# High frequencies and capacitor plates

1. Jul 29, 2009

### jeff1evesque

Hello,

I was wondering at high frequencies, does current literally go through the capacitor plates; from one side to the other? Or is it simply due to charges being stored on the plates, that once the polarity of the circuit has changed, the charges on the plate that has been stored from it's source return back to it's source?

Jeffrey Levesque

2. Jul 29, 2009

### queenofbabes

Re: Capacitors

Nope, the current does not "literally" go through the capacitor plates.

3. Jul 29, 2009

### rock.freak667

Re: Capacitors

It is stored due to the charges but I am not sure what you mean by the last part of your question.

4. Jul 29, 2009

### jeff1evesque

Re: Capacitors

When the current is going a particular direction, the plates charge in a respective fashion. When the current reverses due to the nature of the AC circuitry, does the current go through from one plate to another, or when the current reverses, the stored charges from the plate simply returns to it's source- thus no current went through (between) the capacitor plates?

Thanks,

JL

5. Jul 29, 2009

### rock.freak667

Re: Capacitors

If the current changes direction, then the capacitor will start to discharge.
That is why you can use a capacitor to convert AC to DC

6. Jul 30, 2009

### nickmai123

Re: Capacitors

More specifically, a capacitor is used to filter the DC-output of an AC rectifier. It filters out the current that comes out of the rectifier, since there's no such thing as an ideal rectifier.

Now to your question, when the current reverses in AC, it will flow into the negative plate of the capacitor. In order to balance out that change in charge, the other plate will then discharge. If I'm interpreting your question correctly, then the answer is no; current does not flow through the dielectric. Current only flows straight through a capacitor when dielectric breakdown occurs.