一、電解電容和普通電容簡介

一般來說有極性電容指的都是電解電容一類的電容，雖然(ran)確實(shi)存在著(zhu)無極(ji)性(xing)電(dian)(dian)(dian)解(jie)(jie)電(dian)(dian)(dian)容(rong)(rong)(rong)，但(dan)在市面上(shang)不太常見，而且價格也比較貴(gui)。常見的(de)電(dian)(dian)(dian)解(jie)(jie)電(dian)(dian)(dian)容(rong)(rong)(rong)都是(shi)由(you)陽(yang)極(ji)鋁箔(bo)和陰(yin)極(ji)的(de)電(dian)(dian)(dian)解(jie)(jie)溶液分別形(xing)成兩(liang)個電(dian)(dian)(dian)極(ji)，由(you)陽(yang)極(ji)鋁箔(bo)上(shang)產生的(de)一層氧化鋁膜做為電(dian)(dian)(dian)介質的(de)電(dian)(dian)(dian)容(rong)(rong)(rong)，電(dian)(dian)(dian)解(jie)(jie)電(dian)(dian)(dian)容(rong)(rong)(rong)在電(dian)(dian)(dian)路中也必須注意極(ji)性(xing)。

普通的電(dian)(dian)容(rong)是(shi)(shi)(shi)大部分(fen)(fen)是(shi)(shi)(shi)無極(ji)性(xing)(xing)的，也可以把兩個電(dian)(dian)解電(dian)(dian)容(rong)陽極(ji)或陰極(ji)相對(dui)串連形成(cheng)無極(ji)性(xing)(xing)電(dian)(dian)解電(dian)(dian)容(rong)。一(yi)般(ban)來(lai)說，低于1μF的低值電(dian)(dian)容(rong)大多數(shu)是(shi)(shi)(shi)無極(ji)性(xing)(xing)之(zhi)(zhi)分(fen)(fen)的，但是(shi)(shi)(shi)具有1μF或更大電(dian)(dian)容(rong)值的電(dian)(dian)容(rong)幾乎都是(shi)(shi)(shi)有正負極(ji)之(zhi)(zhi)分(fen)(fen)的。至今為止，常(chang)用有極(ji)性(xing)(xing)電(dian)(dian)容(rong)是(shi)(shi)(shi)電(dian)(dian)解電(dian)(dian)容(rong)，有極(ji)性(xing)(xing)電(dian)(dian)容(rong)的正引線總會長(chang)一(yi)些，即使是(shi)(shi)(shi)標志(zhi)磨損或者被完(wan)全抹去，我(wo)們也能夠辨(bian)認出極(ji)性(xing)(xing)。

該圖片由注冊用戶"天空之城"提供，版權聲明反饋

二、電解電容和普通電容的區別

1、介質不同

有(you)極(ji)性(xing)電(dian)(dian)(dian)容(rong)(rong)大多(duo)采(cai)用電(dian)(dian)(dian)解質(zhi)做介(jie)(jie)質(zhi)材(cai)(cai)料，通常(chang)同體(ti)積的(de)(de)(de)電(dian)(dian)(dian)容(rong)(rong)有(you)極(ji)性(xing)電(dian)(dian)(dian)容(rong)(rong)容(rong)(rong)量(liang)大。另外(wai)，不(bu)同的(de)(de)(de)電(dian)(dian)(dian)解質(zhi)材(cai)(cai)料和工藝制造出的(de)(de)(de)有(you)極(ji)性(xing)電(dian)(dian)(dian)容(rong)(rong)同體(ti)積的(de)(de)(de)容(rong)(rong)量(liang)也(ye)會不(bu)同。再有(you)就是(shi)耐(nai)壓和使用介(jie)(jie)質(zhi)材(cai)(cai)料也(ye)有(you)密切(qie)關系。無極(ji)性(xing)電(dian)(dian)(dian)容(rong)(rong)介(jie)(jie)質(zhi)材(cai)(cai)料也(ye)很多(duo)，大多(duo)采(cai)用金屬氧化膜、滌綸等(deng)。由于介(jie)(jie)質(zhi)的(de)(de)(de)可逆或不(bu)可逆性(xing)能決(jue)定(ding)了有(you)極(ji)、無極(ji)性(xing)電(dian)(dian)(dian)容(rong)(rong)的(de)(de)(de)使用環境。

2、性能不同

性(xing)能(neng)就(jiu)是使(shi)用(yong)(yong)的要(yao)(yao)(yao)求(qiu)，需求(qiu)最大(da)化(hua)就(jiu)是使(shi)用(yong)(yong)的要(yao)(yao)(yao)求(qiu)。如(ru)果在電(dian)(dian)視機里電(dian)(dian)源部分用(yong)(yong)金屬氧化(hua)膜電(dian)(dian)容(rong)器做(zuo)濾(lv)波(bo)(bo)的話，而且要(yao)(yao)(yao)達到濾(lv)波(bo)(bo)要(yao)(yao)(yao)求(qiu)的電(dian)(dian)容(rong)器容(rong)量和耐壓。機殼(ke)內恐怕也就(jiu)只(zhi)能(neng)裝個電(dian)(dian)源了。所以作為濾(lv)波(bo)(bo)只(zhi)能(neng)使(shi)用(yong)(yong)有極性(xing)電(dian)(dian)容(rong)，有極性(xing)電(dian)(dian)容(rong)是不(bu)可(ke)逆的。就(jiu)是說正極必(bi)須接(jie)高電(dian)(dian)位端，負極必(bi)須接(jie)低電(dian)(dian)位端。一般電(dian)(dian)解電(dian)(dian)容(rong)在1微(wei)法拉(la)以上(shang)，做(zuo)偶(ou)合、退偶(ou)合、電(dian)(dian)源濾(lv)波(bo)(bo)等。無極性(xing)電(dian)(dian)容(rong)大(da)多在1微(wei)法拉(la)以下，參與諧振(zhen)、偶(ou)合、選(xuan)頻(pin)(pin)、限流、等。當然也有大(da)容(rong)量高耐壓的，多用(yong)(yong)在電(dian)(dian)力(li)的無功補償(chang)、電(dian)(dian)機的移相、變頻(pin)(pin)電(dian)(dian)源移相等用(yong)(yong)途上(shang)。

