# basic node equitons using kirschoff

#### bumle90

Joined Mar 27, 2005
6
Hello.
I am having a little problems writing nodal equations using kirschoffs law for a pretty basic circuit.
I need to write equations for the nodes : a, b and c.

I have attached circuit drawing as a bmp-file, and hope that somebody can help me out a little.

Many regards from here.

#### bumle90

Joined Mar 27, 2005
6
Ohh and I forgot to mention that
x(t) is the input and y(t) is the output.

#### hgmjr

Joined Jan 28, 2005
9,027
Originally posted by bumle90@Mar 27 2005, 12:27 PM
Hello.
I am having a little problems writing nodal equations using kirschoffs law for a pretty basic circuit.
I need to write equations for the nodes : a, b and c.

I have attached circuit drawing as a bmp-file, and hope that somebody can help me out a little.

Many regards from here.
[post=6445]Quoted post[/post]​
Would you be interested in a solution that uses Millman's Theorem or are you interested in seeing the Kirchoff's Law solution only?

#### bumle90

Joined Mar 27, 2005
6
Originally posted by hgmjr@Mar 27 2005, 07:34 PM
Would you be interested in a solution that uses Millman's Theorem or are you interested in seeing the Kirchoff's Law solution only?
[post=6450]Quoted post[/post]​
Well, I think Kirschoff will suffice.
I would be very grateful.
Thank you very much

#### bumle90

Joined Mar 27, 2005
6
Originally posted by hgmjr@Mar 27 2005, 07:34 PM
Would you be interested in a solution that uses Millman's Theorem or are you interested in seeing the Kirchoff's Law solution only?
[post=6450]Quoted post[/post]​
I have written the following equations: (Are they completely wrong or.. ? )

a: -(Va/R1)+((Va-Vb)/R2)+(C1*(d(y(t)-Va)/dt))=0

b: -((Va-Vb)/R2)+(C2*(d(Vb)/dt))=0

c: -((y(t)-Vc)/R4)+Vc/R3=0