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)(dui)這兩種電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)進(jin)行充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)，對(dui)(dui)鎳鎘電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)組(zu)(zu)采(cai)用脈沖(chong)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)方式，對(dui)(dui)鋰電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)組(zu)(zu)采(cai)用恒流充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)方式，這是依據電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)不同(tong)機理而設(she)(she)計的(de)(de)，真正做到(dao)了一機兩用，此(ci)為該充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器的(de)(de)創(chuang)新點，也是設(she)(she)計的(de)(de)難點。充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器的(de)(de)寬屏LCD可(ke)以同(tong)時(shi)顯(xian)示4組(zu)(zu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器的(de)(de)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)狀態，也可(ke)單獨顯(xian)示一組(zu)(zu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器上電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)各(ge)項參數，做到(dao)了對(dui)(dui)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)過程的(de)(de)實時(shi)監測。

　　系統整體設計

　　系統設計目標是：

　　1．可同時對4組(zu)8.4V的(de)鋰離子電池或9.2V的(de)鎳鎘電池進行充放電。

　　2．可與電池(chi)(chi)組中的(de)芯片通信，判斷電池(chi)(chi)的(de)化(hua)學(xue)性質。

　　3．對于不同化學性質的(de)電池，將采用(yong)相(xiang)應的(de)充(chong)電方式。

　　4．可(ke)與電池(chi)組(zu)中的芯片通信，得到該(gai)電池(chi)組(zu)的電壓(ya)、充電電流、容(rong)量(liang)等參(can)數。

　　5．充電器帶(dai)有LCD，可顯示電池的各項數據。

　　該(gai)充電(dian)器的功能框圖如圖1所示。

　　
       系(xi)統硬件設計

　　總(zong)控(kong)單元的設(she)計與(yu)實現

　　總控單元是由微控制器PIC16F873和鍵盤控制芯片ZLG7289A構成的。主要任(ren)務是負責與各

個充電(dian)(dian)單(dan)(dan)元(yuan)通(tong)信(xin)(xin)，并(bing)處理用戶輸入(ru)與(yu)LCD顯示(shi)信(xin)(xin)息。鍵盤控制芯片在這里負責6個按鍵和12個LED的(de)控制。ZLG7289A與(yu)微控制器之(zhi)間(jian)通(tong)過SPI總線(xian)進(jin)行雙(shuang)向通(tong)信(xin)(xin)。主控單(dan)(dan)元(yuan)每秒查詢(xun)一次(ci)各個充電(dian)(dian)單(dan)(dan)元(yuan)，獲取當(dang)前(qian)充電(dian)(dian)單(dan)(dan)元(yuan)的(de)信(xin)(xin)息，如有無電(dian)(dian)池、電(dian)(dian)池性質、電(dian)(dian)池電(dian)(dian)壓等。之(zhi)后由(you)LCD模塊(kuai)向用戶顯示(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)(shi)一(yi)款(kuan)高(gao)效(xiao)獨立開關(guan)模式鋰(li)離子電(dian)(dian)(dian)(dian)池充電(dian)(dian)(dian)(dian)控(kong)制(zhi)器(qi)(qi)。該控(kong)制(zhi)器(qi)(qi)有(you)4.2V和8.4V兩(liang)個版本。LTC4002-8.4具(ju)(ju)有(you)500kHz開關(guan)頻(pin)率(lv)(lv)，是(shi)(shi)高(gao)效(xiao)電(dian)(dian)(dian)(dian)流(liu)模式的PWM控(kong)制(zhi)器(qi)(qi)。通過(guo)驅動一(yi)個外部P溝道MOSFET，它(ta)可(ke)以(yi)提供4A的充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)，而效(xiao)率(lv)(lv)可(ke)高(gao)達90％。輸(shu)出電(dian)(dian)(dian)(dian)壓(ya)設(she)置為8.4V，最終浮動電(dian)(dian)(dian)(dian)壓(ya)并具(ju)(ju)1％的精度，而充電(dian)(dian)(dian)(dian)準確(que)度為5％。此(ci)外，該器(qi)(qi)件可(ke)在9V～22V范圍內的多(duo)種墻上(shang)適配器(qi)(qi)上(shang)運(yun)行(xing)。與(yu)遲滯(zhi)拓撲(pu)結構充電(dian)(dian)(dian)(dian)器(qi)(qi)相比(bi)，LTC4002-8.4的快速運(yun)行(xing)頻(pin)率(lv)(lv)與(yu)電(dian)(dian)(dian)(dian)流(liu)模式架構使(shi)之能(neng)夠使(shi)用小型電(dian)(dian)(dian)(dian)感(gan)器(qi)(qi)和電(dian)(dian)(dian)(dian)容器(qi)(qi)。

