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。

　　我有(you) 3 周時間完成設計(ji)。我向朋友 Simon 請求幫助，Simon 以前用(yong)凌力爾特公司的(de)(de)(de) IC 搞過(guo)太陽(yang)能供電(dian)設計(ji)。除了一(yi)(yi)臺(tai)(tai)顯示工作(zuo)原理(li)的(de)(de)(de)樣機，Simon 還給了我一(yi)(yi)份原理(li)圖，這臺(tai)(tai)樣機從未連(lian)上太陽(yang)能電(dian)池板測試(shi)過(guo)，但在實(shi)驗室做過(guo)仿真。我很(hen)興奮，有(you)興趣用(yong)真實(shi)的(de)(de)(de)太陽(yang)能電(dian)池板測試(shi)這個設計(ji)，我們準(zhun)備(bei)對樣機進行像(xiang)樣的(de)(de)(de)測試(shi)。

　　一位朋(peng)友借給(gei)我兩塊(kuai) BP 太陽能電(dian)(dian)(dian)(dian)池(chi)(chi)板(ban) （BP380U）。在(zai)大約 20V 最高(gao)輸出電(dian)(dian)(dian)(dian)壓和 4A 最大輸出電(dian)(dian)(dian)(dian)流時，每(mei)塊(kuai)電(dian)(dian)(dian)(dian)池(chi)(chi)板(ban)的峰值功(gong)率都是 80W （實際(ji)規格為(wei)，在(zai) 80W 最大功(gong)率時，電(dian)(dian)(dian)(dian)壓為(wei) 17.6V，電(dian)(dian)(dian)(dian)流為(wei) 4.55A）。把(ba)這(zhe)兩塊(kuai)太陽能電(dian)(dian)(dian)(dian)池(chi)(chi)板(ban)合(he)起來，我希(xi)望在(zai)太陽光(guang)直接(jie)直射在(zai)電(dian)(dian)(dian)(dian)池(chi)(chi)板(ban)上(shang)時，在(zai)峰值條件下能有 8A 的總電(dian)(dian)(dian)(dian)流。太陽能電(dian)(dian)(dian)(dian)池(chi)(chi)板(ban)連(lian)接(jie)到 Simon 的樣機上(shang)沒有幾分鐘(zhong)，系統就充(chong)分運轉了 （圖 1 和圖 2）。通過對樣機的初步測試，查明了幾個故障，后來這(zhe)給(gei)我們節省了大量時間。

　　圖 1：測(ce)試 BP 太陽能電池板， BP380U （0 至 20V 輸(shu)出，4A 峰值功率(lv) 80W）

　　圖 2：最初的太陽能充(chong)電(dian)電(dian)路(lu)樣機(ji)，采用(yong) 12V 海(hai)上(shang)用(yong)深周期電(dian)池 。

　　樣(yang)(yang)(yang)機(ji)(ji)(ji)運行良好(hao)，因此我(wo)購(gou)買了(le)幾(ji)塊凌力爾特公司的演示板，并稍作修改以使其更適合重新(xin)設(she)計過的系統規格要求(qiu)。我(wo)保持樣(yang)(yang)(yang)機(ji)(ji)(ji)作為備(bei)份和參考，同時(shi)我(wo)設(she)計了(le)一(yi)個新(xin)系統。我(wo)們解決了(le)一(yi)些(xie)故障(zhang)后(hou)，通過這些(xie)修改改善了(le)原來的樣(yang)(yang)(yang)機(ji)(ji)(ji)。總之，架構設(she)計仍然是相同的：用 0 至(zhi) 20V 的太陽能電(dian)池板，以 4A 的恒(heng)定電(dian)流給一(yi)個 12V 的電(dian)池充電(dian),

   太(tai)陽能電(dian)池充電(dian)器系統設(she)計

　　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(fang)框圖

　　圖 4：最終的太陽能充電器電路

　　視(shi)太(tai)陽的(de)(de)位置(zhi)不同(tong)而不同(tong)，太(tai)陽能電(dian)(dian)池板(ban)(ban)最初(chu)的(de)(de)輸出電(dian)(dian)壓(ya)(ya)在 0V 到 20V 之(zhi)間變化(hua)，那么就(jiu)用一個(ge)能接受這么寬輸出范圍(wei)的(de)(de)穩壓(ya)(ya)器(qi)，并保(bao)持(chi)吸取低的(de)(de)電(dian)(dian)流(liu) （每個(ge)電(dian)(dian)池板(ban)(ban)上(shang)的(de)(de)輸入電(dian)(dian)流(liu)最大值都是 4A），同(tong)時調節一個(ge)固定的(de)(de)輸出電(dian)(dian)壓(ya)(ya)。這是在 DC1198A-B 演示板(ban)(ban)上(shang)用凌力爾特公(gong)司的(de)(de)微(wei)型模塊 （μModule） DC/DC 降壓(ya)(ya)-升壓(ya)(ya)型開關穩壓(ya)(ya)器(qi) LTM4607 實現的(de)(de)。

