Mutual Inductance Transfer function

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Discussion Overview

The discussion revolves around finding the transfer function Io(s)/Ii(s) for a circuit involving multiple inductors, mutual inductance, and a capacitor. Participants explore various methods for analyzing the circuit, including the use of Thevenin equivalents and mesh analysis.

Discussion Character

  • Homework-related
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant suggests starting from the right-hand side of the circuit to establish a relationship between Io(s) and Ii(s), but expresses concern about the increasing complexity of the equations.
  • Another participant notes that the circuit's complexity is expected due to the presence of four inductors, mutual inductance, and a capacitor, and proposes simplifying the analysis by using a Thevenin equivalent for the input current and resistor R2.
  • A different participant questions the labeling of resistors in the circuit, specifically whether two resistors labeled R2 are indeed the same component, and points out that the equations do not account for LR, only LL.
  • One participant agrees with the suggestion to use a Thevenin equivalent and emphasizes the importance of using Kirchhoff's Voltage Law (KVL) rather than Kirchhoff's Current Law (KCL) for this circuit analysis.
  • There is a recommendation to use lowercase for the Laplace variable s, indicating a preference for notation consistency.

Areas of Agreement / Disagreement

Participants express differing opinions on the best approach to analyze the circuit, with some advocating for Thevenin equivalents and others emphasizing KVL. There is no consensus on the labeling of components or the completeness of the equations presented.

Contextual Notes

Participants note potential confusion regarding the labeling of resistors and the inclusion of certain inductances in the equations. The complexity of the circuit and the methods proposed may depend on specific assumptions about the input current and the circuit configuration.

Who May Find This Useful

This discussion may be useful for students and practitioners working on circuit analysis involving inductors and capacitors, particularly in the context of transfer functions and complex circuit behaviors.

JasonHathaway
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Homework Statement


Find Io(s)/Ii(s)
Untitled.png


Homework Equations


Basic KVL laws.

The Attempt at a Solution


My idea is to start from the RHS of the circuit until I get a relation between Io(s) and Ii(s).
Untitled.png

Capture.png

Actually I stopped at this point, I wondered whether my approach is appropriate or not since the equations is getting longer and longer.

What do you say?
 
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I think you can expect the expressions to get longer and nastier. You've got a circuit with four inductors, a mutual inductance and a capacitor, so it's going to have some complex behavior in its general solution. It would be considerably simpler if the input current was confined to being a single frequency sinewave :smile:

If it were me I'd think of "replacing" the input current and R2 with a Thevenin equivalent just to get rid of one loop, then write mesh equations and use Cramer's Rule to solve symbolically for the capacitor current (mesh 3). Then all the hairy parts will be confined to one step: the hammering out of the two 3 x 3 determinants.
 
JasonHathaway said:

Homework Statement


Find Io(s)/Ii(s)
Untitled.png

In the I2 loop is a resistor R2, but the resistor in parallel with the input source also looks like R2 to me. Are they really both R2?

Also, your equations so far don't include LR; I see LL but not LR.
 
I would agree with gneill to change the current input to a Thevenin.
Then, you stated you want to use KVL but you used KCL instead. Stick to KVL. This is not a complicated circuit. Just two equations.
Also, use lowet case for the Laplace variable s.
 

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