Embedding Engineering Design in a Circuits and Instrumentation Course

Paper ID #11922

Dr. Jacquelyn Kay Nagel, James Madison University

Dr. Jacquelyn K. Nagel is an Assistant Professor in the Department of Engineering at James Madison Uni- versity. She has eight years of diversiﬁed engineering design experience, both in academia and industry, and has experienced engineering design in a range of contexts, including product design, bio-inspired design, electrical and control system design, manufacturing system design, and design for the factory ﬂoor. Dr. Nagel earned her Ph.D. in mechanical engineering from Oregon State University and her M.S. and B.S. in manufacturing engineering and electrical engineering, respectively, from the Missouri University of Science and Technology. Dr. Nagel’s long-term goal is to drive engineering innovation by applying her multidisciplinary engineering expertise to instrumentation and manufacturing challenges. Mr. Stephen Keith Holland, James Madison University

S. Keith Holland received his PhD in Mechanical and Aerospace Engineering from the University of Virginia in 2004. He served as the Vice President for Research and Development with Avir Sensors, LLC prior to joining the Department of Engineering at James Madison University (JMU). At JMU, he developed statics, dynamics, circuits, instrumentation, controls, renewable energy, and engineering study abroad courses. His current research interest include material development for solar energy applications and optoelectronic device development for non-destructive testing and evaluation. Brian Groener , James Madison University Page 26.594.1

c American Society for Engineering Education, 2015

Embedding Engineering Design in a Circuits and Instrumentation Course

Abstract

The junior level circuits and instrumentation course at James Madison University is a 4-credit course with three lectures and one laboratory each week. Fundamentals of DC and AC circuit analysis are covered along with instrumentation topics. The laboratory portion of the course reinforces the concepts learned in lecture and assignments while building skills in circuit prototyping and measurement. Lab exercises have traditionally been a time when students follow a given procedure, collect data, and interpret the data. The highly structured experience often leads to students focusing on the procedure and not fully thinking through the concepts being covered. To encourage a deeper understanding of course concepts and how they translate to physical systems, two open-ended design projects were offered in place of structured labs in the most recent offering the circuits and instrumentation course.

The design projects are undirected experiences that build on the directed experiences in the lecture and lab. Students are challenged to work in teams of four to design, build, test a specific type of circuit. Project one focused on a calibrated instrument that reported the weight of a sample using a strain gage. Project two focused on the design of an analog filtering circuit. No instruction is provided for the projects, rather, a set of design requirements, timetable, and supplemental materials (e.g., data sheets, vendor design briefs, past labs relevant to the design requirements) are given. Students were required to synthesize multiple weeks of course content into a single design project.

This paper reports on our observations and findings for embedding design experiences into a circuits and instrumentation course, as well as descriptions of the design projects. Qualitative and quantitative assessment of student perceptions of learning achieved through the projects was performed using surveys and reflections.

Introduction

The relatively young engineering program at James Madison University has been designed to train the Engineer of 20201,2. The program was developed from the ground up to not be an engineering discipline-specific program, but to provide students training with an emphasis on engineering design, systems thinking, and sustainability. Our vision is to produce cross-disciplinary engineer versatilists. At the heart of this program is the six-course engineering design sequence which provides instruction on design theory (thinking, process, methods, tools, etc.), sustainability, ethics, team management, and technical communication (both oral and written), while incorporating elements of engineering science and analysis. Students apply design instruction in the context of two projects during the six-course sequence—a cornerstone project spanning the fall and spring semesters of the sophomore year, and a capstone project spanning the junior and senior academic years.

The curriculum of our non-discipline specific engineering program, shown graphically in Figure 1, combines a campus-wide, liberal arts general educational core with courses in math, science, engineering design, engineering science, business, systems analysis, and sustainability3,4. Individual skills taught developmentally through the curriculum, beginning with the freshman year, are blended with engineering design theory and utilized in projects in the design sequence. The engineering design sequence is meant to be the core or spine of the engineering curriculum. During the engineering design courses, students not only learn engineering design tools and methods but also learn about creativity, Page 26.594.2 sustainability, business, ethics, values, engineering science, math, and manufacturing. It is during this engineering design sequence where students are provided with a hands-on environment to apply the theory learned in other courses5. Similarly, the engineering science courses provide an opportunity to apply the theory and problem solving processes learned in the engineering design courses.

