一、濾波器是干什么用的

濾波器是由電(dian)(dian)(dian)容、電(dian)(dian)(dian)感(gan)和電(dian)(dian)(dian)阻組(zu)成(cheng)的(de)濾波(bo)電(dian)(dian)(dian)路。濾波(bo)器可以(yi)對電(dian)(dian)(dian)源(yuan)線(xian)中特定頻(pin)率的(de)頻(pin)點或該(gai)頻(pin)點以(yi)外(wai)的(de)頻(pin)率進(jin)行有效濾除(chu)，得到(dao)一個特定頻(pin)率的(de)電(dian)(dian)(dian)源(yuan)信(xin)號(hao)，或消除(chu)一個特定頻(pin)率后的(de)電(dian)(dian)(dian)源(yuan)信(xin)號(hao)。

濾波(bo)器是一(yi)種(zhong)選頻(pin)裝(zhuang)置(zhi)，可(ke)以使信號中特(te)定的(de)頻(pin)率成(cheng)分(fen)通過，而(er)極大(da)地衰減(jian)其他頻(pin)率成(cheng)分(fen)。利用(yong)(yong)濾波(bo)器的(de)這種(zhong)選頻(pin)作用(yong)(yong)，可(ke)以濾除干擾噪聲或(huo)進行頻(pin)譜(pu)分(fen)析。換句話說，凡是可(ke)以使信號中特(te)定的(de)頻(pin)率成(cheng)分(fen)通過，而(er)極大(da)地衰減(jian)或(huo)抑制(zhi)其他頻(pin)率成(cheng)分(fen)的(de)裝(zhuang)置(zhi)或(huo)系(xi)統都稱之為濾波(bo)器。

濾(lv)波器(qi)，是對波進(jin)行過(guo)濾(lv)的器(qi)件。“波”是一個(ge)非常廣泛的物(wu)(wu)理概(gai)念，在電(dian)(dian)子技術領域，“波”被狹義地(di)局(ju)限于(yu)特指(zhi)描述各種物(wu)(wu)理量的取(qu)值隨時(shi)間(jian)(jian)起伏變化的過(guo)程。該過(guo)程通過(guo)各類傳感器(qi)的作用，被轉換為(wei)(wei)(wei)(wei)電(dian)(dian)壓或(huo)(huo)電(dian)(dian)流(liu)的時(shi)間(jian)(jian)函數，稱(cheng)之(zhi)(zhi)為(wei)(wei)(wei)(wei)各種物(wu)(wu)理量的時(shi)間(jian)(jian)波形，或(huo)(huo)者稱(cheng)之(zhi)(zhi)為(wei)(wei)(wei)(wei)信(xin)號。因為(wei)(wei)(wei)(wei)自(zi)變量時(shi)間(jian)(jian)是連續取(qu)值的，所以稱(cheng)之(zhi)(zhi)為(wei)(wei)(wei)(wei)連續時(shi)間(jian)(jian)信(xin)號，又習(xi)慣地(di)稱(cheng)之(zhi)(zhi)為(wei)(wei)(wei)(wei)模(mo)擬信(xin)號（Analog Signal）。

濾波是信(xin)號處理(li)中(zhong)(zhong)的一個重要(yao)概(gai)念，在(zai)直(zhi)流(liu)穩壓電源中(zhong)(zhong)濾波電路的作用是盡可能減(jian)小脈動(dong)的直(zhi)流(liu)電壓中(zhong)(zhong)的交流(liu)成(cheng)(cheng)分(fen)，保(bao)留其直(zhi)流(liu)成(cheng)(cheng)分(fen)，使輸出電壓紋波系數(shu)降低，波形(xing)變得比較平滑。

二、電容器是干什么用的

電(dian)(dian)(dian)(dian)(dian)(dian)容器(qi)(qi)是一種用來存(cun)儲(chu)電(dian)(dian)(dian)(dian)(dian)(dian)能的電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)元件。它(ta)由兩個帶(dai)電(dian)(dian)(dian)(dian)(dian)(dian)的金屬板(ban)構(gou)成(cheng)，之間隔著一層介質(zhi)，通常(chang)是空(kong)氣、塑料或(huo)陶(tao)瓷等(deng)。當電(dian)(dian)(dian)(dian)(dian)(dian)容器(qi)(qi)連接(jie)到電(dian)(dian)(dian)(dian)(dian)(dian)源時，電(dian)(dian)(dian)(dian)(dian)(dian)荷會在金屬板(ban)上積聚，形(xing)成(cheng)電(dian)(dian)(dian)(dian)(dian)(dian)場。電(dian)(dian)(dian)(dian)(dian)(dian)容器(qi)(qi)的大小由其存(cun)儲(chu)電(dian)(dian)(dian)(dian)(dian)(dian)荷量(liang)決(jue)定，也就是電(dian)(dian)(dian)(dian)(dian)(dian)容量(liang)，單位是法拉（F）。

三、濾波器和電容器的區別

雖然濾波器(qi)和(he)電容器(qi)都能(neng)在電路中起到一定的作(zuo)用，但它們(men)在功能(neng)和(he)應用上有(you)很大的不同。下面是其主(zhu)要區別。

1、功能不同

電(dian)容器(qi)用于儲(chu)存電(dian)能，可以(yi)(yi)給電(dian)路提(ti)供電(dian)源。而濾波(bo)器(qi)主(zhu)要是用于處理信(xin)號，可以(yi)(yi)濾除或加強特定頻(pin)率的(de)信(xin)號。雖然(ran)濾波(bo)器(qi)中也包(bao)含電(dian)容器(qi)，但它們起到的(de)作用不同。

2、設計不同

電(dian)容器(qi)(qi)的設計主要考慮其電(dian)容量、工作(zuo)頻率、耐壓能力和(he)(he)脈沖測(ce)試(shi)等因素(su)。而濾(lv)(lv)波(bo)(bo)器(qi)(qi)的設計則側重(zhong)于濾(lv)(lv)波(bo)(bo)的截止頻率、紋波(bo)(bo)抑制、增益和(he)(he)可靠(kao)性等因素(su)。因此，濾(lv)(lv)波(bo)(bo)器(qi)(qi)的設計要比電(dian)容器(qi)(qi)更加復雜和(he)(he)深(shen)入。

3、應用不同

電容器廣泛應用于電源電路、電容式觸摸屏、振蕩電路等方面。例如，在音頻放大器中，電容器可以用于隔離(li)直流(liu)和交流(liu)信(xin)號，以確(que)保放(fang)大器(qi)輸(shu)出的(de)是純凈(jing)的(de)音(yin)頻信(xin)號。

濾波器可(ke)以應用(yong)(yong)于(yu)多種(zhong)電(dian)子設(she)備中。例(li)如，低(di)通(tong)(tong)濾波器可(ke)以用(yong)(yong)于(yu)音頻(pin)處理，高通(tong)(tong)濾波器可(ke)以用(yong)(yong)于(yu)降低(di)高頻(pin)電(dian)源噪聲，帶通(tong)(tong)濾波器可(ke)以用(yong)(yong)于(yu)頻(pin)率選擇電(dian)路。