　　LTM4607 是一(yi)個(ge)(ge)小型 LGA 封裝 （15mm x 15mm x 2.8mm） 的(de)(de)(de)(de)芯片，其中(zhong)包括一(yi)個(ge)(ge)復雜(za)的(de)(de)(de)(de)降(jiang)壓(ya)(ya)(ya)(ya)(ya)-升(sheng)(sheng)壓(ya)(ya)(ya)(ya)(ya)型 DC/DC 開關穩(wen)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)所需(xu)的(de)(de)(de)(de)所有支持控(kong)(kong)制組件(jian)。復雜(za)的(de)(de)(de)(de)開關控(kong)(kong)制電路和 FET 內置到(dao)(dao)微型模(mo)(mo)塊穩(wen)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)中(zhong)，從而(er)使該器(qi)(qi)(qi)件(jian)非常容易(yi)使用。結果是僅需(xu)一(yi)個(ge)(ge)微型模(mo)(mo)塊穩(wen)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)、電感器(qi)(qi)(qi)以及幾個(ge)(ge)電容器(qi)(qi)(qi)和電阻器(qi)(qi)(qi)就完成簡潔規(gui)則的(de)(de)(de)(de)布局。4.5V 至(zhi) 36V 的(de)(de)(de)(de)寬輸(shu)(shu)(shu)入電壓(ya)(ya)(ya)(ya)(ya)范圍至(zhi)固定 20V 輸(shu)(shu)(shu)出(chu) （范圍為 0.8V 至(zhi) 24V） 對于太陽能電池板的(de)(de)(de)(de)特性 （0 至(zhi) 20V 輸(shu)(shu)(shu)出(chu)） 正合(he)適，而(er)且該器(qi)(qi)(qi)件(jian)能加載高達(da) 5A 的(de)(de)(de)(de)升(sheng)(sheng)壓(ya)(ya)(ya)(ya)(ya)模(mo)(mo)式和 10A 的(de)(de)(de)(de)降(jiang)壓(ya)(ya)(ya)(ya)(ya)模(mo)(mo)式。在(zai)太陽能電池板峰(feng)值功率(lv)時，20V 輸(shu)(shu)(shu)入至(zhi) 20V/2.5A 輸(shu)(shu)(shu)出(chu)的(de)(de)(de)(de)效(xiao)率(lv)是 91%，而(er)且積極(ji)利用了降(jiang)壓(ya)(ya)(ya)(ya)(ya)-升(sheng)(sheng)壓(ya)(ya)(ya)(ya)(ya)型寬范圍輸(shu)(shu)(shu)入的(de)(de)(de)(de)好(hao)處。就這(zhe)(zhe)個(ge)(ge)系(xi)統(tong)設計的(de)(de)(de)(de)目(mu)的(de)(de)(de)(de)而(er)言，輸(shu)(shu)(shu)出(chu)調節到(dao)(dao) 20V，用這(zhe)(zhe)個(ge)(ge)輸(shu)(shu)(shu)出(chu)給 LTC1435/LT1620 高效(xiao)率(lv)、低壓(ya)(ya)(ya)(ya)(ya)差電池充電器(qi)(qi)(qi)系(xi)統(tong)供(gong)電。

