Lecture Electric circuit theory: Basic laws - Nguyễn Công Phương

Magnetically Coupled Circuits XIII.Frequency Response. XIV.The Laplace Transform XV.[r]

Electric Circuit Theory

Basic Laws - sites.google.com/site/ncpdhbkhn 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

Basic Laws

1 Ohm’s law

2 Nodes, branches, and loops 3 Kirchhoff’s laws

Basic Laws - sites.google.com/site/ncpdhbkhn Ohm’s law (1)

i R

+ v –

v = Ri

Slope = R

v

i

p(t) = v(t)i(t)

→ p(t) = Ri2(t)

1

i v Gv

R

Ohm’s law (2)

+ –

v

i

i Req

+ v –

Slope = R

v

Basic Laws - sites.google.com/site/ncpdhbkhn Ohm’s law (3)

+ –

i(t)

v

vs = 0

+ –

i(t)

v

R = 0

+ –

i(t)

v

is = 0

+ –

i(t)

v

R = ∞

Basic Laws

1 Ohm’s law

2 Nodes, branches, and loops

Basic Laws - sites.google.com/site/ncpdhbkhn Nodes, branches, and loops (1)

A branch represents a single element

+

– +

–

R1

R2

R3

R4 E1

E2

Nodes, branches, and loops (2)

A node is the point of connection between two or more branches

a b c

d

e f

+

– +

–

R1

R2

R3

R4 E1

E2

Basic Laws - sites.google.com/site/ncpdhbkhn 10 Nodes, branches, and loops (3)

A loop is any closed path in a circuit

b = l + n – 1

+

– +

–

R1

R2

R3

R4 E1

E2