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RLC/LC Circuit - Current??

How do I work out the current through:

A simple LC series circuit, with capacitor charged to initial voltage V(0)?

Thanks.
Original post by Sgt.Incontro
How do I work out the current through:

A simple LC series circuit, with capacitor charged to initial voltage V(0)?

Thanks.


When you say simple LC circuit, how exactly are the two connected together? Are there any dc resistances involved? Is the discharge a step change or is there some other forcing function?

Dependent on how they are connected, the solution may lead to a second order differential equation with complex roots.
Reply 2
Original post by uberteknik
When you say simple LC circuit, how exactly are the two connected together? Are there any dc resistances involved? Is the discharge a step change or is there some other forcing function?

Dependent on how they are connected, the solution may lead to a second order differential equation with complex roots.


Hi mate, pleased to see that someone answered :smile:

Well the question I asked is actually the first part of the a larger question as a whole - I could explain it, but I think you might find it easier to understand from a diagram:

Original post by Sgt.Incontro
Hi mate, pleased to see that someone answered :smile:

Well the question I asked is actually the first part of the a larger question as a whole - I could explain it, but I think you might find it easier to understand from a diagram:



OK. I don't know how much you already know about circuit theory and there are a few ways of tackling this problem. But be warned, the solutions to the textbook 'simpe RLC circuits' are anything but simple and require a substantial amount of explanation / learning depending on what you already know. I'm assuming you have not already covered this or you would not be asking! lol.

To be frank, to explain this in the detail the question seems to be asking for would cover at least a few chapters of an electrical theory text.

You will need to understand Kirchoff's laws, formulating second order differential equations, integration between limits, complex roots, transient and steady state response. More advanced solution methods could use Z transforms or Laplace (S-domain) transforms.

The solutions will lead to exponential functions including damped oscillation and phase shifts in the case of the sinusoid source.

There is no easy way around this, you will have to bite the bullet and study some text books.

Suggested reading:

http://uqu.edu.sa/files2/tiny_mce/plugins/filemanager/files/4220086/Electric_Circuit_9th_edition_-_realmadridar.com.pdf

Chapters 2, 6, 7, 8 & 9.
Reply 4
Original post by uberteknik
OK. I don't know how much you already know about circuit theory and there are a few ways of tackling this problem. But be warned, the solutions to the textbook 'simpe RLC circuits' are anything but simple and require a substantial amount of explanation / learning depending on what you already know. I'm assuming you have not already covered this or you would not be asking! lol.

To be frank, to explain this in the detail the question seems to be asking for would cover at least a few chapters of an electrical theory text.

You will need to understand Kirchoff's laws, formulating second order differential equations, integration between limits, complex roots, transient and steady state response. More advanced solution methods could use Z transforms or Laplace (S-domain) transforms.

The solutions will lead to exponential functions including damped oscillation and phase shifts in the case of the sinusoid source.

There is no easy way around this, you will have to bite the bullet and study some text books.

Suggested reading:

http://uqu.edu.sa/files2/tiny_mce/plugins/filemanager/files/4220086/Electric_Circuit_9th_edition_-_realmadridar.com.pdf

Chapters 2, 6, 7, 8 & 9.


Thank you mate.

I already have done most of the reading for this (pole zero method, transient responses, etc) , I just need to compare answers with people, so I know I am right.

What did you get for the first part?

I will read your link once I get home.

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