　　鋰離子／鎳(nie)鎘(ge)電(dian)池兩用充電(dian)單元的總體(ti)設計(ji)

　　從前面(mian)對LTC4002的(de)(de)分析可知，該芯片是針對鋰離(li)(li)子電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)控(kong)制器，要(yao)實(shi)現對鎳(nie)(nie)鎘(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)需(xu)要(yao)解決以下問(wen)題(ti)：首(shou)先，LTC4002對電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)壓進(jin)行監(jian)測，保(bao)證電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)壓不(bu)超過(guo)8.4V。但對于(yu)鎳(nie)(nie)鎘(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)組，充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)截止電(dian)(dian)(dian)(dian)(dian)(dian)壓可以達到9.2V。其(qi)次(ci)，鎳(nie)(nie)鎘(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)即將(jiang)結(jie)束時，需(xu)要(yao)對電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)進(jin)行以正常(chang)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)30％和10％的(de)(de)涓流(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)。所以，第(di)二(er)個需(xu)要(yao)解決的(de)(de)問(wen)題(ti)是如何(he)控(kong)制恒流(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)大小。此外，對鎳(nie)(nie)鎘(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)應使用脈沖充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)方式。即以1s為(wei)周期，95％的(de)(de)時間(jian)用來(lai)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)，1％的(de)(de)時間(jian)用來(lai)放電(dian)(dian)(dian)(dian)(dian)(dian)，其(qi)余時間(jian)不(bu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)也不(bu)放電(dian)(dian)(dian)(dian)(dian)(dian)。最(zui)后，如何(he)判斷某一個電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)是鋰離(li)(li)子電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)還是鎳(nie)(nie)鎘(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)，因(yin)為(wei)若(ruo)把鋰離(li)(li)子電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)誤(wu)判為(wei)鎳(nie)(nie)鎘(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)，會使充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)壓高于(yu)8.4V，這(zhe)對鋰離(li)(li)子電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)是十分危險的(de)(de)，而將(jiang)鎳(nie)(nie)鎘(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)誤(wu)判為(wei)鋰離(li)(li)子電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)，則可能造成電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)不(bu)足。因(yin)此，必須(xu)保(bao)證極低的(de)(de)誤(wu)判率(lv)。

　　本部(bu)分根據LTC4002的工作原理，設計了(le)既可(ke)(ke)以對(dui)鋰離子電(dian)(dian)(dian)池(chi)進行恒(heng)(heng)流-恒(heng)(heng)壓充(chong)電(dian)(dian)(dian)，又(you)(you)可(ke)(ke)以對(dui)鎳(nie)鎘電(dian)(dian)(dian)池(chi)進行脈沖(chong)式充(chong)電(dian)(dian)(dian)的電(dian)(dian)(dian)路。充(chong)電(dian)(dian)(dian)單元(yuan)的總體功能(neng)框圖如圖2所示。其(qi)中，信號調(diao)理電(dian)(dian)(dian)路使充(chong)電(dian)(dian)(dian)器既可(ke)(ke)以對(dui)8.4V的鋰電(dian)(dian)(dian)池(chi)充(chong)電(dian)(dian)(dian)，又(you)(you)可(ke)(ke)以對(dui)9.2V的鎳(nie)鎘電(dian)(dian)(dian)池(chi)充(chong)電(dian)(dian)(dian)，同時也(ye)起到(dao)控制充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流大(da)小的作用。

　　利用(yong)微控制器控制LTC4002的工(gong)作狀態，配合放電(dian)(dian)電(dian)(dian)路使(shi)充(chong)電(dian)(dian)器可以對鎳鎘電(dian)(dian)池進行脈沖方(fang)式充(chong)電(dian)(dian)。

