一、電阻的種類有哪些

1、按伏安特性分類

可分為線性電阻和非(fei)線性電阻。對大多數導體(ti)來說，在一定(ding)(ding)的溫度下(xia)，其電阻幾乎(hu)維持不變而為一定(ding)(ding)值，這類電阻稱(cheng)為線性電阻。

有(you)些(xie)材料的(de)電(dian)(dian)(dian)(dian)(dian)阻明顯地隨著電(dian)(dian)(dian)(dian)(dian)流(liu)（或電(dian)(dian)(dian)(dian)(dian)壓）而變化(hua)，其伏安特(te)性是一條曲線(xian)(xian)，這(zhe)類電(dian)(dian)(dian)(dian)(dian)阻稱(cheng)為非(fei)(fei)線(xian)(xian)性電(dian)(dian)(dian)(dian)(dian)阻。非(fei)(fei)線(xian)(xian)性電(dian)(dian)(dian)(dian)(dian)阻在(zai)某一給定的(de)電(dian)(dian)(dian)(dian)(dian)壓（或電(dian)(dian)(dian)(dian)(dian)流(liu)）作用下(xia)，電(dian)(dian)(dian)(dian)(dian)壓與電(dian)(dian)(dian)(dian)(dian)流(liu)的(de)比(bi)值為在(zai)該工作點下(xia)的(de)靜態電(dian)(dian)(dian)(dian)(dian)阻，伏安特(te)性曲線(xian)(xian)上的(de)斜率為動(dong)態電(dian)(dian)(dian)(dian)(dian)阻。表(biao)達(da)非(fei)(fei)線(xian)(xian)性電(dian)(dian)(dian)(dian)(dian)阻特(te)性的(de)方式(shi)比(bi)較(jiao)復雜，但這(zhe)些(xie)非(fei)(fei)線(xian)(xian)性關系在(zai)電(dian)(dian)(dian)(dian)(dian)子電(dian)(dian)(dian)(dian)(dian)路中(zhong)得到了廣(guang)泛(fan)的(de)應(ying)用。

2、按材料分類

a.線(xian)繞電(dian)(dian)阻(zu)(zu)器(qi)由電(dian)(dian)阻(zu)(zu)線(xian)繞成電(dian)(dian)阻(zu)(zu)器(qi)，用高(gao)(gao)阻(zu)(zu)合金線(xian)繞在絕(jue)緣骨架上(shang)制成，外面涂有耐熱(re)(re)的(de)釉絕(jue)緣層或(huo)絕(jue)緣漆。繞線(xian)電(dian)(dian)阻(zu)(zu)具(ju)有較(jiao)低的(de)溫度(du)系(xi)數，阻(zu)(zu)值精(jing)度(du)高(gao)(gao)，穩定性(xing)好，耐熱(re)(re)耐腐蝕，主要做精(jing)密大(da)功率電(dian)(dian)阻(zu)(zu)使用，缺點是高(gao)(gao)頻性(xing)能差，時間常數大(da)。

b.碳合成電阻器由碳及合成塑膠壓制成而成。

c.碳膜(mo)(mo)電阻(zu)器在瓷管上鍍(du)上一(yi)層碳而成(cheng)，將(jiang)結晶碳沉積在陶瓷棒骨架(jia)上制成(cheng)。碳膜(mo)(mo)電阻(zu)器成(cheng)本低(di)、性能穩定、阻(zu)值范圍寬、溫度系數和電壓(ya)系數低(di)，是目(mu)前應(ying)用(yong)最廣泛的電阻(zu)器。

d.金(jin)(jin)屬膜電阻(zu)器在(zai)(zai)瓷(ci)管(guan)上鍍(du)上一層金(jin)(jin)屬而成，用(yong)真空蒸發的(de)方法將合金(jin)(jin)材(cai)料蒸鍍(du)于陶(tao)瓷(ci)棒(bang)骨架表面。金(jin)(jin)屬膜電阻(zu)比碳膜電阻(zu)的(de)精度高，穩定性(xing)好(hao)，噪聲(sheng)，溫度系數小。在(zai)(zai)儀(yi)器儀(yi)表及通訊設備(bei)中大量采用(yong)。

e.金屬氧化(hua)膜電阻(zu)(zu)器在瓷管上(shang)鍍(du)上(shang)一(yi)層氧化(hua)錫而成，在絕緣棒上(shang)沉積(ji)一(yi)層金屬氧化(hua)物(wu)。由于其(qi)本身即(ji)是氧化(hua)物(wu)，所以高(gao)溫下穩定，耐(nai)熱(re)沖擊，負載能力強。按(an)用途分，有通用、精密(mi)、高(gao)頻、高(gao)壓、高(gao)阻(zu)(zu)、大功率和電阻(zu)(zu)網絡等。

