最近流傳著(zhu)這樣一條微(wei)博：“請(qing)不要用(yong)iPad的(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)為(wei)iPhone充(chong)(chong)電(dian)(dian)(dian)(dian)，雖(sui)然看起來他們長的(de)(de)一樣，兩者(zhe)的(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓都是5V，iPhone的(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流是1A，而iPad卻是2.1A，根據P=UI可(ke)得(de)iPhone充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)的(de)(de)功率為(wei)5W，而iPad為(wei)10.2W。這樣做的(de)(de)后果是既傷iPhone又(you)傷iPad充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)。”

  微(wei)博一出，四(si)處轉(zhuan)發(fa)，同時(shi)擁有iPad和iPhone的人無不懊悔地(di)反思自己的充電(dian)(dian)行(xing)為。不過，緊接著果殼網“謠言粉碎機”發(fa)文稱，“這條微(wei)博的原始作者并不真正懂得(de)電(dian)(dian)子(zi)知識，只是(shi)單純依據充電(dian)(dian)器(qi)的參數，想當(dang)然地(di)得(de)出了(le)這樣(yang)一個錯誤的結論(lun)。”

  探究：蘋果公司在(zai)充電設計上(shang)有“講究”

  iPad和iPhone充(chong)(chong)(chong)電(dian)(dian)器的(de)設計不同是有原因(yin)的(de)。iPhone的(de)電(dian)(dian)池容量較小，只(zhi)需要1A的(de)充(chong)(chong)(chong)電(dian)(dian)電(dian)(dian)流(liu)就(jiu)能在一個合理的(de)時間(jian)內(nei)完成充(chong)(chong)(chong)電(dian)(dian)，又不損(sun)害電(dian)(dian)池。

  iPad的(de)(de)充(chong)電(dian)器(qi)上(shang)標明了2.1A，指的(de)(de)是iPad的(de)(de)充(chong)電(dian)器(qi)最(zui)(zui)大(da)只(zhi)(zhi)能(neng)輸出2.1A的(de)(de)電(dian)流(liu)(liu)(liu)。當你(ni)用iPad的(de)(de)充(chong)電(dian)器(qi)給iPhone充(chong)電(dian)時(shi)，雖然iPad的(de)(de)充(chong)電(dian)器(qi)最(zui)(zui)大(da)能(neng)夠提(ti)供2.1A的(de)(de)電(dian)流(liu)(liu)(liu)，但由于iPhone只(zhi)(zhi)能(neng)接受1A的(de)(de)電(dian)流(liu)(liu)(liu)，iPad的(de)(de)充(chong)電(dian)器(qi)也會遷(qian)就它。這就好比在四車道的(de)(de)公路上(shang)開(kai)車，遇到收(shou)(shou)費(fei)(fei)站的(de)(de)時(shi)候(hou)，只(zhi)(zhi)有1個收(shou)(shou)費(fei)(fei)亭開(kai)著，那么(me)同(tong)時(shi)通過收(shou)(shou)費(fei)(fei)站的(de)(de)汽車最(zui)(zui)多也就只(zhi)(zhi)有1輛。

  蘋果公司為了讓旗下的所有充電器和數碼產品能夠盡量混用，還在USB接口的兩個數據引腳上增加了分壓電阻，使充電的設備能夠在充電時讀到兩個電壓。當iPad或者iPhone接上充電器時，通過這兩個引腳上不同的電壓就可以區分當前使用的是哪種充電器，也(ye)就能對負載做出相(xiang)應(ying)的調整，從而安全地(di)充(chong)電(dian)。

  實驗：用(yong)iPad充電器給iPhone充電未見異(yi)常(chang)

  為(wei)(wei)了(le)驗(yan)證果殼網“謠(yao)言粉碎機”的(de)(de)結論，本報記(ji)者用iPad和iPhone原裝的(de)(de)充(chong)電器(qi)給(gei)兩(liang)個電量僅余(yu)10%左(zuo)右的(de)(de)iPhone3GS進行充(chong)電，手機始終(zhong)保持(chi)開機，電量充(chong)滿(man)均(jun)為(wei)(wei)3小時左(zuo)右，用iPad充(chong)電器(qi)充(chong)電的(de)(de)iPhone未見任(ren)何異常。