【電(dian)阻(zu)的作用(yong)】電(dian)阻(zu)在電(dian)路中有什么作用(yong) 電(dian)阻(zu)器有哪些分類

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?是一(yi)(yi)個(ge)限(xian)(xian)流(liu)元件(jian),將電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)接在電(dian)(dian)(dian)路(lu)中后,電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)器(qi)的(de)(de)(de)阻(zu)(zu)(zu)(zu)值(zhi)是固定(ding)的(de)(de)(de)一(yi)(yi)般是兩(liang)個(ge)引腳(jiao),它可限(xian)(xian)制(zhi)通過(guo)它所連支(zhi)路(lu)的(de)(de)(de)電(dian)(dian)(dian)流(liu)大小(xiao)?阻(zu)(zu)(zu)(zu)值(zhi)不(bu)能改變的(de)(de)(de)稱為固定(ding)電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)器(qi)?阻(zu)(zu)(zu)(zu)值(zhi)可變的(de)(de)(de)稱為電(dian)(dian)(dian)位器(qi)或可變電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)器(qi)?理想的(de)(de)(de)電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)器(qi)是線性的(de)(de)(de),即通過(guo)電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)器(qi)的(de)(de)(de)瞬(shun)(shun)時電(dian)(dian)(dian)流(liu)與外(wai)加瞬(shun)(shun)時電(dian)(dian)(dian)壓成正比?用于分壓的(de)(de)(de)可變電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)器(qi)?在裸(luo)露的(de)(de)(de)電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)體(ti)上,緊(jin)壓著一(yi)(yi)至兩(liang)個(ge)可移金屬觸點?觸點位置確定(ding)電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)體(ti)任一(yi)(yi)端與觸點間(jian)的(de)(de)(de)阻(zu)(zu)(zu)(zu)值(zhi)?

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小功(gong)率電(dian)阻(zu)器通(tong)常為封裝(zhuang)在塑料外殼中的(de)碳膜(mo)構成(cheng),而(er)大功(gong)率的(de)電(dian)阻(zu)器通(tong)常為繞(rao)線電(dian)阻(zu)器,通(tong)過(guo)將大電(dian)阻(zu)率的(de)金屬絲繞(rao)在瓷心上(shang)而(er)制(zhi)成(cheng)?

如(ru)果一個電(dian)阻(zu)(zu)(zu)器(qi)(qi)(qi)的(de)(de)電(dian)阻(zu)(zu)(zu)值接近(jin)零(ling)歐姆,則該電(dian)阻(zu)(zu)(zu)器(qi)(qi)(qi)對電(dian)流(liu)沒(mei)有阻(zu)(zu)(zu)礙(ai)作(zuo)用,并聯(lian)這種電(dian)阻(zu)(zu)(zu)器(qi)(qi)(qi)的(de)(de)回路被短(duan)路,電(dian)流(liu)無限大(da)?如(ru)果一個電(dian)阻(zu)(zu)(zu)器(qi)(qi)(qi)具(ju)有無限大(da)的(de)(de)或很大(da)的(de)(de)電(dian)阻(zu)(zu)(zu),則串接該電(dian)阻(zu)(zu)(zu)器(qi)(qi)(qi)的(de)(de)回路可看作(zuo)開路,電(dian)流(liu)為零(ling)?工(gong)業中常用的(de)(de)電(dian)阻(zu)(zu)(zu)器(qi)(qi)(qi)介(jie)于(yu)兩種極(ji)端(duan)情況之間(jian),它具(ju)有一定的(de)(de)電(dian)阻(zu)(zu)(zu),可通過一定的(de)(de)電(dian)流(liu),但電(dian)流(liu)不(bu)像短(duan)路時那(nei)樣(yang)大(da)?電(dian)阻(zu)(zu)(zu)器(qi)(qi)(qi)的(de)(de)限流(liu)作(zuo)用類似(si)于(yu)接在(zai)兩根(gen)大(da)直徑管子之間(jian)的(de)(de)小直徑管子限制(zhi)水流(liu)量的(de)(de)作(zuo)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而(er)為一定(ding)值,這(zhe)類(lei)(lei)電(dian)(dian)阻(zu)(zu)稱(cheng)為線(xian)(xian)性(xing)(xing)電(dian)(dian)阻(zu)(zu)?有(you)些材料的(de)(de)電(dian)(dian)阻(zu)(zu)明(ming)顯地(di)隨(sui)著電(dian)(dian)流(liu)(liu)(或電(dian)(dian)壓(ya))而(er)變化,其(qi)伏(fu)—安特性(xing)(xing)是一條曲線(xian)(xian),這(zhe)類(lei)(lei)電(dian)(dian)阻(zu)(zu)稱(cheng)為非(fei)(fei)線(xian)(xian)性(xing)(xing)電(dian)(dian)阻(zu)(zu)?非(fei)(fei)線(xian)(xian)性(xing)(xing)電(dian)(dian)阻(zu)(zu)在某一給定(ding)的(de)(de)電(dian)(dian)壓(ya)(或電(dian)(dian)流(liu)(liu))作用下,電(dian)(dian)壓(ya)與電(dian)(dian)流(liu)(liu)的(de)(de)比值為在該工作點(dian)下的(de)(de)靜態(tai)(tai)電(dian)(dian)阻(zu)(zu),伏(fu)—安特性(xing)(xing)曲線(xian)(xian)上(shang)的(de)(de)斜率(lv)為動態(tai)(tai)電(dian)(dian)阻(zu)(zu)?表達非(fei)(fei)線(xian)(xian)性(xing)(xing)電(dian)(dian)阻(zu)(zu)特性(xing)(xing)的(de)(de)方(fang)式比較復雜,但這(zhe)些非(fei)(fei)線(xian)(xian)性(xing)(xing)關(guan)系在電(dian)(dian)子電(dian)(dian)路中得到了廣泛(fan)的(de)(de)應用?

