Clemson ECE Laboratories
Pre-Labs for ECE 211
Created by Guneet Bedi on 09/03/2012
Last Updated: 12/15/2012
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Clemson ECE Laboratories
ECE 211 - Electrical Engineering
Lab I
Pre-labs for ECE 211
Guneet Bedi
Created: 09/03/2012 Updated: 09/03/2012
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Clemson ECE Laboratories
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Clemson ECE Laboratories
Introduction
• This laboratory course operates in co-ordination with the
companion lecture course, ECE 202, Electric Circuits 1.
• It is intended to enhance the learning experience of the student
in topics encountered in ECE 202.
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Clemson ECE Laboratories
Lab Objectives
• Through this lab, students are expected to:1. Gain proficiency in the use of common measuring
instruments.
2. Compare theoretical predictions with experimental results
and explain any differences.
3. Develop verbal and written communication skills through:a. Maintenance of succinct but complete laboratory notebooks
and reports.
b. Verbal interchanges with the laboratory instructor and other
students.
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Lab Objectives contd…
4. Enhance understanding of the basic electric circuit analysis
concepts including:a. Independent and dependent sources.
b. Passive circuit components (resistors, capacitors, inductors,
and switches).
c. Ohm’s law, Kirchhoff’s voltage law, and Kirchhoff’s current
law.
d. Power and energy relations.
e. Thevenin’s theorem and Norton’s theorem.
f. Superposition
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Student Responsibilities
• The student is expected to be prepared for each lab.
• Active participation by each student in lab activities is
expected.
• The student is expected to ask the teaching assistant any
questions he/she may have.
• The student should understand the concepts and procedure of
each lab.
• The student should remain alert and use common sense while
performing a lab experiment.
• He/she is also responsible for maintaining a laboratory
notebook.
• Students should report any errors in the lab manual to the
teaching assistant.
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Clemson ECE Laboratories
Lab Policy
• Pre-Requisites:- MTHSC 108 and PHYS 122
• Co-Requisites:- ECE 202
• Attendance:- Attendance is mandatory and any absence must
be for a valid excuse and must be documented.
• Late Instructor:- If the instructor is more than 15 minutes
late, students may leave the lab.
• Pre-Lab:- Each lab has a “Preparation” section that should be
read and completed prior to each lab.
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Lab Policy contd…
• Lab Records:- The student must keep all work in preparation
of and obtained during lab in an approved notebook and
prepare a lab report on selected experiments.
• Late Work:- All full lab write-ups are due two weeks from the
date lab is performed. Late work will NOT be accepted.
• Final Exam:- The final exam will be given in lab on the last
meeting. This exam will be closed-book and closed-notes. Use
of calculator is permitted.
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Clemson ECE Laboratories
Grading Policy
• The final grade is determined using the following criteria:Participation:- 10%
Attendance:- 10%
Pre-Lab:- 20%
Lab Reports:- 40%
Final Exam:- 20%
• Grade Scale:A: 90%-100%
B: 80%-89%
C: 70%-79%
D: 60%-69%
F: <60%
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The Laboratory Notebook
• The laboratory notebook should:o Be kept in a sewn and bound or spiral bound notebook.
o Contain the experiment’s title, the date, the equipment and
instruments used, any pertinent circuit diagrams, the procedure
used, the data, and the result analysis.
o Contain plots of data and sketches when these are appropriate
in the recording and analysis of observations.
o Be an accurate and permanent record of the data obtained
during the experiment and the analysis of the results.
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The Laboratory Report
• Your laboratory report must be clear and concise.
• It should be typed on a word processor.
• Use tables, diagrams, sketches, and plots, as necessary to show
what you did, what was observed, and what conclusions you
draw from this.
• Your report should be the result of your individual effort.
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The Laboratory Report-Format
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Tentative Schedule
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Contact Information
• Instructor:
Name: Guneet Bedi
Email: gbedi@clemson.edu
Office: 311 Fluor Daniel (EIB)
Phone: (864)-556-6048
Office Hours: As needed (email for appointment)
• Lab Coordinator:
Name: Dr. Timothy Burg
Email: tburg@clemson.edu
Office: 307 Fluor Daniel (EIB)
Phone: (864)-656-1368
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Clemson ECE Laboratories
Safety
• Electricity, when improperly used, is very dangerous to people
and to equipment.
• This is especially true in an experimental or teaching
laboratory where inexperienced personnel may use electrical
equipment in experimental or nonstandard configuration.
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Safety contd…
• The knowledge and habit-forming experience to work safely
around electrical equipment and the ability to design safe
electrical equipment includes:o Learning the types of electrical injuries and damage.
o How the electrical injuries can be prevented.
o The physiology of electrical injuries.
o Steps to take when accidents occur.
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Clemson ECE Laboratories
Physiology of Electrical Injuries
•
1.
2.
3.
There are three main types of electrical injuries:
Electrical shock
Electrical burns
Falls caused by electrical shock
• A fourth type, 'sunburned' eyes from looking at electric arcs,
such as arc-welding, is very painful and may cause loss of
work time but is usually of a temporary nature.