　　在(zai) 14V 穩定(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)時，LTC1435/LT1620 演(yan)示板 （DC133A） 將(jiang)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)控制到(dao)穩定(ding)的 4A.該(gai)演(yan)示板與 LT1620 數據表第一頁上的應用電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)類似，我將(jiang) FB 電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻器 （110k） 換成一個可變電(dian)(dian)(dian)(dian)(dian)(dian)(dian)位器，以實現輸出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)調節，并將(jiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)浮(fu)(fu)置(zhi)(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)設(she)(she)置(zhi)(zhi)到(dao) 14V.該(gai)演(yan)示板設(she)(she)計(ji)利用 LT1620 軌至(zhi)軌電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)檢(jian)測(ce)放大器，結合 LTC1435 開關(guan)穩壓(ya)(ya)(ya)器電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)的高效率和低(di)壓(ya)(ya)(ya)差能力(li)，形(xing)成了一個效率超(chao)過 95% 的電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器，從(cong)而在(zai) 4A 充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)時僅需要 0.5V 輸入至(zhi)輸出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)差。一個到(dao)地的編程電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)設(she)(she)置(zhi)(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu) （4A），該(gai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)一直是穩定(ding)的，直到(dao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)達(da)到(dao)預設(she)(she)的浮(fu)(fu)置(zhi)(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya) （在(zai)本文(wen)情況下為(wei) 14V） 為(wei)止(zhi)。隨著電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)達(da)到(dao)其滿充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)狀(zhuang)(zhuang)態，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)的編程將(jiang)自(zi)動轉(zhuan)入涓流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)狀(zhuang)(zhuang)態，并就電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的輸出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)而言緩(huan)慢降低(di)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)。這減輕(qing)了由于恒定(ding)過沖電(dian)(dian)(dian)(dian)(dian)(dian)(dian)給電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)造成的壓(ya)(ya)(ya)力(li)。

　　一個(ge)理想二極管電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)設(she)計與 DC133A 充(chong)電(dian)(dian)(dian)(dian)(dian)系(xi)統(tong)(tong)的輸出(chu)串聯，利用 LTC4414 實現電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)保護，并(bing)允(yun)許(xu)(xu)在(zai)充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)以(yi)最小損(sun)耗運行(xing)的同時(shi)使(shi)用電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)。這種自(zi)(zi)動(dong)電(dian)(dian)(dian)(dian)(dian)源(yuan)通(tong)路(lu)(lu)(lu) （PowerPath？） 控制使(shi)外部設(she)備能夠自(zi)(zi)由地用太陽(yang)能電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)板(ban)或電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)供(gong)電(dian)(dian)(dian)(dian)(dian)。當太陽(yang)能電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)板(ban)功率不(bu)足時(shi)，電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)自(zi)(zi)動(dong)轉(zhuan)為(wei)從(cong)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)吸取功率。該電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)設(she)計與 LTC4414 數據表第九頁上(shang)的圖 2 類似(si)。LTC4414 （8 引(yin)線 MSOP 封(feng)裝） 控制一個(ge)外部 P 溝道 MOSFET，以(yi)產生接近理想的二極管功能，用于電(dian)(dian)(dian)(dian)(dian)源(yuan)切(qie)換。這允(yun)許(xu)(xu)多個(ge)電(dian)(dian)(dian)(dian)(dian)源(yuan)高效率進(jin)行(xing)“或” 操作(zuo)；在(zai)本文情況(kuang)下，電(dian)(dian)(dian)(dian)(dian)源(yuan)是太陽(yang)能電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)板(ban)和電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)。當連(lian)接一個(ge)外部設(she)備時(shi)，電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)和充(chong)電(dian)(dian)(dian)(dian)(dian)系(xi)統(tong)(tong)接受負(fu)載狀態。在(zai)無負(fu)載時(shi)，將對電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)電(dian)(dian)(dian)(dian)(dian)。因此該設(she)計允(yun)許(xu)(xu)一起使(shi)用太陽(yang)能電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)板(ban)和電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)供(gong)電(dian)(dian)(dian)(dian)(dian)，同時(shi)運行(xing)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)電(dian)(dian)(dian)(dian)(dian)過程。這一部分沒有演(yan)示板(ban)可用，因此我按照定制電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)板(ban)上(shang)的應(ying)用電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)進(jin)行(xing)設(she)計。

