我們渴望舒服一點的條件是，一個基于水霧系統而讓人涼快的解決方案，以克服困擾這片沙漠的干熱空氣。這可以用一臺由電壓源供電、連著一個帶噴嘴的噴霧水龍帶的水泵實現。噴霧系統的成功要素是電源，這個電源也可以用來給 LED 燈供電，以供夜間照明，或者給其它需要電源的外部設備充電。我們的計劃是，用太陽能電池板給一個海上用的深周期電池充電，然后用這塊電池給其它所有東西供電。隨即，我開始了太陽能電池板電池充電器的設計。

　　我(wo)有(you) 3 周時間完(wan)成設計。我(wo)向朋友 Simon 請求幫(bang)助，Simon 以前用凌力爾特(te)公司的 IC 搞過(guo)太(tai)陽(yang)能供電設計。除了(le)一臺(tai)顯示工作原理(li)(li)的樣(yang)機，Simon 還給了(le)我(wo)一份原理(li)(li)圖(tu)，這(zhe)臺(tai)樣(yang)機從未(wei)連上太(tai)陽(yang)能電池板測(ce)試過(guo)，但在實(shi)驗(yan)室(shi)做(zuo)過(guo)仿真。我(wo)很興奮，有(you)興趣用真實(shi)的太(tai)陽(yang)能電池板測(ce)試這(zhe)個設計，我(wo)們(men)準(zhun)備(bei)對樣(yang)機進(jin)行(xing)像樣(yang)的測(ce)試。

　　一(yi)位朋(peng)友借給(gei)我(wo)兩塊 BP 太(tai)陽能電(dian)池(chi)(chi)板(ban)(ban)(ban) （BP380U）。在(zai)(zai)大(da)約 20V 最高(gao)輸出電(dian)壓和 4A 最大(da)輸出電(dian)流時(shi)(shi)，每塊電(dian)池(chi)(chi)板(ban)(ban)(ban)的(de)峰(feng)值(zhi)功率都是 80W （實際規(gui)格(ge)為(wei)(wei)，在(zai)(zai) 80W 最大(da)功率時(shi)(shi)，電(dian)壓為(wei)(wei) 17.6V，電(dian)流為(wei)(wei) 4.55A）。把(ba)這兩塊太(tai)陽能電(dian)池(chi)(chi)板(ban)(ban)(ban)合(he)起來(lai)，我(wo)希望在(zai)(zai)太(tai)陽光直接直射(she)在(zai)(zai)電(dian)池(chi)(chi)板(ban)(ban)(ban)上時(shi)(shi)，在(zai)(zai)峰(feng)值(zhi)條(tiao)件下能有 8A 的(de)總電(dian)流。太(tai)陽能電(dian)池(chi)(chi)板(ban)(ban)(ban)連接到 Simon 的(de)樣(yang)機(ji)上沒有幾分(fen)鐘，系統就(jiu)充分(fen)運轉了(le) （圖(tu) 1 和圖(tu) 2）。通過對樣(yang)機(ji)的(de)初步測試，查明了(le)幾個故障，后來(lai)這給(gei)我(wo)們節省了(le)大(da)量時(shi)(shi)間。

　　圖 1：測(ce)試 BP 太陽能(neng)電池板， BP380U （0 至(zhi) 20V 輸出，4A 峰(feng)值功率 80W）

　　圖 2：最(zui)初的太陽能充電(dian)電(dian)路樣機，采用 12V 海上用深周期電(dian)池 。

　　樣機運行(xing)良好(hao)，因此我購(gou)買了(le)幾塊凌力爾特公(gong)司的(de)演示板，并稍作修(xiu)改(gai)以(yi)使其更(geng)適合重(zhong)新設計(ji)過的(de)系統規格要求。我保(bao)持(chi)樣機作為備份(fen)和(he)參考，同(tong)時我設計(ji)了(le)一(yi)(yi)個新系統。我們解決了(le)一(yi)(yi)些故障后，通過這些修(xiu)改(gai)改(gai)善了(le)原來的(de)樣機。總(zong)之(zhi)，架構(gou)設計(ji)仍然是相同(tong)的(de)：用 0 至 20V 的(de)太陽能電池(chi)板，以(yi) 4A 的(de)恒(heng)定電流給一(yi)(yi)個 12V 的(de)電池(chi)充電,

