High frequencies and capacitor plates

In summary, the capacitor does not allow current to flow through its plates. Rather, it stores charges on the plates and then releases them when the current changes direction. The capacitor is also commonly used to filter the DC output of an AC rectifier.
  • #1
jeff1evesque
312
0
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
 
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  • #2


Nope, the current does not "literally" go through the capacitor plates.
 
  • #3


It is stored due to the charges but I am not sure what you mean by the last part of your question.
 
  • #4


rock.freak667 said:
It is stored due to the charges but I am not sure what you mean by the last part of your question.

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


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


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.
 

1. What are high frequencies?

High frequencies refer to electromagnetic waves with a high frequency, or rate of oscillation, typically above 20,000 hertz (Hz). These frequencies are often associated with high-pitched sounds and are commonly used in communication and technology.

2. How do high frequencies affect capacitor plates?

High frequencies can cause a phenomenon known as dielectric heating, where the rapid changes in electric fields can generate heat in the capacitor plates. This can lead to a decrease in the capacitor's performance and potential damage.

3. How do capacitor plates work with high frequencies?

Capacitor plates are designed to store and release electrical energy. When exposed to high frequencies, the capacitor plates store and release energy at a faster rate, which can be useful in applications such as filtering and tuning circuits.

4. What is the relationship between high frequencies and the capacitance of a capacitor?

The capacitance of a capacitor is directly proportional to the frequency of the applied voltage. This means that as the frequency increases, the capacitance also increases. This relationship is important in determining the performance of a capacitor in high frequency applications.

5. Can high frequencies damage capacitor plates?

Yes, high frequencies can damage capacitor plates if the voltage and current levels exceed the capacitor's ratings. This can lead to overheating, arcing, and ultimately, failure of the capacitor. It is important to properly select and use capacitors that are designed to handle high frequency applications.

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