　　電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)檢測系(xi)統(tong)與(yu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)串聯(lian)(lian)(lian)，利(li)用(yong)并聯(lian)(lian)(lian)檢測電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)測量(liang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)輸(shu)入充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)和(he)(he)輸(shu)出放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)，而無需(xu)斷開電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)。圖(tu) 3 的(de)方(fang)框圖(tu)僅說明了(le)輸(shu)入充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)。LTC6103 （采用(yong) 8 引(yin)(yin)線(xian) MSOP 封裝，在 4V 至 60V 范圍內工作） 是(shi)(shi)一(yi)個雙路(lu)獨(du)立(li)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)檢測放(fang)大器(qi)，可通(tong)過外部檢測電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)監(jian)視電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)。該(gai)器(qi)件(jian)以(yi) mV 為單位測量(liang)和(he)(he)提(ti)供(gong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)和(he)(he)放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)比率(lv)(lv)輸(shu)出。在本文情況下，它幫助(zhu)指示電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充和(he)(he)放(fang)了(le)多少(shao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)。這是(shi)(shi)一(yi)種以(yi)低功率(lv)(lv)損耗(hao)讀取電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)的(de)方(fang)法，這對(dui)保持一(yi)個高能(neng)效(xiao)系(xi)統(tong)至關重(zhong)要。我(wo)略微調(diao)節了(le) LTC6103 （DC1116A） 演示板(ban)以(yi)實現這一(yi)點。引(yin)(yin)腳(jiao)(jiao) 8 和(he)(he) 7 分(fen)別與(yu)進入電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)通(tong)路(lu) +IN_A 和(he)(he) -IN_A 串聯(lian)(lian)(lian)。這將提(ti)供(gong)進入電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)。引(yin)(yin)腳(jiao)(jiao) 6 和(he)(he) 5 相互(hu)掉換后反著連(lian)(lian)接(jie)，以(yi)測量(liang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)通(tong)路(lu)，+IN_B （引(yin)(yin)腳(jiao)(jiao) 5） 連(lian)(lian)接(jie)到(dao) -IN_A （引(yin)(yin)腳(jiao)(jiao) 7），-IN_B （引(yin)(yin)腳(jiao)(jiao) 6） 連(lian)(lian)接(jie)到(dao) +IN_A （引(yin)(yin)腳(jiao)(jiao) 8）。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)的(de)值以(yi) 10 為倍數改變和(he)(he)調(diao)節，以(yi)便在 0.1Ω 并聯(lian)(lian)(lian)檢測電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)與(yu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)串聯(lian)(lian)(lian)時，輸(shu)出以(yi) 100mV/A 變化。圖(tu) 5 中的(de)萬(wan)用(yong)表顯示整個系(xi)統(tong)的(de)結果。太陽能(neng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)板(ban)輸(shu)出電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)是(shi)(shi) 17.11V，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)為 12.95V，充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)是(shi)(shi) 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 和微控制器讀數

　　我決定(ding)，每次檢查(cha)電(dian)路是否正常運行(xing)時不使(shi)用電(dian)壓表(biao)，因為(wei)電(dian)壓表(biao)在沙漠中難(nan)以攜帶(dai)。為(wei)了避免(mian)攜帶(dai)多個(ge)萬(wan)用表(biao)，我用一(yi)個(ge)微控制(zhi)器和 ADC 來讀(du)取系統(tong)的(de)電(dian)壓值，并在一(yi)般的(de) LCD 顯示屏上(shang)顯示信息。這種方法(fa)可就(jiu)電(dian)路性能(neng)提供實時數據(ju)，而(er)無需連接幾個(ge)萬(wan)用表(biao)。

　　我使(shi)用(yong) DC590B 演示(shi)板和(he) LTC2418 8信(xin)道(dao)(dao) / 16 信(xin)道(dao)(dao) 24 位 ADC 演示(shi)板 DC571A.我的(de)(de)同事 Mark Thoren 給了我 PIC 微(wei)控制(zhi)器(qi)的(de)(de)嵌(qian)入式源代(dai)碼(ma)(ma)樣(yang)(yang)本(ben)(ben)，我微(wei)調了這個(ge)(ge)源代(dai)碼(ma)(ma)樣(yang)(yang)本(ben)(ben)，以跨 LTC2418 上(shang) ADC 的(de)(de)不同通道(dao)(dao)對電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)采樣(yang)(yang)，并(bing)以可接受的(de)(de)分辨率、準(zhun)確地讀出 mV 范圍(wei)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)值。既然基準(zhun)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)的(de)(de)最(zui)大范圍(wei)是 2.5V，那么(me)我用(yong)一種電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)分壓(ya)(ya)(ya)(ya)器(qi)方法來按(an)比(bi)例將電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)降低到(dao) mV 范圍(wei)，以在(zai) ADC 上(shang)實現正確的(de)(de)測(ce)量。通道(dao)(dao)連接到(dao)單(dan)個(ge)(ge)有(you)關的(de)(de)輸入和(he)輸出電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)上(shang)，包括(kuo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)檢(jian)測(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)。這么(me)做(zuo)非常成功，無需多(duo)個(ge)(ge)萬用(yong)表。圖 6 是一個(ge)(ge)有(you)關這個(ge)(ge) LCD 顯(xian)示(shi)屏的(de)(de)全(quan)功能系統的(de)(de)例子。我在(zai) LCD 上(shang)得到(dao)的(de)(de)最(zui)后的(de)(de)顯(xian)示(shi)提(ti)供了有(you)關以下電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)的(de)(de)信(xin)息：變(bian)化(hua)的(de)(de)太(tai)陽能電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya) Vs、充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya) Vc、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya) Vb、以及電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池上(shang)的(de)(de)輸入充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)/放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu) C 和(he) D.在(zai)本(ben)(ben)文情況下，是“C”，它(ta)在(zai)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)。放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)時，程序將改變(bian)到(dao)“D”。

