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 3 周時間完成設(she)計。我(wo)向朋友 Simon 請求(qiu)幫(bang)助，Simon 以(yi)前用(yong)凌力爾特公司的 IC 搞過(guo)(guo)太(tai)陽(yang)能(neng)供電設(she)計。除了一(yi)臺顯示工作原(yuan)理的樣(yang)機，Simon 還給了我(wo)一(yi)份原(yuan)理圖，這(zhe)臺樣(yang)機從未連上太(tai)陽(yang)能(neng)電池板測試過(guo)(guo)，但在實驗室做過(guo)(guo)仿真。我(wo)很興奮(fen)，有興趣用(yong)真實的太(tai)陽(yang)能(neng)電池板測試這(zhe)個設(she)計，我(wo)們準備對樣(yang)機進(jin)行像樣(yang)的測試。

　　一位(wei)朋友借給我(wo)兩塊(kuai)(kuai) BP 太陽(yang)(yang)能電(dian)(dian)池板(ban)(ban)(ban)(ban) （BP380U）。在大約 20V 最高輸出電(dian)(dian)壓(ya)和(he) 4A 最大輸出電(dian)(dian)流時(shi)，每塊(kuai)(kuai)電(dian)(dian)池板(ban)(ban)(ban)(ban)的峰值(zhi)功率都(dou)是(shi) 80W （實際規格為，在 80W 最大功率時(shi)，電(dian)(dian)壓(ya)為 17.6V，電(dian)(dian)流為 4.55A）。把這(zhe)兩塊(kuai)(kuai)太陽(yang)(yang)能電(dian)(dian)池板(ban)(ban)(ban)(ban)合起來(lai)，我(wo)希望在太陽(yang)(yang)光直接直射在電(dian)(dian)池板(ban)(ban)(ban)(ban)上時(shi)，在峰值(zhi)條件下能有 8A 的總電(dian)(dian)流。太陽(yang)(yang)能電(dian)(dian)池板(ban)(ban)(ban)(ban)連(lian)接到 Simon 的樣機上沒有幾(ji)分鐘，系統(tong)就充分運轉了(le) （圖 1 和(he)圖 2）。通過對樣機的初步測試，查明(ming)了(le)幾(ji)個故(gu)障，后來(lai)這(zhe)給我(wo)們節省了(le)大量時(shi)間(jian)。

　　圖 1：測試 BP 太陽能電池板， BP380U （0 至 20V 輸出(chu)，4A 峰值功率(lv) 80W）

　　圖 2：最初(chu)的太陽能充電(dian)電(dian)路樣機，采(cai)用(yong) 12V 海上用(yong)深周期(qi)電(dian)池(chi) 。

　　樣機(ji)(ji)運(yun)行良好(hao)，因此我(wo)購買(mai)了(le)幾塊凌力爾(er)特公司的(de)(de)(de)(de)演(yan)示板(ban)，并稍作修改以使其(qi)更適合重新(xin)設計過的(de)(de)(de)(de)系統(tong)規格要求。我(wo)保持(chi)樣機(ji)(ji)作為備(bei)份(fen)和參考(kao)，同時(shi)我(wo)設計了(le)一(yi)個(ge)新(xin)系統(tong)。我(wo)們解決了(le)一(yi)些(xie)故障(zhang)后，通(tong)過這些(xie)修改改善(shan)了(le)原來的(de)(de)(de)(de)樣機(ji)(ji)。總之，架構設計仍(reng)然是相同的(de)(de)(de)(de)：用 0 至(zhi) 20V 的(de)(de)(de)(de)太陽(yang)能(neng)電(dian)池板(ban)，以 4A 的(de)(de)(de)(de)恒定(ding)電(dian)流給一(yi)個(ge) 12V 的(de)(de)(de)(de)電(dian)池充電(dian),