   太(tai)陽能電池(chi)充電器系統設計(ji)

　　用這些演示板忙活幾天之后，我成功地完成了一個產生預期效果的設計，這設計將適合我們這次旅程。系統的方框圖如圖 3 所示，該圖顯示了一些 IC 和演示板功能。系統的照片如圖 4 所示，顯示了完整的太陽能電池板電池充電器單元。

　　圖 3：系統設計方框圖

　　圖 4：最終的太陽能充電器電路

　　視太(tai)陽的(de)位(wei)置(zhi)不同而不同，太(tai)陽能電(dian)池(chi)板(ban)最初的(de)輸出電(dian)壓(ya)(ya)(ya)在 0V 到 20V 之(zhi)間(jian)變化，那么(me)就用(yong)一個(ge)能接受這么(me)寬輸出范(fan)圍的(de)穩壓(ya)(ya)(ya)器，并保持吸(xi)取低的(de)電(dian)流(liu) （每個(ge)電(dian)池(chi)板(ban)上(shang)的(de)輸入電(dian)流(liu)最大值都是 4A），同時調節(jie)一個(ge)固(gu)定的(de)輸出電(dian)壓(ya)(ya)(ya)。這是在 DC1198A-B 演示板(ban)上(shang)用(yong)凌力爾特公司的(de)微型模塊 （μModule） DC/DC 降壓(ya)(ya)(ya)-升壓(ya)(ya)(ya)型開關穩壓(ya)(ya)(ya)器 LTM4607 實現(xian)的(de)。

　　LTM4607 是(shi)(shi)一(yi)個小(xiao)型 LGA 封裝 （15mm x 15mm x 2.8mm） 的(de)(de)(de)芯片，其中包括一(yi)個復雜的(de)(de)(de)降壓(ya)(ya)(ya)-升壓(ya)(ya)(ya)型 DC/DC 開關(guan)穩壓(ya)(ya)(ya)器(qi)所需的(de)(de)(de)所有支持控制組件(jian)。復雜的(de)(de)(de)開關(guan)控制電(dian)(dian)(dian)(dian)路和 FET 內(nei)置到(dao)微型模塊穩壓(ya)(ya)(ya)器(qi)中，從(cong)而使該(gai)器(qi)件(jian)非(fei)常容易使用(yong)。結(jie)果是(shi)(shi)僅(jin)需一(yi)個微型模塊穩壓(ya)(ya)(ya)器(qi)、電(dian)(dian)(dian)(dian)感器(qi)以及幾個電(dian)(dian)(dian)(dian)容器(qi)和電(dian)(dian)(dian)(dian)阻器(qi)就完成簡潔規則的(de)(de)(de)布(bu)局。4.5V 至 36V 的(de)(de)(de)寬輸(shu)(shu)入電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)范(fan)圍至固定 20V 輸(shu)(shu)出(chu)(chu) （范(fan)圍為 0.8V 至 24V） 對(dui)于太陽(yang)能(neng)電(dian)(dian)(dian)(dian)池(chi)板(ban)的(de)(de)(de)特性 （0 至 20V 輸(shu)(shu)出(chu)(chu)） 正合(he)適，而且該(gai)器(qi)件(jian)能(neng)加載(zai)高(gao)達 5A 的(de)(de)(de)升壓(ya)(ya)(ya)模式和 10A 的(de)(de)(de)降壓(ya)(ya)(ya)模式。在太陽(yang)能(neng)電(dian)(dian)(dian)(dian)池(chi)板(ban)峰值(zhi)功率時，20V 輸(shu)(shu)入至 20V/2.5A 輸(shu)(shu)出(chu)(chu)的(de)(de)(de)效率是(shi)(shi) 91%，而且積極利用(yong)了降壓(ya)(ya)(ya)-升壓(ya)(ya)(ya)型寬范(fan)圍輸(shu)(shu)入的(de)(de)(de)好處。就這(zhe)(zhe)個系統設計的(de)(de)(de)目的(de)(de)(de)而言(yan)，輸(shu)(shu)出(chu)(chu)調節(jie)到(dao) 20V，用(yong)這(zhe)(zhe)個輸(shu)(shu)出(chu)(chu)給 LTC1435/LT1620 高(gao)效率、低壓(ya)(ya)(ya)差電(dian)(dian)(dian)(dian)池(chi)充電(dian)(dian)(dian)(dian)器(qi)系統供(gong)電(dian)(dian)(dian)(dian)。

