【電(dian)阻的作用】電(dian)阻在電(dian)路(lu)中有(you)什么作用 電(dian)阻器(qi)有(you)哪些分(fen)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)一個限流元(yuan)件,將電(dian)(dian)(dian)(dian)阻(zu)(zu)接在(zai)電(dian)(dian)(dian)(dian)路(lu)中后(hou),電(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)的(de)(de)阻(zu)(zu)值(zhi)是(shi)固定的(de)(de)一般是(shi)兩個引(yin)腳,它可(ke)(ke)限制通過它所連支(zhi)路(lu)的(de)(de)電(dian)(dian)(dian)(dian)流大小?阻(zu)(zu)值(zhi)不能改(gai)變(bian)的(de)(de)稱(cheng)為固定電(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)?阻(zu)(zu)值(zhi)可(ke)(ke)變(bian)的(de)(de)稱(cheng)為電(dian)(dian)(dian)(dian)位器(qi)(qi)或可(ke)(ke)變(bian)電(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)?理(li)想(xiang)的(de)(de)電(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)是(shi)線性的(de)(de),即通過電(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)的(de)(de)瞬時電(dian)(dian)(dian)(dian)流與(yu)外(wai)加瞬時電(dian)(dian)(dian)(dian)壓成正比(bi)?用于分壓的(de)(de)可(ke)(ke)變(bian)電(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)?在(zai)裸露的(de)(de)電(dian)(dian)(dian)(dian)阻(zu)(zu)體上,緊壓著一至兩個可(ke)(ke)移金(jin)屬(shu)觸(chu)點(dian)?觸(chu)點(dian)位置確定電(dian)(dian)(dian)(dian)阻(zu)(zu)體任(ren)一端與(yu)觸(chu)點(dian)間的(de)(de)阻(zu)(zu)值(zhi)?

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小功率(lv)電阻器(qi)通常為(wei)封(feng)裝在(zai)塑(su)料外(wai)殼中的(de)(de)碳膜構(gou)成,而大功率(lv)的(de)(de)電阻器(qi)通常為(wei)繞(rao)線(xian)電阻器(qi),通過將大電阻率(lv)的(de)(de)金屬絲繞(rao)在(zai)瓷心(xin)上(shang)而制(zhi)成?

如(ru)果(guo)(guo)一個(ge)電(dian)(dian)阻(zu)器(qi)的(de)(de)電(dian)(dian)阻(zu)值接近零(ling)歐姆,則該(gai)電(dian)(dian)阻(zu)器(qi)對電(dian)(dian)流沒有(you)(you)阻(zu)礙作用,并聯這種(zhong)電(dian)(dian)阻(zu)器(qi)的(de)(de)回(hui)路被短路,電(dian)(dian)流無限大?如(ru)果(guo)(guo)一個(ge)電(dian)(dian)阻(zu)器(qi)具有(you)(you)無限大的(de)(de)或(huo)很(hen)大的(de)(de)電(dian)(dian)阻(zu),則串接該(gai)電(dian)(dian)阻(zu)器(qi)的(de)(de)回(hui)路可(ke)看(kan)作開(kai)路,電(dian)(dian)流為零(ling)?工業中常用的(de)(de)電(dian)(dian)阻(zu)器(qi)介于兩種(zhong)極端情況之(zhi)間,它具有(you)(you)一定的(de)(de)電(dian)(dian)阻(zu),可(ke)通過(guo)一定的(de)(de)電(dian)(dian)流,但電(dian)(dian)流不像短路時那(nei)樣大?電(dian)(dian)阻(zu)器(qi)的(de)(de)限流作用類似于接在兩根(gen)大直(zhi)徑(jing)管(guan)子之(zhi)間的(de)(de)小(xiao)直(zhi)徑(jing)管(guan)子限制水流量的(de)(de)作用?