   太陽能電(dian)池充(chong)電(dian)器系統設計

　　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：系統設計方框(kuang)圖

　　圖 4：最終的太陽能充電器電路

　　視太陽(yang)的位置不同而不同，太陽(yang)能電(dian)(dian)池(chi)(chi)板最(zui)(zui)初的輸出(chu)電(dian)(dian)壓(ya)(ya)(ya)在 0V 到 20V 之間變化，那么就用一個(ge)能接(jie)受這么寬輸出(chu)范圍的穩壓(ya)(ya)(ya)器(qi)(qi)，并(bing)保持(chi)吸取低的電(dian)(dian)流(liu) （每個(ge)電(dian)(dian)池(chi)(chi)板上(shang)的輸入電(dian)(dian)流(liu)最(zui)(zui)大值都是(shi) 4A），同時調節(jie)一個(ge)固(gu)定(ding)的輸出(chu)電(dian)(dian)壓(ya)(ya)(ya)。這是(shi)在 DC1198A-B 演示(shi)板上(shang)用凌力爾特公司的微型(xing)(xing)模塊(kuai) （μModule） DC/DC 降壓(ya)(ya)(ya)-升壓(ya)(ya)(ya)型(xing)(xing)開關穩壓(ya)(ya)(ya)器(qi)(qi) LTM4607 實現的。

　　LTM4607 是(shi)一個(ge)小型(xing)(xing)(xing) LGA 封裝 （15mm x 15mm x 2.8mm） 的(de)(de)(de)芯片，其中包(bao)括一個(ge)復雜的(de)(de)(de)降壓(ya)(ya)(ya)(ya)(ya)-升壓(ya)(ya)(ya)(ya)(ya)型(xing)(xing)(xing) DC/DC 開(kai)關穩(wen)壓(ya)(ya)(ya)(ya)(ya)器所(suo)需的(de)(de)(de)所(suo)有支持(chi)控制(zhi)組(zu)件(jian)(jian)。復雜的(de)(de)(de)開(kai)關控制(zhi)電(dian)(dian)路(lu)和(he) FET 內(nei)置到(dao)微(wei)型(xing)(xing)(xing)模塊穩(wen)壓(ya)(ya)(ya)(ya)(ya)器中，從而使該器件(jian)(jian)非(fei)常容易使用。結果是(shi)僅需一個(ge)微(wei)型(xing)(xing)(xing)模塊穩(wen)壓(ya)(ya)(ya)(ya)(ya)器、電(dian)(dian)感器以及幾個(ge)電(dian)(dian)容器和(he)電(dian)(dian)阻器就(jiu)完(wan)成簡潔規則的(de)(de)(de)布局。4.5V 至(zhi) 36V 的(de)(de)(de)寬(kuan)輸(shu)入電(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)范圍至(zhi)固定 20V 輸(shu)出 （范圍為 0.8V 至(zhi) 24V） 對(dui)于太(tai)(tai)陽能電(dian)(dian)池(chi)板(ban)的(de)(de)(de)特(te)性 （0 至(zhi) 20V 輸(shu)出） 正合適(shi)，而且該器件(jian)(jian)能加(jia)載高(gao)達 5A 的(de)(de)(de)升壓(ya)(ya)(ya)(ya)(ya)模式(shi)和(he) 10A 的(de)(de)(de)降壓(ya)(ya)(ya)(ya)(ya)模式(shi)。在太(tai)(tai)陽能電(dian)(dian)池(chi)板(ban)峰值功率時，20V 輸(shu)入至(zhi) 20V/2.5A 輸(shu)出的(de)(de)(de)效(xiao)率是(shi) 91%，而且積極利用了降壓(ya)(ya)(ya)(ya)(ya)-升壓(ya)(ya)(ya)(ya)(ya)型(xing)(xing)(xing)寬(kuan)范圍輸(shu)入的(de)(de)(de)好處。就(jiu)這個(ge)系統設計的(de)(de)(de)目的(de)(de)(de)而言，輸(shu)出調節到(dao) 20V，用這個(ge)輸(shu)出給 LTC1435/LT1620 高(gao)效(xiao)率、低壓(ya)(ya)(ya)(ya)(ya)差(cha)電(dian)(dian)池(chi)充電(dian)(dian)器系統供電(dian)(dian)。