• Other injuries may be indirectly caused by electrical accidents,
e.g., burns from exploding oil-immersed switch gear or
transformers.
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Prevention of Electrical Injuries
• When hooking up a circuit, connect to the power source last,
while power is off.
• Before making changes in a circuit, turn off or disconnect the
power first, if possible.
• Never work alone where the potential of electric shock exists.
• When changing an energized connection, use only one hand.
Never touch two points in the circuit that are at different
potentials.
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Clemson ECE Laboratories
Prevention of Electrical Injuries contd…
• Know that the circuit and connections are correct before
applying power to the circuit.
• Avoid touching capacitors that may have a residual charge.
The stored energy can cause a severe shock even after a long
period of time.
• Insulate yourself from ground by standing on an insulating mat
where available.
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Clemson ECE Laboratories
After Accident Action
• Shut off all power and remove victim from the electric circuit.
• If the power cannot be shut off immediately, use an insulator
of some sort, such as a wooden pole, to remove victim from
the circuit.
• If you are qualified in CPR, check for ventricular fibrillation or
cardiac arrest. If either is detected, external cardiac massage
should be started at once.
• Notify EMS and the ECE Department at once.
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Clemson ECE Laboratories
After Accident Action contd…
• Check for respiratory failure and take appropriate action.
• Check for and treat other injuries such as fractures from a fall
or burns from current entry and exit sites.
• Investigations are always after accidents. As an engineer you
will be involved as a part of the investigating team or in
providing information to an investigator.
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Emergency Numbers
• Emergency (Fire/EMS):- 911 or 656-2222
• Student Health Center:- 656-2233
• ECE Department Office:- 656-5650
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Safety Video
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Conclusions
• As a professional engineer, it will be your responsibility to
prepare yourself to do your job correctly.
• Learn as much as you can "up front”.
• You will find that as a practicing professional if you wait until
the last minute, you might have to pay a very painful price
emotionally, financially, and professionally.
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Preparations for Next Week
• Reading:- Read the section Use of Lab instruments and
Appendix B, Fundamentals of Electrical Measurement, in the
laboratory manual.
• Writing:- In your laboratory notebook sketch the circuit
diagram for each part of the procedure and create tables
formatted to enter your data.
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Clemson ECE Laboratories
References
• ECE 211 – Electrical Engineering Lab I. Latest Revised July
2010
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Clemson ECE Laboratories
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Clemson ECE Laboratories
ECE 211 - Electrical Engineering
Lab II
Pre-labs for ECE 211
Guneet Bedi
Created: 09/07/2012 Updated: 09/07/2012
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Clemson ECE Laboratories
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Clemson ECE Laboratories
Introduction
• Every engineer relies on equipment to drive and measure an
electrical system under study.
• These devices are rarely ideal, and have their own internal
characteristics which must be accounted for in circuit design
and analysis.
• The internal characteristics of various devices often have a
significant effect on circuit operation.
• Students and engineers should understand the internal
characteristics of the equipment they are using to more
adequately predict actual operation in the lab.
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Clemson ECE Laboratories
One of the major goals of this lab is to familiarize
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techniques for making electrical measurements. Som
necessary to avoid personal or equipment damage. B
following a few simple rules, costly mistakes can be a
Use of Laboratory Instruments-Ammeter
Ammeters and Voltmeters:
The most common measurements are those of voltage
the and voltmeter are represented as shown in Fi
ammeter
• Ammeters are used to measure
flow of electrical current in a circuit.
• For ammeters, it is important that
their internal resistance be very small
(ideally near zero) so they will not
constrict the flow of current.
• Ammeters must always be connected
Figure 1 - Ammeter an
in series in a circuit, never in parallel
Ammeters are used to measure the flow of electrical c
with a voltage source.
devices should not affect the circuit being studied. Th
internal resistance be very small (ideally near zero) so
However, if the ammeter is connected across a voltag
and damage the ammeter. Therefore, ammeters mu
cuit, never in parallel with a voltage source. High
ECE Laboratories
techniques for Clemson
making electrical
measurements. Some understanding of the lab instrum
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necessary to avoid personal or equipment damage. By understanding the device's purpo
following a few simple rules, costly mistakes can be avoided.
Use of Laboratory Instruments-Voltmeter
Ammeters and Voltmeters:
The most common measurements are those of voltages and currents. Throughout this manu
ammeter and voltmeter are represented as shown in Figure 1.
• Voltmeters are used to measure the
potential difference between two
points.
• Since the voltmeter should not affect
the circuit, the voltmeters have very
high (ideally infinite) impedance.
Figure 1 - Ammeter and voltmeter.
Ammeters are used to measure the flow of electrical current in a circuit. Theoretically, mea
devices should not affect the circuit being studied. Thus, for ammeters, it is important th
internal resistance be very small (ideally near zero) so they will not constrict the flow of c
However, if the ammeter is connected across a voltage difference, it will conduct a large
and damage the ammeter. Therefore, ammeters must always be connected in series in
Clemson ECE Laboratories
Instrument Protection Rules
• Set instrument scales to the highest range before applying power.
• Be sure instrument grounds are connected properly. Avoid
accidental grounding of "hot" leads.
