电工面试问题之七

爱城电工

为什么电容器阻断DC 而通AC?

牛肉粉丝

Xc=1/(2Pifc)
+ V+ L. H+ q+ z4 Pif f=0 Xc is infinite, so capacitor block DC.
6 _# z0 i3 ]0 j4 @for AC, frequence is 60Hz(in north american), so Xc is a specific value. as a result , it can conduct AC.

MrElectrician

原帖由 爱城电工 于 2009-1-12 19:16 发表
! {4 }7 U6 V- @+ y0 u为什么电容器阻断DC 而通AC?

I would like to ask a question, just for curiosity, if you do not mind.
& R! j0 d1 ~% \4 B' C0 S" D
Is that a real question during your interview for an electrician job?

shenyang-china

Ha Ha, I think it is a joke. If it  was real, Lz must have lost his job.

wolfgan

电容器你可以想象成为一个容器，是用来装电子的，但是电子是不可以直接从这个容器里跑出去的，他是靠电压的变化或电流的变化来改变两级的电量而形成电流，所以对直流起到了一个不通的，而交流可以通过！！！