　　微控制器通過一定的通信協(xie)議(HDQ16)與智能電池通信，確定其(qi)容量(liang)、化學性質等關鍵參數。

　　信號調理電路的設(she)計

　　為了(le)使(shi)LTC4002可對(dui)高(gao)于8.4V的(de)電(dian)(dian)池進(jin)行恒流(liu)充電(dian)(dian)，并(bing)可調節充電(dian)(dian)電(dian)(dian)流(liu)，在(zai)LTC4002的(de)BAT和SENSE端(duan)與采樣電(dian)(dian)阻之間加入一級信(xin)號調理電(dian)(dian)路(lu)(lu)。該(gai)電(dian)(dian)路(lu)(lu)的(de)主要功(gong)能是對(dui)采樣電(dian)(dian)阻兩端(duan)的(de)信(xin)號進(jin)行運算，針對(dui)不同(tong)化學(xue)性質的(de)電(dian)(dian)池，將相應的(de)信(xin)號送給LTC4002。該(gai)信(xin)號調理電(dian)(dian)路(lu)(lu)如圖(tu)3所示。

這里(li)定義采樣電(dian)(dian)(dian)阻兩(liang)端(duan)的(de)電(dian)(dian)(dian)壓值(zhi)是VBAT和(he)Vsense，那么充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)在(zai)采樣電(dian)(dian)(dian)阻上的(de)壓降(jiang)VRS為：VRS=Vsense-VBAT，該信號為減法器的(de)輸出(chu)(chu)。設乘法器的(de)乘系數為K，那么乘法器的(de)輸出(chu)(chu)為KVRS。對于(yu)鋰(li)子電(dian)(dian)(dian)池，二(er)(er)選(xuan)(xuan)(xuan)一(yi)開關(guan)將選(xuan)(xuan)(xuan)通電(dian)(dian)(dian)池電(dian)(dian)(dian)壓VBAT；對于(yu)鎳鎘電(dian)(dian)(dian)池，二(er)(er)選(xuan)(xuan)(xuan)一(yi)開關(guan)將選(xuan)(xuan)(xuan)通7V恒定電(dian)(dian)(dian)壓。這里(li)設二(er)(er)選(xuan)(xuan)(xuan)一(yi)模(mo)擬開關(guan)的(de)輸出(chu)(chu)為V1，那么加法器的(de)輸出(chu)(chu)Vs應為：Vs=KVRS+V1，這樣一(yi)來，送到LTC4002的(de)BAT和(he)SENSE兩(liang)端(duan)的(de)電(dian)(dian)(dian)壓之(zhi)差應為KVRS。只要正(zheng)確控(kong)制K值(zhi)，就(jiu)可以使(shi)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)為正(zheng)常充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)的(de)1／K。因此，可以通過二(er)(er)選(xuan)(xuan)(xuan)一(yi)開關(guan)控(kong)制電(dian)(dian)(dian)流(liu)為恒流(liu)充(chong)電(dian)(dian)(dian)時的(de)10％或30％。

　　對于LTC4002的(de)BAT端輸(shu)入值，當開關選通鋰離子電(dian)池時，BAT的(de)輸(shu)入即是電(dian)池電(dian)壓。此時，LTC4002可以控制整個鋰離子的(de)充電(dian)過(guo)程。不需任何外界的(de)干預(yu)。

　　當(dang)開關選(xuan)通了7V恒(heng)定(ding)電(dian)(dian)(dian)(dian)(dian)壓(ya)后(hou)，BAT端的(de)輸入恒(heng)定(ding)為7V，此(ci)時(shi)，LTC4002無法知道電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)真實電(dian)(dian)(dian)(dian)(dian)壓(ya)，只認(ren)為電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)壓(ya)為7V。所以，盡管電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)壓(ya)高于(yu)8.4V，仍(reng)會以恒(heng)定(ding)電(dian)(dian)(dian)(dian)(dian)流對(dui)(dui)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)進(jin)行(xing)充電(dian)(dian)(dian)(dian)(dian)。在這種情況下，需要微控(kong)制器的(de)干預，否則，會造成(cheng)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)過充。由于(yu)微控(kong)制器內(nei)部帶有ADC，可(ke)以監測電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)壓(ya)的(de)變(bian)化。當(dang)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)壓(ya)達(da)到指定(ding)值(zhi)時(shi)，減小充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流，直至電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)充滿。這樣就可(ke)以對(dui)(dui)9.2V的(de)鎳(nie)鎘電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)進(jin)行(xing)充電(dian)(dian)(dian)(dian)(dian)了。

　　脈沖充放電(dian)電(dian)路的(de)設計(ji)