• Check polarity markings and connections of instruments
carefully before connecting power.
• Never connect an ammeter across a voltage source.
• Do not exceed the voltage and current ratings of instruments.
• Be sure the fuse and circuit breakers are of suitable value.
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Clemson ECE Laboratories
Lab Objective
• The objective of this lab is to explore some of the internal
characteristics for the NI- ELVIS workstations used in this
course.
• By the end of this lab:o The student should know how to determine the internal
resistance of meters and sources.
o The student should understand how the internal resistance of
these instruments affects the measurements.
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Clemson ECE Laboratories
Equipment Needed
• NI-ELVIS Series II workstation
• Resistance substitution box
• 1kΩ Resistor
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analyzer. All of wh
analyzer. All of whic
– DUT-: virtual gro
– DUT-: virtual37
groun
measurements,
measurements,
im
voltage/current an
voltage/current anal
bipolar junction t
bipolar junction tra
analyzer.
analyzer.
Impedance Analyzer
Clemson ECE Laboratories
NI-ELVIS Series II Workstation Features
• Workstation Power Switch
Figure 1. Isometric View of NI ELVIS II workstation with Prototyping Board
TABLE I.
Figure 1.
Analog
Outputs
Figure 2. NI ELVIS II Series Prototyping
Board
TABLE II.
WORKSTATION FEATURES
User Configurable
User Input/Output
Configurable
Breadboard
Input/Output
Isometric View of NI ELVIS II workstation with Prototyping
Board
TABLE I.
Workstation Power
Switch
Analog Outputs
There are 2
There
are 2 an
AO<0…1>±.
SIGNAL DESCRIPTIONS ON NI ELVIS II PROTOTYPING BOARDThe
.
AO<0…1>±.
the arbitraryThese
wave
the arbitrary wavefor
• Breadboard
Analog Output (AO)
Analog Output (AO)
– Located
WORKSTATION
FEATURES
in the rear of the workstation
– Powers the NI ELVIS II series
– This is the work area on w
User3Configurable
– Figure
shows how the I/
te
User
I/O
– Configurable
BANANA <A…D
connected.
<A…D>
D (see feature
4).
– –TheBANANA
horizontal
connection
D
(see
feature
4).arePo
colored
red
and
blue
c
– BNC <1…2>±:
for
power
and
groun
–used
BNC
<1…2>±:
Posi
the BNC connect
– Thethe
vertical
are ou
BNCcontacts
connector
connect
to
shells
circuits
connect to shells of t
– SCREW TERMIN
– SCREW
TERMINA
terminals
(see feat
terminals (see feature
Function Generator
Analog Inputs
Function
Generator
– FGEN
(Output): t
There are 8 analog input
–Connect
(Output):
–FGEN
SYNC
(Output):
positive
end the
of
–the SYNC
(Output):
5V
FGEN
signal.
Th
positive “+” pin socke
signal
fornegative
theThis
osci“
FGEN
signal.
signal
to the
channel.
channels
–signal
AMThese
(Input):
An
for
the
oscillo
oscilloscope
discussed
amplitude
ofAnal
the F
–the AM
(Input):
Programmable
Functions
–amplitude
FM (Input):
AnI
of the FG
– Thesefrequency
lines labeled
<0…
FGE
–areFM
(Input):ofAnalo
used for static dig
frequency
of
FGEN
signals.
• Prototyping Board Power
• Function Generator
Switch
(FGEN)
– Located in the rear of the workstation
Workstation Power
Switch
Prototyping Board
Power Switch
–
–
–
–
Powers the NI ELVIS II series
Controls power to NI ELVIS Series II prototyping board.
Function
The power LED
lights upGenerator
when the switch is turned ON.
(FGEN)
Function
Generator
The Ready switch should
be green or yellow when
Analog
Input (AI) and
(FGEN)
connected to host.
Programmable Functions
Interface (PFI) signal rows
– Voltage,
Resistance,
and Diode
Jack board.
(red):
Controls power
to NI ELVIS
Series Banana
II prototyping
• Digital Multimeter (DMM)
positive
input
multimeter
in voltage
– The power
LED
lightsfor
up digital
when the
switch is turned
ON.
resistance
diode
measurements.
– The
Readyand
switch
should
be green
or
yellow
when
Prototyping Board
• Power Supplies
– Common
connectedBanana
to host. Jack (black): The common reference
Power Switch
Connectors
connection for digital multimeter voltage, current,
Digital Multimeter
(DMM) Connectors
Digital Multimeter
(DMM) Connectors
resistance,Resistance,
and diode measurements.
Voltage,
and Diode Banana Jack (red):
Current
Banana
positiveininput
for
The positive inputJack
for (red):
digital The
multimeter
voltage
digital
multimeter
current
measurements.
resistance and diode measurements.
– Common Banana
JackSupplies
(black): The common reference
Power
connection for digital multimeter voltage, current,
resistance, andPower
diode Supplies
measurements.
– Current Banana Jack (red): The positive input for
digital multimeter current measurements.
–
–
AI SENSE and AI GND (IN
– These pin sockets are use
be measured has a differ
workstation.
