clear all
close all
clc
format short eng
R1=100;
R2=100;
R3=500;
R4=100;
R5=50;
C1=1e-6;
C2=1e-6;
C3=2e-6;
syms s Vin Va Vb Vc Vd Ve Vf C1 C2 C3 R1 R2 R3 R4 R5 Vout
Zc1=1/(s*C1);
Zc2=1/(s*C2);
Zc3=1/(s*C3);
e(1)=Vin==Va; %KVL Op Amp
e(2)=Ve==Vf;
e(4)=((Va-Vb)/Zc1)-((Vb-Vd)/Zc2)-(Vb/R5)==0; % KCL Node B
e(5)=((Va-Vc)/R1)-((Vc-Vd)/R2)-((Vc-Ve)/Zc3)==0; %KCL Node C
e(6)=((Vb-Vd)/Zc2)-((Vc-Vd)/R2)==0; %KCL Node D
e(7)=((Vc-Ve)/Zc3)-((Ve-Vf)/R3)==0; %KCL Node E
e(8)=((Ve-Vf)/R3)-(Vf/R4)==0; %KCL Node F
sol=solve(e,Va,Vb,Vc,Vd,Ve,Vf,Vout); %Sol
Vout=sol.Vf/R5+R4;
Vout=eval(sol.Vout)
H=Vout/Vin % Gain is output over input
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Sardar Usama
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When I run the code I get Vout= [] H= [Empty System] – Julio Acosta-Silverio May 08 '22 at 19:24
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Please add this comment to your question. As it stands now there's no question in your question. – GrapefruitIsAwesome May 08 '22 at 20:59
1 Answers
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You can't define resistors R1 R2 R3 R4 R5
as symbols when you already have their values, they got overwritten. Same for capacitors, C2 C3
, and give some value for Vin
in order to get value for Vout. Also, don't put the equations as a vector against variables, Vout
is not a variable. just write the equations individually and leave the variables for MATLAB to determine automatically. Finally check the formula for Vout = Vf/R5 + R4
, is it accurate?
clear, clc
R1 = 100; R2 = 100; R3 = 500; R4 = 100; R5 = 50;
C1 = 1e-6; C2 = 1e-6; C3 = 2e-6;
Vin = 5; % Give it some value to get Vout
syms s Va Vb Vc Vd Ve Vf
Zc1=1/(s*C1);
Zc2=1/(s*C2);
Zc3=1/(s*C3);
e1 = Vin == Va; % KVL Op Amp
e2 = Ve == Vf;
e4 = (Va-Vb)/Zc1 - (Vb-Vd)/Zc2 - Vb/R5 == 0; % KCL Node B
e5 = (Va-Vc)/R1 - (Vc-Vd)/R2 - (Vc-Ve)/Zc3 == 0; % KCL Node C
e6 = (Vb-Vd)/Zc2 - (Vc-Vd)/R2 == 0; % KCL Node D
e7 = (Vc-Ve)/Zc3 - (Ve-Vf)/R3 == 0; % KCL Node E
e8 = (Ve-Vf)/R3 - Vf/R4 == 0; % KCL Node F
sol = solve(e1,e2,e4,e5,e6,e7,e8); %Sol
Vout = sol.Vf/R5 + R4;
H = Vout/Vin % Gain is output over input
Output:
H =
20
20
20

AboAmmar
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