　　由于LTC4002是恒流充電控制芯片，因此，必須使(shi)(shi)(shi)用(yong)微控制器(qi)控制其(qi)充電使(shi)(shi)(shi)能引腳COMP。當需要LTC4002輸出充電脈(mo)沖(chong)時，使(shi)(shi)(shi)控制COMP引腳的端口變為(wei)高(gao)阻態，使(shi)(shi)(shi)COMP引腳自行升至360mV以上時，便有充電電流輸出。放電時，必須將(jiang)COMP引腳拉低(di)，使(shi)(shi)(shi)LTC4002關斷(duan)充電電流。之后，再(zai)打開放電電路。微控制器(qi)選用(yong)PIC16F873，它(ta)是一(yi)款(kuan)基于Fla

sh的8位(wei)微控制器(qi)。內部有(you)定(ding)時器(qi)、看門狗電路、10位(wei)ADC等(deng)模塊。

　　微控(kong)制(zhi)器以1s為周期對鎳鎘電池進(jin)行脈(mo)沖充放電。

　　系統軟件設計

　　系(xi)統軟件總體設計

　　充(chong)(chong)電(dian)(dian)(dian)單(dan)(dan)元中的(de)微(wei)控制器主(zhu)要負責充(chong)(chong)電(dian)(dian)(dian)過程(cheng)的(de)控制和與總控板的(de)通(tong)信，程(cheng)序(xu)流(liu)程(cheng)如(ru)(ru)圖4所示。充(chong)(chong)電(dian)(dian)(dian)單(dan)(dan)元首先判斷(duan)是否(fou)有電(dian)(dian)(dian)池，如(ru)(ru)果有電(dian)(dian)(dian)池放(fang)(fang)入，則(ze)判斷(duan)充(chong)(chong)放(fang)(fang)電(dian)(dian)(dian)狀(zhuang)態(tai)，默認是充(chong)(chong)電(dian)(dian)(dian)狀(zhuang)態(tai)，該狀(zhuang)態(tai)可由總控單(dan)(dan)元改(gai)變(bian)。若充(chong)(chong)電(dian)(dian)(dian)單(dan)(dan)元處于充(chong)(chong)電(dian)(dian)(dian)狀(zhuang)態(tai)，則(ze)繼續判斷(duan)電(dian)(dian)(dian)池的(de)化(hua)學性(xing)質，針對不同的(de)電(dian)(dian)(dian)池采(cai)用不同的(de)充(chong)(chong)電(dian)(dian)(dian)方式。若處于放(fang)(fang)電(dian)(dian)(dian)狀(zhuang)態(tai)，則(ze)對電(dian)(dian)(dian)池組(zu)進行放(fang)(fang)電(dian)(dian)(dian)，直到電(dian)(dian)(dian)池電(dian)(dian)(dian)壓低于閾值電(dian)(dian)(dian)壓后(hou)，轉為(wei)充(chong)(chong)電(dian)(dian)(dian)狀(zhuang)態(tai)。

　　除主程序(xu)外，總(zong)控單(dan)(dan)元與(yu)充電(dian)(dian)單(dan)(dan)元的(de)通信是(shi)(shi)在中(zhong)斷服務程序(xu)中(zhong)實現的(de)。當充電(dian)(dian)單(dan)(dan)元收到總(zong)控單(dan)(dan)元的(de)指(zhi)令后，進入中(zhong)斷。若指(zhi)令是(shi)(shi)查詢(xun)數(shu)據(ju)(ju)指(zhi)令，則向總(zong)控單(dan)(dan)元發送需要(yao)的(de)數(shu)據(ju)(ju)。若是(shi)(shi)充電(dian)(dian)狀態設置(zhi)指(zhi)令，則依據(ju)(ju)指(zhi)令設置(zhi)充電(dian)(dian)單(dan)(dan)元的(de)充電(dian)(dian)狀態。

　　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(ke)以通(tong)過HDQ總線對智(zhi)能(neng)電(dian)池進(jin)行讀操作。HDQ16接口協(xie)議是基于指(zhi)(zhi)(zhi)令(ling)的(de)(de)協(xie)議。一個處理器發送(song)8位(wei)(wei)指(zhi)(zhi)(zhi)令(ling)碼(ma)給智(zhi)能(neng)電(dian)池，這個8位(wei)(wei)的(de)(de)指(zhi)(zhi)(zhi)令(ling)碼(ma)由(you)兩部分組成，7位(wei)(wei)HDQ16指(zhi)(zhi)(zhi)令(ling)碼(ma)(位(wei)(wei)0～6)和1位(wei)(wei)讀／寫指(zhi)(zhi)(zhi)令(ling)。讀／寫指(zhi)(zhi)(zhi)令(ling)指(zhi)(zhi)(zhi)示智(zhi)能(neng) 電(dian)池存儲接下來的(de)(de)16位(wei)(wei)數據(ju)到一個指(zhi)(zhi)(zhi)定的(de)(de)寄存器，或(huo)者從(cong)指(zhi)(zhi)(zhi)定的(de)(de)寄存器輸出16位(wei)(wei)數據(ju)。在HDQ16里(li)，數據(ju)字(zi)節(指(zhi)(zhi)(zhi)令(ling))或(huo)者字(zi)(數據(ju))的(de)(de)最不重要的(de)(de)位(wei)(wei)會(hui)優先傳輸。