　　在 14V 穩(wen)定電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)時，LTC1435/LT1620 演(yan)(yan)示(shi)板 （DC133A） 將(jiang)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流控制到(dao)穩(wen)定的(de) 4A.該(gai)演(yan)(yan)示(shi)板與 LT1620 數據表第(di)一頁上(shang)的(de)應用電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路類似，我將(jiang) FB 電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi) （110k） 換成(cheng)一個(ge)可變電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)位器(qi)，以實現輸出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)調節，并將(jiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)浮置(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)設置(zhi)到(dao) 14V.該(gai)演(yan)(yan)示(shi)板設計利用 LT1620 軌(gui)至(zhi)軌(gui)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流檢測放(fang)大(da)器(qi)，結合 LTC1435 開關穩(wen)壓(ya)(ya)(ya)(ya)器(qi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路的(de)高效率(lv)(lv)和低(di)壓(ya)(ya)(ya)(ya)差能力，形(xing)成(cheng)了一個(ge)效率(lv)(lv)超過 95% 的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)，從而(er)在 4A 充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流時僅需要 0.5V 輸入至(zhi)輸出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)差。一個(ge)到(dao)地的(de)編(bian)程電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流設置(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流 （4A），該(gai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流一直是(shi)穩(wen)定的(de)，直到(dao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)達(da)到(dao)預設的(de)浮置(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya) （在本文情況(kuang)下(xia)為(wei) 14V） 為(wei)止(zhi)。隨著(zhu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)達(da)到(dao)其(qi)滿充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)狀態(tai)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路的(de)編(bian)程將(jiang)自動(dong)轉入涓流充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)狀態(tai)，并就電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)輸出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)而(er)言緩(huan)慢(man)降低(di)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流。這減(jian)輕了由于(yu)恒(heng)定過沖電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)給電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)造成(cheng)的(de)壓(ya)(ya)(ya)(ya)力。

　　一(yi)個(ge)理想(xiang)二(er)極(ji)管電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)設(she)計與 DC133A 充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)系(xi)統(tong)的(de)(de)輸(shu)出(chu)串聯，利用 LTC4414 實現電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)保(bao)護，并(bing)允許(xu)在(zai)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)以最小(xiao)損耗運行(xing)(xing)的(de)(de)同時使(shi)用電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)。這(zhe)種自動電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)通(tong)路(lu)(lu)(lu) （PowerPath？） 控制使(shi)外(wai)部(bu)設(she)備(bei)能(neng)(neng)(neng)夠自由地(di)用太(tai)陽(yang)(yang)能(neng)(neng)(neng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)板或電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)供(gong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)。當太(tai)陽(yang)(yang)能(neng)(neng)(neng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)板功率(lv)(lv)不足時，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)自動轉為(wei)從電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)吸取功率(lv)(lv)。該電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)設(she)計與 LTC4414 數據表第九頁(ye)上的(de)(de)圖(tu) 2 類(lei)似。LTC4414 （8 引線 MSOP 封裝(zhuang)） 控制一(yi)個(ge)外(wai)部(bu) P 溝道 MOSFET，以產(chan)生(sheng)接近理想(xiang)的(de)(de)二(er)極(ji)管功能(neng)(neng)(neng)，用于電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)切換。這(zhe)允許(xu)多個(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)高效(xiao)率(lv)(lv)進行(xing)(xing)“或” 操(cao)作；在(zai)本文情況下(xia)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)是太(tai)陽(yang)(yang)能(neng)(neng)(neng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)板和電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)。當連接一(yi)個(ge)外(wai)部(bu)設(she)備(bei)時，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)和充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)系(xi)統(tong)接受負(fu)載狀態。在(zai)無負(fu)載時，將(jiang)對電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)。因此(ci)該設(she)計允許(xu)一(yi)起使(shi)用太(tai)陽(yang)(yang)能(neng)(neng)(neng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)板和電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)供(gong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，同時運行(xing)(xing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)過程。這(zhe)一(yi)部(bu)分沒(mei)有演示板可用，因此(ci)我按照(zhao)定制電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)板上的(de)(de)應用電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)進行(xing)(xing)設(she)計。

