REVIEW OF LECTURES 05-08REVIEW OF LECTURES 05-08 07/23/2013 ECE225 CIRCUIT ANALYSIS. Contents of...

transcript

CIRCUITS by Ulaby & MaharbizAll rights reserved. Do not reproduce or distribute.

REVIEW OF LECTURES 05-08REVIEW OF LECTURES 05 08

07/23/2013 ECE225 CIRCUIT ANALYSIS

Contents of Midterm #2Midterm #2 Schecule: 10:45~13:15 July 25 Thursday

L t 05 08

Midterm #2 Schecule: 10:45 13:15, July 25, Thursday

Sections 3.5-3.6; 4.3-4.7; 5.2-5.3. Lectures 05-08 Sections 3.5 3.6; 4.3 4.7; 5.2 5.3.

Office hours this week• Double office hour on Today

• No office hour on Thursday, July 25 (Midterm#2 day)

9:30am~10:30 am & 16:00~17:00

No office hour on Thursday, July 25 (Midterm#2 day)

• TA office hour remain unchanged

Summary of Chapter 3 (part 3)y p (p )

Thévenin’s Theorem

Linear two-terminal circuit can be replaced by an

equivalent circuit composed of a voltage

source and a series resistor

voltage across output with no load (open circuit)

inTh RR

Resistance at terminals with all Resistance at terminals with all independent circuit sources set to zero

Linear two-terminal circuit can be replaced by an equivalent be replaced by an equivalent circuit composed of a current source and parallel resistor

Current through output with short circuit

Resistance at terminals with all circuit sources set to zero

How Do We Find Thévenin/Norton E i l t Ci it ?Equivalent Circuits ? Method 1: Open circuit/Short circuit Method 1: Open circuit/Short circuit

1. Analyze circuit to find

2. Analyze circuit to find

Note: This method is applicable to Note: This method is applicable to any circuit, whether or not it contains dependent sources.

How Do We Find Thévenin/Norton E i l t Ci it ?Equivalent Circuits?Method 2: Equivalent ResistanceMethod 2: Equivalent Resistance

1. Analyze circuit to find either

or 2 ll d d b2. Deactivate all independent sources by replacing voltage sources with short circuits and current sources with open circuits.3. Simplify circuit to find equivalent resistance

Note: This method does not apply to circuits that contain dependent sources.p

Example 3-11: RTh

(Ci i h d d )Replace with SC (Circuit has no dependent sources)

Replace with OC

How Do We Find Thévenin/Norton E i l t Ci it ?Equivalent Circuits?

Method 3:

and Science Press p

E l ( t )

To find

Example (cont.)

In many situations, we want to y ,maximize power transfer to the load

and Science Press

National Technology and Science Press

Summary of Chapter 4y p

Use nodal analysis as before, but with “golden rules”

N No current into op amp

No voltage drop across op amp input

Do not apply KCL at op amp output

Noninverting Amplifierg p

At node

Rvv non

spn vvv

(max) = Vcc

Inverting Amplifierg p

0 pn vv

p pRelate output voltage to input current sourcep

Summing Amplifierg p

Example 4-3: p

Solution:

Note negative gain of channel 1

“Buffers” Sections of CircuitBuffers Sections of Circuit

depends on both input and load iresistors

is immune to input and load resistors

What is the op amp doing?

y p ( )

Passive element that stores energy in electric fieldPassive element that stores energy in electric field

Parallel plate capacitor

0 1 tdtit

For DC, capacitor looks like open circuitlike open circuit

Voltage on capacitor must be continuous (no abrupt change)abrupt change)

Energy Stored in Capacitorgy p

Capacitor Response: Given v(t), determine i(t), p(t), and w(t)

C = C =

At dc no currents flow through capacitors: open circuits At dc no currents flow through capacitors: open circuits

Capacitors in Seriesp

Use KVL, current same ,through each capacitor

Capacitors in Parallelp

Use KCL, voltage same , gacross each capacitor

NCCCCC 321eq

Voltage Divisiong

Passive element that stores energy in magnetic fieldgy g

Solenoid Wound Inductor

1 tidttvL

At dc, inductor looks like a short circuit

Current through inductor Current through inductor must be continuous (no abrupt change)

lANL 2

Inductor Response to p

Inductors in Series

Use KVL, current is same ,through all inductors

Inductors in Parallel

V lt i ll Voltage is same across all inductors

Inductors add together in the same way resistors do

At dc no voltage across inductors: short circuit At dc no voltage across inductors: short circuit

REVIEW OF LECTURES 05-08REVIEW OF LECTURES 05-08 07/23/2013 ECE225 CIRCUIT ANALYSIS. Contents of...

Documents