按材料分類

a?線繞電(dian)(dian)阻(zu)器(qi)由(you)電(dian)(dian)阻(zu)線繞成電(dian)(dian)阻(zu)器(qi) 用高阻(zu)合(he)金線繞在絕緣(yuan)(yuan)骨(gu)架上制成,外面涂有(you)耐熱(re)的釉絕緣(yuan)(yuan)層(ceng)或絕緣(yuan)(yuan)漆?繞線電(dian)(dian)阻(zu)具有(you)較低的溫度(du)系數(shu),阻(zu)值精度(du)高,穩定性(xing)好,耐熱(re)耐腐(fu)蝕,主要做(zuo)精密大功率電(dian)(dian)阻(zu)使用,缺(que)點是高頻性(xing)能差,時間常(chang)數(shu)大?

b?碳合(he)成(cheng)(cheng)電(dian)阻器由(you)碳及合(he)成(cheng)(cheng)塑膠壓(ya)制成(cheng)(cheng)而成(cheng)(cheng)?

c?碳(tan)膜(mo)電(dian)阻(zu)器在瓷管上(shang)鍍上(shang)一層碳(tan)而成(cheng)(cheng),將結晶(jing)碳(tan)沉(chen)積在陶瓷棒骨架上(shang)制成(cheng)(cheng)?碳(tan)膜(mo)電(dian)阻(zu)器成(cheng)(cheng)本低?性能穩(wen)定?阻(zu)值范圍寬?溫度系數和電(dian)壓(ya)系數低,是目前(qian)應用最(zui)廣泛的電(dian)阻(zu)器?

d?金(jin)(jin)屬膜電阻器在瓷管上鍍上一層金(jin)(jin)屬而成,用(yong)真空蒸發的方法(fa)將合金(jin)(jin)材(cai)料(liao)蒸鍍于陶瓷棒骨架表面?

金屬膜(mo)電(dian)阻比(bi)碳(tan)膜(mo)電(dian)阻的精度高,穩定性好(hao),噪聲,溫度系數小(xiao)?在儀器儀表及通訊設備中大(da)量采(cai)用?

e?金屬氧化膜電阻器在(zai)瓷(ci)管上鍍上一層氧(yang)化錫(xi)而成(cheng),在(zai)絕緣(yuan)棒上沉積一層金屬氧(yang)化物?由于其本(ben)身即是氧(yang)化物,所以高(gao)(gao)溫下穩定,耐熱沖擊,負載能力強 按用(yong)途分,有通用(yong)?精密(mi)?高(gao)(gao)頻?高(gao)(gao)壓?高(gao)(gao)阻?大功(gong)率(lv)和電阻網絡等(deng)?

