本文是對直流電源五大常見問題的知識問答，針對直流電源在日常使用過程中，覺遇到的直流電源整改、降壓及用途等等方面的問題，進行回答，提供解決的思路及簡單的解決方法。

一、直流電源、單相電、交流電源、三相電的異同？

　　直流電源有正、負兩個電極，正極的電位高，負極的電位低，當兩個電極與電路連通后，能夠使電路兩端之間維持恒定的電位差，從而在外電路中形成由正極到負極的電流，如干電池，蓄電池

相就是相位，發電廠出來有三根火線一根零線，三根火線兩兩間相位相差120度，單相電指的就是其中一根火線和共用零線。
單相電火線和零線電壓220V，而三相電火線與火線之間電壓380V這是我國的標準，電壓波形是正弦波Vt=Vrms*SIN（wt+A）。
三相電都是火線，摸那一條都不成，兩根之間是380V，每根與零線間是220V，也就是我們日常使用的。

二、萬能充電源怎樣改成直流電源？

　　萬能充的兩條輸出線就是直流正負極。只要電壓合適電流不過載，可以直接當直流電源使用。對電源要求高的用電器，可以在接用電器之間加裝穩壓和濾波電子元件。

三、直流電源怎樣單獨給IC供電?

　　我想單獨用一個直流電源給IC供電，是不是直接把他接上IC的電源腳即可，地線是否直接與線路板接在一起，當需要它所在的線路板正常工作時，會燒掉電源或者IC嗎?

　　首先要分清是在高壓區或者低壓區主要區別與地線，高壓區的地線就是市電經過整流后形成的直流電的負極也就是電源地，低壓區的地線是從變壓器出來。它跟大地(地線)一般都是接通的，也就是功率地。

　　假如你的IC在低壓斷工作。你就放心的接個電源就是沒什么可注意的。成品的電源輸出都是屬于低壓區的

　　IC用在高壓區就多多注意了，要做到這這兩點就不會燒IC了
　　1.供電的電源的地不能夠與所在線路板的地有任何關系。
　　2.供電的電源不能是三腳插頭。或者金屬外殼。不能接地

四、直流電源如何降壓？

　　用7805能得到5V電壓或1A的電流.一般要用散熱器.串聯二極管每個二級極的電壓降約1V 。
電池還是用12-5的dc-dc好點，7805是線性電源，太浪費電了，現在高檔的dc-dc可以做到90%以上的能源利用率。

五、家用的電源是直流電源嗎？

　　家用的電源是交流電，干電池是典型的直流電源。
　　直(zhi)流(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)是(shi)指方向和時間不(bu)作周(zhou)期性變(bian)(bian)化(hua)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)，但電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)大(da)小可(ke)能(neng)不(bu)固定，而產(chan)生(sheng)波(bo)形(xing)(xing)。又稱恒定電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)。所(suo)通過的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)稱直(zhi)流(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)，是(shi)由直(zhi)流(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)和電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻構成(cheng)的(de)(de)閉(bi)合導電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)回路(lu)(lu)。在該電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)中(zhong)，形(xing)(xing)成(cheng)恒定的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)場(chang)，在電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)外，正電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)荷經電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻從(cong)高電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)勢(shi)處(chu)流(liu)(liu)(liu)(liu)向低(di)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)勢(shi)處(chu)，在電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)內，靠電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)的(de)(de)非靜(jing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)力(li)的(de)(de)作用，克(ke)服靜(jing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)力(li)，再從(cong)低(di)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)勢(shi)處(chu)到(dao)達高電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)勢(shi)處(chu)，如此循(xun)環，構成(cheng)閉(bi)合的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)線。所(suo)以，在直(zhi)流(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)中(zhong)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)的(de)(de)作用是(shi)提供不(bu)隨時間變(bian)(bian)化(hua)的(de)(de)恒定電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)勢(shi)，為(wei)在電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻上(shang)消耗的(de)(de)焦耳熱補充能(neng)量。