General Information and Introduction

This laboratory course is designed to be the experimental companion to ESE 216 Electrical Circuits and Systems II.  The course is intended to enhance the students' understanding of important analytical principles developed in EE 216 by engaging them in the real-world application of these principles in the laboratory.  An equally important purpose of the course is to further develop the students' laboratory practice for experimentally testing and evaluating electrical circuits and systems.  It is important that students develop this practice using modern lab equipment similar to that which is used in industry.  Due to computational power of PCs; they are being increasingly used to acquire experimental data, to control laboratory instruments, to process experimental data, and to provide a highly flexible means for visualizing experimental data.  For most of these functions the PC is providing real-time or near real-time support.  LabView by National Instruments is one of the most popular software tools for these purposes.  It is also a useful tool for analysis, with some functions similar to MatLab.  It is one of a core of staple software tools for electrical engineers, as are Maple, MatLab, Electronics Workbench and SPICE.

The course syllabus is a mix of scripted laboratory experiments and mini-projects.  The scripted experiments have been prepared to compliment your study in ESE 216.  In addition, there is a LabView Introduction and two mini-projects; spaced evenly throughout the course.  The mini-projects are  open-ended exercises that require students to develop experimental solutions to specified problems.  The mini-projects are problem solving exercises that to varying degrees will involve electrical circuit/system design, construct of a prototype, and testing/evaluation of the prototype.  The LabView Introduction will require the development of a laboratory application using LabView virtual instruments (VIs).

Course Outcomes

While taking this lab you will learn:

1. To apply the concepts and analytical principles developed in ESE216 to analyze electric (RLC) and electronic (diodes, transistors, op-amps) circuits. [a1,a3]
2. Understanding of the operation of op-amps, diodes and transistors in order to build circuits. [a2]
3. Learning to conduct experiments involving electric and electronic components and to analyze and interpret the measurements results. [b]
4. Designing, contruct and characterize electric and electronic circuits according to specification (such as filters, diode circuits and transistor amplifiers). [c]
5. Getting familiar with state of the art electronic test equipment (such as digital scope, waveform generator, FFT module, Benchlink) and hardware/software tools (LabView, PSpice) to characterize the behavior of electric and electronic devices and circuits. [k]
6. Improve your ability to communicate effectively through weekly written reports and lab notebooks [g].

Code of Academic Integrity:

Using or attempting to use unauthorized assistance, material, or lab results or solutions (in part or whole) is a violation of the Code of Academic Integrity and will result in a zero grade for the course.

Tentative Syllabus (Do Not use for Spring 09)  

*Mini-Projects are open-ended exercises that require students students to realize experimental solution to specified problems

Course Location:     RCA lab, Room 101 Moore School

Course Materials:

a. ESE 206 web site: http://www.seas.upenn.edu/~ese206
b. RCA Lab web site: http://www.ese.upenn.edu/rca/
c. Lab Notebook
d. Lab Report
e. Tool-set

Reference Materials:

ESE 216 Texts:

1. J. D. Irwin and R. Mark Nelms, BASIC ENGINEERING CIRCUIT ANALYSIS, 8th Edition, J. Wiley, 2005.
2. A. S. Sedra & K. C. Smith, MICROELECTRONIC CIRCUITS, 5th Edition, Oxford Univ Press, 2004.

Alternative References

3. R. E. Thomas & A. J. Rosa, THE ANALYSIS AND DESIGN OF LINEAR CIRCUITS, Prentice Hall, 1994.
4. USING LABVIEW, Video Training Tape, National Instruments.

Laboratory Related References

1. E. Slutsky and D. Messaros, "Introduction to Electrical Engineering Laboratories, Prentice Hall, Upper Saddle River, 1992
2. J. Getty, Lab Manual for "Analysis and Design of Linear Circuits", Prentice Hall, Upper Saddle River, 1994
3. Horowitz and Hill, "The Art of Electronics," Cambridge Univ. Press.