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(bian)而為一定值(zhi),這類(lei)電(dian)阻(zu)稱(cheng)為線性電(dian)阻(zu)?有(you)些(xie)材料的(de)(de)(de)電(dian)阻(zu)明顯(xian)地(di)隨著電(dian)流(liu)(或電(dian)壓)而變(bian)化,其(qi)伏—安特性是一條(tiao)曲線,這類(lei)電(dian)阻(zu)稱(cheng)為非(fei)線性電(dian)阻(zu)?非(fei)線性電(dian)阻(zu)在(zai)某一給(gei)定的(de)(de)(de)電(dian)壓(或電(dian)流(liu))作用(yong)下,電(dian)壓與電(dian)流(liu)的(de)(de)(de)比(bi)值(zhi)為在(zai)該工作點下的(de)(de)(de)靜態(tai)電(dian)阻(zu),伏—安特性曲線上的(de)(de)(de)斜率為動態(tai)電(dian)阻(zu)?表達(da)非(fei)線性電(dian)阻(zu)特性的(de)(de)(de)方式比(bi)較復雜(za),但這些(xie)非(fei)線性關系(xi)在(zai)電(dian)子電(dian)路(lu)中得(de)到了廣(guang)泛的(de)(de)(de)應(ying)用(yong)?

按材料分類

a?線繞(rao)(rao)電(dian)阻(zu)器由電(dian)阻(zu)線繞(rao)(rao)成電(dian)阻(zu)器 用高阻(zu)合(he)金線繞(rao)(rao)在絕(jue)(jue)緣骨架上制成,外面涂有(you)耐熱(re)(re)的(de)釉絕(jue)(jue)緣層或(huo)絕(jue)(jue)緣漆?繞(rao)(rao)線電(dian)阻(zu)具有(you)較低的(de)溫度系(xi)數(shu),阻(zu)值精(jing)度高,穩定性好,耐熱(re)(re)耐腐蝕(shi),主要(yao)做精(jing)密大(da)功率(lv)電(dian)阻(zu)使用,缺點是高頻性能差(cha),時間常(chang)數(shu)大(da)?

b?碳合(he)成(cheng)電阻(zu)器由碳及合(he)成(cheng)塑膠壓制(zhi)成(cheng)而成(cheng)?

c?碳(tan)(tan)膜電阻(zu)器(qi)在瓷(ci)管(guan)上(shang)鍍上(shang)一(yi)層(ceng)碳(tan)(tan)而成(cheng),將結晶(jing)碳(tan)(tan)沉積在陶(tao)瓷(ci)棒骨架上(shang)制成(cheng)?碳(tan)(tan)膜電阻(zu)器(qi)成(cheng)本(ben)低(di)?性能穩(wen)定?阻(zu)值(zhi)范圍寬?溫度(du)系數(shu)和電壓(ya)系數(shu)低(di),是目前應(ying)用最廣泛的電阻(zu)器(qi)?

d?金屬膜電阻(zu)器(qi)在瓷管上鍍(du)上一層金屬而(er)成,用真空蒸發的方法將合金材料蒸鍍(du)于陶瓷棒骨架表面?

金屬膜(mo)電阻(zu)(zu)比碳膜(mo)電阻(zu)(zu)的精度(du)高,穩定性(xing)好,噪聲,溫度(du)系(xi)數(shu)小?在(zai)儀(yi)器(qi)儀(yi)表及通(tong)訊設備中大量采用?

e?金屬氧化膜電阻器在(zai)瓷(ci)管上(shang)鍍上(shang)一層(ceng)氧化(hua)(hua)錫(xi)而成,在(zai)絕緣(yuan)棒上(shang)沉積一層(ceng)金屬氧化(hua)(hua)物?由于(yu)其本身即是氧化(hua)(hua)物,所(suo)以高溫下穩(wen)定(ding),耐熱沖擊,負載能(neng)力強 按用(yong)途分,有通(tong)用(yong)?精(jing)密?高頻?高壓?高阻?大功率和(he)電(dian)阻網絡等?