　　圖 6:LCD 讀數(shu)：Vs （太陽能電(dian)(dian)池板(ban)電(dian)(dian)壓）；Vc （充(chong)電(dian)(dian)電(dian)(dian)路(lu)電(dian)(dian)壓）；Vb （電(dian)(dian)池電(dian)(dian)壓）；C = 充(chong)電(dian)(dian)電(dian)(dian)流 （4.3A），用DC590B PIC 微控(kong)(kong)制器控(kong)(kong)制；用 LTC2418 演(yan)示(shi)板(ban) DC571 ADC 讀取電(dian)(dian)壓，該演(yan)示(shi)板(ban)由 LTM4601演(yan)示(shi)板(ban) DC1041A 微型模塊降壓型穩壓器供電(dian)(dian)。

　　注意，DC590B 演示板不是靠 12V 軌(gui)供電，而(er)是靠 5V 軌(gui)供電。需要一個(ge)降(jiang)(jiang)壓(ya)(ya)型穩(wen)壓(ya)(ya)器(qi)(qi)將(jiang)電壓(ya)(ya)從電池(chi)的(de) 12V 降(jiang)(jiang)低到 5V.這個(ge)降(jiang)(jiang)壓(ya)(ya)型穩(wen)壓(ya)(ya)器(qi)(qi)將(jiang)必須是高效(xiao)率的(de)，因為電源將(jiang)來自太陽能電池(chi)板和電池(chi)，我不想因運行(xing) LCD 顯示屏(ping)和微(wei)控制器(qi)(qi)而(er)耗費大量功率。我使用 LTM4601 微(wei)型模塊 DC/DC 開關穩(wen)壓(ya)(ya)器(qi)(qi)演示板 DC1041A.

　　LTM4601 是(shi)一個(ge) LGA 封裝的(de)(de) 15mm x 15mm x 2.8mm 微型模(mo)塊 DC/DC 開(kai)關穩壓器(qi)，在 12A 最大(da)負載電(dian)流時，輸(shu)(shu)入(ru)為(wei) 4.5V 至 20V，輸(shu)(shu)出(chu)為(wei) 0.6V 至 5V.LTM4601 的(de)(de)設計(ji)使得非常(chang)容易從 12V 電(dian)池提(ti)供(gong)一個(ge)穩定的(de)(de) 5V 輸(shu)(shu)出(chu)。該(gai)微型模(mo)塊包(bao)括(kuo)所有控制(zhi)支(zhi)持組件，如電(dian)阻器(qi)、電(dian)容器(qi)、MOSFET 和電(dian)感(gan)器(qi)。在這個(ge)系統中，效率大(da)約為(wei) 90%，使用最小的(de)(de)電(dian)池電(dian)流，極大(da)地(di)延(yan)長(chang)了電(dian)池壽命。更(geng)容易的(de)(de)是(shi)，輸(shu)(shu)出(chu)電(dian)壓用一個(ge)電(dian)阻器(qi)設置(zhi)，如果我(wo)需要一個(ge)不同的(de)(de)電(dian)壓軌 （例如 3.3V、2.5V、1.8V、1.5V 和 1.2V），那么在演示板上用一條跨接線(xian)可以非常(chang)容易地(di)改變(bian)這個(ge)輸(shu)(shu)出(chu)電(dian)壓。