　　電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)檢(jian)測系統與電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)串(chuan)聯(lian)(lian)，利(li)用并聯(lian)(lian)檢(jian)測電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi)(qi)測量電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)(de)(de)輸(shu)入(ru)(ru)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)和(he)(he)輸(shu)出(chu)(chu)(chu)放電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)，而(er)無需斷(duan)開電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)。圖(tu)(tu) 3 的(de)(de)(de)方(fang)框圖(tu)(tu)僅說明了輸(shu)入(ru)(ru)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)。LTC6103 （采用 8 引(yin)(yin)(yin)(yin)(yin)線 MSOP 封裝(zhuang)，在(zai) 4V 至 60V 范圍內(nei)工(gong)作） 是一(yi)個雙路(lu)獨(du)立電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)檢(jian)測放大器(qi)(qi)，可通(tong)過外部檢(jian)測電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi)(qi)監視(shi)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)。該器(qi)(qi)件以(yi) mV 為單(dan)位測量和(he)(he)提(ti)(ti)供電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)和(he)(he)放電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)比率(lv)輸(shu)出(chu)(chu)(chu)。在(zai)本(ben)文情(qing)況下，它幫助指示(shi)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)充(chong)和(he)(he)放了多少電(dian)(dian)(dian)(dian)(dian)(dian)量。這是一(yi)種以(yi)低(di)功(gong)率(lv)損耗讀(du)取(qu)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)的(de)(de)(de)方(fang)法(fa)，這對保持一(yi)個高能效系統至關(guan)重要。我(wo)略微調(diao)節了 LTC6103 （DC1116A） 演示(shi)板以(yi)實現(xian)這一(yi)點。引(yin)(yin)(yin)(yin)(yin)腳(jiao) 8 和(he)(he) 7 分別與進(jin)入(ru)(ru)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)通(tong)路(lu) +IN_A 和(he)(he) -IN_A 串(chuan)聯(lian)(lian)。這將(jiang)提(ti)(ti)供進(jin)入(ru)(ru)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)的(de)(de)(de)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)。引(yin)(yin)(yin)(yin)(yin)腳(jiao) 6 和(he)(he) 5 相(xiang)互掉換后反著連接，以(yi)測量電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)放電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)通(tong)路(lu)，+IN_B （引(yin)(yin)(yin)(yin)(yin)腳(jiao) 5） 連接到(dao) -IN_A （引(yin)(yin)(yin)(yin)(yin)腳(jiao) 7），-IN_B （引(yin)(yin)(yin)(yin)(yin)腳(jiao) 6） 連接到(dao) +IN_A （引(yin)(yin)(yin)(yin)(yin)腳(jiao) 8）。電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi)(qi)的(de)(de)(de)值以(yi) 10 為倍(bei)數(shu)改變(bian)和(he)(he)調(diao)節，以(yi)便在(zai) 0.1Ω 并聯(lian)(lian)檢(jian)測電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi)(qi)與電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)串(chuan)聯(lian)(lian)時，輸(shu)出(chu)(chu)(chu)以(yi) 100mV/A 變(bian)化。圖(tu)(tu) 5 中的(de)(de)(de)萬用表顯示(shi)整(zheng)個系統的(de)(de)(de)結果。太(tai)陽(yang)能電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)板輸(shu)出(chu)(chu)(chu)電(dian)(dian)(dian)(dian)(dian)(dian)壓是 17.11V，電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)壓為 12.95V，充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)是 3.58A.

