恒流電源是指電(dian)源(yuan)(yuan)無論什(shen)么時候輸出的(de)電(dian)流(liu)大小都是一(yi)樣(yang)的(de)，不會隨著外界環(huan)境或者是內(nei)在電(dian)壓(ya)(ya)的(de)變(bian)化而(er)有所變(bian)化，在日常(chang)生活中(zhong)，恒流(liu)電(dian)源(yuan)(yuan)是非常(chang)少見(jian)(jian)的(de)，比較常(chang)見(jian)(jian)的(de)就(jiu)是恒壓(ya)(ya)電(dian)源(yuan)(yuan)，人(ren)們對于恒流(liu)電(dian)源(yuan)(yuan)的(de)理(li)解是比較難的(de)，那么本文就(jiu)從5中(zhong)情況(kuang)來說明下恒流(liu)電(dian)源(yuan)(yuan)。

　　情況一、如(ru)果電(dian)(dian)(dian)(dian)源(yuan)(yuan)是(shi)空載，那(nei)么電(dian)(dian)(dian)(dian)阻R就(jiu)(jiu)是(shi)無(wu)窮大的(de)，而電(dian)(dian)(dian)(dian)壓U等于電(dian)(dian)(dian)(dian)流與電(dian)(dian)(dian)(dian)阻相乘(cheng)，所以(yi)，如(ru)果電(dian)(dian)(dian)(dian)源(yuan)(yuan)可以(yi)輸(shu)出(chu)1A的(de)電(dian)(dian)(dian)(dian)流，而電(dian)(dian)(dian)(dian)源(yuan)(yuan)電(dian)(dian)(dian)(dian)流輸(shu)出(chu)大小為1，這(zhe)樣電(dian)(dian)(dian)(dian)壓就(jiu)(jiu)是(shi)100v，因(yin)為電(dian)(dian)(dian)(dian)流是(shi)恒(heng)定(ding)不(bu)變的(de)，所以(yi)電(dian)(dian)(dian)(dian)壓最大輸(shu)出(chu)值就(jiu)(jiu)是(shi)100v。但是(shi)電(dian)(dian)(dian)(dian)源(yuan)(yuan)電(dian)(dian)(dian)(dian)壓是(shi)不(bu)能(neng)(neng)無(wu)窮大的(de)，所以(yi)，電(dian)(dian)(dian)(dian)流的(de)輸(shu)出(chu)只能(neng)(neng)是(shi)很小的(de)，可以(yi)忽(hu)略(lve)不(bu)計，即0A。

　　情(qing)況二、如(ru)果(guo)電(dian)阻是(shi)200歐，但是(shi)電(dian)源(yuan)的輸出值為100.，這樣的話電(dian)流(liu)的輸出值只能為0.5。電(dian)流(liu)=電(dian)壓/電(dian)阻。

　　情況三、電(dian)(dian)阻(zu)假設為100歐，電(dian)(dian)源可以輸(shu)出電(dian)(dian)壓100，這(zhe)樣(yang)電(dian)(dian)源的(de)電(dian)(dian)流(liu)就可以達到1A，同樣(yang)的(de)道理，電(dian)(dian)流(liu)=電(dian)(dian)壓/電(dian)(dian)阻(zu)。

　　按照以(yi)上情(qing)況，電(dian)(dian)(dian)(dian)阻值繼續降低(di)，變為(wei)50歐的(de)話，根據(ju)以(yi)上的(de)公式電(dian)(dian)(dian)(dian)流(liu)=電(dian)(dian)(dian)(dian)壓(ya)/電(dian)(dian)(dian)(dian)阻，電(dian)(dian)(dian)(dian)流(liu)的(de)輸出(chu)值就(jiu)變為(wei)2A了，但(dan)是(shi)恒流(liu)電(dian)(dian)(dian)(dian)源要求(qiu)的(de)輸出(chu)電(dian)(dian)(dian)(dian)流(liu)是(shi)恒定的(de)，所(suo)(suo)(suo)以(yi)必須保持在(zai)1A的(de)電(dian)(dian)(dian)(dian)流(liu)輸出(chu)，所(suo)(suo)(suo)以(yi)在(zai)電(dian)(dian)(dian)(dian)阻變為(wei)50歐的(de)時(shi)候，電(dian)(dian)(dian)(dian)流(liu)輸出(chu)值還是(shi)只能為(wei)1A，所(suo)(suo)(suo)以(yi)，這時(shi)候電(dian)(dian)(dian)(dian)壓(ya)就(jiu)必須降低(di)為(wei)50V，所(suo)(suo)(suo)以(yi)這依然是(shi)符合科(ke)學規律的(de)。

　　如(ru)果說電阻降(jiang)到最低(di)為(wei)0，又或者是成(cheng)為(wei)短路，那么輸出電流(liu)還是1A的(de)話(hua)，電壓就只能降(jiang)為(wei)1V。

　　所以(yi)，通過以(yi)上幾種(zhong)情況(kuang)的說明，如果負載的電阻(zu)變(bian)(bian)大(da)(da)或是變(bian)(bian)小(xiao)，根(gen)據(ju)正常情況(kuang)，電流(liu)達不(bu)(bu)到恒定(ding)要求的輸出(chu)值時，那(nei)么輸出(chu)電壓(ya)就(jiu)會(hui)自動變(bian)(bian)大(da)(da)或是變(bian)(bian)小(xiao)，當電阻(zu)非常小(xiao)的時候(hou)，電壓(ya)的輸出(chu)電流(liu)就(jiu)會(hui)保持在一個(ge)恒定(ding)不(bu)(bu)變(bian)(bian)的值，這時候(hou)的電源(yuan)就(jiu)會(hui)出(chu)在恒流(liu)工作狀(zhuang)態，電阻(zu)逐漸變(bian)(bian)小(xiao)，那(nei)么電壓(ya)也會(hui)規律(lv)變(bian)(bian)化(hua)，這就(jiu)是恒流(liu)電源(yuan)的概念。