Variable Power Sup
– SUPPLY+:
Positi
Variable
Power Suppli
feature
5
in
Tab
– SUPPLY+: Positive
+12V.
feature 5 in Table
– +12V.
GROUND: Groun
–
SUPPLY-:Ground
Nega
– GROUND:
(see
feature
5
in T
– SUPPLY-: Negativ
12V.
(see feature 5 in Tab
12V.
DC Power Supplies (
Laboratories
ter provides an overview of the Clemson
devices ECE
present
in the NI ELVIS II Series workstation. These38de
software to include soft front panel (SFP) instruments, LabVIEW Express VIs, and SignalExpress bl
Launcher
he NI
ECE ELVIS
department,Instrument
the use of NI ELVIS
II Series with SFP instruments will be discussed exclu
P, as the name implies, is the software version of the front panel of an NI ELVIS device.
mx Instrument Launcher:
LNIS Instrument Launcher provides access to the NI ELVISmx SFP instruments. Launch the Instrument
• Launch
InstrumentInstruments>>NI
Launcher byELVISmx>>NI
navigating ELVISmx
to Start>>All
Start>>All
Programthe
Files>>National
Instrument La
Files>>National
Instruments>>NI
UI shown Program
in Figure 4. To launch an
instrument, click the button corresponding
to the desired instru
P, the workstation
should be powered
with the USB
READY lightLauncher.
lit, otherwise an error occurs. If said
ELVISmx>>NI
ELVISmx
Instrument
wer on the workstation, check connection to host PC, and open SFP again.
Figure 4. NI ELVISmx Instrument Launcher
8. Mode: Selects between “Auto” and “Manual” ranging of the instrument. It is recommended to
Clemson ECE Laboratories
(default). If “Manual” is selected, then the Range menu is enabled and different ranges can be39
sele
NI ELVIS Instrument Launcher-DMM
1. Display
2. Modes
3. Connections
4. Acquisition mode
5. Help
6. Run/Stop
7. Null offset
8. Mode
output can be obtained via two routes: the FGEN BNC output channel (see feature 4 in Table 1) or t
ECE Laboratories
40
sockets (see feature 3 Clemson
in Table 2).
Shown below is the FGEN SFP in Figure 7, as well as an explan
The FGEN signal is referenced with respect to GROUND.
NI ELVIS Instrument Launcher-FGEN
1. Frequency Display
2. Waveform Selectors
3. Waveform Characteristics
4. Sweep Settings
5. Manual Mode
6. Signal Route
7. Sweep
Clemson
ECE
Laboratories
The variable power
supply
consists
of two channels that supply adjustable output voltages from
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channel and 0 to -12V on the SUPPLY- channel. The SUPPLY+ and SUPPLY- channels are availa
rows (see feature 3 in Table 2). The output voltages are referenced to GROUND. Shown below is th
as an explanation of the important controls.
NI ELVIS Instrument Launcher-VPS
1. Voltage Display
2. Manual Mode
3. Output Voltage Controls
4. Sweep Settings
1. Sweep
Figure 8. VPS SFP with important controls labeled
Clemson ECE Laboratories
Procedure-Getting Started
1. Turn on computer.
2. Turn on NI-ELVIS power switch (right corner on the back).
3. Turn on the NI-ELVIS Prototyping Board Power switch (at
upper right corner, on top).
4. Launch NI-ELVISMX INSTRUMENTS program.
5. Launch the NI-ELVIS DMM instrument.
6. Launch the NI-ELVIS VPS (Variable Power Supply)
instrument.
7. Arrange the instruments on the computer screen for your
convenience.
8. Set DMM to measure DC Volts. Specify the range to be 60V.
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Clemson ECE Laboratories
Procedure-NULL OFFSET for Voltmeter
• Electrical drift sometimes causes shifts in the ZERO point
indicated by measurement instruments.
• To eliminate the shift, the NI-ELVIS provides a NULL
OFFSET function that subtracts the value indicated at the
instant NULL OFFSET is turned on.
•
1.
2.
3.
To set the voltmeter’s NULL OFFSET:
Plug leads into the DMM “VΩ” and “COM” jacks.
Clip the leads together, let the voltage reading stabilize.
Turn on “Null Offset”.
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Clemson ECE Laboratories
Procedure-DC Resistance of DMM
Voltmeter
• Set the VPS “Supply +” voltage
to +10.00 Volts. “STOP” the VPS.
• Set up the circuit as shown in
figure.
• Use the NI-ELVIS DMM for the
voltmeter and the VPS for the
power supply.
• Set the resistor R to 0Ω by
shorting the resistor’s leads.
• “RUN” the VPS and record the
voltage indicated by the meter.
• Remove the short across R.
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Clemson ECE Laboratories
Procedure-DC Resistance of DMM
Voltmeter contd…
• Increase the resistance R so that the meter reading drops by
one half of the original value.
• Record the final resistance R and measured voltage.
• “STOP” the VPS.
• Use the DMM ohmmeter to measure the actual resistance R.
• Record the measured value.
• From these readings, use voltage division to calculate RVi, the
equivalent internal resistance of the voltmeter.
