【電(dian)阻的作(zuo)(zuo)用】電(dian)阻在電(dian)路中有(you)什么作(zuo)(zuo)用 電(dian)阻器有(you)哪(na)些分類

電阻在電路中有什么作用

電阻器在日常生活中一般直接稱為電阻?是(shi)一(yi)個(ge)限流元件,將電(dian)(dian)阻接(jie)在(zai)電(dian)(dian)路(lu)中后,電(dian)(dian)阻器(qi)(qi)的(de)(de)(de)阻值是(shi)固定(ding)的(de)(de)(de)一(yi)般是(shi)兩(liang)個(ge)引腳,它(ta)可(ke)限制通(tong)過它(ta)所連支路(lu)的(de)(de)(de)電(dian)(dian)流大小?阻值不(bu)能(neng)改(gai)變(bian)的(de)(de)(de)稱為固定(ding)電(dian)(dian)阻器(qi)(qi)?阻值可(ke)變(bian)的(de)(de)(de)稱為電(dian)(dian)位器(qi)(qi)或可(ke)變(bian)電(dian)(dian)阻器(qi)(qi)?理想的(de)(de)(de)電(dian)(dian)阻器(qi)(qi)是(shi)線(xian)性的(de)(de)(de),即通(tong)過電(dian)(dian)阻器(qi)(qi)的(de)(de)(de)瞬時電(dian)(dian)流與外加瞬時電(dian)(dian)壓(ya)成(cheng)正比?用于分壓(ya)的(de)(de)(de)可(ke)變(bian)電(dian)(dian)阻器(qi)(qi)?在(zai)裸露的(de)(de)(de)電(dian)(dian)阻體(ti)上(shang),緊壓(ya)著一(yi)至(zhi)兩(liang)個(ge)可(ke)移金屬(shu)觸(chu)(chu)點?觸(chu)(chu)點位置確定(ding)電(dian)(dian)阻體(ti)任(ren)一(yi)端與觸(chu)(chu)點間的(de)(de)(de)阻值?

該圖片由注冊用戶"橘子de殿堂"提供，版權聲明反饋

小功率電(dian)阻(zu)器(qi)通(tong)常為(wei)封裝在(zai)塑料外殼中(zhong)的(de)(de)碳膜構成,而(er)(er)大(da)功率的(de)(de)電(dian)阻(zu)器(qi)通(tong)常為(wei)繞線電(dian)阻(zu)器(qi),通(tong)過(guo)將大(da)電(dian)阻(zu)率的(de)(de)金屬(shu)絲繞在(zai)瓷心上(shang)而(er)(er)制(zhi)成?

如(ru)果一(yi)個電(dian)(dian)阻(zu)(zu)器(qi)的(de)(de)電(dian)(dian)阻(zu)(zu)值接(jie)近零歐姆,則該電(dian)(dian)阻(zu)(zu)器(qi)對電(dian)(dian)流沒(mei)有阻(zu)(zu)礙作(zuo)用(yong)(yong),并聯這種電(dian)(dian)阻(zu)(zu)器(qi)的(de)(de)回路被短(duan)路,電(dian)(dian)流無限(xian)大(da)(da)?如(ru)果一(yi)個電(dian)(dian)阻(zu)(zu)器(qi)具有無限(xian)大(da)(da)的(de)(de)或很(hen)大(da)(da)的(de)(de)電(dian)(dian)阻(zu)(zu),則串接(jie)該電(dian)(dian)阻(zu)(zu)器(qi)的(de)(de)回路可(ke)看作(zuo)開路,電(dian)(dian)流為零?工(gong)業中常用(yong)(yong)的(de)(de)電(dian)(dian)阻(zu)(zu)器(qi)介于(yu)兩種極端情況之間,它(ta)具有一(yi)定的(de)(de)電(dian)(dian)阻(zu)(zu),可(ke)通過一(yi)定的(de)(de)電(dian)(dian)流,但電(dian)(dian)流不像短(duan)路時(shi)那樣大(da)(da)?電(dian)(dian)阻(zu)(zu)器(qi)的(de)(de)限(xian)流作(zuo)用(yong)(yong)類似于(yu)接(jie)在兩根大(da)(da)直徑(jing)管子之間的(de)(de)小直徑(jing)管子限(xian)制水流量的(de)(de)作(zuo)用(yong)(yong)?

