一、保險絲電阻一般是多大
保(bao)險絲作為保(bao)障電路(lu)安全的元器件,一(yi)般是熔(rong)點較(jiao)低的金屬材(cai)質的,其(qi)本身具有一(yi)定的電阻(zu),那么保(bao)險絲電阻(zu)多大(da)呢?
正常(chang)(chang)情況下(xia),導線可(ke)以通過(guo)電(dian)(dian)流,它的電(dian)(dian)阻是(shi)比(bi)(bi)較小的,在(zai)一般(ban)的電(dian)(dian)路(lu)(lu)計算中通常(chang)(chang)不計,而保(bao)險絲的電(dian)(dian)阻要比(bi)(bi)等長(chang)的導線更大,這(zhe)樣才能在(zai)短路(lu)(lu)時及時熔斷,保(bao)護電(dian)(dian)路(lu)(lu),普(pu)通的保(bao)險絲電(dian)(dian)阻一般(ban)是(shi)在(zai)0.33Ω-1Ω范圍(wei)內(nei)。
二、保險絲電阻大還是小好
保險絲(si)的電(dian)阻有(you)(you)大有(you)(you)小(xiao),不(bu)同電(dian)阻大小(xiao)的熔斷(duan)器在實(shi)際應用過程中的表現也有(you)(you)所不(bu)同,那么大電(dian)阻的保險絲(si)好(hao)還是小(xiao)電(dian)阻的保險絲(si)好(hao)呢?
一(yi)般來說(shuo)(shuo),保(bao)(bao)險(xian)絲電(dian)(dian)阻(zu)(zu)的(de)選擇(ze)要(yao)根(gen)據(ju)實際情(qing)況選,總體來說(shuo)(shuo),建議選大(da)(da)點(dian)電(dian)(dian)阻(zu)(zu)的(de)保(bao)(bao)險(xian)絲,主(zhu)要(yao)原(yuan)因(yin)是:根(gen)據(ju)保(bao)(bao)險(xian)絲的(de)熔(rong)(rong)(rong)斷(duan)(duan)原(yuan)理,保(bao)(bao)險(xian)絲利用電(dian)(dian)流(liu)(liu)(liu)的(de)熱效應來控制通過(guo)的(de)電(dian)(dian)流(liu)(liu)(liu)大(da)(da)小,當通過(guo)的(de)電(dian)(dian)流(liu)(liu)(liu)超過(guo)限(xian)定值時(shi),保(bao)(bao)險(xian)絲就會熔(rong)(rong)(rong)斷(duan)(duan);根(gen)據(ju)公式Q=I2RT可(ke)知,保(bao)(bao)險(xian)絲的(de)電(dian)(dian)阻(zu)(zu)越大(da)(da),在電(dian)(dian)流(liu)(liu)(liu)相(xiang)同和通電(dian)(dian)時(shi)間相(xiang)同的(de)情(qing)況下,產生的(de)熱量就會越大(da)(da),越容(rong)易熔(rong)(rong)(rong)斷(duan)(duan),對于保(bao)(bao)護電(dian)(dian)路(lu)更好。如(ru)果保(bao)(bao)險(xian)絲的(de)電(dian)(dian)阻(zu)(zu)比較小的(de)話,那(nei)么即使(shi)通過(guo)大(da)(da)電(dian)(dian)流(liu)(liu)(liu)也無法及時(shi)熔(rong)(rong)(rong)斷(duan)(duan),不(bu)安(an)全。
當然,保險絲的(de)(de)電(dian)阻(zu)(zu)也(ye)不(bu)宜(yi)太(tai)大(da)了(le)(le),不(bu)然稍微過一些大(da)的(de)(de)電(dian)流(liu)就熔(rong)斷(duan)了(le)(le),影響家用(yong)(yong)電(dian)器的(de)(de)正常使用(yong)(yong),一般建議根(gen)據電(dian)線(xian)大(da)小和(he)家用(yong)(yong)電(dian)器的(de)(de)負荷來選擇(ze)合適(shi)電(dian)阻(zu)(zu)大(da)小的(de)(de)保險絲。