E E 1205

E E 1205

Lecture 05 - Thévenin and Norton Equivalent Circuits

Thévenin and Norton Equivalents

VTh

RTh a

b

IN RTh

a

b

=

Th Th NV R I ThN

Th

VIR

Combining Voltage Sources

10 V

15 V

25 V=

a

a

b

b

Voltage sources areadded algebraically

Combining Voltage Sources

10 V

15 V

5 V=

a

a

b

b

Voltage sources areadded algebraically

Combining Voltage Sources

5 V 10 V

b

a

Don’t do this.

Why is this illogical?Whose fundamental circuitlaw is violated by this?

Combining Current Sources

5 A 10 A

b

a

15 A

a

b

=

Current sources areadded algebraically

Combining Current Sources

5 A 10 A

b

a

5 A

a

b

=

Current sources areadded algebraically

Combining Current Sources

5 A

10 A

b

aDon’t do this.

Why is this illogical?Whose fundamental circuitlaw is violated by this?

Source Transformations Simplify Circuits (1/5)

144 V

18

4 A36

20

100 V

47 A 4

b

a

Source Transformations Simplify Circuits (2/5)

8A 18 4 A36

20

100 V

4 188 V

a

b

Source Transformations Simplify Circuits (3/5)

12 A 12

24

288 V

b

a

Source Transformations Simplify Circuits (4/5)

12 A 12 24 12 A

a

b

Source Transformations Simplify Circuits (5/5)

24 A 8

a

b

192 V

8 a

b