Dr. Jorge J. Santiago-Aviles
Room 360 GRW
Telephone: 215-898-5340
E-mail: santiago_at_seas.upenn.edu

RCA Lab Assistant:
Mr. Sansern Somboonsong
101 Moore, RCA Lab
Telephone: 215-898-8508
E-mail: sansern_at_seas.upenn.edu

Lab Manager:
Mr. Sid Deliwala
101 Moore, RCA Lab
Telephone: 215-898-8508
E-mail: deliwala_at_seas.upenn.edu

TAs and Graders:

Samyukta Atthipalli, samyukta_at_seas.upenn.edu (Tuesday Section)
Preeti Rajendran, preetir_at_seas.upenn.edu (Wednesday Section)
Deepti Bhogle, deeptib_at_seas.upenn.edu (Friday Section)
David Wang, waddavi_at_seas.upenn.edu

1. Each lab session lasts three hours and starts promptly.  A brief introduction may be given by the instructor at the beginning of the lab.  Everybody has to finish on time, so please time yourself carefully.  Doing the pre-lab can save you a lot of time.
2. Preparing the lab is very important, as it will save you time and allows you to work more efficiently.  The pre-lab includes reading the lab assignment in advance, and doing the pre-lab exercises specific to each lab experiment or mini-project. All pre-lab assignments have to be handed in at the start of the lab (no late submissoins will be accepted). Write your name, lab title, lab section and your name on the pre-lab assignment.
3. Review the material prior to coming to the lab; consult the textbook(s) if required. Sketch anticipated graphical results, and get an idea of the approximate range and scale of the quantities you will be measuring.
4. As part of the lab preparation, you can use Electronic Workbench or SPICE to simulate the actual experiments you will be doing in the lab or drawing the schematics of the test set up.  Spice is available in the PC labs or on Eniac, Electronic Workbench is available on the PCs in the RCA lab. You can paste the result of the simulations in the notebook.  Make sure you label the graphs and tables clearly.
5. Student partnerships: Each lab is done in groups of two. The team approach encourages interaction and helps with the debugging and data collection.
6. Lab notebook: Each student  has a lab notebook and is responsible for recording the measurement data and any observations which will be helpful for writing your lab report. One lab report needs to be handed in per group (see Guidelines on writing lab reports later on).
7. Pre-labs: The prelabs have to be handed in at the start of each lab. In case you need the results of the prelabs for the experiments during the lab, you may want to make a copy of the prelab or write down the results in your lab notebook. Each student has to do his/her own prelab.
8. Collaboration:  Students are working in groups of two in the laboratory.  This encourages team work and makes the conduct of the experiments more efficient.  You can collaborate on the pre-lab and on interpretation of the measured data.  However, each student is responsible for writing the pre-lab.  Copying of data from other groups or submitting contrived or altered information is in violation of the Code of Academic Integrity and will result in a zero grade for the course.  The lab report is a joined effort and each students should contribute equally to writing the report.
9. Each lab notebook needs to be signed and dated by the instructor or TA before leaving the lab.  The students are responsible for securing the signature
10. Tool-set:  You probably still have the toolset from your ESE205 lab. Besides the instruments and electronic components you will be using a variety of tools and cables.  Each student group should have their own toolset (protoboard, one wire stripper, one long nose players and a small screwdriver kit). This is available from the RCA lab for $20.
11. Instruments and supplies:  The major instruments you will need are permanently installed in the stations. A selection of wires, cables and connectors are contained in blue boxes and available from the instrument room (one box per station only).  At the end of the lab session the contents of the box should be checked, reassembled in the box and returned to the instrument room.  Reusable small parts (resisters, capacitors, transistors, ICs) will be available in the bins in the lab area.  Capacitors, transistors and integrated circuits (ICs) can be reused and should be left on the table in the same manner as they were obtained (stretch the leads if necessary).
12. Our goal is to make this lab as paperless as possible. For that reason you will capture scope graphs with Benchlink and save the graph as a file in your directory. Add your name, your partner's name, date and lab number (or name) to the graphics before saving this file in your directory. You can paste the graphs later into your report. The Benchlink file format "pcx" can be directly inserted in a MS Word document. Or if you prefer, you can use Hypersnap to take a screen capture of the Benchlink window and save it as a .GIF file. You can make one printout in the lab to paste in your lab notebook.
13. Leave your workplace at least as clean and tidy as you found it.  Please put everything back in its proper place before you depart the RCA Lab.