特殊電阻器

1?保(bao)險電(dian)(dian)阻(zu)(zu):又叫熔斷(duan)(duan)電(dian)(dian)阻(zu)(zu)器(qi),在正常情況下起著電(dian)(dian)阻(zu)(zu)和保(bao)險絲(si)(si)(si)的雙重(zhong)作(zuo)用(yong),當電(dian)(dian)路出現故障而(er)使(shi)其功(gong)(gong)率超過額定功(gong)(gong)率時,它(ta)會像保(bao)險絲(si)(si)(si)一樣(yang)熔斷(duan)(duan)使(shi)連接電(dian)(dian)路斷(duan)(duan)開?保(bao)險絲(si)(si)(si)電(dian)(dian)阻(zu)(zu)一般電(dian)(dian)阻(zu)(zu)值(zhi)都(dou)小(xiao)(0.33Ω~10KΩ),功(gong)(gong)率也較小(xiao)?保(bao)險絲(si)(si)(si)電(dian)(dian)阻(zu)(zu)器(qi)常用(yong)型(xing)號有:RF10型(xing)?RF111-5保(bao)險絲(si)(si)(si)電(dian)(dian)阻(zu)(zu)器(qi)的符號型(xing)?RRD0910型(xing)?RRD0911型(xing)等?

2?敏(min)(min)感電阻(zu)(zu)器(qi):是指(zhi)其電阻(zu)(zu)值對于某種(zhong)物(wu)理量(如溫度?濕度?光照?電壓?機械(xie)力(li)?以(yi)及氣體濃度等)具有敏(min)(min)感特性,當這些物(wu)理量發(fa)生變(bian)化(hua)時,敏(min)(min)感電阻(zu)(zu)的(de)(de)阻(zu)(zu)值就會隨(sui)物(wu)理量變(bian)化(hua)而發(fa)生改(gai)變(bian),呈現不(bu)同(tong)的(de)(de)電阻(zu)(zu)值?根據對不(bu)同(tong)物(wu)理量敏(min)(min)感,敏(min)(min)感電阻(zu)(zu)器(qi)可分為(wei)熱敏(min)(min)?濕敏(min)(min)?光敏(min)(min)?壓敏(min)(min)?力(li)敏(min)(min)?磁敏(min)(min)和氣敏(min)(min)等類型敏(min)(min)感電阻(zu)(zu)?敏(min)(min)感電阻(zu)(zu)器(qi)所用的(de)(de)材料幾乎都是半導(dao)體材料,這類電阻(zu)(zu)器(qi)也稱為(wei)半導(dao)體電阻(zu)(zu)器(qi)?

熱敏電阻的(de)阻(zu)(zu)值隨(sui)溫(wen)(wen)(wen)度變(bian)化而變(bian)化,溫(wen)(wen)(wen)度升高阻(zu)(zu)為負溫(wen)(wen)(wen)度系(xi)數(NTC)熱(re)敏(min)(min)電阻(zu)(zu)?應用較(jiao)多的(de)是負溫(wen)(wen)(wen)度系(xi)數熱(re)敏(min)(min)電阻(zu)(zu),又可分為普(pu)通型(xing)負溫(wen)(wen)(wen)度系(xi)數熱(re)敏(min)(min)電阻(zu)(zu);穩壓(ya)型(xing)負溫(wen)(wen)(wen)度系(xi)數熱(re)敏(min)(min)電阻(zu)(zu);測溫(wen)(wen)(wen)型(xing)負溫(wen)(wen)(wen)度系(xi)數熱(re)敏(min)(min)電阻(zu)(zu)等? 光(guang)(guang)敏(min)(min)電阻(zu)(zu)是電阻(zu)(zu)的(de)阻(zu)(zu)值隨(sui)入(ru)射(she)光(guang)(guang)的(de)強弱(ruo)變(bian)化而改變(bian),當入(ru)射(she)光(guang)(guang)增(zeng)強時(shi),光(guang)(guang)敏(min)(min)電阻(zu)(zu)的(de)減(jian)小,入(ru)射(she)光(guang)(guang)減(jian)弱(ruo)時(shi)電阻(zu)(zu)值增(zeng)大?