ge)(ge)tDH:DV時間間隔，以便允許主機或智(zhi)能(neng)電池采樣(yang)數(shu)據位(wei)(wei)。

　　在負邊界開始通(tong)信后(hou)，最(zui)(zui)后(hou)一(yi)部分通(tong)過返回給HDQ16引腳一(yi)個邏輯高(gao)狀態，至少保持(chi)tSSU:B時間(jian)間(jian)隔來停止(zhi)傳輸。最(zui)(zui)后(hou)一(yi)個邏輯高(gao)狀態必須保持(chi)一(yi)個tCYCH:B時間(jian)間(jian)隔，以便有時間(jian)讓塊(kuai)傳輸完全(quan)停止(zhi)。

　　如(ru)果發(fa)(fa)生(sheng)通信(xin)錯誤(e.g.，tCYCB>250μs)，主機就(jiu)發(fa)(fa)送(song)給智(zhi)能(neng)電(dian)(dian)池(chi)一(yi)個(ge)BREAK信(xin)號，讓其控制(zhi)串行接口。當(dang)HDQ16引腳(jiao)在一(yi)個(ge)時(shi)間間隔(ge)，或者更(geng)長時(shi)間里(li)為(wei)邏輯(ji)低(di)狀態(tai)時(shi)，智(zhi)能(neng)電(dian)(dian)池(chi)就(jiu)會偵測(ce)BREAK。然后(hou)，HDQ16引腳(jiao)回到其正(zheng)常預設高邏輯(ji)狀態(tai)一(yi)個(ge)tBR時(shi)間間隔(ge)。然后(hou)，智(zhi)能(neng)電(dian)(dian)池(chi)就(jiu)準備從主機那里(li)接收(shou)指令。

　　HDQ16引腳是開(kai)漏的，需要一個(ge)外部的上(shang)拉電阻。

　　圖5是(shi)用邏輯分析儀(yi)顯示(shi)的一次HDQ總線上的通信波形(xing)。

　　本文提出的(de)充電(dian)(dian)(dian)(dian)(dian)(dian)系統從(cong)技術上很好地(di)(di)解(jie)決了上述(shu)問題，通過(guo)LCD顯示屏可(ke)以清晰便(bian)捷地(di)(di)讀出電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)的(de)剩余容量(liang)、已有充放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)次數、充電(dian)(dian)(dian)(dian)(dian)(dian)及放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流、電(dian)(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)(dian)壓、容量(liang)統計和電(dian)(dian)(dian)(dian)(dian)(dian)池特性等(deng)重要內容，并且通過(guo)設定，可(ke)以判斷電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)是否(fou)達(da)到報廢標(biao)準，及時(shi)提醒操(cao)作(zuo)者更新電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)。為電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)維(wei)護保(bao)養工作(zuo)提供明確的(de)參考數據，降低了對操(cao)作(zuo)人員專業技術水平(ping)的(de)要求，保(bao)證了列車尾部電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)的(de)安全使(shi)用。