什么是電感器, 它在電路中有什么作用？t如何運用的?

電(dian)(dian)感是衡(heng)量(liang)(liang)(liang)線(xian)(xian)圈(quan)(quan)產生電(dian)(dian)磁感應(ying)能力的(de)(de)物(wu)理量(liang)(liang)(liang)。給一個線(xian)(xian)圈(quan)(quan)通(tong)(tong)入(ru)電(dian)(dian)流，線(xian)(xian)圈(quan)(quan)周(zhou)圍就(jiu)會產生磁場(chang)，線(xian)(xian)圈(quan)(quan)就(jiu)有(you)磁通(tong)(tong)量(liang)(liang)(liang)通(tong)(tong)過(guo)(guo)。通(tong)(tong)入(ru)線(xian)(xian)圈(quan)(quan)的(de)(de)電(dian)(dian)源(yuan)越(yue)大，磁場(chang)就(jiu)越(yue)強，通(tong)(tong)過(guo)(guo)線(xian)(xian)圈(quan)(quan)的(de)(de)磁通(tong)(tong)量(liang)(liang)(liang)就(jiu)越(yue)大。實驗證明，通(tong)(tong)過(guo)(guo)線(xian)(xian)圈(quan)(quan)的(de)(de)磁通(tong)(tong)量(liang)(liang)(liang)和(he)通(tong)(tong)入(ru)的(de)(de)電(dian)(dian)流是成正比的(de)(de)，它們(men)的(de)(de)比值叫(jiao)(jiao)做自感系數(shu)，也叫(jiao)(jiao)做電(dian)(dian)感。如果通(tong)(tong)過(guo)(guo)線(xian)(xian)圈(quan)(quan)的(de)(de)磁通(tong)(tong)量(liang)(liang)(liang)用φ表示，電(dian)流用(yong)I表示，電感用(yong)L表(biao)示(shi)，那(nei)么(me)

L＝ φ／I

     電(dian)感的單位是亨（H），也(ye)常用毫亨（mH）或微亨（uH）做(zuo)單位。1H=1000mH，1H=1000000uH。



     電(dian)(dian)感(gan)只能對(dui)非穩恒電(dian)(dian)流起作用，它(ta)的(de)特點(dian)兩端電(dian)(dian)壓正比(bi)于(yu)通(tong)過他的(de)電(dian)(dian)流的(de)瞬時變化(hua)率（導(dao)數），比(bi)例(li)系數就是它(ta)的(de)“自(zi)感” 



     電(dian)(dian)感起(qi)作用(yong)的(de)(de)原因是(shi)它(ta)在通過(guo)(guo)非(fei)(fei)穩恒電(dian)(dian)流時產生(sheng)變(bian)(bian)化的(de)(de)磁場(chang)，而(er)這(zhe)個磁場(chang)又(you)會(hui)反過(guo)(guo)來影響電(dian)(dian)流，所(suo)以(yi)(yi)，這(zhe)么說來，任(ren)何一個導體(ti)，只要它(ta)通過(guo)(guo)非(fei)(fei)穩恒電(dian)(dian)流，就會(hui)產生(sheng)變(bian)(bian)化的(de)(de)磁場(chang)，就會(hui)反過(guo)(guo)來影響電(dian)(dian)流，所(suo)以(yi)(yi)任(ren)何導體(ti)都(dou)會(hui)有自感現象產生(sheng)



     在(zai)主板(ban)上可以(yi)看(kan)到很多(duo)銅線纏繞的線圈，這(zhe)個線圈就叫電(dian)(dian)感(gan)(gan)，電(dian)(dian)感(gan)(gan)主要分(fen)為磁(ci)心(xin)(xin)電(dian)(dian)感(gan)(gan)和(he)空(kong)心(xin)(xin)電(dian)(dian)感(gan)(gan)兩種，磁(ci)心(xin)(xin)電(dian)(dian)感(gan)(gan)電(dian)(dian)感(gan)(gan)量大(da)常用在(zai)濾(lv)波電(dian)(dian)路(lu)，空(kong)心(xin)(xin)電(dian)(dian)感(gan)(gan)電(dian)(dian)感(gan)(gan)量較小，常用于(yu)高頻電(dian)(dian)路(lu)。 



     電(dian)(dian)感的特(te)性與電(dian)(dian)容的特(te)性正好相反，它(ta)具有阻止交流(liu)電(dian)(dian)通(tong)過而讓直流(liu)電(dian)(dian)順利通(tong)過的特(te)性。電(dian)(dian)感的特(te)性是通(tong)直流(liu)、阻交流(liu)，頻(pin)率越高，線圈阻抗越大。電(dian)(dian)感器在電(dian)(dian)路中經常和電(dian)(dian)容一起工作，構(gou)成LC濾波器、LC振蕩器(qi)等(deng)。另外，人們(men)還利用電感的特性，制造了阻流圈(quan)、變壓(ya)器(qi)、繼電器(qi)等(deng)。 



【電(dian)感(gan)器的種類】



  按(an)照外形(xing)，電感器可分為空心(xin)電感器(空心線圈)與實心(xin)電感器(qi)(實(shi)心線圈)。按照工作性質(zhi)，電(dian)感器可分為高(gao)頻電(dian)感器(各種天線(xian)線(xian)圈(quan)、振蕩線(xian)圈(quan))和低頻電感器(各種扼流圈、濾波線圈等)。按(an)照封裝形式，電(dian)(dian)(dian)感(gan)(gan)(gan)(gan)(gan)器(qi)可分(fen)為普通電(dian)(dian)(dian)感(gan)(gan)(gan)(gan)(gan)器(qi)、色環(huan)(huan)電(dian)(dian)(dian)感(gan)(gan)(gan)(gan)(gan)器(qi)、環(huan)(huan)氧樹脂(zhi)電(dian)(dian)(dian)感(gan)(gan)(gan)(gan)(gan)器(qi)、貼片電(dian)(dian)(dian)感(gan)(gan)(gan)(gan)(gan)器(qi)等(deng)。按(an)照電(dian)(dian)(dian)感(gan)(gan)(gan)(gan)(gan)量，電(dian)(dian)(dian)感(gan)(gan)(gan)(gan)(gan)器(qi)可分(fen)為固(gu)定電(dian)(dian)(dian)感(gan)(gan)(gan)(gan)(gan)器(qi)和可調(diao)電(dian)(dian)(dian)感(gan)(gan)(gan)(gan)(gan)器(qi)。 



電感(gan)作用：通直流，阻(zu)交流：濾波、振蕩、延遲、陷波 



在電(dian)子線(xian)(xian)路中，電(dian)感(gan)線(xian)(xian)圈對交流(liu)有(you)限(xian)流(liu)作用，它與(yu)電(dian)阻器(qi)或電(dian)容器(qi)能組成高通或低(di)通濾波器(qi)、移(yi)相電(dian)路及(ji)諧(xie)振(zhen)電(dian)路等(deng)；變(bian)(bian)壓器(qi)可以進(jin)行交流(liu)耦(ou)合、變(bian)(bian)壓、變(bian)(bian)流(liu)和阻抗變(bian)(bian)換等(deng)