【電(dian)阻的作用】電(dian)阻在電(dian)路中有(you)什(shen)么(me)作用 電(dian)阻器(qi)有(you)哪些分(fen)類(lei)

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(ge)(ge)限(xian)流(liu)(liu)元(yuan)件,將電(dian)(dian)阻(zu)(zu)(zu)(zu)接在電(dian)(dian)路中(zhong)后,電(dian)(dian)阻(zu)(zu)(zu)(zu)器(qi)的(de)阻(zu)(zu)(zu)(zu)值是(shi)固(gu)定(ding)的(de)一般是(shi)兩個(ge)(ge)引腳(jiao),它可限(xian)制(zhi)通(tong)過它所連(lian)支路的(de)電(dian)(dian)流(liu)(liu)大小?阻(zu)(zu)(zu)(zu)值不能(neng)改變(bian)(bian)的(de)稱(cheng)為(wei)固(gu)定(ding)電(dian)(dian)阻(zu)(zu)(zu)(zu)器(qi)?阻(zu)(zu)(zu)(zu)值可變(bian)(bian)的(de)稱(cheng)為(wei)電(dian)(dian)位器(qi)或可變(bian)(bian)電(dian)(dian)阻(zu)(zu)(zu)(zu)器(qi)?理想的(de)電(dian)(dian)阻(zu)(zu)(zu)(zu)器(qi)是(shi)線性的(de),即通(tong)過電(dian)(dian)阻(zu)(zu)(zu)(zu)器(qi)的(de)瞬時電(dian)(dian)流(liu)(liu)與外加瞬時電(dian)(dian)壓成(cheng)正比?用(yong)于分壓的(de)可變(bian)(bian)電(dian)(dian)阻(zu)(zu)(zu)(zu)器(qi)?在裸露(lu)的(de)電(dian)(dian)阻(zu)(zu)(zu)(zu)體上,緊壓著一至兩個(ge)(ge)可移金屬觸(chu)點?觸(chu)點位置確定(ding)電(dian)(dian)阻(zu)(zu)(zu)(zu)體任(ren)一端(duan)與觸(chu)點間的(de)阻(zu)(zu)(zu)(zu)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(lv)電(dian)(dian)阻(zu)器通常(chang)為封(feng)裝在塑料外(wai)殼中的(de)(de)碳膜構成(cheng),而大(da)功率(lv)的(de)(de)電(dian)(dian)阻(zu)器通常(chang)為繞線電(dian)(dian)阻(zu)器,通過將大(da)電(dian)(dian)阻(zu)率(lv)的(de)(de)金屬絲繞在瓷心上而制成(cheng)?

如果(guo)一(yi)(yi)個電(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)的(de)電(dian)(dian)(dian)(dian)阻(zu)(zu)值接(jie)(jie)近(jin)零歐姆(mu),則該(gai)電(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)對電(dian)(dian)(dian)(dian)流(liu)沒有(you)(you)阻(zu)(zu)礙作用(yong),并聯這種(zhong)電(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)的(de)回路(lu)(lu)被短路(lu)(lu),電(dian)(dian)(dian)(dian)流(liu)無限大(da)(da)?如果(guo)一(yi)(yi)個電(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)具有(you)(you)無限大(da)(da)的(de)或很大(da)(da)的(de)電(dian)(dian)(dian)(dian)阻(zu)(zu),則串(chuan)接(jie)(jie)該(gai)電(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)的(de)回路(lu)(lu)可看作開路(lu)(lu),電(dian)(dian)(dian)(dian)流(liu)為零?工(gong)業中常(chang)用(yong)的(de)電(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)介(jie)于兩種(zhong)極端情況之(zhi)間,它具有(you)(you)一(yi)(yi)定的(de)電(dian)(dian)(dian)(dian)阻(zu)(zu),可通過(guo)一(yi)(yi)定的(de)電(dian)(dian)(dian)(dian)流(liu),但電(dian)(dian)(dian)(dian)流(liu)不像(xiang)短路(lu)(lu)時那樣大(da)(da)?電(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)的(de)限流(liu)作用(yong)類似于接(jie)(jie)在兩根大(da)(da)直(zhi)徑管(guan)子(zi)之(zhi)間的(de)小直(zhi)徑管(guan)子(zi)限制水流(liu)量的(de)作用(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(hu)維持不變而為一定值,這(zhe)類電(dian)(dian)(dian)阻(zu)(zu)稱(cheng)(cheng)為線(xian)性(xing)(xing)電(dian)(dian)(dian)阻(zu)(zu)?有些材料的(de)電(dian)(dian)(dian)阻(zu)(zu)明顯地隨著電(dian)(dian)(dian)流(liu)(liu)(或電(dian)(dian)(dian)壓)而變化,其伏—安(an)特性(xing)(xing)是一條曲線(xian),這(zhe)類電(dian)(dian)(dian)阻(zu)(zu)稱(cheng)(cheng)為非(fei)(fei)線(xian)性(xing)(xing)電(dian)(dian)(dian)阻(zu)(zu)?非(fei)(fei)線(xian)性(xing)(xing)電(dian)(dian)(dian)阻(zu)(zu)在某(mou)一給定的(de)電(dian)(dian)(dian)壓(或電(dian)(dian)(dian)流(liu)(liu))作用下(xia),電(dian)(dian)(dian)壓與電(dian)(dian)(dian)流(liu)(liu)的(de)比值為在該(gai)工(gong)作點下(xia)的(de)靜態電(dian)(dian)(dian)阻(zu)(zu),伏—安(an)特性(xing)(xing)曲線(xian)上的(de)斜率為動態電(dian)(dian)(dian)阻(zu)(zu)?表(biao)達(da)非(fei)(fei)線(xian)性(xing)(xing)電(dian)(dian)(dian)阻(zu)(zu)特性(xing)(xing)的(de)方(fang)式比較復雜,但這(zhe)些非(fei)(fei)線(xian)性(xing)(xing)關(guan)系在電(dian)(dian)(dian)子電(dian)(dian)(dian)路中(zhong)得(de)到了廣泛的(de)應用?