RVi = R.
VHalf
10 - VHalf
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Clemson ECE Laboratories
Procedure-DC Resistance of DMM
Ammeter
• Set the VPS “Supply +” voltage to
+10.00 Volts.
• “RUN” the VPS and measure the
actual voltage using the DMM
voltmeter. Record the actual voltage.
• “STOP” the VPS.
• To use the DMM as an ammeter,
move the DMM cables to “A” and
“COM” and switch the DMM to
measure DC Amps.
• Set up the circuit as shown in figure.
• Use the NI-ELVIS DMM for the
ammeter and the VPS for the power
supply.
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Clemson ECE Laboratories
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Procedure-DC Resistance of DMM
Ammeter contd…
•
•
•
•
•
•
Set the resistor R to 1 MΩ resistance.
“RUN” the VPS.
Record the resistance R and the current indicated by the ammeter.
Adjust R to 100kΩ.
Record the resistance R and the current indicated by the ammeter.
Continue to decrease the resistance R until the ammeter reading
drops to one half of the original value.
• Record the final resistance R and measured current.
• Use the DMM ohmmeter to measure the actual final resistance R.
• From these readings, use current division to calculate RAi, the
equivalent internal resistance of the ammeter.
I Half
R
= I 3.
RAi + R
RAi » R
Clemson ECE Laboratories
Procedure-Output Resistance of VPS
Supply +
• Set the VPS “Supply +” voltage
to +0.5 Volts.
• Use the DMM to measure the
actual voltage.
• Record the actual voltage.
• Construct the circuit shown in
figure.
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Clemson ECE Laboratories
Procedure-Output Resistance of VPS
Supply + contd…
•
•
•
•
Adjust the resistor R to 10kΩ.
“RUN” the VPS.
Record the resistance R and the measured voltage.
Adjust the resistance R so that the meter reading drops to one
half of the original value.
• Record the R and V values.
• From these readings, use voltage division to determine RVPS.
RVPS = Rx .
Where,
0.5 - VHalf
VHalf
RVi ´ R
Rx =
»R
R + RVi
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Clemson ECE Laboratories
Procedure-Output Resistance of FGEN
• Construct the circuit shown in
figure.
• Set the FGEN to output a sine
wave with p-p amplitude of 1.41V
and frequency 100 Hz.
• Set the DMM to measure AC
Volts. Keep in mind that the
voltmeter’s display shows the
value of RMS voltage, where for
a sinusoidal waveform,
VRMS =
Vpeak
2
=
Vp- p
2 2
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Clemson ECE Laboratories
Procedure-Output Resistance of FGEN
contd…
•
•
•
•
Adjust the resistor R to 100 kΩ.
“RUN” the FGEN.
Record the resistance and the measured voltage.
Adjust the resistance R so that the meter reading drops to one
half of the original value.
• Record the R and V values.
• From these readings, use voltage division to determine
RFGEN, the equivalent internal resistance of the Function
Generator.
RFGEN = Rx .
Where,
1.414 - VHalf , p- p
VHalf , p- p
RVi ´ R
Rx =
»R
R + RVi
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Clemson ECE Laboratories
Lab 2-Student Tasks
• Students are required to submit a lab report on this experiment.
• Students MUST strictly adhere to the format as described in
the lab manual.
• For the ‘Questions’ section of the lab report, the students are
required to solve the problems given as a part of ‘Probing
Further’ section of this lab in the manual.
• Your report is due in TWO WEEKS from today.
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Clemson ECE Laboratories
Preparations for Next Week
• Read the introductory material in the ECE 202 textbook
describing the passive sign convention for circuit elements.
• Review the lab manual section Use of Laboratory Instruments.
• Calculate the values of voltage, current, and power
absorbed/delivered for each circuit element in Figure 3.1 (i.e.
do Part 0 of the Procedure).
• Sketch in your lab notebook the circuit diagrams to be used in
each part of the procedure and have a table prepared for each
part in order to record data.
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Clemson ECE Laboratories
References
• ECE 211 – Electrical Engineering Lab I. Latest Revised July
2010.
• Otago University Electronics Group-NI ELVIS II Orientation
Manual.
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Clemson ECE Laboratories
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Clemson ECE Laboratories
ECE 211 - Electrical Engineering
Lab III
Pre-labs for ECE 211
Guneet Bedi
Created: 09/13/2012 Updated: 09/16/2012
56
Clemson ECE Laboratories
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Clemson ECE Laboratories
Introduction
• Voltage and current values may be used to determine the
power consumed (or provided) by an electrical circuit.
• Electric power consumption is a very important factor in all
electrical applications, ranging from portable computers to
megawatt industrial complexes.
• Thus, an understanding of power and how it is measured is
vital to all engineers.
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Clemson ECE Laboratories
Electric Charge-A Brief Review
• The charge is bipolar, i.e. electrical effects are described in
terms of positive and negative charges.
• The electric charge exists in discrete quantities, which are
integral multiples of the electronic charge, 1.6022×10-19 C.
• Electrical effects are attributed to both the separation of
charge and charges in motion.
