什么是大功率繞線電阻？

大功率繞線電阻的額定功率通常在1W以上，甚(shen)至高達幾(ji)百(bai)(bai)瓦，可以在較高的環境(jing)溫(wen)度下(xia)使用。電(dian)阻(zu)值可以從(cong)零點(dian)幾(ji)歐(ou)姆(mu)到幾(ji)百(bai)(bai)千歐(ou)姆(mu)，一般電(dian)阻(zu)精(jing)度為±5%和±10%。大(da)功率繞(rao)線(xian)電(dian)阻(zu)的組成部分(fen)有骨架、繞(rao)組、端子和保護層。

大功(gong)率繞(rao)線電阻(zu)的阻(zu)值是(shi)多(duo)少(shao)？

大(da)(da)功率(lv)繞線(xian)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)是由電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)絲繞在絕(jue)緣框(kuang)架上制(zhi)成(cheng)的(de)固定電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi)。電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)絲一般采用鎳(nie)鉻、錳銅等(deng)合(he)金制(zhi)成(cheng)，絕(jue)緣骨架通(tong)常為(wei)(wei)氧化鋁(lv)陶瓷，封(feng)裝材料(liao)有絕(jue)緣漆、硅樹(shu)脂、油(you)漆、陶瓷、鋁(lv)殼(ke)等(deng)。以(yi)ResistorToday的(de)大(da)(da)功率(lv)繞線(xian)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)為(wei)(wei)例。 HS系(xi)(xi)列大(da)(da)功率(lv)繞線(xian)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)阻(zu)值范圍為(wei)(wei)5mΩ-100KΩ。線(xian)繞電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi)是用鎳(nie)鉻線(xian)、錳銅線(xian)、康銅線(xian)繞在瓷管上制(zhi)成(cheng)的(de)。它(ta)們(men)分(fen)為(wei)(wei)固定式(shi)和(he)可調(diao)式(shi)。大(da)(da)功率(lv)線(xian)繞電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi)的(de)優點：極高的(de)阻(zu)值精度(du)、工(gong)作(zuo)時噪音(yin)低、穩定可靠、溫度(du)系(xi)(xi)數小、能耐高溫，在環(huan)境(jing)溫度(du)170℃下仍能正常工(gong)作(zuo)。線(xian)繞電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)的(de)缺點：尺寸大(da)(da)、阻(zu)值低，大(da)(da)多在100KΩ以(yi)下。另外，由于(yu)結構原(yuan)因，其(qi)分(fen)布電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)和(he)電(dian)(dian)(dian)(dian)(dian)(dian)感較大(da)(da)，不能用于(yu)高頻電(dian)(dian)(dian)(dian)(dian)(dian)路。由于(yu)繞線(xian)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)對電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)起到(dao)扼流(liu)作(zuo)用，電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)很難通(tong)過。

電(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)在使用過程中不能超(chao)過電(dian)(dian)(dian)阻(zu)(zu)器(qi)(qi)的(de)(de)[敏感詞(ci)]工作(zuo)電(dian)(dian)(dian)壓(ya)。例如1/4W 10K電(dian)(dian)(dian)阻(zu)(zu)的(de)(de)[敏感詞(ci)]工作(zuo)電(dian)(dian)(dian)壓(ya)為V==50V，而不是 4.0 中的(de)(de) 250V。或者1/4W 1M，計(ji)算V==500V此時(shi)的(de)(de)[敏感詞(ci)]工作(zuo)電(dian)(dian)(dian)壓(ya)是4.0中的(de)(de)250V，不是計(ji)算出來的(de)(de)500V，取兩(liang)者中較小的(de)(de)值(zhi)。大功(gong)(gong)率(lv)電(dian)(dian)(dian)阻(zu)(zu)的(de)(de)阻(zu)(zu)值(zhi)與其功(gong)(gong)率(lv)沒有[敏感詞(ci)]恒定的(de)(de)關系。當(dang)(dang)電(dian)(dian)(dian)壓(ya)一定時(shi)，電(dian)(dian)(dian)功(gong)(gong)率(lv)與電(dian)(dian)(dian)阻(zu)(zu)值(zhi)成反比(bi)；當(dang)(dang)電(dian)(dian)(dian)流一定時(shi)，電(dian)(dian)(dian)功(gong)(gong)率(lv)與電(dian)(dian)(dian)阻(zu)(zu)值(zhi)成正比(bi)。

控(kong)制柜(ju)為什么要用大(da)功率繞線電阻

并不(bu)是控(kong)(kong)制(zhi)柜(ju)一定要(yao)用(yong)大(da)功(gong)率(lv)(lv)繞線電(dian)(dian)阻(zu)(zu)，而是大(da)功(gong)率(lv)(lv)線繞電(dian)(dian)阻(zu)(zu)必須(xu)完(wan)成其(qi)控(kong)(kong)制(zhi)所需(xu)要(yao)的功(gong)能。如果不(bu)需(xu)要(yao)，可以完(wan)全(quan)使(shi)用(yong)。許多(duo)控(kong)(kong)制(zhi)柜(ju)不(bu)需(xu)要(yao)大(da)功(gong)率(lv)(lv)繞線電(dian)(dian)阻(zu)(zu)，而且這種(zhong)需(xu)要(yao)也很少。例如，大(da)量普通電(dian)(dian)機啟(qi)動(dong)控(kong)(kong)制(zhi)柜(ju)不(bu)需(xu)要(yao)大(da)功(gong)率(lv)(lv)線繞電(dian)(dian)阻(zu)(zu)，而電(dian)(dian)機變頻啟(qi)動(dong)控(kong)(kong)制(zhi)柜(ju)則需(xu)要(yao)大(da)功(gong)率(lv)(lv)線繞電(dian)(dian)阻(zu)(zu)作為制(zhi)動(dong)電(dian)(dian)阻(zu)(zu)。