Concept explainers
- (a) Find I1 and I2 in the circuit of Fig. 13.111 below.
- (b) Switch the dot on one of the windings. Find I1 and I2 again.
(a)
Calculate the value of currents
Answer to Problem 46P
The currents
Explanation of Solution
Given data:
Refer to Figure 13.111 in the textbook for the transformer circuit with given values.
Calculation:
In Figure 13.111, reflect the secondary circuit to the primary circuit. Consider the expression to find the input impedance
Write the Matlab code to find the input impedance.
n=2;
w=1;
R1=10;
L1=16;
ZL=12-i*8;
Z1=R1+i*(w*L1);
Zin= Z1+(ZL/n^2)
The Matlab output is given below.
Zin = 13 + 14i
From the Matlab output, the input impedance is,
Calculate the secondary side voltage source after reflection.
Substitute
The reduced circuit from Figure 13.111is drawn and it is shown in Figure 1.
From Figure 1, write the expression using Kirchhoff’s voltage law.
Substitute
Write the expression for the current
Substitute
Conclusion:
Thus, the currents
(b)
Calculate the value of currents
Answer to Problem 46P
The currents
Explanation of Solution
Calculation:
Consider that the dot in the secondary side is switched to the down side. Switching a dot will not affect the impedance
Calculate the secondary side voltage source after reflection when the dot is switched.
Substitute
The reduced circuit from Figure 13.111 is drawn and it is shown in Figure 2.
From Figure 1, write the expression using Kirchhoff’s voltage law.
Substitute
Write the expression for the current
Substitute
Conclusion:
Thus, the currents
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Chapter 13 Solutions
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