按材料分類

a?線(xian)繞(rao)(rao)電(dian)(dian)阻(zu)器由電(dian)(dian)阻(zu)線(xian)繞(rao)(rao)成電(dian)(dian)阻(zu)器 用高阻(zu)合(he)金線(xian)繞(rao)(rao)在絕(jue)緣(yuan)(yuan)骨架上制成,外面涂有耐熱(re)的(de)釉絕(jue)緣(yuan)(yuan)層或絕(jue)緣(yuan)(yuan)漆?繞(rao)(rao)線(xian)電(dian)(dian)阻(zu)具有較低的(de)溫度系(xi)數,阻(zu)值精度高,穩(wen)定(ding)性好,耐熱(re)耐腐蝕,主要(yao)做精密大(da)功率(lv)電(dian)(dian)阻(zu)使用,缺(que)點是高頻性能(neng)差,時間(jian)常(chang)數大(da)?

b?碳(tan)合成(cheng)電阻器由碳(tan)及(ji)合成(cheng)塑膠壓(ya)制(zhi)成(cheng)而成(cheng)?

c?碳(tan)膜(mo)電(dian)阻器在(zai)瓷(ci)管上(shang)(shang)鍍上(shang)(shang)一層碳(tan)而成(cheng),將(jiang)結晶碳(tan)沉積在(zai)陶瓷(ci)棒(bang)骨架上(shang)(shang)制成(cheng)?碳(tan)膜(mo)電(dian)阻器成(cheng)本低?性能穩定(ding)?阻值范圍寬?溫(wen)度系數(shu)和電(dian)壓(ya)系數(shu)低,是目前應(ying)用最廣泛的電(dian)阻器?

d?金屬膜(mo)電阻器在瓷管上(shang)鍍上(shang)一(yi)層金屬而成,用真空蒸發的方法(fa)將(jiang)合金材料蒸鍍于(yu)陶(tao)瓷棒骨架(jia)表(biao)面(mian)?

金屬膜電阻比碳膜電阻的精度高,穩(wen)定性好(hao),噪聲,溫度系數小?在儀器儀表(biao)及通訊設備中大量采(cai)用?

e?金屬氧化膜電阻器在瓷管上鍍上一層(ceng)氧化(hua)錫而成,在絕緣(yuan)棒上沉積一層(ceng)金(jin)屬(shu)氧化(hua)物?由于(yu)其本身即(ji)是氧化(hua)物,所以高溫下(xia)穩(wen)定,耐熱(re)沖(chong)擊,負載能力強 按用(yong)途分,有(you)通用(yong)?精密?高頻?高壓?高阻?大功率和(he)電阻網(wang)絡等(deng)?

