How can I build a circuit solver in matlab ?

I am a beginner in Matlab. I want to bulid a program which will take input the nodes and the resistance,current source or voltage source present in between the nodes and will show me the output of the branch currents along with the node voltages.

This is the code I found in a blog http://matlabbyexamples.blogspot.com/2011/11/circuit-solver-using-matlab-programming.html and modified a little bit. This code only shows output of the node voltages.

NetList=input('input node and resistance');

Vnod=input('input voltage and node');

%NetList=[1 2 2; 1 3 4; 2 3 5.2; 3 4 6; 2 4 3];

%Vnod=[1 6; 4 0];

l=size(NetList,1);
N=max([NetList(:,1) ;
NetList(:,2)]); 
A=zeros(N,N);
 B=zeros(N,1);

   for i=1:l
         n1=NetList(i,1);
         n2=NetList(i,2);
         if n1==n2
         else
            A(n1,n2)=A(n1,n2)-1/NetList(i,3);
            A(n2,n1)=A(n2,n1)-1/NetList(i,3);
            A(n1,n1)=A(n1,n1)+1/NetList(i,3);
            A(n2,n2)=A(n2,n2)+1/NetList(i,3);
        end
   end

   for i=1:size(Vnod,1)
          A(Vnod(i,1),:)=zeros(1,N);
          A(Vnod(i,1),Vnod(i,1))=1;
          B(Vnod(i,1),1)=Vnod(i,2);
   end

   Vo=A\B; 

   disp(Vo);

It can solve the following types of circuits taking input as matrix and give output only the node voltages

But I can't solve the circuits in which voltage source is present between any two nodes other than ground.

I want to build a simple program which will solve the above problem and give output the branch currents along with the node voltages.

[Emanuele Zanetti]

Hello,

I have the same issue. Did you find a solution for this problem?

Answer 1

[Bardo]

Hi,

you need to familiarize yourself with MNA equations, see a nice explanation in

SCAM - Symbolic Circuit Analysis in MatLab