4IntroductionThis 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.
5Lab Objectives Through this lab, students are expected to:- Gain proficiency in the use of common measuring instruments.Compare theoretical predictions with experimental results and explain any differences.Develop verbal and written communication skills through:-Maintenance of succinct but complete laboratory notebooks and reports.Verbal interchanges with the laboratory instructor and other students.
6Lab Objectives contd…Enhance understanding of the basic electric circuit analysis concepts including:-Independent and dependent sources.Passive circuit components (resistors, capacitors, inductors, and switches).Ohm’s law, Kirchhoff’s voltage law, and Kirchhoff’s current law.Power and energy relations.Thevenin’s theorem and Norton’s theorem.Superposition
7Student 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.
8Lab Policy Pre-Requisites:- MTHSC 108 and PHYS 122 Co-Requisites:- ECE 202Attendance:- 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.
9Lab 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.
10Grading PolicyThe 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%
11The Laboratory Notebook The laboratory notebook should:-Be kept in a sewn and bound or spiral bound notebook.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.Contain plots of data and sketches when these are appropriate in the recording and analysis of observations.Be an accurate and permanent record of the data obtained during the experiment and the analysis of the results.
12The Laboratory ReportYour 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.
15Contact InformationInstructor:Name: Guneet BediOffice: 311 Fluor Daniel (EIB)Phone: (864)Office Hours: As needed ( for appointment)Lab Coordinator:Name: Dr. Timothy BurgOffice: 307 Fluor Daniel (EIB)Phone: (864)
16SafetyElectricity, 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.
17Safety contd…The knowledge and habit-forming experience to work safely around electrical equipment and the ability to design safe electrical equipment includes:-Learning the types of electrical injuries and damage.How the electrical injuries can be prevented.The physiology of electrical injuries.Steps to take when accidents occur.
18Physiology of Electrical Injuries There are three main types of electrical injuries:Electrical shockElectrical burnsFalls caused by electrical shockA 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.
19Prevention 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.
20Prevention 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.
21After Accident ActionShut 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.
22After 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.
23Emergency Numbers Emergency (Fire/EMS):- 911 or 656-2222 Student Health Center:ECE Department Office:
25ConclusionsAs 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.
26Preparations 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.
27ReferencesECE 211 – Electrical Engineering Lab I. Latest Revised July 2010
31IntroductionEvery 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.
32Use of Laboratory Instruments-Ammeter Ammeters are used to measure the 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 in series in a circuit, never in parallel with a voltage source.
33Use of Laboratory Instruments-Voltmeter 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.
34Instrument 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.
35Lab ObjectiveThe 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:-The student should know how to determine the internal resistance of meters and sources.The student should understand how the internal resistance of these instruments affects the measurements.
36Equipment Needed NI-ELVIS Series II workstation Resistance substitution box1kΩ Resistor
37NI-ELVIS Series II Workstation Features Workstation Power SwitchPrototyping Board Power SwitchDigital Multimeter (DMM) ConnectorsBreadboardFunction Generator (FGEN)Power Supplies
38NI ELVIS Instrument Launcher Launch the Instrument Launcher by navigating to Start>>All Program Files>>National Instruments>>NI ELVISmx>>NI ELVISmx Instrument Launcher.
39NI ELVIS Instrument Launcher-DMM DisplayModesConnectionsAcquisition modeHelpRun/StopNull offsetMode
40NI ELVIS Instrument Launcher-FGEN Frequency DisplayWaveform SelectorsWaveform CharacteristicsSweep SettingsManual ModeSignal RouteSweep
41NI ELVIS Instrument Launcher-VPS Voltage DisplayManual ModeOutput Voltage ControlsSweep SettingsSweep
42Procedure-Getting Started Turn on computer.Turn on NI-ELVIS power switch (right corner on the back).Turn on the NI-ELVIS Prototyping Board Power switch (at upper right corner, on top).Launch NI-ELVISMX INSTRUMENTS program.Launch the NI-ELVIS DMM instrument.Launch the NI-ELVIS VPS (Variable Power Supply) instrument.Arrange the instruments on the computer screen for your convenience.Set DMM to measure DC Volts. Specify the range to be 60V.
43Procedure-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.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”.
44Procedure-DC Resistance of DMM Voltmeter Set the VPS “Supply +” voltage to 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.
45Procedure-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.
46Procedure-DC Resistance of DMM Ammeter Set the VPS “Supply +” voltage to 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.
47Procedure-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.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.
48Procedure-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.
49Procedure-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.Where,
50Procedure-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,
51Procedure-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.Where,
52Lab 2-Student TasksStudents 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.
53Preparations 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.
54ReferencesECE 211 – Electrical Engineering Lab I. Latest Revised July 2010.Otago University Electronics Group-NI ELVIS II Orientation Manual.
