DC Circuit Analysis Problem

[abc_123]

I have a DC circuit analysis problem that I would like some help with. It is some time since I have completed any nodal / mesh analysis and all examples are very simple so do not really help with this problem.



As you can see the image shows a problem that involves two voltage sources and four resistors.

The problem I have is that I need to create equations for the currents Ia and Ib. I need these equations in terms of Vx, Vy Vz, R3 and R4. Is this possible? Can someone provide a worked solution?

Thanks!

 

[KlausST]

Hi,

First calculate the voltages without V2.
Then calculate the impedance at both connections of v2 as if v2 didn't exist.

Add the impedances, that is wgat v2 sees.
To calculate the currents you have to subtract voltage v2 - ( virt_diff_voltage) and divide it by the impedance.

Now you should be able to calculate all.

Good luck
Klaus

 

[zorro]

The problem I have is that I need to create equations for the currents Ia and Ib. I need these equations in terms of Vx, Vy Vz, R3 and R4. Is this possible?

Of course it's possible. This is nodal analysis. You can solve for Ia and Ib in terms of V1, V2 and the R's (Vx, Vy and Vz must not appear in the final solution).

The most simple way is using superposotion.
1) calculate Ia and Ib produced by V1 with V2=0
2) calculate Ia and Ib produced by V2 with V1=0
3) add results

Regards

Z