【電(dian)阻的作(zuo)(zuo)用】電(dian)阻在電(dian)路中有什么作(zuo)(zuo)用 電(dian)阻器有哪(na)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)(shi)一個限(xian)流元件,將電(dian)(dian)阻(zu)(zu)(zu)接(jie)在電(dian)(dian)路中后,電(dian)(dian)阻(zu)(zu)(zu)器(qi)(qi)的(de)阻(zu)(zu)(zu)值是(shi)(shi)固定(ding)的(de)一般是(shi)(shi)兩個引腳,它可(ke)限(xian)制通過(guo)(guo)它所連支(zhi)路的(de)電(dian)(dian)流大小?阻(zu)(zu)(zu)值不能改(gai)變(bian)的(de)稱(cheng)(cheng)為固定(ding)電(dian)(dian)阻(zu)(zu)(zu)器(qi)(qi)?阻(zu)(zu)(zu)值可(ke)變(bian)的(de)稱(cheng)(cheng)為電(dian)(dian)位器(qi)(qi)或可(ke)變(bian)電(dian)(dian)阻(zu)(zu)(zu)器(qi)(qi)?理想的(de)電(dian)(dian)阻(zu)(zu)(zu)器(qi)(qi)是(shi)(shi)線性(xing)的(de),即(ji)通過(guo)(guo)電(dian)(dian)阻(zu)(zu)(zu)器(qi)(qi)的(de)瞬時電(dian)(dian)流與(yu)外加瞬時電(dian)(dian)壓成(cheng)正比?用于分壓的(de)可(ke)變(bian)電(dian)(dian)阻(zu)(zu)(zu)器(qi)(qi)?在裸(luo)露的(de)電(dian)(dian)阻(zu)(zu)(zu)體上,緊壓著一至兩個可(ke)移(yi)金(jin)屬觸(chu)點?觸(chu)點位置確定(ding)電(dian)(dian)阻(zu)(zu)(zu)體任(ren)一端與(yu)觸(chu)點間的(de)阻(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

小功率電(dian)阻(zu)(zu)器通常為封裝在(zai)塑料外殼中的碳膜構成(cheng),而(er)大功率的電(dian)阻(zu)(zu)器通常為繞線(xian)電(dian)阻(zu)(zu)器,通過(guo)將大電(dian)阻(zu)(zu)率的金(jin)屬絲繞在(zai)瓷心上而(er)制成(cheng)?

如果一(yi)個電(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)(qi)(qi)的(de)(de)電(dian)(dian)(dian)(dian)阻(zu)(zu)值(zhi)接近零歐姆,則該電(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)(qi)(qi)對電(dian)(dian)(dian)(dian)流沒有(you)阻(zu)(zu)礙作用(yong)(yong),并聯(lian)這種電(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)(qi)(qi)的(de)(de)回路(lu)被(bei)短(duan)路(lu),電(dian)(dian)(dian)(dian)流無限大?如果一(yi)個電(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)(qi)(qi)具(ju)有(you)無限大的(de)(de)或(huo)很大的(de)(de)電(dian)(dian)(dian)(dian)阻(zu)(zu),則串接該電(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)(qi)(qi)的(de)(de)回路(lu)可看作開路(lu),電(dian)(dian)(dian)(dian)流為零?工業中常用(yong)(yong)的(de)(de)電(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)(qi)(qi)介于兩種極端情況之間(jian),它具(ju)有(you)一(yi)定的(de)(de)電(dian)(dian)(dian)(dian)阻(zu)(zu),可通過(guo)一(yi)定的(de)(de)電(dian)(dian)(dian)(dian)流,但電(dian)(dian)(dian)(dian)流不像短(duan)路(lu)時那樣大?電(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)(qi)(qi)的(de)(de)限流作用(yong)(yong)類似于接在兩根(gen)大直徑(jing)管(guan)子之間(jian)的(de)(de)小直徑(jing)管(guan)子限制水流量的(de)(de)作用(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(ji)乎維持不變而為一(yi)定值,這(zhe)類電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)稱為線(xian)(xian)性電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)?有些材料的電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)明顯地隨著(zhu)電(dian)(dian)(dian)流(或電(dian)(dian)(dian)壓(ya))而變化,其伏—安(an)特性是(shi)一(yi)條曲(qu)線(xian)(xian),這(zhe)類電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)稱為非線(xian)(xian)性電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)?非線(xian)(xian)性電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)在某(mou)一(yi)給定的電(dian)(dian)(dian)壓(ya)(或電(dian)(dian)(dian)流)作用下,電(dian)(dian)(dian)壓(ya)與電(dian)(dian)(dian)流的比值為在該工作點下的靜態(tai)電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu),伏—安(an)特性曲(qu)線(xian)(xian)上(shang)的斜率為動(dong)態(tai)電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)?表達(da)非線(xian)(xian)性電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)特性的方式比較復雜,但(dan)這(zhe)些非線(xian)(xian)性關系在電(dian)(dian)(dian)子電(dian)(dian)(dian)路中得到(dao)了廣泛的應用?