A.  Grading:

The overall grade will be based on the labs (75%) and a final in-lab examination (25%). The lab grades (75%) will be determined as follows.

1. Individual Pre-Lab: 10% Jointly submitted lab reports: 40%
2. Lab notebook: 25%

You cannot pass the class unless you also have a passing grade in the final in-lab examination.

The pre-lab has to be handed on at the start of the lab. Each pre-lab needs to have a cover sheet with the title of the lab, lab section, date and student's name. Students need to be prepared to answer questions related to the reading assignments, pre-lab calculations and general lab preparation.

Make sure you fully understand the concepts and if necessary review the material in the ESE216 textbook(s).  You can use Spice or Electronics Workbench to verify your calculations and also to determine the effect of changing component values.  However, SPice or EWB is never a substitute for calculations!

The notebooks and reports are graded according to the guidelines spelled out in the section on Guidelines for the Lab Notebook and Lab Report . Attention will be paid to clarity of presentation, neatness, pre-lab preparation, experimental procedure, data recording and presentation, discussion of the results.

B. Lab Report and Notebook Turn-In Policy: The lab reports and your lab notebook are due the following week at the beginning of your lab session.  In the event a lab report is due on a day when the University is officially closed (e.g. holiday or weather); the report will be due by 4:00 PM of the first day that classes resume after the closing.

Students are permitted up to TWO one week latenesses without penalty.  That is on three occasions lab reports may be turned in on the next lab session.  No other late turn-in of reports will be accepted for any reason.  Reports not turned in accordance with this policy will receive zero grade.  Students are expected to manage their three allowed latenesses to allow for unforeseen situations that will result in reports to be turned in late.

C. Lab Work Makeup Policy:

All laboratory work has to  be completed during the designated lab period.  Students who miss a lab session due to a documented emergency are expected to schedule a makeup time with the RCA Lab staff to conduct the missed lab work.  Reports are still due in accordance with the policy stated above.

Each group of students is required to maintain a laboratory notebook (e.g. "Lab Notebook" from Roaring Springs or "Computation Book" of Esselte, or a similar bound notebook) which is used to take notes during the lab sesseion, record, data, circuit analyses, calculations, graphs, etc.  It needs the be well organized, and the material clearly and neatly presented. The lab notebook should have numbered pages, quad ruled.

The goal of the lab notebook is to keep complete and accurate records of your work in the lab. Typically, the noteboek entry will include measurement set-up including names and models of the instruments, all connections between the "DUT (Devide Under Test)" and the instruments, every calculation, comparison between calculated and measured values, and screenshot of the key measurements, observations, etc. Note that pasting parts of your lab report in your notebook is not acceptable. The goal is to use the notes you took in the lab notebook to write you lab report later on.. By keeping a good lab notebook, you will also learn how to document the development of projects which often can lead to inventions or patent applications.

Here are instructions on keeping a good notebook.  Grading will be done in accordance with these instructions.

A. Write your names, course title and number on the front page.  Include your phone number and e-mail address in case your notebook gets misplaced.

B. Place a Table of Contents in the front of the notebook with the following format, neatly printed:

(1) dates and page numbers spanning all of the entries for the experiment;
(2) experiment or mini-project number and title;
(3) students' names;

C. Make all entries in ink.

D. Use all pages consecutively.  Leave no blank pages.

E. Do not have any loose pages in the notebook.

F. Each page should be numbered.

G. A typical entry for each lab experiment consist of the following (25 points total for notebook):

1. Title of the experiment, date and name of partner. (start on a new page)

2. Objective of the lab experiment. 3. Experimental procedure: (25 points) Show the measurement set-up (schematics); record the data, sketches and observations.  When recording data always mention the instruments used (e.g. Digital Oscilloscope HP 54600B or multi-meter HP 34401A).  An example of a schematic of the experimental set up is shown in the figure below.