特殊電阻器

1?保(bao)(bao)(bao)險(xian)(xian)電(dian)(dian)(dian)阻(zu):又叫熔斷(duan)電(dian)(dian)(dian)阻(zu)器(qi),在正常情況(kuang)下起著電(dian)(dian)(dian)阻(zu)和保(bao)(bao)(bao)險(xian)(xian)絲(si)(si)的雙重作用,當電(dian)(dian)(dian)路出現故障而使其功率超過額定功率時,它(ta)會像保(bao)(bao)(bao)險(xian)(xian)絲(si)(si)一樣(yang)熔斷(duan)使連接電(dian)(dian)(dian)路斷(duan)開?保(bao)(bao)(bao)險(xian)(xian)絲(si)(si)電(dian)(dian)(dian)阻(zu)一般電(dian)(dian)(dian)阻(zu)值(zhi)都小(0.33Ω~10KΩ),功率也較小?保(bao)(bao)(bao)險(xian)(xian)絲(si)(si)電(dian)(dian)(dian)阻(zu)器(qi)常用型(xing)號有:RF10型(xing)?RF111-5保(bao)(bao)(bao)險(xian)(xian)絲(si)(si)電(dian)(dian)(dian)阻(zu)器(qi)的符號型(xing)?RRD0910型(xing)?RRD0911型(xing)等?

2?敏(min)(min)(min)感(gan)(gan)電阻(zu)(zu)器:是指其電阻(zu)(zu)值對(dui)于某種物(wu)理量(如溫度?濕(shi)度?光照?電壓?機(ji)械力?以(yi)及(ji)氣(qi)體(ti)(ti)濃度等)具(ju)有敏(min)(min)(min)感(gan)(gan)特性,當這些物(wu)理量發生(sheng)變化(hua)時,敏(min)(min)(min)感(gan)(gan)電阻(zu)(zu)的(de)(de)阻(zu)(zu)值就會隨物(wu)理量變化(hua)而發生(sheng)改變,呈現不(bu)同的(de)(de)電阻(zu)(zu)值?根據對(dui)不(bu)同物(wu)理量敏(min)(min)(min)感(gan)(gan),敏(min)(min)(min)感(gan)(gan)電阻(zu)(zu)器可分(fen)為(wei)熱敏(min)(min)(min)?濕(shi)敏(min)(min)(min)?光敏(min)(min)(min)?壓敏(min)(min)(min)?力敏(min)(min)(min)?磁敏(min)(min)(min)和(he)氣(qi)敏(min)(min)(min)等類(lei)型敏(min)(min)(min)感(gan)(gan)電阻(zu)(zu)?敏(min)(min)(min)感(gan)(gan)電阻(zu)(zu)器所(suo)用(yong)的(de)(de)材(cai)料(liao)幾乎都是半導(dao)體(ti)(ti)材(cai)料(liao),這類(lei)電阻(zu)(zu)器也(ye)稱為(wei)半導(dao)體(ti)(ti)電阻(zu)(zu)器?

熱敏電阻的阻(zu)值(zhi)隨溫(wen)度(du)變(bian)化而(er)變(bian)化,溫(wen)度(du)升高阻(zu)為(wei)(wei)負(fu)(fu)(fu)(fu)溫(wen)度(du)系(xi)(xi)(xi)數(NTC)熱敏(min)(min)電(dian)阻(zu)?應用(yong)較多的是負(fu)(fu)(fu)(fu)溫(wen)度(du)系(xi)(xi)(xi)數熱敏(min)(min)電(dian)阻(zu),又可(ke)分為(wei)(wei)普通型負(fu)(fu)(fu)(fu)溫(wen)度(du)系(xi)(xi)(xi)數熱敏(min)(min)電(dian)阻(zu);穩壓型負(fu)(fu)(fu)(fu)溫(wen)度(du)系(xi)(xi)(xi)數熱敏(min)(min)電(dian)阻(zu);測(ce)溫(wen)型負(fu)(fu)(fu)(fu)溫(wen)度(du)系(xi)(xi)(xi)數熱敏(min)(min)電(dian)阻(zu)等? 光(guang)(guang)(guang)敏(min)(min)電(dian)阻(zu)是電(dian)阻(zu)的阻(zu)值(zhi)隨入(ru)(ru)射(she)光(guang)(guang)(guang)的強(qiang)弱變(bian)化而(er)改(gai)變(bian),當入(ru)(ru)射(she)光(guang)(guang)(guang)增強(qiang)時(shi),光(guang)(guang)(guang)敏(min)(min)電(dian)阻(zu)的減(jian)小,入(ru)(ru)射(she)光(guang)(guang)(guang)減(jian)弱時(shi)電(dian)阻(zu)值(zhi)增大?