特殊電阻器

1?保(bao)(bao)險(xian)電(dian)(dian)阻(zu):又(you)叫熔(rong)斷電(dian)(dian)阻(zu)器(qi),在正常情況下起著電(dian)(dian)阻(zu)和保(bao)(bao)險(xian)絲的(de)雙重作(zuo)用(yong),當電(dian)(dian)路出(chu)現故障而(er)使(shi)其(qi)功(gong)率超過額定功(gong)率時,它會像保(bao)(bao)險(xian)絲一(yi)樣熔(rong)斷使(shi)連接電(dian)(dian)路斷開?保(bao)(bao)險(xian)絲電(dian)(dian)阻(zu)一(yi)般電(dian)(dian)阻(zu)值都小(xiao)(0.33Ω~10KΩ),功(gong)率也較小(xiao)?保(bao)(bao)險(xian)絲電(dian)(dian)阻(zu)器(qi)常用(yong)型(xing)號有(you):RF10型(xing)?RF111-5保(bao)(bao)險(xian)絲電(dian)(dian)阻(zu)器(qi)的(de)符號型(xing)?RRD0910型(xing)?RRD0911型(xing)等?

2?敏(min)(min)(min)感(gan)(gan)電(dian)(dian)阻器(qi):是指其電(dian)(dian)阻值(zhi)對于某種物理量(liang)(liang)(如溫度(du)?濕(shi)度(du)?光照?電(dian)(dian)壓(ya)?機械(xie)力?以及氣體濃度(du)等)具有敏(min)(min)(min)感(gan)(gan)特性,當這(zhe)些物理量(liang)(liang)發生變(bian)化(hua)時,敏(min)(min)(min)感(gan)(gan)電(dian)(dian)阻的阻值(zhi)就會隨物理量(liang)(liang)變(bian)化(hua)而發生改變(bian),呈現不同(tong)的電(dian)(dian)阻值(zhi)?根據(ju)對不同(tong)物理量(liang)(liang)敏(min)(min)(min)感(gan)(gan),敏(min)(min)(min)感(gan)(gan)電(dian)(dian)阻器(qi)可分為熱敏(min)(min)(min)?濕(shi)敏(min)(min)(min)?光敏(min)(min)(min)?壓(ya)敏(min)(min)(min)?力敏(min)(min)(min)?磁敏(min)(min)(min)和(he)氣敏(min)(min)(min)等類型敏(min)(min)(min)感(gan)(gan)電(dian)(dian)阻?敏(min)(min)(min)感(gan)(gan)電(dian)(dian)阻器(qi)所用(yong)的材料幾乎都是半導體材料,這(zhe)類電(dian)(dian)阻器(qi)也稱為半導體電(dian)(dian)阻器(qi)?

熱敏電阻的(de)(de)(de)阻(zu)(zu)(zu)(zu)(zu)值(zhi)隨溫(wen)(wen)度變(bian)化(hua)(hua)而變(bian)化(hua)(hua),溫(wen)(wen)度升高(gao)阻(zu)(zu)(zu)(zu)(zu)為負(fu)溫(wen)(wen)度系數(shu)(NTC)熱敏(min)電(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)?應用較多的(de)(de)(de)是負(fu)溫(wen)(wen)度系數(shu)熱敏(min)電(dian)(dian)阻(zu)(zu)(zu)(zu)(zu),又可分為普(pu)通型負(fu)溫(wen)(wen)度系數(shu)熱敏(min)電(dian)(dian)阻(zu)(zu)(zu)(zu)(zu);穩壓型負(fu)溫(wen)(wen)度系數(shu)熱敏(min)電(dian)(dian)阻(zu)(zu)(zu)(zu)(zu);測溫(wen)(wen)型負(fu)溫(wen)(wen)度系數(shu)熱敏(min)電(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)等? 光(guang)(guang)(guang)敏(min)電(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)是電(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)的(de)(de)(de)阻(zu)(zu)(zu)(zu)(zu)值(zhi)隨入射(she)光(guang)(guang)(guang)的(de)(de)(de)強弱變(bian)化(hua)(hua)而改變(bian),當(dang)入射(she)光(guang)(guang)(guang)增強時,光(guang)(guang)(guang)敏(min)電(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)的(de)(de)(de)減小,入射(she)光(guang)(guang)(guang)減弱時電(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)值(zhi)增大?