Equivalent Circuits

Contents

Finding equivalent resistance
Finding Thévenin voltage
Finding Norton current
Check Equivalent resistance
Maximum Power Transfer

Finding equivalent resistance

R = [20 5 6];
RT = 1/sum(1./R(1:2)) + R(3);
fprintf('Equivalent Resistance: %g Ohm\n',RT);

Equivalent Resistance: 10 Ohm

Finding Thévenin voltage

vs = 10;
vth = R(2)*vs/(R(1)+R(2));
fprintf('vth %g V\n',vth);

vth 2 V

Finding Norton current

vx = (vs/R(1))*rparallel(R);
isc = vx/R(3);
fprintf('vx %g V, isc %g A\n',vx,isc);

vx 1.2 V, isc 0.2 A

Check Equivalent resistance

fprintf('RTH = %g ohm\n',vth/isc);

RTH = 10 ohm

Maximum Power Transfer

rho = linspace(0,8,240);
pratio = rho./(1+rho).^2;
plot(rho,pratio,'LineWidth',2);
axis([0 8 0 0.25]);
grid;
xlabel('Normalized Resistance (R_L/R_{Th})');
ylabel('Normalized Power (P_L/P_{Th})');