I'm having some issues with these two exercises about Thevenin and Norton equivalent circuits with dependent voltages.
1) Determine the equivalent Thevenin Circuit seen by the terminals ab
So first thing, I apply KVL:
V110*I1+I1*R1+I1*R2=0 \(\Leftrightarrow\) I1 = 1 A
V1 + R2*I1  Vth = 0 \(\Leftrightarrow\) Vth = 10 V
(Vth = Vab)
All fine. But now to determine the Rth I would need to know the Isc, the current in short circuit that passes through a and b.
Again I try to apply KVL
10 V1 + V1 + R1*I2 + R2*I1=0
and KCL
Isc + I1 = I2
Results in a equation with 2 variables I1 and Isc which I can't solve.
10 I1 + V1 + R1*(Isc + I1) + R2*I1 = 0
What I am missing or doing wrong?
2) Determine the equivalent of Thevenin and Norton seen by the terminals ab
I try to apply KVL and KCL.
I3 = Current that passes rightleft through the dependent voltage 5*Ix
IR2 = Current that passes downup through the resistance R2
Ix = I1+IR2+I2
5*IxIx*R1IR2*R2=0 \(\Leftrightarrow\) Ix = (R2*I1R2*I2) / (5R1R2) = 5.45 A
With Ix I determine IR2= 9.55 A
The Vth or Vab would be IR2*R2 = 38.2 V which is wrong.
What am I doing wrong?
How would I then determine the IN?
Should I try to apply the sobreposition theorem and to the first exercise as well?
(IN = Current equivalent of Norton, short circuit)
By the way the solution is:
1) Vth = 10 V; Rth = 16 ohm
2) Vth = 48.571 V; IN=8 A; Rth=RN= 3.238 ohm
1) Determine the equivalent Thevenin Circuit seen by the terminals ab
So first thing, I apply KVL:
V110*I1+I1*R1+I1*R2=0 \(\Leftrightarrow\) I1 = 1 A
V1 + R2*I1  Vth = 0 \(\Leftrightarrow\) Vth = 10 V
(Vth = Vab)
All fine. But now to determine the Rth I would need to know the Isc, the current in short circuit that passes through a and b.
Again I try to apply KVL
10 V1 + V1 + R1*I2 + R2*I1=0
and KCL
Isc + I1 = I2
Results in a equation with 2 variables I1 and Isc which I can't solve.
10 I1 + V1 + R1*(Isc + I1) + R2*I1 = 0
What I am missing or doing wrong?
2) Determine the equivalent of Thevenin and Norton seen by the terminals ab
I try to apply KVL and KCL.
I3 = Current that passes rightleft through the dependent voltage 5*Ix
IR2 = Current that passes downup through the resistance R2
Ix = I1+IR2+I2
5*IxIx*R1IR2*R2=0 \(\Leftrightarrow\) Ix = (R2*I1R2*I2) / (5R1R2) = 5.45 A
With Ix I determine IR2= 9.55 A
The Vth or Vab would be IR2*R2 = 38.2 V which is wrong.
What am I doing wrong?
How would I then determine the IN?
Should I try to apply the sobreposition theorem and to the first exercise as well?
(IN = Current equivalent of Norton, short circuit)
By the way the solution is:
1) Vth = 10 V; Rth = 16 ohm
2) Vth = 48.571 V; IN=8 A; Rth=RN= 3.238 ohm
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