　　圖 5：萬用表顯示 17.11V 太陽能電池板輸出，12.95V 電池充電電壓；3.58A電池充電電流

ADC 和微(wei)控制器讀(du)數(shu)

　　我(wo)(wo)決定，每次檢查電(dian)路是否正常運行時不使用電(dian)壓(ya)表(biao)(biao)，因(yin)為電(dian)壓(ya)表(biao)(biao)在(zai)沙漠(mo)中難(nan)以攜帶。為了避免攜帶多個萬(wan)用表(biao)(biao)，我(wo)(wo)用一個微控制(zhi)器和 ADC 來讀取系統的(de)電(dian)壓(ya)值，并在(zai)一般(ban)的(de) LCD 顯示(shi)屏上(shang)顯示(shi)信息(xi)。這種(zhong)方法(fa)可就電(dian)路性能提供實(shi)時數(shu)據，而無需連接幾個萬(wan)用表(biao)(biao)。

　　我(wo)使用(yong) DC590B 演示板(ban)和(he) LTC2418 8信道 / 16 信道 24 位 ADC 演示板(ban) DC571A.我(wo)的同事(shi) Mark Thoren 給了我(wo) PIC 微(wei)(wei)控制器的嵌(qian)入式(shi)源代碼樣本(ben)，我(wo)微(wei)(wei)調(diao)了這(zhe)個(ge)源代碼樣本(ben)，以(yi)跨(kua) LTC2418 上(shang)(shang) ADC 的不(bu)同通(tong)道對電(dian)(dian)壓(ya)(ya)采樣，并以(yi)可接(jie)受的分辨(bian)率、準確(que)(que)地讀出(chu) mV 范圍的電(dian)(dian)壓(ya)(ya)值。既(ji)然(ran)基(ji)準電(dian)(dian)壓(ya)(ya)的最大(da)范圍是 2.5V，那么我(wo)用(yong)一種電(dian)(dian)壓(ya)(ya)分壓(ya)(ya)器方法來按(an)比例將電(dian)(dian)壓(ya)(ya)降低到(dao)(dao) mV 范圍，以(yi)在 ADC 上(shang)(shang)實(shi)現正確(que)(que)的測(ce)(ce)量。通(tong)道連接(jie)到(dao)(dao)單個(ge)有關(guan)的輸(shu)入和(he)輸(shu)出(chu)電(dian)(dian)壓(ya)(ya)上(shang)(shang)，包(bao)括電(dian)(dian)流(liu)檢(jian)測(ce)(ce)電(dian)(dian)壓(ya)(ya)。這(zhe)么做非常(chang)成功，無需多(duo)個(ge)萬用(yong)表。圖 6 是一個(ge)有關(guan)這(zhe)個(ge) LCD 顯(xian)示屏(ping)的全功能系統(tong)的例子。我(wo)在 LCD 上(shang)(shang)得到(dao)(dao)的最后的顯(xian)示提供了有關(guan)以(yi)下電(dian)(dian)壓(ya)(ya)的信息：變(bian)化的太陽能電(dian)(dian)源電(dian)(dian)壓(ya)(ya) Vs、充電(dian)(dian)電(dian)(dian)路(lu)電(dian)(dian)壓(ya)(ya) Vc、電(dian)(dian)池電(dian)(dian)壓(ya)(ya) Vb、以(yi)及(ji)電(dian)(dian)池上(shang)(shang)的輸(shu)入充電(dian)(dian)/放電(dian)(dian)電(dian)(dian)流(liu) C 和(he) D.在本(ben)文(wen)情況下，是“C”，它在充電(dian)(dian)。放電(dian)(dian)時(shi)，程序將改變(bian)到(dao)(dao)“D”。