　　總之，兩(liang)塊 BP 太陽(yang)能電(dian)池板，每塊在(zai)(zai) 4A 電(dian)流(liu)時都有 0 至(zhi) 20V 的(de)(de)(de)輸出，這兩(liang)塊太陽(yang)能電(dian)池板由 20V 輸出的(de)(de)(de) LTM4607 降壓(ya)/升壓(ya)型(xing)微(wei)型(xing)模塊開(kai)關穩壓(ya)器調節，然后再(zai)到 14V 輸入(ru)的(de)(de)(de) LTC1435/LT1620 電(dian)池充(chong)電(dian)器，通(tong)過(guo)一(yi)個理想二極管(guan) MOSFET 控制器 LTC4414、一(yi)個串聯的(de)(de)(de)電(dian)流(liu)檢測放(fang)大器 LTC6103，最終進入(ru)電(dian)池；以穩定的(de)(de)(de) 4A 電(dian)流(liu)充(chong)電(dian)。在(zai)(zai)這個設計中，由 LTC2418 在(zai)(zai)不(bu)同的(de)(de)(de)級獲取 ADC 讀數，并將讀數送至(zhi)由 LTM4601 微(wei)型(xing)模塊開(kai)關穩壓(ya)器供電(dian)的(de)(de)(de) DC590B 演示(shi)(shi)板微(wei)控制器，以在(zai)(zai) LCD 上顯示(shi)(shi)結果。圖 7 顯示(shi)(shi)正在(zai)(zai)運行(xing)的(de)(de)(de)整個系統(tong)。

　　圖 7：運行中的(de)整(zheng)個(ge)系統設(she)計

　　噴霧系統的機械設計

　　有了一個正(zheng)常工作的(de)(de)太(tai)陽能(neng)充電器(qi)和穩定的(de)(de) 12V 輸出，我就準備好著手組裝(zhuang)噴霧系(xi)統了。去一趟五(wu)金店(dian)就得到(dao)了我需要的(de)(de)材料：艙底(di)污水(shui)泵(beng)、水(shui)龍(long)(long)帶(dai)(dai)連(lian)接器(qi)、水(shui)龍(long)(long)帶(dai)(dai)夾(jia)具、轉接器(qi)和噴霧系(xi)統。水(shui)龍(long)(long)帶(dai)(dai)長約 15 英尺，擰在轉接器(qi)螺釘(ding)上，用水(shui)龍(long)(long)帶(dai)(dai)夾(jia)具固(gu)定到(dao)水(shui)泵(beng)上，噴霧系(xi)統固(gu)定在末端，有 5 個噴霧嘴(zui)。底(di)艙污水(shui)泵(beng)靠最大(da)值為 12V 的(de)(de)電壓(ya)運行，水(shui)壓(ya)可以通過降低(di)電壓(ya)來控制。

　　為了實現(xian)靈活(huo)性(xing)，我安裝(zhuang)了一(yi)(yi)個(ge)(ge)穩壓(ya)(ya)器(qi)(qi)，該穩壓(ya)(ya)器(qi)(qi)可(ke)以接受 12V 輸(shu)(shu)入(ru)，并將輸(shu)(shu)入(ru)轉換成可(ke)變的(de) 12V 輸(shu)(shu)出(chu)(chu)。這(zhe)要求 LTM4607 設計(ji)(ji)有降壓(ya)(ya)/升壓(ya)(ya)特(te)性(xing)。該器(qi)(qi)件使用一(yi)(yi)個(ge)(ge)反(fan)饋電(dian)阻(zu)(zu)器(qi)(qi)控(kong)(kong)制(zhi)輸(shu)(shu)出(chu)(chu)電(dian)壓(ya)(ya)。一(yi)(yi)個(ge)(ge) 50k 的(de)可(ke)變旋鈕(niu)電(dian)位器(qi)(qi)取代了電(dian)阻(zu)(zu)器(qi)(qi)，從而非常容易(yi)控(kong)(kong)制(zhi) 0.8V 至 12V 的(de)輸(shu)(shu)出(chu)(chu)。還串聯了一(yi)(yi)個(ge)(ge) 5.62k 的(de)電(dian)阻(zu)(zu)器(qi)(qi)，以限(xian)制(zhi)輸(shu)(shu)出(chu)(chu)電(dian)壓(ya)(ya)，保持輸(shu)(shu)出(chu)(chu)低于 15V.該設計(ji)(ji)通過(guo)旋轉一(yi)(yi)個(ge)(ge)旋鈕(niu)實現(xian)了水壓(ya)(ya)控(kong)(kong)制(zhi)。

