Voltage drop over dependent current source?

[Inertigratus]

I have a circuit with 3 meshes for which I have to find the mesh currents, and I have.
However, I just thought that there might be a voltage drop over the dependent current source in the circuit, which would change the mesh current equations.
The CCCS is shared by two meshes.
When I did the calculations I simply ignored the CCCS.
Any ideas?

 

[gneill]

I have a circuit with 3 meshes for which I have to find the mesh currents, and I have.
However, I just thought that there might be a voltage drop over the dependent current source in the circuit, which would change the mesh current equations.
The CCCS is shared by two meshes.
When I did the calculations I simply ignored the CCCS.
Any ideas?

Can you post the circuit diagram?

 

[Inertigratus]

Sure, http://img692.imageshack.us/img692/7081/namnlskei.jpg
I'm not asking for the solution, just wondering what I should do with the dependent source when writing the mesh equations?

 

[gneill]

Two suggestions. First, you could convert the current source and the 4R resistor in parallel with it to a Thevenin equivalent voltage source. That would let you write the KVL mesh equations without worrying about mystery voltages. It would also reduce the circuit to just two loops.

Second, you could introduce a new variable, say v_x, which is the voltage drop across the current source, and one new equation (with a new variable you need another equation). This equation would be the additional constraint on the mesh currents implied by the current source, namely i₂ - i₃ = k*i₁.

I think that the first suggestion would be simpler. Note that the third mesh current i₃ is strictly dependent upon the voltage v_x via Ohm's Law with the 4R resistor.

 

[Inertigratus]

I see, thanks!
So it's possible to use Thévenin and Norton equivalents when the sources are dependent as well?

 

[gneill]

I see, thanks!
So it's possible to use Thévenin and Norton equivalents when the sources are dependent as well?

Sure, as long as you maintain the dependencies through the calculations.