　　圖 6:LCD 讀(du)數：Vs （太(tai)陽能電(dian)(dian)(dian)池(chi)板(ban)電(dian)(dian)(dian)壓(ya)）；Vc （充電(dian)(dian)(dian)電(dian)(dian)(dian)路電(dian)(dian)(dian)壓(ya)）；Vb （電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓(ya)）；C = 充電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu) （4.3A），用(yong)(yong)DC590B PIC 微控制(zhi)(zhi)器控制(zhi)(zhi)；用(yong)(yong) LTC2418 演示板(ban) DC571 ADC 讀(du)取電(dian)(dian)(dian)壓(ya)，該演示板(ban)由 LTM4601演示板(ban) DC1041A 微型模(mo)塊(kuai)降壓(ya)型穩壓(ya)器供電(dian)(dian)(dian)。

　　注意，DC590B 演(yan)示板(ban)不(bu)是(shi)(shi)靠 12V 軌(gui)供電(dian)，而是(shi)(shi)靠 5V 軌(gui)供電(dian)。需要(yao)一個降(jiang)壓(ya)型穩壓(ya)器(qi)將(jiang)電(dian)壓(ya)從電(dian)池的 12V 降(jiang)低(di)到(dao) 5V.這個降(jiang)壓(ya)型穩壓(ya)器(qi)將(jiang)必須(xu)是(shi)(shi)高效率(lv)的，因為電(dian)源將(jiang)來自(zi)太(tai)陽能(neng)電(dian)池板(ban)和電(dian)池，我不(bu)想因運(yun)行 LCD 顯(xian)示屏和微(wei)控(kong)制器(qi)而耗費大量功率(lv)。我使(shi)用 LTM4601 微(wei)型模塊(kuai) DC/DC 開關穩壓(ya)器(qi)演(yan)示板(ban) DC1041A.

　　LTM4601 是一(yi)(yi)個(ge) LGA 封裝的(de)(de)(de)(de) 15mm x 15mm x 2.8mm 微型模(mo)(mo)塊 DC/DC 開關穩壓(ya)器(qi)(qi)，在(zai)(zai) 12A 最大(da)負(fu)載電(dian)(dian)(dian)流時(shi)，輸(shu)入為 4.5V 至 20V，輸(shu)出(chu)為 0.6V 至 5V.LTM4601 的(de)(de)(de)(de)設(she)計使(shi)(shi)得非常容(rong)(rong)易從 12V 電(dian)(dian)(dian)池提供一(yi)(yi)個(ge)穩定(ding)的(de)(de)(de)(de) 5V 輸(shu)出(chu)。該(gai)微型模(mo)(mo)塊包括所有(you)控(kong)制(zhi)支持(chi)組件，如(ru)(ru)電(dian)(dian)(dian)阻器(qi)(qi)、電(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)、MOSFET 和電(dian)(dian)(dian)感(gan)器(qi)(qi)。在(zai)(zai)這個(ge)系統(tong)中，效率(lv)大(da)約為 90%，使(shi)(shi)用(yong)最小的(de)(de)(de)(de)電(dian)(dian)(dian)池電(dian)(dian)(dian)流，極大(da)地(di)延(yan)長了電(dian)(dian)(dian)池壽(shou)命(ming)。更容(rong)(rong)易的(de)(de)(de)(de)是，輸(shu)出(chu)電(dian)(dian)(dian)壓(ya)用(yong)一(yi)(yi)個(ge)電(dian)(dian)(dian)阻器(qi)(qi)設(she)置，如(ru)(ru)果我(wo)需要一(yi)(yi)個(ge)不同的(de)(de)(de)(de)電(dian)(dian)(dian)壓(ya)軌 （例如(ru)(ru) 3.3V、2.5V、1.8V、1.5V 和 1.2V），那么在(zai)(zai)演(yan)示板上(shang)用(yong)一(yi)(yi)條跨接線(xian)可以(yi)非常容(rong)(rong)易地(di)改變(bian)這個(ge)輸(shu)出(chu)電(dian)(dian)(dian)壓(ya)。

