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)
0 u8 n3 K7 w9 I; u" I8 n+ s' ?if f=0 Xc is infinite, so capacitor block DC.
5 X1 F$ K) L0 {" t1 Pfor 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
& m5 R6 g& ?2 V( s: D+ m为什么电容器阻断DC 而通AC?

- D& u& M9 A( ?- f; c$ t
I would like to ask a question, just for curiosity, if you do not mind.

3 C; ?% ~. l; f) G! O, L# j1 ^7 F5 VIs 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！！！