當我們不知道貼片電容的正負極時,我們可以用萬用表來測量它。
貼片電容器,又稱SMD電容器,表面安裝電容器,其外觀通常是[敏感詞]、黑色或淺藍色。它可分為兩類:非極性和極性。現在我們主要討論正負極與極性貼片電容器的區別。
這樣,我(wo)們(men)首先假設某個極(ji)端的(de)(de)"極(ji),指針萬(wan)用(yong)表(biao)R*100或(huo)R*1K塊(kuai),然后假設"極(ji)和萬(wan)用(yong)表(biao)的(de)(de)黑(hei)色表(biao)筆,另一個電極(ji)和萬(wan)用(yong)表(biao)的(de)(de)紅色表(biao)筆,寫(xie)下針停止(zhi)的(de)(de)刻度。
然后放電電容器(觸(chu)摸兩個引線),然后調(diao)整(zheng)兩個筆(bi)并重新測量(liang)。 在兩次測量(liang)中,針的最(zui)后一次停止在左(zuo)邊(bian)(或電阻(zu)大(da)),黑色筆(bi)與電解電容器的正(zheng)極(ji)連(lian)接(jie)。
鋁電解電容器的正負電極區別于測量電容器上的黑色塊是負電極,在PCB的電容位置有兩個半圓,彩色半圓對應一個負極,用針對和錯來區分正長腳和負長腳,短腳對應負極。
電(dian)容極之(zhi)間的電(dian)介(jie)質不是絕(jue)對(dui)絕(jue)緣子,其電(dian)阻(zu)不是無限的,而是一(yi)(yi)個(ge)有限值,一(yi)(yi)般(ban)大(da)于1000兆赫。電(dian)容器兩極之(zhi)間的電(dian)阻(zu)稱為絕(jue)緣電(dian)阻(zu)或泄漏電(dian)阻(zu)。
只(zhi)有當電(dian)(dian)(dian)(dian)(dian)解電(dian)(dian)(dian)(dian)(dian)容器的(de)(de)(de)正極為正極和負(fu)端子電(dian)(dian)(dian)(dian)(dian)源為負(fu)值(zhi)時屏障的(de)(de)(de)紅色手(shou)表筆,電(dian)(dian)(dian)(dian)(dian)解電(dian)(dian)(dian)(dian)(dian)容器的(de)(de)(de)漏電(dian)(dian)(dian)(dian)(dian)流(liu)較小(漏電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)阻(zu)較大(da))。相反(fan),電(dian)(dian)(dian)(dian)(dian)解電(dian)(dian)(dian)(dian)(dian)容器的(de)(de)(de)漏電(dian)(dian)(dian)(dian)(dian)流(liu)增加(泄漏電(dian)(dian)(dian)(dian)(dian)阻(zu)減小)。