　　總之(zhi)，兩(liang)塊(kuai)(kuai) BP 太(tai)陽(yang)能(neng)電(dian)(dian)池(chi)板(ban)，每塊(kuai)(kuai)在 4A 電(dian)(dian)流(liu)時(shi)都(dou)有 0 至(zhi) 20V 的(de)輸(shu)出，這(zhe)兩(liang)塊(kuai)(kuai)太(tai)陽(yang)能(neng)電(dian)(dian)池(chi)板(ban)由(you) 20V 輸(shu)出的(de) LTM4607 降(jiang)壓(ya)(ya)/升(sheng)壓(ya)(ya)型微(wei)型模(mo)塊(kuai)(kuai)開(kai)關穩壓(ya)(ya)器(qi)調節，然后再到 14V 輸(shu)入(ru)的(de) LTC1435/LT1620 電(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)器(qi)，通過一個理想二極管 MOSFET 控制器(qi) LTC4414、一個串聯(lian)的(de)電(dian)(dian)流(liu)檢測放大器(qi) LTC6103，最終進(jin)入(ru)電(dian)(dian)池(chi)；以(yi)穩定的(de) 4A 電(dian)(dian)流(liu)充(chong)(chong)電(dian)(dian)。在這(zhe)個設計中，由(you) LTC2418 在不同的(de)級獲(huo)取 ADC 讀數，并將讀數送(song)至(zhi)由(you) LTM4601 微(wei)型模(mo)塊(kuai)(kuai)開(kai)關穩壓(ya)(ya)器(qi)供(gong)電(dian)(dian)的(de) DC590B 演示板(ban)微(wei)控制器(qi)，以(yi)在 LCD 上顯示結果(guo)。圖(tu) 7 顯示正在運行(xing)的(de)整個系統。

　　圖(tu) 7：運行中(zhong)的整個系統(tong)設計

　　噴霧系統的機械設計

　　有(you)了(le)一(yi)個正常工作的(de)太陽能充電(dian)器和穩(wen)定的(de) 12V 輸出(chu)，我就(jiu)準備好著手(shou)組(zu)裝(zhuang)噴霧(wu)系(xi)(xi)統了(le)。去一(yi)趟(tang)五金(jin)店就(jiu)得到了(le)我需要(yao)的(de)材料：艙底(di)污(wu)水泵(beng)、水龍(long)帶連接器、水龍(long)帶夾具、轉(zhuan)接器和噴霧(wu)系(xi)(xi)統。水龍(long)帶長約 15 英尺，擰(ning)在轉(zhuan)接器螺釘上，用水龍(long)帶夾具固(gu)定到水泵(beng)上，噴霧(wu)系(xi)(xi)統固(gu)定在末端(duan)，有(you) 5 個噴霧(wu)嘴。底(di)艙污(wu)水泵(beng)靠最(zui)大值為 12V 的(de)電(dian)壓運行，水壓可以通過(guo)降(jiang)低電(dian)壓來控制。

　　為了實現(xian)靈活(huo)性(xing)，我安裝(zhuang)了一(yi)個(ge)穩壓(ya)器(qi)，該穩壓(ya)器(qi)可以(yi)接受 12V 輸入(ru)，并(bing)將輸入(ru)轉(zhuan)換成可變(bian)的 12V 輸出。這要(yao)求 LTM4607 設計有降壓(ya)/升(sheng)壓(ya)特性(xing)。該器(qi)件使用(yong)一(yi)個(ge)反(fan)饋電(dian)(dian)阻器(qi)控制輸出電(dian)(dian)壓(ya)。一(yi)個(ge) 50k 的可變(bian)旋(xuan)鈕電(dian)(dian)位器(qi)取代了電(dian)(dian)阻器(qi)，從而非常容易(yi)控制 0.8V 至 12V 的輸出。還串聯了一(yi)個(ge) 5.62k 的電(dian)(dian)阻器(qi)，以(yi)限(xian)制輸出電(dian)(dian)壓(ya)，保持輸出低于 15V.該設計通過(guo)旋(xuan)轉(zhuan)一(yi)個(ge)旋(xuan)鈕實現(xian)了水壓(ya)控制。