　　在 14V 穩定(ding)(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)時(shi)，LTC1435/LT1620 演示(shi)板 （DC133A） 將充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流控制到(dao)穩定(ding)(ding)的(de) 4A.該(gai)(gai)演示(shi)板與(yu) LT1620 數據表第一頁(ye)上的(de)應(ying)用電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)類似，我將 FB 電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)器 （110k） 換成(cheng)一個(ge)可變電(dian)(dian)(dian)(dian)(dian)(dian)(dian)位器，以(yi)實現輸(shu)出電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)調節，并將電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)浮置(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)設(she)置(zhi)到(dao) 14V.該(gai)(gai)演示(shi)板設(she)計(ji)利(li)用 LT1620 軌(gui)至軌(gui)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流檢(jian)測放大器，結合(he) LTC1435 開關穩壓(ya)(ya)器電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)的(de)高效率和低(di)壓(ya)(ya)差能力，形(xing)成(cheng)了一個(ge)效率超過 95% 的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器，從(cong)而在 4A 充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流時(shi)僅需要 0.5V 輸(shu)入至輸(shu)出電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)差。一個(ge)到(dao)地的(de)編程(cheng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流設(she)置(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流 （4A），該(gai)(gai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流一直(zhi)是(shi)穩定(ding)(ding)的(de)，直(zhi)到(dao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)達到(dao)預設(she)的(de)浮置(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya) （在本文情況下為 14V） 為止。隨著(zhu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)達到(dao)其滿充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)狀態，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)的(de)編程(cheng)將自動轉入涓(juan)流充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)狀態，并就電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)輸(shu)出電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)而言緩慢(man)降低(di)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流。這(zhe)減輕了由(you)于恒定(ding)(ding)過沖電(dian)(dian)(dian)(dian)(dian)(dian)(dian)給電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)造成(cheng)的(de)壓(ya)(ya)力。

　　一(yi)個理想二(er)(er)極(ji)管(guan)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)設計與 DC133A 充電(dian)(dian)(dian)(dian)(dian)(dian)系(xi)統(tong)的輸出串(chuan)聯，利(li)用(yong)(yong) LTC4414 實現電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)保(bao)護，并(bing)允許在(zai)充電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)以(yi)最小(xiao)損耗運(yun)行的同時使用(yong)(yong)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)。這種自動電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)通路(lu)(lu) （PowerPath？） 控(kong)制使外(wai)部設備能(neng)(neng)(neng)夠自由(you)地(di)用(yong)(yong)太(tai)(tai)陽(yang)能(neng)(neng)(neng)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)板(ban)或(huo)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)供(gong)電(dian)(dian)(dian)(dian)(dian)(dian)。當(dang)太(tai)(tai)陽(yang)能(neng)(neng)(neng)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)板(ban)功率不足時，電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)自動轉為從電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)吸取(qu)功率。該(gai)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)設計與 LTC4414 數據表第九頁上(shang)的圖 2 類似。LTC4414 （8 引線 MSOP 封裝(zhuang)） 控(kong)制一(yi)個外(wai)部 P 溝(gou)道(dao) MOSFET，以(yi)產生(sheng)接(jie)近理想的二(er)(er)極(ji)管(guan)功能(neng)(neng)(neng)，用(yong)(yong)于電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)切換。這允許多個電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)高效率進行“或(huo)” 操作；在(zai)本文(wen)情況(kuang)下(xia)，電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)是太(tai)(tai)陽(yang)能(neng)(neng)(neng)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)板(ban)和電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)。當(dang)連接(jie)一(yi)個外(wai)部設備時，電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)和充電(dian)(dian)(dian)(dian)(dian)(dian)系(xi)統(tong)接(jie)受負載(zai)狀態。在(zai)無負載(zai)時，將對電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)充電(dian)(dian)(dian)(dian)(dian)(dian)。因(yin)此(ci)(ci)該(gai)設計允許一(yi)起(qi)使用(yong)(yong)太(tai)(tai)陽(yang)能(neng)(neng)(neng)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)板(ban)和電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)供(gong)電(dian)(dian)(dian)(dian)(dian)(dian)，同時運(yun)行電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)充電(dian)(dian)(dian)(dian)(dian)(dian)過程(cheng)。這一(yi)部分沒(mei)有演示板(ban)可用(yong)(yong)，因(yin)此(ci)(ci)我(wo)按(an)照定制電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)板(ban)上(shang)的應用(yong)(yong)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)進行設計。