Figure: Sketch of the experimental set up with indication of the Ground terminals, instruments and interconnections: (a) using a single point of contact for the ground; (b) using a ground bus on the protoboard to connect the components and instruments to ground.

Also label the recorded data including the units. It is recommended that you make some quick, but neat sketches of the data to ensure they make sense before leaving the lab.  The data must always be entered manually in your notebook while doing the experiments. 4. Observation that will help you later with writing the lab report

5. Discussions and conclusions.

H. Make sure a complete, labeled diagram is included for all the circuits of the experiments.

I. Record all the observation directly in your notebook while you are doing the experiments.  Keep good records which would enable you or someone else to repeat the experiment and obtain the same results.  Do not erase material. If a mistake is made, cross it out neatly.  You should still be able to read the incorrect data after you draw a line through it. Do not make any changes in your report after the lab has been completed.

J. When you capture a graph from the scope, using Benchlink, you should save it as file in your directory and make an entry (rough sketch and the name of the graphs) in your lab notebook. You can then paste the captured graph later in your notebook and also in your lab report. Make sure you have recorded the units of the vertical (in V/division) and horizontal (in s/division) axes.  You should also annotate the graph with your name, date and lab number or title.

K. Recorded data should be entered in table format. Tables must have column headings and units. You can use these data points to generate a graph with Excel of Matlab for use in your lab report. Label graphs clearly including a title, labeled axes and units.

L. You and the lab partner must sign and date the notebooks at the end of the lab session and before asking for the instructors signature.

For specific guidelines and clarifications click here.
For an example of a lab notebook entry: see Lab notebook entry example

General Guidelines

Each group has to submit one report for each session handed in for grading.  This is separate from the notebook.  Writing the report should be a joint effort between the two students.  Indicate in the report who wrote which sections .  The main purpose for the report is to communicate the results to others and to enable others to duplicate the work in a straight forward manner.  On the other hand, the lab notebook is for your own benefit and record keeping.

When preparing the lab report you can use a word processor (it may save you time to have a template that you follow for each lab, according to the guidelines described below).  Feel free to use a spreadsheet or MatLab (or any other appropriate analysis and graphing program) to analyze and present your data in a graphical form.  You can also include result of Electronic Workbench or Spice simulation in the report if appropriate.

Reports are to be either neatly hand written or typed (or a combination of both) and should contain the following information.  A report should be concise but thorough. The typical length is no more than 5 pages.

A. Title, date and name of two students in the group.

B. Follow the following format (65 points total for report):
 

1. Introduction:  objective of the experiment (10 points)

2. Experimental results: (30 points) Show the measurement set-up (schematics) including the instruments used (with model numbers); the measured data (you can copy materials from your Lab Notebook and paste them into your Lab Report). If you like, you can use a graphics program (spreadsheet, or math program such as MatLab) to present your data more neatly and  paste these figures or tables in the report.  Make sure that the actual data points are indicated on the graphs and not just an interpolated line. For measurements done with the scope you can paste the captured scope images into the report. Label the graphs clearly so that each graph is identified. Make sure the scale and units are visible; if they are not include these in the figure captions.

Not only should the results be presented but more importantly the measured results should be explained and interpreted.
    Compare the measured results with the expected ones (from your pre-lab and/or simulations).
    Explain any deviations between the theoretical and experimental results.

3. Conclusion. (25 points)

This is an important part of the report.  The conclusion should contain the following items:

- Summary of the results;
- Mention briefly what you have learned;

  4. Sign and date the entry.

Graphs and Data Presentation

Graphs are often used to present data, visualize the result and analyse the measurments. Graphs should always contain the following:
 

• Title
• Date
• Axes with  labels,  scales, and units
• The dependent variable is usually represented on the horizontal axis and the dependent variable on the vertical axis.
• Measurment points: each measured data point should be indicated by a symbol. Symbols are usually connected by a smooth line.
• Theoretical results. In many cases you will also graph the theoretical results (e.g. from calculations) on the same graph as the one with the experemental results.
• Theoretical results are usually graphed as a smooth line without using symbols. If you plotting more than one line on a graph, label each graph clearly.