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Clemson ECE Laboratories
Voltage
• Whenever positive and negative charges are separated, energy
is expended.
• Voltage is the energy per unit charge created by the separation.
• It can be expressed in differential form as:
dw
v=
dq
where,
v=voltage in volts
w=energy in joules
q=charge in coulombs
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Clemson ECE Laboratories
Current
• Electric current is defined as the rate of charge flow.
• It can be expressed in differential form as:
dq
i=
dt
where
i=current in amperes
q=charge in coulombs
t=time in seconds
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Clemson ECE Laboratories
Power
• Power is the time rate of expending or absorbing energy.
• Mathematically, energy per unit time can be expressed in
differential form as:
dw
p=
dt
where
p=power in watts
w=energy in joules
t=time in seconds
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Clemson ECE Laboratories
Power in terms of Voltage & Current
dw æ dw ö æ dq ö
p=
=ç ÷ç ÷
dt è dq ø è dt ø
so,
p = vi
where
p=power in watts
v=voltage in volts
i=current in amperes
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Clemson ECE Laboratories
Passive Sign Convention
• Whenever
the
reference
direction for the current in an
element is in the direction of the
reference voltage drop across
the element (as shown in
figure), use a positive sign in
any expression that relates the
voltage to the current.
• Otherwise, use a negative sign.
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One of the major goals of this lab is to familiarize
65 t
techniques for making electrical measurements. Som
necessary to avoid personal or equipment damage. B
following a few simple rules, costly mistakes can be a
Use of Laboratory Instruments-Ammeter
Ammeters and Voltmeters:
The most common measurements are those of voltage
the and voltmeter are represented as shown in Fi
ammeter
• Ammeters are used to measure
flow of electrical current in a circuit.
• For ammeters, it is important that
their internal resistance be very small
(ideally near zero) so they will not
constrict the flow of current.
• Ammeters must always be connected
Figure 1 - Ammeter an
in series in a circuit, never in parallel
Ammeters are used to measure the flow of electrical c
with a voltage source.
devices should not affect the circuit being studied. Th
internal resistance be very small (ideally near zero) so
However, if the ammeter is connected across a voltag
and damage the ammeter. Therefore, ammeters mu
cuit, never in parallel with a voltage source. High
ECE Laboratories
techniques for Clemson
making electrical
measurements. Some understanding of the lab instrum
66
necessary to avoid personal or equipment damage. By understanding the device's purpo
following a few simple rules, costly mistakes can be avoided.
Use of Laboratory Instruments-Voltmeter
Ammeters and Voltmeters:
The most common measurements are those of voltages and currents. Throughout this manu
ammeter and voltmeter are represented as shown in Figure 1.
• Voltmeters are used to measure the
potential difference between two
points.
• Since the voltmeter should not affect
the circuit, the voltmeters have very
high (ideally infinite) impedance.
Figure 1 - Ammeter and voltmeter.
Ammeters are used to measure the flow of electrical current in a circuit. Theoretically, mea
devices should not affect the circuit being studied. Thus, for ammeters, it is important th
internal resistance be very small (ideally near zero) so they will not constrict the flow of c
However, if the ammeter is connected across a voltage difference, it will conduct a large
and damage the ammeter. Therefore, ammeters must always be connected in series in
Clemson ECE Laboratories
Lab Objective
• By the end of this lab, the student should know:o How to make DC measurements of voltages and currents.
o How to determine power dissipation/delivery for circuit
elements, branches, and various combinations of elements and
branches.
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Equipment Needed
• NI-ELVIS Series II workstation
• Two 510Ω Resistors
• One 1kΩ Resistor
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Clemson ECE Laboratories
Procedure-Theoretical Calculation of
Voltage, Current & Power
• For the circuit given in figure, calculate the voltages across
and currents through each circuit element.
• Using these values, determine the power absorbed or
delivered by each circuit element.
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Clemson ECE Laboratories
Procedure-Experimental Circuit Voltage
Measurements
70
• Set up the circuit in figure.
• Adjust the output of the DC power supply to 10V.
• Using the DMM function in the NI-ELVIS workstation measure the
voltage across each individual circuit element.
• For each measured voltage, determine the percent difference from
the theoretical value.
Clemson ECE Laboratories
Procedure-Experimental Circuit Current
Measurements
• Set up the circuit in figure.
• Adjust the output of the DC power supply to 10V.
• Using the DMM function in the NI-ELVIS workstation
measure the current through each individual circuit element.
• For each measured current, determine the percent difference
from the theoretical value.
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Clemson ECE Laboratories
Procedure-Experimental Circuit Power
Calculation
• Using your experimental voltage and current measurement data,
calculate the power absorbed or delivered by each circuit element.
• Compare this power obtained with the values obtained through
theoretical circuit analysis.
• Calculate the percent difference from the theoretical values.
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Lab 3-Student Tasks
• Students are required to solve the ‘Probing Further’ section,
given in the lab manual, in their laboratory notebooks.
• Lab notebooks are due on the same day as your report for lab
2.
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Preparations for Next Week
• Calculate the voltages and currents for each resistor shown in
the circuit of Figure 4.1 in your lab manual (i.e. do Part 0 of
the Procedure).
