電(dian)(dian)感(gan)是(shi)(shi)電(dian)(dian)子電(dian)(dian)路(lu)或裝置的(de)(de)(de)屬性之一，指(zhi)的(de)(de)(de)是(shi)(shi)：當(dang)電(dian)(dian)流改變(bian)時(shi)，因(yin)電(dian)(dian)磁(ci)感(gan)應而(er)產(chan)生(sheng)抵抗電(dian)(dian)流改變(bian)的(de)(de)(de)電(dian)(dian)動勢電(dian)(dian)路(lu)中的(de)(de)(de)任(ren)何電(dian)(dian)流，會(hui)產(chan)生(sheng)磁(ci)場(chang)，磁(ci)場(chang)的(de)(de)(de)磁(ci)通量又(you)作用于電(dian)(dian)路(lu)上(shang)。

    電路中的任何電流，會產生磁場，磁場的磁通量又作用于電路上。依據楞次定律，此磁通會借由感應出的電壓（反電動勢）而傾向于抵抗電流的改變。大功率線圈盤磁(ci)通改變量(liang)對電流(liu)改變量(liang)的(de)(de)比值(zhi)稱為自感(gan)(gan)，自感(gan)(gan)通常(chang)也就直接稱作是(shi)這個電路(lu)的(de)(de)電感(gan)(gan)。

    電(dian)感線圈在電(dian)路(lu)中的(de)作用：

    1.阻交流(liu)：在交流(liu)電(dian)路中，電(dian)感(gan)會(hui)有阻抗，即XL，整(zheng)個電(dian)路的電(dian)流(liu)會(hui)變小，對交流(liu)有一定的阻礙作用。

    2.細化解說(shuo)：在(zai)電(dian)子(zi)線路(lu)中，電(dian)感(gan)線圈(quan)對交(jiao)流有限(xian)流作用，它(ta)與(yu)電(dian)阻器(qi)或電(dian)容器(qi)能組成高通或低通濾(lv)波器(qi)、移相電(dian)路(lu)及諧(xie)振電(dian)路(lu)等；

    3.基(ji)本(ben)作用：濾波、振蕩、延遲、陷波等。

    4.形象說(shuo)法：“通直流(liu)，阻交流(liu)”。

    5.通直流：所謂通直流就是指在直流電路中，大功率線圈盤電感的作(zuo)用(yong)就相當于一根導(dao)線，不起(qi)任何作(zuo)用(yong)。

    電(dian)(dian)(dian)(dian)感線圈(quan)的(de)作用(yong)是阻(zu)礙(ai)(ai)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)的(de)變化，但是這種(zhong)作用(yong)與電(dian)(dian)(dian)(dian)阻(zu)阻(zu)礙(ai)(ai)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)流(liu)(liu)(liu)(liu)(liu)通(tong)作用(yong)是有(you)區別(bie)的(de)。電(dian)(dian)(dian)(dian)阻(zu)阻(zu)礙(ai)(ai)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)流(liu)(liu)(liu)(liu)(liu)通(tong)作用(yong)是以消耗電(dian)(dian)(dian)(dian)能為其標志，而電(dian)(dian)(dian)(dian)感阻(zu)礙(ai)(ai)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)的(de)變化則純粹(cui)是不(bu)讓電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)變化，當電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)增加時(shi)電(dian)(dian)(dian)(dian)感阻(zu)礙(ai)(ai)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)的(de)增加，當電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)減小時(shi)電(dian)(dian)(dian)(dian)感阻(zu)礙(ai)(ai)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)的(de)減小。