    An example of a graph is shown below


 

Depending on the range of the variables you can use the following scales for the graph:
 

• Cartesian scale: when both horizontal and vertical variables lie withing a small range. An example is the graph given above.
• Semi-log scale: when one of the variable vary over a large range (e.g. an exponential such as the current in a diode).
• Log-log scale: when both variable vary over a large range (e.g. the transfer function of a filter, or the gain of an amplifier vs. frequency).


Graphs can be plotted using Excel, Matlab or any other suitable software program.

An example of a graph plotted on a linear and a semi-log scale. Notice that in the semi-log case one can easily read the values of the current for small voltages whereas in the linear case the currents corresponding to voltages smaller than 0.75V are all compressed on the horizontal axis, giving a value of 0mA



(a) Cartesion (linear) scales




 (b) Semi-Log Scale

Captured Scope Images.

Images from the scope, captured with Benchlink can be pasted into the lab. Make sure you label each graph and include units and scale. An example of a captured scope image is shown below.



Figure: Capatured scope picture showing the input voltage Vin (top trace) and the voltage V2 over capacitor C (bottom trace). The bottom trace is used to find the rise and fall times. The vertical scale for both graphs is 2V/div and the horizontal scale is 0.2ms/div.

Data Analysis, Accuracy and Precision (see also Lab 0 Introduction)

A measurement can never be done with absolute accuracy. There will always be a difference between  the measured quantity and the true value which is called the accuracy of a measurment. Accuracy is related to the quality of the measurement data and the sources of errors that are present during the measuremets. The precision of a measurement indicates the repeatablility of independent readings made by the same instrument. By taking the average of multiple readings one can estimate what the precision of a measurement is by comparing it to the average value. It should be noted that precise measuement data may is not necessarily be accurate due to for instance (systematic) errors made during the measurements, by using uncalibrated equipment or entering the wrong data. This raises the question about the source of errors and how to minimize them.
 


Figure illustrating the difference between precise and accurate measurements.


Here are some sources of errors:

• Systematic errors: caused by wrongly calibrated equipment, environmental influences (e.g. temperature, pressure and humidity) and systematically reading or entering the data incorrectly. Systematic errors can not be reduced by averaging multiple independent measurments. Random or statistical errors: these are caused by a variety or sources and are  randomly distributed. These errors can usually be reduced by taking multiple measurements and averaging them.
• Instrument accuracy and tolerance (expressed as a % of the measurement).


Meaningful significant numbers Since a measurement has always a limited accuracy, one has to take this into account when recording the measured data. Each quantity is represented by a  number that consists of:

• Significant figures Location of the decimal point
• Units


The significant figures and the position of the decimal point indicate the accuracy of the measurements. Assume that you measure a voltage over a resistance. Each of the following numbers indicate a level of certainty about the value of the measured voltage:

• 7.3 V:         indicates that the value is closer to 7.3V than to 7.2 or 7.4V
• 7.30 V:       indicates that the value is closer to  7.30 than to 7.29 or 7.31. In other words, by adding an additional number one indicates that one knows the value up to 3 significant numbers.


The last digit in a number indicates the level of uncertainty, so do not use more digits than can be justified based on the level of accuracy.
Assume that you have measured a resistor with 3 significant figures (what is quite accurate for a resistor), one can than use any of the following representations:
 

• 47.5 KOhm 475 x 10² Ohm 0.0475 MOhm
• However, do not write: 47500.0 Ohm since that would imply that you have determined the value to an accuracy of 0.1 Ohm or with 6 significant figures!
Use power of 10 to indicate the number of significant digits (e.g. 475 x 10² instead of 47500).

For additional  report guidelines click here.

Useful links

• Lab Safety
• Good Lab Practice
• Benchlink
• ESE Undergraduate lab
• Resistance Code Calculator
• Help with components
• Circuit Grounds and Grounding Practices
• Description of a typical workbench
• How Things Work (Electronics)
• IEEE Virtual Museum (history of EE, transistors, chips, etc.)
• PSICE with Capture Tutorial
• SPice manual
• How to Plot with MATLAB
• Wikipedia