　　電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)檢(jian)(jian)測(ce)系統與電(dian)(dian)(dian)(dian)(dian)池(chi)串(chuan)聯，利(li)用并聯檢(jian)(jian)測(ce)電(dian)(dian)(dian)(dian)(dian)阻器(qi)(qi)測(ce)量(liang)電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)輸(shu)入(ru)充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)和輸(shu)出(chu)放電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)，而無需斷開電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)。圖(tu) 3 的(de)(de)方框圖(tu)僅說明了(le)(le)輸(shu)入(ru)充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)。LTC6103 （采(cai)用 8 引(yin)線 MSOP 封裝，在 4V 至(zhi) 60V 范圍內工作） 是一個(ge)雙路(lu)(lu)獨立電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)檢(jian)(jian)測(ce)放大器(qi)(qi)，可(ke)通(tong)(tong)過外部檢(jian)(jian)測(ce)電(dian)(dian)(dian)(dian)(dian)阻器(qi)(qi)監視電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)。該器(qi)(qi)件(jian)以(yi)(yi) mV 為單位測(ce)量(liang)和提供電(dian)(dian)(dian)(dian)(dian)池(chi)充電(dian)(dian)(dian)(dian)(dian)和放電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)的(de)(de)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)比率(lv)輸(shu)出(chu)。在本文情況下，它幫(bang)助(zhu)指示電(dian)(dian)(dian)(dian)(dian)池(chi)充和放了(le)(le)多(duo)少電(dian)(dian)(dian)(dian)(dian)量(liang)。這是一種(zhong)以(yi)(yi)低功率(lv)損耗讀取電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)的(de)(de)方法，這對保持一個(ge)高(gao)能(neng)效系統至(zhi)關重要。我略(lve)微調節了(le)(le) LTC6103 （DC1116A） 演示板以(yi)(yi)實(shi)現這一點。引(yin)腳(jiao) 8 和 7 分(fen)別(bie)與進(jin)入(ru)電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)通(tong)(tong)路(lu)(lu) +IN_A 和 -IN_A 串(chuan)聯。這將提供進(jin)入(ru)電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)。引(yin)腳(jiao) 6 和 5 相互掉換后反著連(lian)接，以(yi)(yi)測(ce)量(liang)電(dian)(dian)(dian)(dian)(dian)池(chi)放電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)通(tong)(tong)路(lu)(lu)，+IN_B （引(yin)腳(jiao) 5） 連(lian)接到 -IN_A （引(yin)腳(jiao) 7），-IN_B （引(yin)腳(jiao) 6） 連(lian)接到 +IN_A （引(yin)腳(jiao) 8）。電(dian)(dian)(dian)(dian)(dian)阻器(qi)(qi)的(de)(de)值以(yi)(yi) 10 為倍數(shu)改變(bian)和調節，以(yi)(yi)便在 0.1Ω 并聯檢(jian)(jian)測(ce)電(dian)(dian)(dian)(dian)(dian)阻器(qi)(qi)與電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)串(chuan)聯時，輸(shu)出(chu)以(yi)(yi) 100mV/A 變(bian)化。圖(tu) 5 中的(de)(de)萬用表顯示整個(ge)系統的(de)(de)結果。太陽能(neng)電(dian)(dian)(dian)(dian)(dian)池(chi)板輸(shu)出(chu)電(dian)(dian)(dian)(dian)(dian)壓是 17.11V，電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)壓為 12.95V，充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(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(he)微控制器讀(du)數

　　我決定，每次檢查電路是否正常運(yun)行時(shi)不使用電壓(ya)表(biao)，因為電壓(ya)表(biao)在沙(sha)漠中難以攜帶(dai)(dai)。為了避免攜帶(dai)(dai)多個萬(wan)用表(biao)，我用一個微控制器和 ADC 來讀取系(xi)統的電壓(ya)值，并在一般的 LCD 顯(xian)示屏上顯(xian)示信息。這種方法可就(jiu)電路性能提供實時(shi)數據，而無需連接幾(ji)個萬(wan)用表(biao)。