3、容量不同

電解電容(rong)(rong)的容(rong)(rong)量(liang)要比普通電容(rong)(rong)大。

4、結構不同

原則(ze)上講(jiang)不考慮尖端(duan)放電的(de)情況下(xia)，使用(yong)(yong)環境需要什(shen)么形(xing)狀的(de)電容都可(ke)以。通常(chang)用(yong)(yong)的(de)電解電容（有(you)極性電容）是圓(yuan)(yuan)形(xing)，方型(xing)(xing)用(yong)(yong)的(de)很(hen)少。無(wu)極性電容形(xing)狀千(qian)奇百變。像管型(xing)(xing)、變形(xing)長方形(xing)、片型(xing)(xing)、方型(xing)(xing)、圓(yuan)(yuan)型(xing)(xing)、組合方型(xing)(xing)及(ji)圓(yuan)(yuan)型(xing)(xing)等(deng)等(deng)。當(dang)然還有(you)無(wu)形(xing)的(de)，這里(li)無(wu)形(xing)指的(de)就(jiu)是分布電容。對于分布電容在(zai)高頻(pin)和(he)中頻(pin)器件(jian)中決不可(ke)忽視。

三、無極性電容可以代替有極性電容嗎

理想的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)容(rong)(rong)，本來(lai)是沒有(you)(you)極(ji)(ji)性(xing)(xing)的(de)(de)(de)(de)。但(dan)是在實際(ji)中，為(wei)(wei)(wei)了(le)(le)獲得大(da)容(rong)(rong)量，就(jiu)使用了(le)(le)某些特殊的(de)(de)(de)(de)材料(liao)和(he)結(jie)構，這(zhe)就(jiu)導致了(le)(le)實際(ji)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)容(rong)(rong)有(you)(you)些是有(you)(you)極(ji)(ji)性(xing)(xing)的(de)(de)(de)(de)。常見的(de)(de)(de)(de)有(you)(you)極(ji)(ji)性(xing)(xing)電(dian)(dian)(dian)(dian)容(rong)(rong)有(you)(you)鋁(lv)電(dian)(dian)(dian)(dian)解電(dian)(dian)(dian)(dian)容(rong)(rong)，鉭電(dian)(dian)(dian)(dian)解電(dian)(dian)(dian)(dian)容(rong)(rong)等。電(dian)(dian)(dian)(dian)解電(dian)(dian)(dian)(dian)容(rong)(rong)一般(ban)是容(rong)(rong)量相(xiang)對比較大(da)的(de)(de)(de)(de)。如果要做一個(ge)大(da)容(rong)(rong)量的(de)(de)(de)(de)無(wu)極(ji)(ji)性(xing)(xing)電(dian)(dian)(dian)(dian)容(rong)(rong)，就(jiu)沒那么容(rong)(rong)易了(le)(le)，體(ti)積會變(bian)得很大(da)。這(zhe)就(jiu)是為(wei)(wei)(wei)什么在實際(ji)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)路中，為(wei)(wei)(wei)什么會有(you)(you)那么多(duo)的(de)(de)(de)(de)有(you)(you)極(ji)(ji)性(xing)(xing)電(dian)(dian)(dian)(dian)容(rong)(rong)了(le)(le)——因(yin)為(wei)(wei)(wei)它(ta)(ta)體(ti)積比較小，同時又因(yin)為(wei)(wei)(wei)這(zhe)樣(yang)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)路中電(dian)(dian)(dian)(dian)壓(ya)只有(you)(you)一個(ge)方(fang)向，所以有(you)(you)極(ji)(ji)性(xing)(xing)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)容(rong)(rong)就(jiu)能(neng)派上(shang)用場。我們(men)(men)使用有(you)(you)極(ji)(ji)性(xing)(xing)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)容(rong)(rong)，就(jiu)是避(bi)開它(ta)(ta)的(de)(de)(de)(de)缺(que)點，利(li)用它(ta)(ta)的(de)(de)(de)(de)優點。我們(men)(men)可以這(zhe)樣(yang)來(lai)理解：有(you)(you)極(ji)(ji)性(xing)(xing)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)容(rong)(rong)實際(ji)上(shang)是一個(ge)只能(neng)按一個(ge)電(dian)(dian)(dian)(dian)壓(ya)方(fang)向使用的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)容(rong)(rong)。而無(wu)極(ji)(ji)性(xing)(xing)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)容(rong)(rong)，則兩個(ge)電(dian)(dian)(dian)(dian)壓(ya)方(fang)向都(dou)能(neng)使用。因(yin)此(ci)，單從電(dian)(dian)(dian)(dian)壓(ya)方(fang)向這(zhe)一點上(shang)來(lai)說，無(wu)極(ji)(ji)性(xing)(xing)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)容(rong)(rong)是比有(you)(you)極(ji)(ji)性(xing)(xing)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)容(rong)(rong)要好的(de)(de)(de)(de)。

從上面的分析可以看出來，使用無極性的電容代(dai)替有(you)極性的電容是完全(quan)可以的——只(zhi)要容量、工作電壓、體積(ji)等能滿足要求即(ji)可替換(huan)。