How can I represent this circuit in state space?

[Emmanouel]

I have this circuit and I must represent it in state space. I know the process because I have done similar ones but having trouble with this one. I have found the Kirchhoff equtations for the 2 loops and for the upper juction, whatever I do after I can't end up to two equations x'1 and x'2.

• First loop: V(t)=V(R1)+V(c1)+V(R2)
• Second loop: V(R3)+V(c2)=V(R2)+V(c1)
• Junction: i(t)=i(R3)+i(c1) or i(t)=i(c2)+i(R2) => i(c1)=i(R3)+i(t) and i(c2)=i(R2)+i(t)

I know that V(C1)=x1 ,and V(c2)=x2 and i(c1)=c1*x'1 , i(c2)=c2*x'2

http://www.mathworks.com/matlabcentral/answers/uploaded_files/21768/circuit.bmp

 

[berkeman]

I have this circuit and I must represent it in state space. I know the process because I have done similar ones but having trouble with this one. I have found the Kirchhoff equtations for the 2 loops and for the upper juction, whatever I do after I can't end up to two equations x'1 and x'2.

• First loop: V(t)=V(R1)+V(c1)+V(R2)
• Second loop: V(R3)+V(c2)=V(R2)+V(c1)
• Junction: i(t)=i(R3)+i(c1) or i(t)=i(c2)+i(R2) => i(c1)=i(R3)+i(t) and i(c2)=i(R2)+i(t)

I know that V(C1)=x1 ,and V(c2)=x2 and i(c1)=c1*x'1 , i(c2)=c2*x'2

http://www.mathworks.com/matlabcentral/answers/uploaded_files/21768/circuit.bmp

Welcome to the PF.

Is this question for schoolwork? If so, I can move it to the schoolwork forums for you.

 

[donpacino]

can you post a circuit schematic...

You need to get your equations in terms of known values, such as inputs and component values.
example. if you want to find the voltage across a resistor 2, instead of saying V(source)-V(resistor_1)-V(resistor_2)=zero, say V_out=V_in*R_1/(R_1+R_2)

does that make sense?