　　一個塊的(de)(de)傳(chuan)輸包(bao)括三個不(bu)同的(de)(de)部(bu)分(fen)。第一部(bu)分(fen)經由主(zhu)機(ji)或者智能電池(chi)把(ba)HDQ16引腳置(zhi)邏輯低狀態一個tSTRH：B時間(jian)后(hou)開(kai)始(shi)發送。接下(xia)來的(de)(de)部(bu)分(fen)是真正的(de)(de)數(shu)(shu)據傳(chuan)輸，數(shu)(shu)據位(wei)在tDSU:B時間(jian)間(jian)隔(ge)里是有效的(de)(de)，負(fu)邊界用來開(kai)始(shi)通信。數(shu)(shu)據位(wei)被保持一個tDH:DV時間(jian)間(jian)隔(ge)，以便允(yun)許主(zhu)機(ji)或智能電池(chi)采樣數(shu)(shu)據位(wei)。

　　在負邊界(jie)開始通信后，最后一(yi)部分通過(guo)返(fan)回給HDQ16引腳一(yi)個(ge)邏輯高狀態，至少保(bao)持tSSU:B時(shi)(shi)間(jian)(jian)間(jian)(jian)隔來停止傳輸(shu)(shu)。最后一(yi)個(ge)邏輯高狀態必須保(bao)持一(yi)個(ge)tCYCH:B時(shi)(shi)間(jian)(jian)間(jian)(jian)隔，以便有時(shi)(shi)間(jian)(jian)讓塊傳輸(shu)(shu)完全停止。

　　如果(guo)發(fa)生(sheng)通信錯誤(e.g.，tCYCB>250μs)，主機(ji)就發(fa)送(song)給智(zhi)能電池一(yi)(yi)個(ge)(ge)BREAK信號，讓其控制串行接口。當(dang)HDQ16引腳(jiao)在一(yi)(yi)個(ge)(ge)時間間隔，或(huo)者更長(chang)時間里(li)(li)為邏(luo)輯(ji)低(di)狀態時，智(zhi)能電池就會偵測BREAK。然后，HDQ16引腳(jiao)回到其正常預(yu)設高邏(luo)輯(ji)狀態一(yi)(yi)個(ge)(ge)tBR時間間隔。然后，智(zhi)能電池就準備從主機(ji)那里(li)(li)接收指令。

　　HDQ16引腳是開漏的(de)，需要一個外部的(de)上拉電阻。

　　圖(tu)5是用邏輯分析儀顯示的一次HDQ總線上的通信波(bo)形。

　　本文提(ti)出的(de)(de)(de)(de)充電(dian)(dian)(dian)系統從技術上很好地解決了上述(shu)問題，通過(guo)LCD顯示屏可(ke)以清晰便捷地讀出電(dian)(dian)(dian)源的(de)(de)(de)(de)剩余容(rong)量(liang)(liang)、已有充放電(dian)(dian)(dian)次數、充電(dian)(dian)(dian)及(ji)放電(dian)(dian)(dian)電(dian)(dian)(dian)流、電(dian)(dian)(dian)池電(dian)(dian)(dian)壓、容(rong)量(liang)(liang)統計和(he)電(dian)(dian)(dian)池特(te)性(xing)等重要內容(rong)，并(bing)且通過(guo)設定，可(ke)以判斷電(dian)(dian)(dian)源是否達到報廢(fei)標準(zhun)，及(ji)時提(ti)醒操(cao)作者更新電(dian)(dian)(dian)源。為(wei)電(dian)(dian)(dian)源維護保(bao)養工作提(ti)供明確的(de)(de)(de)(de)參考數據，降低了對操(cao)作人員專業技術水平的(de)(de)(de)(de)要求，保(bao)證了列車尾部電(dian)(dian)(dian)源的(de)(de)(de)(de)安全(quan)使用。