3、特殊電阻器

a.保險電(dian)(dian)阻(zu)(zu)：又(you)叫(jiao)熔斷電(dian)(dian)阻(zu)(zu)器，在正常(chang)情況下起著電(dian)(dian)阻(zu)(zu)和保險絲的(de)雙重(zhong)作用(yong)，當電(dian)(dian)路出現(xian)故障而使其功(gong)率超過額定(ding)功(gong)率時，它會像保險絲一樣熔斷使連接電(dian)(dian)路斷開(kai)。保險絲電(dian)(dian)阻(zu)(zu)一般電(dian)(dian)阻(zu)(zu)值都小（0.33Ω～10KΩ），功(gong)率也較小。保險絲電(dian)(dian)阻(zu)(zu)器常(chang)用(yong)型號(hao)有：RF10型、RF111-5保險絲電(dian)(dian)阻(zu)(zu)器的(de)符號(hao)型、RRD0910型、RRD0911型等。

b.敏(min)感電(dian)(dian)阻(zu)(zu)(zu)(zu)器：是(shi)指其電(dian)(dian)阻(zu)(zu)(zu)(zu)值對于某種物理(li)量(liang)（如溫度、濕度、光照、電(dian)(dian)壓、機械力(li)、以(yi)及(ji)氣體(ti)濃(nong)度等）具有敏(min)感特性，當這些物理(li)量(liang)發生(sheng)變(bian)(bian)化時，敏(min)感電(dian)(dian)阻(zu)(zu)(zu)(zu)的阻(zu)(zu)(zu)(zu)值就會隨(sui)物理(li)量(liang)變(bian)(bian)化而發生(sheng)改變(bian)(bian)，呈現不(bu)(bu)同的電(dian)(dian)阻(zu)(zu)(zu)(zu)值。根(gen)據對不(bu)(bu)同物理(li)量(liang)敏(min)感，敏(min)感電(dian)(dian)阻(zu)(zu)(zu)(zu)器可分為熱敏(min)、濕敏(min)、光敏(min)、壓敏(min)、力(li)敏(min)、磁敏(min)和氣敏(min)等類(lei)型敏(min)感電(dian)(dian)阻(zu)(zu)(zu)(zu)。敏(min)感電(dian)(dian)阻(zu)(zu)(zu)(zu)器所(suo)用的材料幾(ji)乎都(dou)是(shi)半導體(ti)材料，這類(lei)電(dian)(dian)阻(zu)(zu)(zu)(zu)器也稱為半導體(ti)電(dian)(dian)阻(zu)(zu)(zu)(zu)器。

c.熱(re)(re)敏(min)(min)(min)電(dian)(dian)阻的阻值(zhi)(zhi)隨溫(wen)(wen)(wen)度(du)(du)(du)變(bian)化而變(bian)化，溫(wen)(wen)(wen)度(du)(du)(du)升高阻為(wei)負溫(wen)(wen)(wen)度(du)(du)(du)系(xi)(xi)數(shu)（NTC）熱(re)(re)敏(min)(min)(min)電(dian)(dian)阻。應用較(jiao)多的是負溫(wen)(wen)(wen)度(du)(du)(du)系(xi)(xi)數(shu)熱(re)(re)敏(min)(min)(min)電(dian)(dian)阻，又可分為(wei)普通(tong)型(xing)(xing)負溫(wen)(wen)(wen)度(du)(du)(du)系(xi)(xi)數(shu)熱(re)(re)敏(min)(min)(min)電(dian)(dian)阻；穩壓型(xing)(xing)負溫(wen)(wen)(wen)度(du)(du)(du)系(xi)(xi)數(shu)熱(re)(re)敏(min)(min)(min)電(dian)(dian)阻；測溫(wen)(wen)(wen)型(xing)(xing)負溫(wen)(wen)(wen)度(du)(du)(du)系(xi)(xi)數(shu)熱(re)(re)敏(min)(min)(min)電(dian)(dian)阻等。光敏(min)(min)(min)電(dian)(dian)阻是電(dian)(dian)阻的阻值(zhi)(zhi)隨入(ru)射(she)光的強(qiang)弱(ruo)變(bian)化而改變(bian)，當入(ru)射(she)光增強(qiang)時(shi)，光敏(min)(min)(min)電(dian)(dian)阻的減小，入(ru)射(she)光減弱(ruo)時(shi)電(dian)(dian)阻值(zhi)(zhi)增大。