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Clemson ECE Laboratories
References
• ECE 211 – Electrical Engineering Lab I. Latest Revised July
2010.
• Electric Circuits 8th Edition by James W. Nilsson & Susan A.
Riedel.
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Clemson ECE Laboratories
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Clemson ECE Laboratories
ECE 211 - Electrical Engineering
Lab IV
Pre-labs for ECE 211
Guneet Bedi
Created: 09/24/2012 Updated: 09/24/2012
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Clemson ECE Laboratories
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Clemson ECE Laboratories
Introduction
• B2 Spice v5 is an integrated circuit design, simulation, and
analysis software
• It contains a mixed mode simulator based partly on the
Berkeley SPICE simulator and partly on the Georgia Tech
XSPICE simulator
• B2 Spice v5 is an application with two separate subprograms:
the B2 Spice main program, and the Database Editor
• It allows you to perform realistic simulations on your circuit
without the need of any physical component or any expensive
test equipment
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Clemson ECE Laboratories
Lab Objective
• This lab should give the student a basic understanding of how
to use B2 Spice to simulate circuit operating conditions.
• After this lab, the student should be able to use B2 Spice to
solve or check basic circuit problems.
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Clemson ECE Laboratories
Equipment Needed
• A computer with B2 Spice loaded and ready to use.
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Clemson ECE Laboratories
Procedure-Theoretical Calculation of
Voltage & Current
• For the circuit given in figure, calculate the voltages across
and currents through each resistor.
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Clemson ECE Laboratories
Procedure-Opening Software & Creating
New Project
• Double click on B2SpiceV5 shortcut icon on desktop
• The following window will appear
• File->New->Project(Check Schematic & Enter Project Name)->Ok
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Clemson ECE Laboratories
Procedure-Placing Resistors
• Common parts->Resistor(simple)(R)
• Place resistor as desired on the workspace
• Double click on the resistor placed to modify its default
parameters
• Right click on the resistor placed for more options(e.g. rotate
clockwise)
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Clemson ECE Laboratories
Procedure-Placing Voltage Source
• Common parts->Voltage Source(V)
• Place the voltage source as desired on the workspace
• Double click on the voltage source placed to modify its default
parameters
• Right click on the voltage source placed for more options(e.g.
rotate clockwise)
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Clemson ECE Laboratories
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Procedure-Placing Ammeter/Voltmeter
• Common parts->Ammeter(1)/Voltmeter(2) (Horizontal/Vertical)
• Place the ammeter/voltmeter as desired on the workspace
• Double click on the ammeter/voltmeter placed to modify its
default parameters
• Right click on the ammeter/voltmeter placed for more options(e.g.
rotate clockwise)
Clemson ECE Laboratories
87
Procedure-Placing Ground
•
•
•
•
Common parts->Ground(0)
Place the ground as desired on the workspace
Ground default parameters cannot be changed
Right click on the ground placed for more options(e.g. rotate
clockwise)
Clemson ECE Laboratories
88
Procedure-Connecting Circuit Components
Press to draw circuit lines
• On clicking the draw circuit lines symbol, one can draw circuit lines
to connect circuit components together
• To discontinue drawing the circuit line press esc
Clemson ECE Laboratories
Procedure-Running Simulations
Pause Simulation
Run
• After setting up the circuit and placing the meters in the proper
positions, press Run to simulate the circuit
• To stop simulation, click Simulation->Stop and Reset
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Test Circuit 1
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Test Circuit 2
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92
Test Circuit 3
How does V across & I through each
resistor vary with the given combinations
of resistor values?
Clemson ECE Laboratories
Lab 4-Student Tasks
• Students are required to solve the ‘Probing Further’ section,
given in the lab manual, in their laboratory notebooks.
• Lab notebooks are due on the same day as your report for lab
2.
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Clemson ECE Laboratories
Preparations for Next Week
• Read the material in the textbook that describes Kirchhoff's
Voltage Law, Kirchhoff's Current Law, voltage division,
current division, and equivalent resistance combinations.
• Before coming to class, analyze each circuit and determine the
theoretical values that should be obtained during the lab.
• Verify your calculations by performing B2 Spice simulations
for each circuit.
• Record both your calculations and simulation results in your
laboratory notebook.
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Clemson ECE Laboratories
References
• ECE 211 – Electrical Engineering Lab I. Latest Revised July
2010.
• B2Spice Version 5 User’s Manual by Manual by Thien
Nguyen, Christopher Hsiong and Jon Engelbert © 1996 2005, Beige Bag Software, Inc.
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Clemson ECE Laboratories
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Clemson ECE Laboratories
ECE 211 - Electrical Engineering
Lab V
Pre-labs for ECE 211
Guneet Bedi
Created: 10/01/2012 Updated: 10/01/2012
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Clemson ECE Laboratories
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Clemson ECE Laboratories
Introduction
• An understanding of the basic laws of electrical voltages and
currents is essential to electrical engineering.
• Circuit analysis is dependent upon knowing the nature of the
laws governing voltage and current characteristics.
