Mesh current equation in matrix form

In summary, the conversation discusses how to solve a circuit using Cramer's rule and addresses the effects of a controlled current source in the circuit. It is suggested to insert a controlled voltage source in series with a specific resistor to accurately account for the effects of the current source. The conversation also mentions the importance of considering the potential drop across the resistor in loop 3 caused by the mesh current in loop 1.
  • #1
vizakenjack
57
4
Member warned to use the Formatting Template for homework
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i3 -?

This is how I tried to solve using cramer's rule (denominator is the determinant of the matrix, while numerator is the determinant of the modified matrix)
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I ignored the prefix Kilo, but the method is right. So I get a different value for i3.

Does anyone know what's wrong?
 
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  • #2
Your mesh equations do not appear to take into account the effects of the controlled current source in loop 1.
 
  • #3
gneill said:
Your mesh equations do not appear to take into account the effects of the controlled current source in loop 1.
But it does? You don't need to set up equation for it, because i1 = 0.001Vx
 
  • #4
vizakenjack said:
But it does? You don't need to set up equation for it, because i1 = 0.001Vx
So where are it's effects on the rest of the circuit? Hypothetically, suppose it was changed to i1 = 0.003Vx. Shouldn't that change be reflected in your mesh equations? Where would the changes appear?

The controlled current source as a mesh current must create a potential difference across the 1 kΩ resistor in loop 3. You can't just ignore that.

Big hint: To address this, insert an appropriate controlled voltage source in series with the 1 kΩ resistor.
 
  • #5
gneill said:
Big hint: To address this, insert an appropriate controlled voltage source in series with the 1 kΩ resistor.

Why would I insert something just randomly? I don't get these riddles!
 
  • #6
vizakenjack said:
Why would I insert something just randomly? I don't get these riddles!
It's not random. The controlled voltage source expresses the controlled current source's effect on loop 3. Loop 1's mesh current flows through the 1k resistor of loop 3 and creates a potential drop across it. The inserted voltage source represents that potential drop.
 

FAQ: Mesh current equation in matrix form

What is the mesh current equation in matrix form?

The mesh current equation in matrix form is a mathematical representation of Kirchhoff's Voltage Law (KVL) for a circuit. It is used to solve for the unknown mesh currents in a circuit with multiple meshes, and is written in the form of Ax = b, where A is the coefficient matrix, x is the vector of mesh currents, and b is the vector of voltage sources.

How is the mesh current equation derived?

The mesh current equation is derived by applying KVL to each mesh in a circuit. By summing the voltage drops around each mesh and setting them equal to the corresponding voltage source, a system of linear equations is formed. This system can then be written in matrix form and solved to find the mesh currents.

What is the advantage of using the mesh current equation in matrix form?

The advantage of using the mesh current equation in matrix form is that it allows for a systematic and efficient way to solve for multiple mesh currents in a circuit. By writing the equations in matrix form, it becomes easier to solve using techniques such as Gaussian elimination or Cramer's rule.

Can the mesh current equation be applied to any circuit?

Yes, the mesh current equation can be applied to any circuit, as long as it follows the principles of KVL and has multiple meshes. It is commonly used in circuits with resistors, voltage sources, and current sources.

Are there any limitations to using the mesh current equation in matrix form?

One limitation of using the mesh current equation in matrix form is that it can become complex and cumbersome for circuits with a large number of meshes. In such cases, it may be more efficient to use other methods, such as nodal analysis. Additionally, the mesh current equation assumes that the circuit is in a steady state, and does not take into account transient effects.

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