　　然后，我就可以測試(shi)我的(de)全(quan)功能噴(pen)霧(wu)系統(tong)了。結果，水泵(beng)導致最大約 6A 的(de)電(dian)(dian)(dian)(dian)池放(fang)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流，這(zhe)意(yi)味著，在(zai)(zai)峰值(zhi)輸出時，水泵(beng)約從每塊太(tai)陽能電(dian)(dian)(dian)(dian)池板獲得 4A 電(dian)(dian)(dian)(dian)流。控制水泵(beng)速度(du)和壓力(li)的(de)好處(chu)是，我可以將壓力(li)降到足夠(gou)低，以降低電(dian)(dian)(dian)(dian)池的(de)放(fang)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流，并全(quan)部靠(kao)太(tai)陽能電(dian)(dian)(dian)(dian)池板運(yun)行(xing)(xing)水泵(beng)，以節省電(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)量，這(zhe)樣做非常有(you)效。通(tong)過(guo)這(zhe)種方法，我們能夠(gou)在(zai)(zai)營地全(quan)天(tian)運(yun)行(xing)(xing)噴(pen)霧(wu)系統(tong)，而不必擔心電(dian)(dian)(dian)(dian)池放(fang)電(dian)(dian)(dian)(dian)，耽誤夜(ye)間用(yong)于 LED 照明系統(tong)。

　　LED 照明

　　隨著(zhu)電(dian)源(yuan)的(de)(de)完成，我就可(ke)(ke)以(yi)(yi)增加(jia)電(dian)路，在(zai)晚上高效率(lv)地提(ti)供(gong)照(zhao)明了(le)。LED 足夠亮(liang)，可(ke)(ke)以(yi)(yi)照(zhao)亮(liang)房間(jian)，這(zhe)在(zai)以(yi)(yi)前是不可(ke)(ke)想象的(de)(de)，但(dan)是新的(de)(de)技術(shu)進步(bu)已經為(wei) LED 照(zhao)明的(de)(de)新時(shi)代創造(zao)了(le)條件。尤其是，PhilipsLumileds Luxeon LED 在(zai) 1000mA 時(shi)可(ke)(ke)以(yi)(yi)提(ti)供(gong)超過 100 流明的(de)(de)光(guang)。我配備了(le)一(yi)個(ge) LumiLED 陣列，使(shi)用 LTC3475 （16 引線 TSSOP 耐熱增強型封(feng)裝(zhuang)） 雙路 1.5A 恒定(ding)電(dian)流 LED 驅動器 DC923A 演(yan)示(shi)(shi)板(ban)。它(ta)設(she)計成用一(yi)個(ge)寬范圍輸(shu)入電(dian)壓(ya) （4V 至 30V） 驅動兩個(ge)信(xin)道，每(mei)個(ge)信(xin)道 1.5A.12V 電(dian)池(chi)直接(jie)連接(jie)到演(yan)示(shi)(shi)板(ban)的(de)(de)輸(shu)入，為(wei)每(mei)個(ge)通(tong)道 3 個(ge)串聯的(de)(de) LED 燈供(gong)電(dian)，當兩個(ge)通(tong)道都接(jie)通(tong)時(shi)，總(zong)共(gong)有 6 個(ge) LED.這(zhe)些 LED 出奇地亮(liang)，用一(yi)塊柔光(guang)布遮上時(shi)，足夠照(zhao)亮(liang)我們整(zheng)個(ge)營地。晚上的(de)(de)放電(dian)電(dian)流全部來自電(dian)池(chi)，因(yin)為(wei)太(tai)陽能電(dian)池(chi)板(ban)夜間(jian)提(ti)供(gong)零電(dian)力。以(yi)(yi) 2A 的(de)(de)總(zong)放電(dian)電(dian)流，可(ke)(ke)以(yi)(yi)整(zheng)晚為(wei)這(zhe)些燈供(gong)電(dian)。到接(jie)近中(zhong)午(wu)或偏下午(wu)時(shi)，電(dian)池(chi)再次充滿(man)電(dian)，為(wei)給噴霧系統供(gong)電(dian)做(zuo)好了(le)準(zhun)備，在(zai)早午(wu)餐后，噴霧系統就可(ke)(ke)以(yi)(yi)讓我們感到涼爽(shuang)了(le)。