• This lab studies Kirchhoff's Voltage Law, Kirchhoff's Current
Law, voltage division, current division, and equivalent
resistance.
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Clemson ECE Laboratories
Series Equivalent Resistance
Req = R1 + R2 + R3 + R4 + R5 + R6 + R7
k
Req = å Ri = R1 + R2 + ...+ Rk
i=1
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Clemson ECE Laboratories
Parallel Equivalent Resistance
1
1 1
1
1
= + + +
Req R1 R2 R3 R4
k
1
1
1 1
1
= å = + + ... +
Req i=1 Ri R1 R2
Rk
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Clemson ECE Laboratories
Voltage-Divider Circuit
vs = iR1 + iR2
vs
i=
R1 + R2
R1
v1 = iR1 = vs
R1 + R2
R2
v2 = iR2 = vs
R1 + R2
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Clemson ECE Laboratories
Current-Divider Circuit
R1 R2
v = i1 R1 = i2 R2 =
is
R1 + R2
R2
i1 = is
R1 + R2
R1
i2 = is
R1 + R2
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Clemson ECE Laboratories
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Kirchhoff’s Current Law
• The algebraic sum of all the currents at any node in a circuit equals
zero.
• Using the convention that currents leaving the node are considered
positive and that entering the nodes are considered negative, the above
circuit yields the four equations.
Clemson ECE Laboratories
105
Kirchhoff’s Voltage Law
• The algebraic sum of all the voltages around any closed path in a
circuit equals zero.
• Here we elect to trace the closed path clockwise, assigning a positive
algebraic sign to voltage drops.
• Starting at node d leads to the expression:
vl - vc + v1 - vs = 0
Clemson ECE Laboratories
Lab Objective
• By the end of this lab, the student should understand KVL,
KCL, voltage division, current division, and equivalent
resistance combinations.
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Clemson ECE Laboratories
Equipment Needed
• NI-ELVIS workstation
• Resistance substitution box
• Individual resistors (510Ω, 1kΩ (2), 1.5kΩ, 2kΩ (2), 3kΩ,
3.9kΩ, 4.3kΩ, 5.1kΩ)
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Clemson ECE Laboratories
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Procedure-Equivalent Resistance
•
•
•
•
Set up the circuit as shown in figure.
Adjust the output of the DC power supply to 10V.
Measure and record the total current into the circuit.
Using the measured current and voltage, determine the equivalent
resistance of the parallel components in the circuit.
• Replace the resistors with a resistance substitution box set to the equivalent
resistance and measure the current as before.
• Compare the experimentally determined equivalent resistance to the
theoretical value.
Clemson ECE Laboratories
Procedure-Current Division & Kirchhoff's
Current Law (KCL)
• Set up the circuit as shown in
figure.
• Adjust the output of the DC
power supply to 10V.
• Begin with R2=510Ω and
measure the currents I1, I2 and
I 3.
• Repeat with R2=1kΩ, 2kΩ,
3kΩ, 4.3kΩ and 5.1kΩ.
• Compare
the
measured
currents to those calculated
using current divider relation.
• Determine whether or not
each set of measurements
agrees with KCL.
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Clemson ECE Laboratories
Procedure-Voltage Division
• Set up the circuit as shown
in figure.
• Adjust the output of the DC
power supply to 10V.
• Begin with R=510Ω and
measure the voltage across
each resistor.
• Repeat with R=1kΩ, 2kΩ,
3kΩ, 4.3kΩ and 5.1kΩ.
• Compare the measured
voltages to those calculated
using the voltage divider
relation.
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Clemson ECE Laboratories
Procedure-Kirchhoff’s Voltage Law
(KVL) (Single Loop)
• Set up the circuit as shown
in figure.
• Adjust the output of the DC
power supply to 10V.
• Measure the voltage across
each component.
• Compare the measured
voltages to those calculated
using the voltage divider
relation.
• Determine whether or not
your measurements agree
with KVL.
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Clemson ECE Laboratories
Procedure-Kirchhoff’s Voltage Law
(KVL) (Multiple Loops)
• Set up the circuit as shown
in figure.
• Adjust the output of the DC
power supply to 10V.
• Measure the voltage across
each component in loop 1.
• Repeat for loop 2 and 3.
• Compare your measured
values with the terms in the
KVL equation written for
each loop.
• Determine whether or not
your measurements agree
with KVL.
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Clemson ECE Laboratories
Lab 5-Student Tasks
• Students are required to submit a lab report on this experiment.
• Students MUST strictly adhere to the format as described in
the lab manual.
• For the ‘Questions’ section of the lab report, the students are
required to solve the problems given as a part of ‘Probing
Further’ section of this lab in the manual.
• Your report is due in TWO WEEKS from today.
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Clemson ECE Laboratories
Preparations for Next Week
• Read the material in the textbook that describes Thévenin's
equivalence theorem and maximum power transfer.
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Clemson ECE Laboratories
References
• ECE 211 – Electrical Engineering Lab I. Latest Revised July
2010.
• Electric Circuits 8th Edition by James W. Nilsson & Susan A.
Riedel.
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Clemson ECE Laboratories
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