　　我使用 DC590B 演示板和 LTC2418 8信(xin)(xin)道(dao) / 16 信(xin)(xin)道(dao) 24 位 ADC 演示板 DC571A.我的(de)(de)(de)(de)同事 Mark Thoren 給(gei)了(le)(le)(le)我 PIC 微控制器的(de)(de)(de)(de)嵌入(ru)式(shi)源(yuan)代(dai)碼樣(yang)本(ben)(ben)，我微調了(le)(le)(le)這(zhe)(zhe)個(ge)源(yuan)代(dai)碼樣(yang)本(ben)(ben)，以跨 LTC2418 上(shang)(shang)(shang) ADC 的(de)(de)(de)(de)不同通道(dao)對電(dian)(dian)(dian)(dian)(dian)壓(ya)采(cai)樣(yang)，并以可接受(shou)的(de)(de)(de)(de)分辨率、準確地讀(du)出(chu) mV 范(fan)(fan)圍的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)值。既然基準電(dian)(dian)(dian)(dian)(dian)壓(ya)的(de)(de)(de)(de)最(zui)大范(fan)(fan)圍是 2.5V，那么我用一種電(dian)(dian)(dian)(dian)(dian)壓(ya)分壓(ya)器方法來按比例將(jiang)電(dian)(dian)(dian)(dian)(dian)壓(ya)降低到 mV 范(fan)(fan)圍，以在 ADC 上(shang)(shang)(shang)實現(xian)正確的(de)(de)(de)(de)測量。通道(dao)連接到單個(ge)有關的(de)(de)(de)(de)輸入(ru)和輸出(chu)電(dian)(dian)(dian)(dian)(dian)壓(ya)上(shang)(shang)(shang)，包括電(dian)(dian)(dian)(dian)(dian)流檢(jian)測電(dian)(dian)(dian)(dian)(dian)壓(ya)。這(zhe)(zhe)么做(zuo)非常(chang)成功，無需多個(ge)萬(wan)用表。圖(tu) 6 是一個(ge)有關這(zhe)(zhe)個(ge) LCD 顯示屏的(de)(de)(de)(de)全(quan)功能系統的(de)(de)(de)(de)例子(zi)。我在 LCD 上(shang)(shang)(shang)得到的(de)(de)(de)(de)最(zui)后的(de)(de)(de)(de)顯示提供(gong)了(le)(le)(le)有關以下電(dian)(dian)(dian)(dian)(dian)壓(ya)的(de)(de)(de)(de)信(xin)(xin)息：變化(hua)的(de)(de)(de)(de)太陽能電(dian)(dian)(dian)(dian)(dian)源(yuan)電(dian)(dian)(dian)(dian)(dian)壓(ya) Vs、充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)路電(dian)(dian)(dian)(dian)(dian)壓(ya) Vc、電(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)壓(ya) Vb、以及電(dian)(dian)(dian)(dian)(dian)池上(shang)(shang)(shang)的(de)(de)(de)(de)輸入(ru)充電(dian)(dian)(dian)(dian)(dian)/放電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流 C 和 D.在本(ben)(ben)文情況下，是“C”，它(ta)在充電(dian)(dian)(dian)(dian)(dian)。放電(dian)(dian)(dian)(dian)(dian)時，程序將(jiang)改(gai)變到“D”。

　　圖 6:LCD 讀數：Vs （太陽能電(dian)(dian)池板電(dian)(dian)壓(ya)(ya)(ya)(ya)）；Vc （充電(dian)(dian)電(dian)(dian)路電(dian)(dian)壓(ya)(ya)(ya)(ya)）；Vb （電(dian)(dian)池電(dian)(dian)壓(ya)(ya)(ya)(ya)）；C = 充電(dian)(dian)電(dian)(dian)流(liu) （4.3A），用(yong)DC590B PIC 微(wei)控(kong)制(zhi)器(qi)控(kong)制(zhi)；用(yong) LTC2418 演(yan)示板 DC571 ADC 讀取(qu)電(dian)(dian)壓(ya)(ya)(ya)(ya)，該演(yan)示板由 LTM4601演(yan)示板 DC1041A 微(wei)型模(mo)塊(kuai)降(jiang)壓(ya)(ya)(ya)(ya)型穩壓(ya)(ya)(ya)(ya)器(qi)供電(dian)(dian)。

