廈(sha)門君朗益電(dian)動(dong)(dong)(dong)車有限公(gong)司以交通運輸為(wei)主，老爺車翻新，建立了完(wan)善的產品體系。主營：電(dian)動(dong)(dong)(dong)車，電(dian)動(dong)(dong)(dong)旅游觀光車，電(dian)動(dong)(dong)(dong)巡(xun)邏車，電(dian)動(dong)(dong)(dong)環衛車，電(dian)動(dong)(dong)(dong)消(xiao)防車，電(dian)瓶車租(zu)賃(lin)、保(bao)養維(wei)修等。

如(ru)果電(dian)(dian)(dian)壓(ya)的(de)大小及方(fang)向都(dou)不隨時(shi)間(jian)(jian)變(bian)化，則稱之為(wei)穩恒電(dian)(dian)(dian)壓(ya)或恒定電(dian)(dian)(dian)壓(ya)，簡稱為(wei)直流電(dian)(dian)(dian)壓(ya)，用大寫(xie)字(zi)母U表示。如(ru)果電(dian)(dian)(dian)壓(ya)的(de)大小及方(fang)向隨時(shi)間(jian)(jian)變(bian)化，則稱為(wei)變(bian)動電(dian)(dian)(dian)壓(ya)。對電(dian)(dian)(dian)路分析(xi)來說，一種(zhong)為(wei)重要(yao)的(de)變(bian)動電(dian)(dian)(dian)壓(ya)是正(zheng)弦交(jiao)流電(dian)(dian)(dian)壓(ya)（簡稱交(jiao)流電(dian)(dian)(dian)壓(ya)

廈門君朗益電(dian)(dian)動車(che)(che)有限(xian)公司(si)以交(jiao)通運輸(shu)為主(zhu)，建(jian)立了完善(shan)的產品體系。主(zhu)營：電(dian)(dian)動車(che)(che)，電(dian)(dian)動旅(lv)游觀光車(che)(che)，電(dian)(dian)動巡邏車(che)(che)，電(dian)(dian)動環衛車(che)(che)，電(dian)(dian)動消防(fang)車(che)(che)，電(dian)(dian)瓶車(che)(che)租(zu)賃(lin)、保養維修等。

原則上說(shuo)，參考(kao)點(dian)可以任(ren)意選(xuan)定。在電(dian)(dian)(dian)工(gong)領域，通常選(xuan)電(dian)(dian)(dian)路里的(de)接地點(dian)為參考(kao)點(dian)，在電(dian)(dian)(dian)子電(dian)(dian)(dian)路里，常取機(ji)殼為參考(kao)點(dian)。在實際應用時，僅知(zhi)道兩(liang)(liang)點(dian)間的(de)電(dian)(dian)(dian)壓往往不夠，還(huan)要求知(zhi)道這兩(liang)(liang)點(dian)中哪一(yi)點(dian)電(dian)(dian)(dian)位高(gao)，哪一(yi)點(dian)電(dian)(dian)(dian)位低(di)。例如，對于半導(dao)(dao)體(ti)二極(ji)管來(lai)說(shuo)，還(huan)有(you)其陽(yang)極(ji)電(dian)(dian)(dian)位高(gao)于陰極(ji)電(dian)(dian)(dian)位時才導(dao)(dao)通；對于直流(liu)電(dian)(dian)(dian)動機(ji)來(lai)說(shuo)，繞組兩(liang)(liang)端的(de)電(dian)(dian)(dian)位高(gao)低(di)不同

廈門君朗(lang)益電(dian)(dian)(dian)動(dong)車(che)(che)有限公司以交通運輸為主，老(lao)爺(ye)車(che)(che)租賃，建立了完善的產品體系。主營：電(dian)(dian)(dian)動(dong)車(che)(che)，老(lao)爺(ye)車(che)(che)翻新，電(dian)(dian)(dian)動(dong)旅游觀光(guang)車(che)(che)，臺州老(lao)爺(ye)車(che)(che)，電(dian)(dian)(dian)動(dong)巡邏車(che)(che)，電(dian)(dian)(dian)動(dong)環衛車(che)(che)，電(dian)(dian)(dian)動(dong)消防車(che)(che)，電(dian)(dian)(dian)瓶車(che)(che)租賃、保養維修等。

電(dian)壓的國際單位制為伏(fu)(fu)特(te)（V，簡(jian)稱伏(fu)(fu)），常用(yong)的單位還(huan)有毫伏(fu)(fu)（mV）、微伏(fu)(fu)（μV）、千伏(fu)(fu)（kV）等。此概念與水位高低所造成(cheng)的水壓相似。需要指出(chu)的是，“電(dian)壓”一(yi)詞一(yi)般只用(yong)于(yu)電(dian)路當中，“電(dian)勢差”和“電(dian)位差”則普遍應用(yong)于(yu)一(yi)切(qie)電(dian)現(xian)象當中。