電阻器有哪些分類

按伏安特性分類

對大多數導體來說,在一定的溫度下,其電阻幾乎維持不變而(er)為一(yi)定(ding)值(zhi),這類電(dian)(dian)(dian)(dian)阻(zu)(zu)稱為線(xian)性電(dian)(dian)(dian)(dian)阻(zu)(zu)?有些材料的(de)電(dian)(dian)(dian)(dian)阻(zu)(zu)明(ming)顯(xian)地隨著電(dian)(dian)(dian)(dian)流(liu)(或電(dian)(dian)(dian)(dian)壓)而(er)變化,其(qi)伏(fu)—安(an)特(te)性是一(yi)條曲(qu)線(xian),這類電(dian)(dian)(dian)(dian)阻(zu)(zu)稱為非線(xian)性電(dian)(dian)(dian)(dian)阻(zu)(zu)?非線(xian)性電(dian)(dian)(dian)(dian)阻(zu)(zu)在某(mou)一(yi)給(gei)定(ding)的(de)電(dian)(dian)(dian)(dian)壓(或電(dian)(dian)(dian)(dian)流(liu))作用下(xia)(xia),電(dian)(dian)(dian)(dian)壓與電(dian)(dian)(dian)(dian)流(liu)的(de)比值(zhi)為在該工(gong)作點(dian)下(xia)(xia)的(de)靜態(tai)電(dian)(dian)(dian)(dian)阻(zu)(zu),伏(fu)—安(an)特(te)性曲(qu)線(xian)上的(de)斜(xie)率為動態(tai)電(dian)(dian)(dian)(dian)阻(zu)(zu)?表達非線(xian)性電(dian)(dian)(dian)(dian)阻(zu)(zu)特(te)性的(de)方式比較復雜,但這些非線(xian)性關系在電(dian)(dian)(dian)(dian)子電(dian)(dian)(dian)(dian)路中(zhong)得到(dao)了廣泛的(de)應用?

按材料分類

a?線(xian)繞(rao)電阻(zu)(zu)(zu)器由電阻(zu)(zu)(zu)線(xian)繞(rao)成電阻(zu)(zu)(zu)器 用高(gao)(gao)阻(zu)(zu)(zu)合金線(xian)繞(rao)在絕(jue)緣骨架上制成,外面涂有(you)(you)耐熱(re)的釉絕(jue)緣層(ceng)或絕(jue)緣漆?繞(rao)線(xian)電阻(zu)(zu)(zu)具(ju)有(you)(you)較低(di)的溫(wen)度(du)(du)系數,阻(zu)(zu)(zu)值精度(du)(du)高(gao)(gao),穩定(ding)性好,耐熱(re)耐腐蝕,主要做精密(mi)大功率電阻(zu)(zu)(zu)使用,缺點是高(gao)(gao)頻(pin)性能差,時間(jian)常數大?

b?碳合(he)(he)成(cheng)電阻器由碳及合(he)(he)成(cheng)塑膠壓制成(cheng)而(er)成(cheng)?

c?碳膜電阻器在瓷管上鍍(du)上一層碳而成,將結晶碳沉(chen)積在陶瓷棒骨架上制成?碳膜電阻器成本(ben)低?性能穩定?阻值范圍寬?溫(wen)度系數(shu)(shu)和(he)電壓系數(shu)(shu)低,是目前應用最廣泛的電阻器?

d?金(jin)屬膜電阻器在(zai)瓷管上(shang)鍍(du)上(shang)一層(ceng)金(jin)屬而(er)成,用(yong)真空蒸發的方法將合金(jin)材料蒸鍍(du)于陶瓷棒骨架表(biao)面?

金(jin)屬膜電(dian)阻比(bi)碳膜電(dian)阻的精度高,穩(wen)定性好,噪聲,溫度系(xi)數小?在儀器儀表(biao)及通訊(xun)設(she)備(bei)中大量(liang)采用?

e?金屬氧化膜電阻器(qi)在瓷(ci)管上鍍(du)上一(yi)層(ceng)氧化(hua)錫而成,在絕緣棒上沉積(ji)一(yi)層(ceng)金屬氧化(hua)物?由于其(qi)本身即(ji)是氧化(hua)物,所以高溫下穩定,耐熱沖擊,負載能(neng)力(li)強(qiang) 按用途分(fen),有通用?精密?高頻?高壓?高阻(zu)?大功率和電阻(zu)網絡等?

