Modelling this circuit

sajti99

Joined Jun 25, 2022
2
Hello Leute,

I've been having a hard time with my school project and wondered if you could help me.
My task is that I have to modell a circuit of wireless charging (seen on the picture).
For help I was given this Wikipedia link and later on I was told by my teacher that my main goal should be writing and solving the differential equations that determine this circuit and thus be able to say how much current flows through Rl for given Vs.

So far I've read countless of topics regarding this project (Including this site's part for AC current.), but the thing is, I'm still struggling with the mathematical aspect of it.

And for this I'm reaching out to you guys, with hope that some could help me out on this one.

Thank you in advance!

ps: I only need guidance not solving the whole thing for me (before anyone accuses).

RBR1317

Joined Nov 13, 2010
712
This appears to be a steady-state AC analysis with coupled coils, so I would ditch the recommendation to solve with differential equations. What I have not seen is the coupling coefficient between the coils. I would assume that Rs & Rr is the wire resistance of the corresponding coil. Also, is Vs a measured value or a voltage source; if the latter, then what is the internal impedance of the source? The value of Cs is not relevant if the source impedance is zero, or if Vs is a measured value. To go any further I would need to go back and review how to do basic circuit analysis with coupled coils.
Also see: https://en.wikipedia.org/wiki/Resonant_inductive_coupling

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sajti99

Joined Jun 25, 2022
2
This appears to be a steady-state AC analysis with coupled coils, so I would ditch the recommendation to solve with differential equations. What I have not seen is the coupling coefficient between the coils. I would assume that Rs & Rr is the wire resistance of the corresponding coil. Also, is Vs a measured value or a voltage source; if the latter, then what is the internal impedance of the source? The value of Cs is not relevant if the source impedance is zero, or if Vs is a measured value. To go any further I would need to go back and review how to do basic circuit analysis with coupled coils.
Also see: https://en.wikipedia.org/wiki/Resonant_inductive_coupling
The thing is, I can't really ditch the diff. eq. part because that's the way I HAVE to solve it (according to my teacher...)
Yeah,Vs is an AC voltage source. The value of any measure/constant is open to me (again, according to my teacher), but I need to able to say why I chose that exact number.