按材料分類

a?線(xian)繞(rao)電(dian)阻器(qi)由(you)電(dian)阻線(xian)繞(rao)成電(dian)阻器(qi) 用高阻合(he)金線(xian)繞(rao)在絕緣骨架上制(zhi)成,外面涂有耐熱(re)的(de)釉絕緣層(ceng)或絕緣漆?繞(rao)線(xian)電(dian)阻具有較(jiao)低的(de)溫度系數,阻值精度高,穩定(ding)性好,耐熱(re)耐腐蝕,主要做精密(mi)大(da)功率電(dian)阻使用,缺點是高頻性能差,時間(jian)常數大(da)?

b?碳合成(cheng)電(dian)阻器由碳及合成(cheng)塑(su)膠(jiao)壓制成(cheng)而(er)成(cheng)?

c?碳(tan)(tan)(tan)膜電(dian)阻(zu)器在瓷(ci)(ci)管(guan)上鍍上一層(ceng)碳(tan)(tan)(tan)而成(cheng),將結(jie)晶碳(tan)(tan)(tan)沉積在陶(tao)瓷(ci)(ci)棒骨架上制(zhi)成(cheng)?碳(tan)(tan)(tan)膜電(dian)阻(zu)器成(cheng)本低(di)?性能(neng)穩定?阻(zu)值范圍寬?溫(wen)度系數和電(dian)壓系數低(di),是目前應用最廣(guang)泛的(de)電(dian)阻(zu)器?

d?金(jin)屬膜電阻(zu)器(qi)在瓷(ci)管上鍍上一層金(jin)屬而成,用真空蒸發的方(fang)法將合(he)金(jin)材料蒸鍍于(yu)陶瓷(ci)棒骨架表面?

金屬膜電(dian)阻比碳膜電(dian)阻的精度(du)(du)高,穩定性好,噪聲,溫度(du)(du)系數(shu)小?在(zai)儀(yi)器儀(yi)表及通訊設備(bei)中大量采用(yong)?

e?金屬氧化膜電阻器在瓷管上鍍上一層氧化(hua)錫而(er)成(cheng),在絕緣(yuan)棒上沉積(ji)一層金屬氧化(hua)物?由于(yu)其(qi)本(ben)身(shen)即是(shi)氧化(hua)物,所以高溫下(xia)穩定,耐熱沖擊,負載能力(li)強(qiang) 按(an)用途(tu)分(fen),有通用?精(jing)密?高頻?高壓?高阻(zu)?大(da)功(gong)率和電阻(zu)網絡等(deng)?

