- #1
Anton Alice
- 68
- 1
First of all, hello.
I have a problem in understanding the skin effect.
Often I read, that the skin effect is directly caused by eddy fields inside the conductor, which oppose the "desired" current flow. Problem at this is, that the eddy fields are not in phase with the desired current. The opposing current, caused by the eddy fields would be maximal, when the time-derivative of the desired current was maximal, but not the current itself. The current could be zero, while its time derivative is maximal (for example a sine).
But I also doubt my doubt:
If you look at a simple circuit with a solenoid, which is connected to a voltage supply via a switch:
-if the switch is open, nothing happens
-if the switch is closed, the inductivity of the circuit (i.e. the solenoid) responses to that singularity, which is caused by closing the switch. The response is an opposing high voltage, which inhibits the current flow in the beginning. So the current at time t=0 is zero. It is only inhibited.
Now, if I kind of apply the argument from above to this solenoid-example, I could ask myself: Why doesn't that opposing voltage create an opposing current flow? So the current at time t=0 should not only be inhibited, but also inverted.
Reality shows, that the current is not inverted, but only inhibited. And the same inhibition occurs during the skin effect. This would approve the explanation with the eddy fields.
Now I want to know, what of the above said makes sense, and eventually how the skin effect actually works?
I also have a second question:
The term skin effect is connected to "skin depth". But the term "skin depth" also occurs in relation to propagating EM-waves, which for example penetrate a conductor, and get reflected. Now I wonder, if there is a connection between skin effect and EM-waves?
I have a problem in understanding the skin effect.
Often I read, that the skin effect is directly caused by eddy fields inside the conductor, which oppose the "desired" current flow. Problem at this is, that the eddy fields are not in phase with the desired current. The opposing current, caused by the eddy fields would be maximal, when the time-derivative of the desired current was maximal, but not the current itself. The current could be zero, while its time derivative is maximal (for example a sine).
But I also doubt my doubt:
If you look at a simple circuit with a solenoid, which is connected to a voltage supply via a switch:
-if the switch is open, nothing happens
-if the switch is closed, the inductivity of the circuit (i.e. the solenoid) responses to that singularity, which is caused by closing the switch. The response is an opposing high voltage, which inhibits the current flow in the beginning. So the current at time t=0 is zero. It is only inhibited.
Now, if I kind of apply the argument from above to this solenoid-example, I could ask myself: Why doesn't that opposing voltage create an opposing current flow? So the current at time t=0 should not only be inhibited, but also inverted.
Reality shows, that the current is not inverted, but only inhibited. And the same inhibition occurs during the skin effect. This would approve the explanation with the eddy fields.
Now I want to know, what of the above said makes sense, and eventually how the skin effect actually works?
I also have a second question:
The term skin effect is connected to "skin depth". But the term "skin depth" also occurs in relation to propagating EM-waves, which for example penetrate a conductor, and get reflected. Now I wonder, if there is a connection between skin effect and EM-waves?