　　注意，DC590B 演(yan)示(shi)板(ban)(ban)不(bu)(bu)是靠 12V 軌供電，而(er)是靠 5V 軌供電。需要一個降壓(ya)型(xing)穩(wen)壓(ya)器(qi)(qi)將(jiang)電壓(ya)從電池(chi)的(de) 12V 降低到 5V.這個降壓(ya)型(xing)穩(wen)壓(ya)器(qi)(qi)將(jiang)必須是高效率(lv)的(de)，因為電源將(jiang)來自(zi)太(tai)陽能(neng)電池(chi)板(ban)(ban)和電池(chi)，我(wo)不(bu)(bu)想因運(yun)行(xing) LCD 顯示(shi)屏和微控制器(qi)(qi)而(er)耗費大量功(gong)率(lv)。我(wo)使用 LTM4601 微型(xing)模塊 DC/DC 開關穩(wen)壓(ya)器(qi)(qi)演(yan)示(shi)板(ban)(ban) DC1041A.

　　LTM4601 是一(yi)(yi)(yi)個(ge) LGA 封裝的(de) 15mm x 15mm x 2.8mm 微(wei)(wei)型模(mo)塊 DC/DC 開關穩壓器(qi)，在(zai) 12A 最大(da)負載電(dian)(dian)流時，輸(shu)(shu)入為 4.5V 至(zhi) 20V，輸(shu)(shu)出(chu)為 0.6V 至(zhi) 5V.LTM4601 的(de)設計使得非(fei)常(chang)(chang)容(rong)(rong)易(yi)從(cong) 12V 電(dian)(dian)池(chi)提供一(yi)(yi)(yi)個(ge)穩定的(de) 5V 輸(shu)(shu)出(chu)。該微(wei)(wei)型模(mo)塊包括所有(you)控制支持組件，如(ru)電(dian)(dian)阻器(qi)、電(dian)(dian)容(rong)(rong)器(qi)、MOSFET 和電(dian)(dian)感器(qi)。在(zai)這個(ge)系統中，效(xiao)率大(da)約為 90%，使用(yong)(yong)最小(xiao)的(de)電(dian)(dian)池(chi)電(dian)(dian)流，極大(da)地延長了電(dian)(dian)池(chi)壽命。更容(rong)(rong)易(yi)的(de)是，輸(shu)(shu)出(chu)電(dian)(dian)壓用(yong)(yong)一(yi)(yi)(yi)個(ge)電(dian)(dian)阻器(qi)設置(zhi)，如(ru)果我需要一(yi)(yi)(yi)個(ge)不(bu)同的(de)電(dian)(dian)壓軌 （例如(ru) 3.3V、2.5V、1.8V、1.5V 和 1.2V），那么在(zai)演示板上用(yong)(yong)一(yi)(yi)(yi)條跨(kua)接(jie)線可以(yi)非(fei)常(chang)(chang)容(rong)(rong)易(yi)地改(gai)變這個(ge)輸(shu)(shu)出(chu)電(dian)(dian)壓。