特殊電阻器

1?保(bao)(bao)險(xian)(xian)電(dian)阻(zu)(zu):又叫熔斷(duan)(duan)電(dian)阻(zu)(zu)器(qi),在正常(chang)情況(kuang)下起(qi)著電(dian)阻(zu)(zu)和保(bao)(bao)險(xian)(xian)絲(si)的雙重作用(yong),當電(dian)路出現(xian)故障而使其功率(lv)超過額定功率(lv)時(shi),它會像(xiang)保(bao)(bao)險(xian)(xian)絲(si)一樣熔斷(duan)(duan)使連接電(dian)路斷(duan)(duan)開(kai)?保(bao)(bao)險(xian)(xian)絲(si)電(dian)阻(zu)(zu)一般電(dian)阻(zu)(zu)值都小(xiao)(0.33Ω~10KΩ),功率(lv)也(ye)較小(xiao)?保(bao)(bao)險(xian)(xian)絲(si)電(dian)阻(zu)(zu)器(qi)常(chang)用(yong)型(xing)(xing)號有(you):RF10型(xing)(xing)?RF111-5保(bao)(bao)險(xian)(xian)絲(si)電(dian)阻(zu)(zu)器(qi)的符(fu)號型(xing)(xing)?RRD0910型(xing)(xing)?RRD0911型(xing)(xing)等?

2?敏(min)(min)(min)(min)(min)感(gan)電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)器:是指(zhi)其電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)值(zhi)對于某種物(wu)(wu)理(li)量(liang)(如溫度?濕度?光照?電(dian)(dian)(dian)壓?機械力?以(yi)及氣體(ti)(ti)濃度等)具有敏(min)(min)(min)(min)(min)感(gan)特性,當(dang)這些物(wu)(wu)理(li)量(liang)發生(sheng)變化時,敏(min)(min)(min)(min)(min)感(gan)電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)的(de)阻(zu)(zu)(zu)(zu)值(zhi)就會(hui)隨物(wu)(wu)理(li)量(liang)變化而發生(sheng)改變,呈現(xian)不同(tong)的(de)電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)值(zhi)?根(gen)據對不同(tong)物(wu)(wu)理(li)量(liang)敏(min)(min)(min)(min)(min)感(gan),敏(min)(min)(min)(min)(min)感(gan)電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)器可分為熱敏(min)(min)(min)(min)(min)?濕敏(min)(min)(min)(min)(min)?光敏(min)(min)(min)(min)(min)?壓敏(min)(min)(min)(min)(min)?力敏(min)(min)(min)(min)(min)?磁敏(min)(min)(min)(min)(min)和氣敏(min)(min)(min)(min)(min)等類型(xing)敏(min)(min)(min)(min)(min)感(gan)電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)?敏(min)(min)(min)(min)(min)感(gan)電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)器所用的(de)材(cai)料幾(ji)乎都是半(ban)導體(ti)(ti)材(cai)料,這類電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)器也稱為半(ban)導體(ti)(ti)電(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)器?

熱敏電阻的阻(zu)(zu)值隨溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)變(bian)化(hua)(hua)而(er)變(bian)化(hua)(hua),溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)升高阻(zu)(zu)為負(fu)溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)系(xi)數(shu)(NTC)熱(re)敏(min)電(dian)(dian)(dian)阻(zu)(zu)?應用較多的是負(fu)溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)系(xi)數(shu)熱(re)敏(min)電(dian)(dian)(dian)阻(zu)(zu),又可分為普通(tong)型負(fu)溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)系(xi)數(shu)熱(re)敏(min)電(dian)(dian)(dian)阻(zu)(zu);穩壓型負(fu)溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)系(xi)數(shu)熱(re)敏(min)電(dian)(dian)(dian)阻(zu)(zu);測溫(wen)(wen)(wen)(wen)(wen)(wen)型負(fu)溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)系(xi)數(shu)熱(re)敏(min)電(dian)(dian)(dian)阻(zu)(zu)等? 光(guang)敏(min)電(dian)(dian)(dian)阻(zu)(zu)是電(dian)(dian)(dian)阻(zu)(zu)的阻(zu)(zu)值隨入(ru)射光(guang)的強弱變(bian)化(hua)(hua)而(er)改變(bian),當(dang)入(ru)射光(guang)增(zeng)強時(shi)(shi),光(guang)敏(min)電(dian)(dian)(dian)阻(zu)(zu)的減小,入(ru)射光(guang)減弱時(shi)(shi)電(dian)(dian)(dian)阻(zu)(zu)值增(zeng)大?