Electrical Engineering Challenge #7

[ttokoro]

In these days, www.academia.edu shows me a lot of contents of electrical engineering.

I am interested in one book, "Circuit Analysis I with MATLAB® Applications", Orchard Publications. The top cover page shows this circuit problem. It may be the best question of this book that Matlab can use to solve it.

I try to solve this one by Mathcad Prime 10.

I am standing Mathcad side. So, try and Challenge it!

[AlanStevens · Accepted solution]

The Matlab instructions don't reflect the problem correctly! They should be:

G = [35/50-1j*3/50, -1/5; -1/10, 1/10+1j*1/10];
I = [1; 0];
V = G\I;
Ix = 5*V(2,1)/4;
magIx = abs(Ix);
theta = angle(Ix)*180/pi;

giving the result:

magnitude = 1.47 A theta = -48.81 deg

Alan

[StuartBruff]

Oops!  Forgot to add the simple way of doing it ...

[StuartBruff]

Stuart

[-MFra-]

It should be noted that an electrolytic capacitor in an AC circuit is not really suitable as it must be polarized.

[-MFra-]

The circuit was interesting, so I analyzed it by applying the results of network topology. Having defined the branch equations and the  node voltage vectors as well as the branch voltage and current vectors, I applied the method of node voltages. I obtain the same results by applying the analysis method based on independent meshes and the method based on independent cutting sets. In the following photos there are all the calculations:

[StuartBruff]

Nice.

Out of idle curiosity, how did you produce the graphs (eg, drawing package, application, or Mathcad)? 

I'm reasonably sure that Mathcad could be induced (*) to draw them, including the filled arrowheads.  I wouldn't be surprised if somebody's done it (or several somebodies, independently).

Stuart

(*) Possibly by vile imprecations, threats, or withholding its pocket money.

[-MFra-]

Someone at Electrical Engineering on Stack Exchange told me that there are programs that do all this, but I don't know which ones. I drew all the graphs myself with Paint based on the network topology dictates and deduced from the texts of W. K. Chen and Chua-Desoer and Kuh. I agree that they could also be done with Mathcad. You just have to try.