Lecture Electric circuit theory: Circuit theorems - Nguyễn Công Phương

Lecture Electric circuit theory: Circuit theorems presents the following content: Source transformation, linearity and superposition, Thévenin Equivalent Subcircuits, Norton Equivalent Subcircuits, maximum power transfer.

Electric Circuit Theory

Circuit Theorems

Nguy ễ n Công Ph ươ ng

Circuit Theorems - sites.google.com/site/ncpdhbkhn 2

Contents

I Basic Elements Of Electrical Circuits

II Basic Laws

III Electrical Circuit Analysis

IV Circuit Theorems

V Active Circuits

VI Capacitor And Inductor

VII First Order Circuits

VIII.Second Order Circuits

IX Sinusoidal Steady State Analysis

X AC Power Analysis

XI Three-phase Circuits

XII Magnetically Coupled Circuits

XIII.Frequency Response

XIV.The Laplace Transform

XV Two-port Networks

Circuit Theorems

1 Source Transformation

2 Linearity and Superposition

3 Thévenin Equivalent Subcircuits

4 Norton Equivalent Subcircuits

5 Maximum Power Transfer

=

Circuit Theorems

1 Source Transformation

2 Linearity and Superposition

3 Thévenin Equivalent Subcircuits

4 Norton Equivalent Subcircuits

5 Maximum Power Transfer

Linearity and Superposition (1)

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+ –

Linearity and Superposition (2)

Linear and Superposition (3)

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Linear and Superposition (4)

Linear and Superposition (5)

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Linear and Superposition (6)

Linear and Superposition (7)

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1 2

E

R J i

j

= +

=

Linear and Superposition (8)

1 Deactivate E 2 & J, find i 2 | E1

2 Deactivate E 1 & J, find i 2 | E2

3 Deactivate E 1 & E 2 , find i 2 | J

4 Find i 2 = i 2 | E1 + i 2 | E2 + i 2 | J

Linear and Superposition (9)

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+

+

= +

+

+

10 2 6

) 10 2 ( 6 )

(

4 3

2

4 3

2

234

R R

R

R R

E E

= +

Linear and Superposition (10)

+

+

= +

+

+

10 2 4

) 10 2 ( 4 )

(

4 3

1

4 3

1

134

R R

R

R R

= +

= 2 134 6 3 9

2134 R R

R

Ex 2

Linear and Superposition (11)

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J J

12 3 4

20

1.39 A 2.4 2 10

J

E i

Linear and Superposition (12)

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Circuit Theorems

1 Source Transformation

2 Linearity and Superposition

3 Thévenin Equivalent Subcircuits

4 Norton Equivalent Subcircuits

5 Maximum Power Transfer

Thévenin Equivalent Subcircuits (1)

R eq

E eq

–

Thévenin Equivalent Subcircuits (2)

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+ –

v

i

R L

+ –

E eq : the open-circuit voltage at the terminals

R eq : the input or equivalent resistance at the terminals

when the independent sources are deactivated

Thévenin Equivalent Subcircuits (3)

Req : the input or equivalent resistance at the terminals

when the independent sources are deactivated

20 6.67 30

=

+

=

Thévenin Equivalent Subcircuits (4)

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Req : the input or equivalent resistance at the terminals

when the independent sources are deactivated

Thévenin Equivalent Subcircuits (5)

Thévenin Equivalent Subcircuits (6)

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Thévenin Equivalent Subcircuits (7)

c

resistance at the terminals

when the independent

sources are deactivated

b

R3a

Thévenin Equivalent Subcircuits (8)

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resistance at the terminals

when the independent

sources are deactivated

b

R3a

Thévenin Equivalent Subcircuits (9)

c

eq L

eq L

E i

Thévenin Equivalent Subcircuits (10)

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Thévenin Equivalent Subcircuits (11)

Thévenin Equivalent Subcircuits (12)

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Thévenin Equivalent Subcircuits (13)

Thévenin Equivalent Subcircuits (14)

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Thévenin Equivalent Subcircuits (15)

Thévenin Equivalent Subcircuits (16)

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Circuit Theorems

1 Source Transformation

2 Linearity and Superposition

3 Thévenin Equivalent Subcircuits

4 Norton Equivalent Subcircuits

5 Maximum Power Transfer

Norton Equivalent Subcircuits (1)

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+ –

v

i

R L

J eq : the short-circuit through the terminals

R eq : the input or equivalent resistance at the terminals

when the independent sources are deactivated

+ –

v

i

R L

J eq R eq

Norton Equivalent Subcircuits (2)

10

= 3A

=

Req : the input or equivalent resistance at the terminals

when the independent sources are deactivated

0.55 A

v i

–

Norton Equivalent Subcircuits (3)

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Norton Equivalent Subcircuits (4)

a

v i

Norton Equivalent Subcircuits (5)

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resistance at the terminals

when the independent

sources are deactivated

b

R3a

Norton Equivalent Subcircuits (6)

resistance at the terminals

when the independent

sources are deactivated

b

R3a

Norton Equivalent Subcircuits (7)

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eq

eq

J R

=

Ex 2

Norton Equivalent Subcircuits (8)

Norton Equivalent Subcircuits (9)

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Ex 3

Norton Equivalent Subcircuits (10)

eq

E i

Ex 3

Thévenin & Norton Equivalent Subcircuits (1)

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+ –

v

i

R L

+ –

eq

E R

i

→ = open-circuit

short-circuit

Thévenin & Norton Equivalent Subcircuits (2)

eq

E

v R

= open-circuit =

short-circuit 10.67

4.44 2.40

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Circuit Theorems

1 Source Transformation

2 Linearity and Superposition

3 Thévenin Equivalent Subcircuits

4 Norton Equivalent Subcircuits

5 Maximum Power Transfer

Maximum Power Transfer (1)

+ –

eq L

E i

Maximum Power Transfer (2)

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