我們都知(zhi)道中國(guo)的(de)(de)市電(dian)(dian)是220V，但是并不是每個國(guo)家(jia)的(de)(de)電(dian)(dian)壓都一樣(yang)的(de)(de)，比如(ru)(ru)我們臨近的(de)(de)日本(ben)市電(dian)(dian)就有(you)100V和(he)200V兩種，不過雖然(ran)電(dian)(dian)壓不同，但是如(ru)(ru)果你海淘日本(ben)的(de)(de)電(dian)(dian)動牙刷(shua)等小(xiao)家(jia)電(dian)(dian)產品，買(mai)回來也(ye)是可(ke)以(yi)直接充電(dian)(dian)的(de)(de)，因為許多(duo)小(xiao)功(gong)率的(de)(de)電(dian)(dian)器電(dian)(dian)壓都是全(quan)球通用的(de)(de)。那么他們是如(ru)(ru)何(he)做到的(de)(de)呢？

因為筆(bi)記本(ben)(ben)電(dian)腦等(deng)小功率電(dian)器使用的(de)是(shi)開(kai)關電(dian)源(yuan)，開(kai)關電(dian)源(yuan)可以較低的(de)成本(ben)(ben)實現對寬(kuan)幅(fu)電(dian)壓(ya)的(de)適應，也就是(shi)輸(shu)入電(dian)壓(ya)無論是(shi)100還是(shi)250V，輸(shu)出電(dian)壓(ya)都可以穩定(ding)在額定(ding)電(dian)壓(ya)上。

筆記本電(dian)(dian)腦、手機充電(dian)(dian)器、音(yin)響、電(dian)(dian)視等數碼家(jia)電(dian)(dian)的正常工作(zuo)電(dian)(dian)壓(ya)都是5-20V左右，我們家(jia)用(yong)(yong)插座上(shang)的電(dian)(dian)壓(ya)則(ze)是110V-220V之間，因此這些電(dian)(dian)器實際(ji)上(shang)都需要開關電(dian)(dian)源（或俗稱(cheng)變(bian)(bian)壓(ya)器）來降低(di)(di)電(dian)(dian)壓(ya)后使用(yong)(yong)。有變(bian)(bian)壓(ya)器的存在，變(bian)(bian)壓(ya)器本身(shen)可以對電(dian)(dian)流狀況進行調(diao)制(zhi)，給低(di)(di)壓(ya)電(dian)(dian)器以合適的電(dian)(dian)壓(ya)，所以這樣就不用(yong)(yong)考慮(lv)電(dian)(dian)壓(ya)不同的問(wen)題了。

但是(shi)充電(dian)(dian)器生產廠家告(gao)訴(su)打擊需要(yao)注意的(de)(de)(de)是(shi)冰箱，電(dian)(dian)飯煲這些(xie)大功率的(de)(de)(de)電(dian)(dian)器則不同，他(ta)們(men)的(de)(de)(de)主要(yao)工(gong)作(zuo)原件(jian)是(shi)電(dian)(dian)熱絲，這種(zhong)部件(jian)不像數碼家電(dian)(dian)的(de)(de)(de)元件(jian)那樣只能在低電(dian)(dian)壓(ya)下(xia)工(gong)作(zuo)，是(shi)可以直接承受市(shi)電(dian)(dian)電(dian)(dian)壓(ya)的(de)(de)(de)，如(ru)果(guo)市(shi)電(dian)(dian)電(dian)(dian)壓(ya)不正常(chang)，那么這些(xie)電(dian)(dian)器就很難正常(chang)工(gong)作(zuo)，或需要(yao)添加額外(wai)(wai)(wai)的(de)(de)(de)電(dian)(dian)源設備。所(suo)以如(ru)果(guo)你要(yao)海(hai)淘國外(wai)(wai)(wai)的(de)(de)(de)大型電(dian)(dian)器，則要(yao)額外(wai)(wai)(wai)注意電(dian)(dian)壓(ya)的(de)(de)(de)問題了，否則很可能無法工(gong)作(zuo)或者燒壞(huai)