ASSIGNMENTS DUE
• Today (Tuesday/Wednesday):• Will do Computer Project #5 in Class (CP-5)• Activities 38-1, 38-2 (In Class)
• Thursday:• Experiment #9 Report Due• Activities 39-1, 39-2 (In Class)
• Next Monday:• Homework #14 Due• Experiment #10 Report Due• Computer Project #5 Report Due• Activity 40-1, Experiment 11 (In Class)
FINAL EXAM
• Wednesday, May 7
• 8 - 11 am
• Sage 3303 for All Sections
• 2-8 1/2 x 11 inch Crib Sheets
• Laplace Tables Will Be Included with the Final Exam
• Students with Conflict should Notify Prof. Jennings ([email protected])
REVIEW
0 0
0 0
series parallel
eq 0
Series Resonance: Parallel Resonance:
X 0 at B 0 at
1 1
LC LC
1 L CQ Q R
R C L
Z ( ) MINIM
eq 0UM Z ( ) MAXIMUM
NOTES ON RESONANCE
• In “real” circuits, often do not have a “pure” Series or pure Parallel situation:• Inductors always have Rw
• Elements may not all be in series or parallel• Will still have Resonance, but at a slightly
different Resonant Frequency• May have Multiple Resonances in same Circuit• Define Resonance as when X (series-like circuit)
or B (parallel-like circuit) => 0 • Let’s do a problem => Activity 38-1
ACTIVITY 38-1a
V
j L 20
100 j
C
CV
L V R V
4
4 2 2
100 j10 CZ j L 20
1 10 C
4
4 2 2 4 2 2
100 10 C 20 j L
1 10 C 1 10 C
R( ) jX( )
ACTIVITY 38-1a
V
j L 20
100 j
C
CV
L V R V
4
4 2 2 4 2 2
100 10 C Z 20 j L
1 10 C 1 10 C
40
0 0 4 2 20
10 CX( ) 0 L
1 10 C
20 4 2
1 1
LC 10 C
ACTIVITY 38-1a
V
j L 20
100 j
C
CV
L V R V
20 4 2
1 1
LC 10 C
114,142 radians/sec
LC
0 10,000 radians/sec
ACTIVITY 38-1b
V
0j (5mH) 20
100 0
j
(1 F)
CV
L V R V
0 4 2 20
100Z( ) 20 70
1 10 C
0V 70/0 Volts
0I V/Z 1/0 Amps
I
0 10,000 radians/sec
ACTIVITY 38-1b
V
0j (5mH) 20
100 0
j
(1 F)
CV
L V R V
0V 70/0 Volts
I
0 10,000 radians/sec
0L 0V j (.005)I 50/90 Volts
0RV 20I 20/0 Volts
L R CV V V V 0I 1/0 Amps
ACTIVITY 38-1c
V
0j (5mH) 20
100 0
j
(1 F)
CV
L V R V
I
20 4 2
1 1
LC 10 C 2
0 0 does not exist if 0
4 2
1 1 L 10,000
LC 10 C C
AC PSPICE
• Now want to simulate AC Circuits using PSpice:• AC Sources• C’s and L’s
• Usually want to look at behavior as a function of Frequency:• AC Sweep (Schematics)• .ac Statement (Circuit file)
AC PSPICE-CIRCUIT FILE
• AC Voltage Source:V 1 0 AC 10
• AC Current Source:I 0 1 AC 3
• Do Not have to designate frequency when specifying source:• Do later with .ac statement
AC PSPICE-SCHEMATICS• AC Voltage Source:• Use VAC • Doubleclick on VAC• Designate Amplitude and Phase
• AC Current Source with Schematics:• Use IAC; Designate same as VAC
• Do Not have to designate frequency when specifying source:• Do later with AC Sweep in Analysis
AC PSPICE
• Capacitors/Inductors:C 1 0 2u
L 1 0 .1m• Start “name” with C or L• Connected between nodes 1 and 0 (+, -)• C = 2 uF; L = .1mH• Do Not need Initial Conditions for AC
Steady State• Use IC’s when doing Transient Analysis• Doubleclick C and L in Schematics to set
Values and IC’s
AC PSPICE• .ac Statement:
.ac lin 400 10 16k• Perform AC Sweep (Sweep AC
frequencies)• Perform a linear sweep (will do decade
sweeps later)• Divide frequency range into 400 points• starting frequency = 10 Hz (note: f)• ending frequency = 16 kHZ
AC PSPICE
• In Schematics:• Doubleclick Set Up Analysis• Choose AC Sweep and Doubleclick• Choose Type of Sweep• Choose Start and End Frequencies• Choose Number of Points• Remember PSpice uses Frequencies in Hz
ACTIVITY 38-2• Similar to Activity 38-1:
• Not a “Pure” Parallel Resonant Circuit• Inductor has Winding Resistance• Want to see how this affects Resonance
• Let Rw = 10-9 ~ 0, 2 ohms
• When Rw = 0, fo ~ 8 kHz, Qparallel ~ 10
• See what happens when Rw = 2 ohms
• Let’s Practice using Schematics
ACTIVITY 38-2• Need to Set X Axis to Linear:
• Probe automatically uses a Log scale• Go to Plot, X Axis Settings, Linear
• To Look at Amplitude/Magnitude:• Plot Vm(1)@1 or Im(C)@1• Amplitude/Magnitude of the Voltage at Node 1
for Case 1 (Rw = 10-9 ohms)
• To Look at Angle/Phase:• Plot Vp(1)@2 or Ip(C)@1• Angle/Phase of the Voltage at Node 1 for Case
2 (Rw = 2 ohms)
ACTIVITY 38-2• With RW = 10-9 Ohms:
• f0=7.985 kHz
• iC,max = 10 Amps
• Qparallel = 10
• With RW = 2 Ohms:• f0 = 8.225 kHZ
• iC,max = 3.47 Amps
• Qparallel = 3.47
• Change f0 a little
• Reduce Qparallel a lot:
COMPUTER PROJECT 5
• Circuit is both “Series-like” and “Parallel-like”:• Will have both Series and Parallel
Resonances• Resonances occur at different frequencies• Identify by Minimum or Maximum of /Z/• /Z/ is a Minimum at Series Resonance• /Z/ is a Maximum at Parallel Resonance
COMPUTER PROJECT 5
• PSpice wants frequencies in Hertz:• Project asks to sweep • Must convert = 2 f• Plot as function of = f * 6.28• Use Linear X Axis
• Note: Zin = Vin / Iin
• Vin = Volts
• => Yin = Iin /1 Siemons
o/0 1