　　總之，兩塊(kuai)(kuai)(kuai) BP 太(tai)陽能電(dian)(dian)池板，每塊(kuai)(kuai)(kuai)在(zai)(zai) 4A 電(dian)(dian)流(liu)(liu)時都有 0 至 20V 的(de)(de)輸出(chu)，這兩塊(kuai)(kuai)(kuai)太(tai)陽能電(dian)(dian)池板由(you) 20V 輸出(chu)的(de)(de) LTM4607 降壓(ya)/升壓(ya)型微型模塊(kuai)(kuai)(kuai)開關穩(wen)(wen)壓(ya)器(qi)(qi)(qi)(qi)調(diao)節，然后再到 14V 輸入的(de)(de) LTC1435/LT1620 電(dian)(dian)池充(chong)電(dian)(dian)器(qi)(qi)(qi)(qi)，通過(guo)一個理想二極管 MOSFET 控制器(qi)(qi)(qi)(qi) LTC4414、一個串聯的(de)(de)電(dian)(dian)流(liu)(liu)檢測(ce)放大器(qi)(qi)(qi)(qi) LTC6103，最(zui)終進入電(dian)(dian)池；以穩(wen)(wen)定的(de)(de) 4A 電(dian)(dian)流(liu)(liu)充(chong)電(dian)(dian)。在(zai)(zai)這個設計中，由(you) LTC2418 在(zai)(zai)不同的(de)(de)級獲取 ADC 讀數，并(bing)將讀數送至由(you) LTM4601 微型模塊(kuai)(kuai)(kuai)開關穩(wen)(wen)壓(ya)器(qi)(qi)(qi)(qi)供(gong)電(dian)(dian)的(de)(de) DC590B 演示板微控制器(qi)(qi)(qi)(qi)，以在(zai)(zai) LCD 上顯示結果。圖 7 顯示正(zheng)在(zai)(zai)運行(xing)的(de)(de)整(zheng)個系統。

　　圖 7：運行中的整個系統設計

　　噴霧系統的機械設計

　　有了(le)一(yi)個正常工作的太陽(yang)能充電器和(he)(he)穩定的 12V 輸出，我(wo)就(jiu)準備好(hao)著手組裝(zhuang)噴(pen)霧(wu)系(xi)統了(le)。去一(yi)趟五金店就(jiu)得到(dao)了(le)我(wo)需要的材料：艙底污水(shui)泵(beng)(beng)、水(shui)龍帶(dai)連接器、水(shui)龍帶(dai)夾具、轉(zhuan)接器和(he)(he)噴(pen)霧(wu)系(xi)統。水(shui)龍帶(dai)長約 15 英(ying)尺，擰在(zai)轉(zhuan)接器螺釘上，用水(shui)龍帶(dai)夾具固定到(dao)水(shui)泵(beng)(beng)上，噴(pen)霧(wu)系(xi)統固定在(zai)末端，有 5 個噴(pen)霧(wu)嘴。底艙污水(shui)泵(beng)(beng)靠最大值為 12V 的電壓運行，水(shui)壓可以通(tong)過(guo)降低電壓來控制。

　　為了(le)實現(xian)靈活性(xing)，我安裝了(le)一個(ge)(ge)穩壓器，該穩壓器可(ke)(ke)以(yi)接受 12V 輸(shu)(shu)(shu)入(ru)，并將輸(shu)(shu)(shu)入(ru)轉換成可(ke)(ke)變(bian)的(de) 12V 輸(shu)(shu)(shu)出(chu)。這要求 LTM4607 設計有(you)降壓/升壓特(te)性(xing)。該器件(jian)使用(yong)一個(ge)(ge)反饋(kui)電(dian)阻器控(kong)(kong)制(zhi)輸(shu)(shu)(shu)出(chu)電(dian)壓。一個(ge)(ge) 50k 的(de)可(ke)(ke)變(bian)旋(xuan)(xuan)鈕電(dian)位器取(qu)代了(le)電(dian)阻器，從而非常容易(yi)控(kong)(kong)制(zhi) 0.8V 至 12V 的(de)輸(shu)(shu)(shu)出(chu)。還串聯(lian)了(le)一個(ge)(ge) 5.62k 的(de)電(dian)阻器，以(yi)限制(zhi)輸(shu)(shu)(shu)出(chu)電(dian)壓，保持輸(shu)(shu)(shu)出(chu)低(di)于 15V.該設計通過旋(xuan)(xuan)轉一個(ge)(ge)旋(xuan)(xuan)鈕實現(xian)了(le)水壓控(kong)(kong)制(zhi)。