58IntroductionVoltage 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.
59Electric 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, ×10-19 C.Electrical effects are attributed to both the separation of charge and charges in motion.
60VoltageWhenever 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:where,v=voltage in voltsw=energy in joulesq=charge in coulombs
61Current Electric current is defined as the rate of charge flow. It can be expressed in differential form as:wherei=current in amperesq=charge in coulombst=time in seconds
62Power Power is the time rate of expending or absorbing energy. Mathematically, energy per unit time can be expressed in differential form as:wherep=power in wattsw=energy in joulest=time in seconds
63Power in terms of Voltage & Current so, where p=power in watts v=voltage in volts i=current in amperes
64Passive 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.
65Use of Laboratory Instruments-Ammeter Ammeters are used to measure the 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 in series in a circuit, never in parallel with a voltage source.
66Use of Laboratory Instruments-Voltmeter 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.
67Lab Objective By the end of this lab, the student should know:- How to make DC measurements of voltages and currents.How to determine power dissipation/delivery for circuit elements, branches, and various combinations of elements and branches.
68Equipment Needed NI-ELVIS Series II workstation Two 510Ω Resistors One 1kΩ Resistor
69Procedure-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.
70Procedure-Experimental Circuit Voltage 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 voltage across each individual circuit element.For each measured voltage, determine the percent difference from the theoretical value.
71Procedure-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.
72Procedure-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.
73Lab 3-Student TasksStudents 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.
74Preparations 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).
75ReferencesECE 211 – Electrical Engineering Lab I. Latest Revised July 2010.Electric Circuits 8th Edition by James W. Nilsson & Susan A. Riedel.
79IntroductionB2 Spice v5 is an integrated circuit design, simulation, and analysis softwareIt contains a mixed mode simulator based partly on the Berkeley SPICE simulator and partly on the Georgia Tech XSPICE simulatorB2 Spice v5 is an application with two separate subprograms: the B2 Spice main program, and the Database EditorIt allows you to perform realistic simulations on your circuit without the need of any physical component or any expensive test equipment
80Lab ObjectiveThis 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.
81Equipment NeededA computer with B2 Spice loaded and ready to use.
82Procedure-Theoretical Calculation of Voltage & Current For the circuit given in figure, calculate the voltages across and currents through each resistor.
83Procedure-Opening Software & Creating New Project Double click on B2SpiceV5 shortcut icon on desktopThe following window will appearFile->New->Project(Check Schematic & Enter Project Name)->Ok
84Procedure-Placing Resistors Common parts->Resistor(simple)(R)Place resistor as desired on the workspaceDouble click on the resistor placed to modify its default parametersRight click on the resistor placed for more options(e.g. rotate clockwise)
85Procedure-Placing Voltage Source Common parts->Voltage Source(V)Place the voltage source as desired on the workspaceDouble click on the voltage source placed to modify its default parametersRight click on the voltage source placed for more options(e.g. rotate clockwise)
86Procedure-Placing Ammeter/Voltmeter Common parts->Ammeter(1)/Voltmeter(2) (Horizontal/Vertical)Place the ammeter/voltmeter as desired on the workspaceDouble click on the ammeter/voltmeter placed to modify its default parametersRight click on the ammeter/voltmeter placed for more options(e.g. rotate clockwise)
87Procedure-Placing Ground Common parts->Ground(0)Place the ground as desired on the workspaceGround default parameters cannot be changedRight click on the ground placed for more options(e.g. rotate clockwise)
88Procedure-Connecting Circuit Components Press to draw circuit linesOn clicking the draw circuit lines symbol, one can draw circuit lines to connect circuit components togetherTo discontinue drawing the circuit line press esc
89Procedure-Running Simulations Pause SimulationRunAfter setting up the circuit and placing the meters in the proper positions, press Run to simulate the circuitTo stop simulation, click Simulation->Stop and Reset
92Test Circuit 3 How does V across & I through each resistor vary with the given combinationsof resistor values?
93Lab 4-Student TasksStudents 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.
94Preparations 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.
99IntroductionAn 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.
104Kirchhoff’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.
105Kirchhoff’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 positivealgebraic sign to voltage drops.Starting at node d leads to the expression:
106Lab ObjectiveBy the end of this lab, the student should understand KVL, KCL, voltage division, current division, and equivalent resistance combinations.
108Procedure-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.
109Procedure-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 I3.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.
110Procedure-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.
111Procedure-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.
112Procedure-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.
113Lab 5-Student TasksStudents 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.
114Preparations for Next Week Read the material in the textbook that describes Thévenin's equivalence theorem and maximum power transfer.
115ReferencesECE 211 – Electrical Engineering Lab I. Latest Revised July 2010.Electric Circuits 8th Edition by James W. Nilsson & Susan A. Riedel.