　　然后(hou)，我就(jiu)可以(yi)測試我的全功能(neng)噴霧(wu)系(xi)統了。結果(guo)，水(shui)泵導致最大約 6A 的電(dian)(dian)(dian)(dian)(dian)池(chi)放(fang)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流，這(zhe)意味(wei)著，在峰值輸出時，水(shui)泵約從每塊太陽能(neng)電(dian)(dian)(dian)(dian)(dian)池(chi)板(ban)獲得 4A 電(dian)(dian)(dian)(dian)(dian)流。控制(zhi)水(shui)泵速度和壓力(li)的好(hao)處是，我可以(yi)將壓力(li)降(jiang)到(dao)足夠低，以(yi)降(jiang)低電(dian)(dian)(dian)(dian)(dian)池(chi)的放(fang)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流，并(bing)全部靠太陽能(neng)電(dian)(dian)(dian)(dian)(dian)池(chi)板(ban)運行(xing)(xing)水(shui)泵，以(yi)節省電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)量，這(zhe)樣(yang)做非(fei)常(chang)有效(xiao)。通過這(zhe)種方法，我們(men)能(neng)夠在營(ying)地全天(tian)運行(xing)(xing)噴霧(wu)系(xi)統，而不必擔心電(dian)(dian)(dian)(dian)(dian)池(chi)放(fang)電(dian)(dian)(dian)(dian)(dian)，耽誤夜間用于 LED 照(zhao)明(ming)系(xi)統。

　　LED 照明

　　隨著電源的(de)完成，我就(jiu)可(ke)以(yi)增(zeng)加電路，在(zai)晚上(shang)(shang)高效率地(di)提(ti)供(gong)(gong)照明了(le)。LED 足夠亮(liang)(liang)(liang)，可(ke)以(yi)照亮(liang)(liang)(liang)房(fang)間(jian)，這在(zai)以(yi)前是(shi)不可(ke)想(xiang)象(xiang)的(de)，但是(shi)新(xin)的(de)技(ji)術進步已經為(wei) LED 照明的(de)新(xin)時(shi)代創(chuang)造了(le)條件。尤(you)其是(shi)，PhilipsLumileds Luxeon LED 在(zai) 1000mA 時(shi)可(ke)以(yi)提(ti)供(gong)(gong)超過 100 流(liu)(liu)明的(de)光。我配(pei)備了(le)一(yi)個 LumiLED 陣列，使用(yong)(yong) LTC3475 （16 引線 TSSOP 耐熱增(zeng)強型封裝） 雙路 1.5A 恒定電流(liu)(liu) LED 驅動(dong)器 DC923A 演示(shi)板。它設計成用(yong)(yong)一(yi)個寬范圍輸(shu)入電壓 （4V 至(zhi) 30V） 驅動(dong)兩(liang)個信道(dao)(dao)，每(mei)個信道(dao)(dao) 1.5A.12V 電池(chi)直接連接到演示(shi)板的(de)輸(shu)入，為(wei)每(mei)個通(tong)道(dao)(dao) 3 個串(chuan)聯(lian)的(de) LED 燈(deng)供(gong)(gong)電，當兩(liang)個通(tong)道(dao)(dao)都接通(tong)時(shi)，總(zong)共有 6 個 LED.這些 LED 出奇地(di)亮(liang)(liang)(liang)，用(yong)(yong)一(yi)塊(kuai)柔光布遮(zhe)上(shang)(shang)時(shi)，足夠照亮(liang)(liang)(liang)我們整個營地(di)。晚上(shang)(shang)的(de)放電電流(liu)(liu)全(quan)部來自(zi)電池(chi)，因為(wei)太(tai)陽能電池(chi)板夜間(jian)提(ti)供(gong)(gong)零電力。以(yi) 2A 的(de)總(zong)放電電流(liu)(liu)，可(ke)以(yi)整晚為(wei)這些燈(deng)供(gong)(gong)電。到接近中午(wu)或偏下(xia)午(wu)時(shi)，電池(chi)再(zai)次充滿電，為(wei)給噴霧系統供(gong)(gong)電做(zuo)好了(le)準(zhun)備，在(zai)早(zao)午(wu)餐后，噴霧系統就(jiu)可(ke)以(yi)讓我們感到涼(liang)爽(shuang)了(le)。