　　然后，我就可以(yi)測試我的(de)(de)全(quan)功能噴霧系(xi)(xi)統了(le)。結果，水(shui)泵(beng)導致最大約 6A 的(de)(de)電(dian)(dian)(dian)(dian)池放電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流，這意味(wei)著，在(zai)(zai)峰(feng)值輸出時，水(shui)泵(beng)約從每塊(kuai)太陽(yang)能電(dian)(dian)(dian)(dian)池板獲(huo)得 4A 電(dian)(dian)(dian)(dian)流。控(kong)制水(shui)泵(beng)速度(du)和(he)壓力(li)的(de)(de)好處(chu)是(shi)，我可以(yi)將(jiang)壓力(li)降到足夠低，以(yi)降低電(dian)(dian)(dian)(dian)池的(de)(de)放電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流，并全(quan)部(bu)靠太陽(yang)能電(dian)(dian)(dian)(dian)池板運行水(shui)泵(beng)，以(yi)節省(sheng)電(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)量，這樣做非常有效。通過這種方法，我們能夠在(zai)(zai)營地全(quan)天(tian)運行噴霧系(xi)(xi)統，而不必擔心電(dian)(dian)(dian)(dian)池放電(dian)(dian)(dian)(dian)，耽誤夜間用于 LED 照明系(xi)(xi)統。

　　LED 照明

　　隨著(zhu)電(dian)(dian)(dian)(dian)(dian)(dian)源的(de)(de)完(wan)成，我(wo)(wo)就可(ke)以增加電(dian)(dian)(dian)(dian)(dian)(dian)路，在(zai)晚上高(gao)效(xiao)率地提(ti)(ti)供照(zhao)(zhao)(zhao)明了(le)。LED 足夠亮，可(ke)以照(zhao)(zhao)(zhao)亮房間(jian)，這在(zai)以前是(shi)不可(ke)想象(xiang)的(de)(de)，但是(shi)新的(de)(de)技術進步(bu)已經為(wei)(wei)(wei) LED 照(zhao)(zhao)(zhao)明的(de)(de)新時(shi)代創造了(le)條件。尤(you)其是(shi)，PhilipsLumileds Luxeon LED 在(zai) 1000mA 時(shi)可(ke)以提(ti)(ti)供超過 100 流(liu)(liu)明的(de)(de)光。我(wo)(wo)配備(bei)了(le)一個(ge)(ge) LumiLED 陣列(lie)，使用(yong)(yong) LTC3475 （16 引線 TSSOP 耐熱(re)增強型封裝） 雙路 1.5A 恒定電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu) LED 驅(qu)動器 DC923A 演(yan)示(shi)板。它設計(ji)成用(yong)(yong)一個(ge)(ge)寬范圍輸入電(dian)(dian)(dian)(dian)(dian)(dian)壓 （4V 至 30V） 驅(qu)動兩個(ge)(ge)信道，每(mei)個(ge)(ge)信道 1.5A.12V 電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)直接連接到演(yan)示(shi)板的(de)(de)輸入，為(wei)(wei)(wei)每(mei)個(ge)(ge)通道 3 個(ge)(ge)串聯(lian)的(de)(de) LED 燈(deng)供電(dian)(dian)(dian)(dian)(dian)(dian)，當兩個(ge)(ge)通道都接通時(shi)，總(zong)共有 6 個(ge)(ge) LED.這些 LED 出(chu)奇地亮，用(yong)(yong)一塊柔光布遮上時(shi)，足夠照(zhao)(zhao)(zhao)亮我(wo)(wo)們整個(ge)(ge)營地。晚上的(de)(de)放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)全部來自(zi)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)，因為(wei)(wei)(wei)太(tai)陽能電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)板夜間(jian)提(ti)(ti)供零電(dian)(dian)(dian)(dian)(dian)(dian)力(li)。以 2A 的(de)(de)總(zong)放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)，可(ke)以整晚為(wei)(wei)(wei)這些燈(deng)供電(dian)(dian)(dian)(dian)(dian)(dian)。到接近(jin)中(zhong)午或偏下(xia)午時(shi)，電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)再(zai)次充(chong)滿(man)電(dian)(dian)(dian)(dian)(dian)(dian)，為(wei)(wei)(wei)給噴霧系統(tong)供電(dian)(dian)(dian)(dian)(dian)(dian)做好了(le)準(zhun)備(bei)，在(zai)早午餐(can)后，噴霧系統(tong)就可(ke)以讓我(wo)(wo)們感到涼爽了(le)。