該圖片由注冊用戶"天空之城"提供，版權聲明反饋

二、電阻器選用的方法

1、固定電阻器的選用

固定(ding)電(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)器(qi)(qi)(qi)有(you)多種(zhong)類型，選擇哪一種(zhong)材料和(he)結構的電(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)器(qi)(qi)(qi)，應根據應用(yong)(yong)電(dian)(dian)(dian)(dian)路的具體要(yao)求而定(ding)。高頻電(dian)(dian)(dian)(dian)路應選用(yong)(yong)分(fen)布電(dian)(dian)(dian)(dian)感和(he)分(fen)布電(dian)(dian)(dian)(dian)容(rong)小(xiao)的非(fei)線(xian)(xian)繞電(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)器(qi)(qi)(qi)，例如碳膜(mo)(mo)(mo)電(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)器(qi)(qi)(qi)、金屬電(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)器(qi)(qi)(qi)和(he)金屬氧化膜(mo)(mo)(mo)電(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)器(qi)(qi)(qi)，薄膜(mo)(mo)(mo)電(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)器(qi)(qi)(qi)，厚膜(mo)(mo)(mo)電(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)器(qi)(qi)(qi)，合金電(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)器(qi)(qi)(qi)，防腐蝕鍍膜(mo)(mo)(mo)電(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)器(qi)(qi)(qi)等。高增(zeng)益小(xiao)信號放大電(dian)(dian)(dian)(dian)路應選用(yong)(yong)低噪聲電(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)器(qi)(qi)(qi)，例如金屬膜(mo)(mo)(mo)電(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)器(qi)(qi)(qi)、碳膜(mo)(mo)(mo)電(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)器(qi)(qi)(qi)和(he)線(xian)(xian)繞電(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)器(qi)(qi)(qi)，而不能使用(yong)(yong)噪聲較大的合成碳膜(mo)(mo)(mo)電(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)器(qi)(qi)(qi)和(he)有(you)機實(shi)心電(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)器(qi)(qi)(qi)。

所選(xuan)(xuan)電(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi)(qi)的(de)電(dian)(dian)(dian)(dian)(dian)阻(zu)值應(ying)(ying)(ying)接近應(ying)(ying)(ying)用(yong)(yong)(yong)電(dian)(dian)(dian)(dian)(dian)路(lu)中(zhong)計(ji)算值的(de)一(yi)(yi)(yi)個(ge)標(biao)稱值，應(ying)(ying)(ying)優先選(xuan)(xuan)用(yong)(yong)(yong)標(biao)準系列的(de)電(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi)(qi)。一(yi)(yi)(yi)般(ban)電(dian)(dian)(dian)(dian)(dian)路(lu)使用(yong)(yong)(yong)的(de)電(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi)(qi)允許誤差(cha)為(wei)±5%~±10%。精密儀器(qi)(qi)及特殊電(dian)(dian)(dian)(dian)(dian)路(lu)中(zhong)使用(yong)(yong)(yong)的(de)電(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi)(qi)，應(ying)(ying)(ying)選(xuan)(xuan)用(yong)(yong)(yong)精密電(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi)(qi)，對精密度為(wei)1%以內的(de)電(dian)(dian)(dian)(dian)(dian)阻(zu)，如0.01%，0.1%，0.5%這(zhe)些量級的(de)電(dian)(dian)(dian)(dian)(dian)阻(zu)應(ying)(ying)(ying)采用(yong)(yong)(yong)捷比(bi)信(xin)電(dian)(dian)(dian)(dian)(dian)阻(zu)。所選(xuan)(xuan)電(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi)(qi)的(de)額定(ding)功率(lv)(lv)，要符合應(ying)(ying)(ying)用(yong)(yong)(yong)電(dian)(dian)(dian)(dian)(dian)路(lu)中(zhong)對電(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi)(qi)功率(lv)(lv)容量的(de)要求，一(yi)(yi)(yi)般(ban)不應(ying)(ying)(ying)隨意加(jia)大或減小電(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi)(qi)的(de)功率(lv)(lv)。

若電(dian)路(lu)要求是功(gong)率型電(dian)阻(zu)器，則其(qi)額定功(gong)率可高(gao)于實際應用(yong)電(dian)路(lu)要求功(gong)率的1~2倍。

2、熔斷電阻器的選用

熔(rong)斷(duan)電(dian)阻(zu)器具有保護(hu)功能的(de)電(dian)阻(zu)器。選用(yong)時應考慮其雙重性能，根據電(dian)路的(de)具體要求(qiu)選擇其阻(zu)值和功率等參數。既(ji)要保證(zheng)(zheng)它(ta)在過(guo)(guo)負荷時能快速(su)熔(rong)斷(duan)，又(you)要保證(zheng)(zheng)它(ta)在正(zheng)常條件(jian)下能長期(qi)穩定(ding)的(de)工作(zuo)。電(dian)阻(zu)值過(guo)(guo)大或(huo)功率過(guo)(guo)大，均不能起到保護(hu)作(zuo)用(yong)。

三、電阻器選用的基本原則

1、選擇通(tong)過認(ren)證機構認(ren)證的(de)生產線制造(zao)出(chu)的(de)執行高(gao)水平標準的(de)電阻器(qi)。

2、選擇具備功能優(you)勢(shi)(shi)、質量優(you)勢(shi)(shi)、效(xiao)率(lv)優(you)勢(shi)(shi)、功能價格(ge)比優(you)勢(shi)(shi)、服務優(you)勢(shi)(shi)的制造商(shang)生產的電阻器。

3、選擇能滿足上述要求的上型號目錄的制造商，并向其直接訂購電阻器。