特殊電阻器

1?保(bao)險電(dian)(dian)阻(zu)(zu):又叫熔斷(duan)電(dian)(dian)阻(zu)(zu)器,在正常情況(kuang)下起著電(dian)(dian)阻(zu)(zu)和保(bao)險絲的(de)雙(shuang)重作用,當電(dian)(dian)路出現(xian)故障而(er)使(shi)其功率(lv)超過額定功率(lv)時(shi),它會像保(bao)險絲一樣熔斷(duan)使(shi)連接電(dian)(dian)路斷(duan)開?保(bao)險絲電(dian)(dian)阻(zu)(zu)一般電(dian)(dian)阻(zu)(zu)值都小(0.33Ω~10KΩ),功率(lv)也較小?保(bao)險絲電(dian)(dian)阻(zu)(zu)器常用型(xing)號有:RF10型(xing)?RF111-5保(bao)險絲電(dian)(dian)阻(zu)(zu)器的(de)符號型(xing)?RRD0910型(xing)?RRD0911型(xing)等?

2?敏(min)感(gan)(gan)電(dian)(dian)阻(zu)(zu)(zu)(zu)器:是指其電(dian)(dian)阻(zu)(zu)(zu)(zu)值(zhi)(zhi)對于(yu)某種物(wu)理量(如溫(wen)度?濕(shi)度?光照?電(dian)(dian)壓?機(ji)械(xie)力?以及氣體(ti)濃度等(deng))具有敏(min)感(gan)(gan)特(te)性,當(dang)這些(xie)物(wu)理量發生變(bian)化時,敏(min)感(gan)(gan)電(dian)(dian)阻(zu)(zu)(zu)(zu)的(de)阻(zu)(zu)(zu)(zu)值(zhi)(zhi)就會隨物(wu)理量變(bian)化而發生改變(bian),呈現不同(tong)的(de)電(dian)(dian)阻(zu)(zu)(zu)(zu)值(zhi)(zhi)?根據對不同(tong)物(wu)理量敏(min)感(gan)(gan),敏(min)感(gan)(gan)電(dian)(dian)阻(zu)(zu)(zu)(zu)器可分為(wei)熱敏(min)?濕(shi)敏(min)?光敏(min)?壓敏(min)?力敏(min)?磁敏(min)和(he)氣敏(min)等(deng)類型(xing)敏(min)感(gan)(gan)電(dian)(dian)阻(zu)(zu)(zu)(zu)?敏(min)感(gan)(gan)電(dian)(dian)阻(zu)(zu)(zu)(zu)器所用(yong)的(de)材料幾(ji)乎都是半(ban)(ban)導(dao)體(ti)材料,這類電(dian)(dian)阻(zu)(zu)(zu)(zu)器也稱為(wei)半(ban)(ban)導(dao)體(ti)電(dian)(dian)阻(zu)(zu)(zu)(zu)器?

熱敏電阻的阻(zu)(zu)(zu)(zu)值(zhi)(zhi)隨(sui)溫(wen)(wen)度(du)(du)(du)變(bian)化而變(bian)化,溫(wen)(wen)度(du)(du)(du)升高(gao)阻(zu)(zu)(zu)(zu)為負(fu)(fu)溫(wen)(wen)度(du)(du)(du)系數(shu)(shu)(NTC)熱(re)敏電(dian)阻(zu)(zu)(zu)(zu)?應(ying)用(yong)較多的是(shi)負(fu)(fu)溫(wen)(wen)度(du)(du)(du)系數(shu)(shu)熱(re)敏電(dian)阻(zu)(zu)(zu)(zu),又(you)可(ke)分為普通型(xing)負(fu)(fu)溫(wen)(wen)度(du)(du)(du)系數(shu)(shu)熱(re)敏電(dian)阻(zu)(zu)(zu)(zu);穩壓型(xing)負(fu)(fu)溫(wen)(wen)度(du)(du)(du)系數(shu)(shu)熱(re)敏電(dian)阻(zu)(zu)(zu)(zu);測溫(wen)(wen)型(xing)負(fu)(fu)溫(wen)(wen)度(du)(du)(du)系數(shu)(shu)熱(re)敏電(dian)阻(zu)(zu)(zu)(zu)等? 光(guang)(guang)敏電(dian)阻(zu)(zu)(zu)(zu)是(shi)電(dian)阻(zu)(zu)(zu)(zu)的阻(zu)(zu)(zu)(zu)值(zhi)(zhi)隨(sui)入(ru)射(she)光(guang)(guang)的強(qiang)弱變(bian)化而改變(bian),當入(ru)射(she)光(guang)(guang)增(zeng)強(qiang)時(shi),光(guang)(guang)敏電(dian)阻(zu)(zu)(zu)(zu)的減小,入(ru)射(she)光(guang)(guang)減弱時(shi)電(dian)阻(zu)(zu)(zu)(zu)值(zhi)(zhi)增(zeng)大?