Y E Calculus 1 Liberal Arts Core Liberal Arts Core Liberal Arts Core Physics 1 A R Introduction to Calculus 2 Liberal Arts Core Liberal Arts Core Physics 2 1 Engineering

Y Engineering E Calculus 3 Liberal Arts Core Design 1 Liberal Arts Core Chemistry 1 A R Linear Algebra & Engineering Engineering Statics & Dynamics Chemistry 2 2 Different Eq. Design 2 Management 1

Y Instrumentation & Engineering Engineering E Thermal-Fluids 1 Circuits Design 3 Management 2 Liberal Arts Core A R Materials & Engineering Thermal-Fluids 2 Liberal Arts Core Liberal Arts Core 3 Mechanics Design 4

Y Sustainability Engineering E Fundamentals Systems Analysis Design 5 Technical Elective Liberal Arts Core A R Sustainability & Engineering Technical Elective Technical Elective Liberal Arts Core 4 Design (LCA) Design 6

Figure 1: Schematic illustrating the engineering curriculum4.

Introductory electrical engineering courses have traditionally focused on problem solving and analysis theorems, which are often complemented by laboratory experience. What this structure lacks is a way to motivate the students, and provide experience with building practical circuits. To make a required course relevant, practical, and engaging while still providing the necessary instruction in fundamentals open-ended projects are often added6-9. Engineering curricula often heavily emphasize scientific and mathematic calculations. While computational mastery is critical for engineering students, it is also important for students to use quantitative results to reason about problems within systems and make necessary adjustments. Projects allow students to practice this aspect of engineering10.

The viewpoint at James Madison University on design projects is that they challenge students to synthesize multiple course concepts and work in teams to create something practical or relevant, thus reinforcing the need for learning the theoretical concepts required in a course. Therefore, each engineering design and the majority of engineering science courses implement a course project. All projects within the curriculum are team-based; therefore training in teamwork is a thread throughout the design sequence of the curriculum. Beginning in their first year, students work in small teams toward a project goal (changes each semester and by instructor) and receive training in the context of how group processes and collaborative learning influence the professional development of an engineer. Formal training in team building, team dynamics, and team management begins in the first semester of the second year in ENGR 231 – Engineering Design I. In this course students are taught the five stages of team development by Tuckman and spend the first three weeks working on team assignments to tease out each members’ behavior and values that impact or influence the role they take within a team. Additionally, students learn about constructive and destructive conflict, characteristics of successful teams, team structures, and elements of effective team meetings. And teams synthesize this information Page 26.594.3 into a team code of conduct. Following Engineering Design I students developmentally build on the foundational knowledge of teamwork in the design sequence. Thus, teamwork is not taught in the engineering sciences courses.

In this paper we explain the open-ended lab design projects offered in the junior level circuits and instrumentation course at James Madison University. The projects were offered across two sections with different instructors in a single semester. The following section provides background information on implementing open-ended or design projects in introductory circuits courses and labs. The next section describes the circuits and instrumentation course at James Madison University to provide some context for the lab projects. The remainder of the paper focuses on the lab design projects including assessment, student feedback, and observations. The paper ends with recommendations and future work.

Literature Review of Circuits and Instrumentation Course Projects There is mounting evidence that pedagogies of engagement result in higher learning and greater retention11,12. A deeper level of learning beyond surface learning occurs when students actively engage in the topic, rather than passively accept information. To be actively involved in learning, students must engage in such higher-order thinking tasks as analysis, synthesis, and evaluation, which are not facilitated through traditional lecture or labs that explain every step. Introductory computer and electrical engineering courses have traditionally focused on theory and quantitative analysis, which are often complemented by laboratory experience. What this structure lacks is a way to motivate or engage students in learning. It has been shown that, “The shift toward more theory in the engineering curriculum has produced graduates with far less experience in the practice of engineering and design than those of years past”13. Consequently, some programs have begun to build introductory circuits courses around the laboratory or offer open-ended design projects.

Colorado University completely restructured their electrical engineering labs in 1999 in order to provide its graduates with more engineering practice. These labs consist of a main eight week design project in which students undergo the complete design-build-test cycle of a project of their choosing14. Past themes have included Rube Goldberg contraptions, sensors measuring a physical quantity, and assistive devices for people affected by cerebral palsy. Moreover, the design focused labs significantly increased retention numbers and helped to give meaning to physics and calculus courses15. Illinois University created a new introductory course encouraging self-directly learning and skill development through the design of an autonomous electric vehicle16. This allows students to apply what they have learned throughout the course and develop creative problem solving skills when faced with difficulties while working on their project. The University of Manitoba observed an increase in student motivation, engagement, and enrollment when it switched its structured laboratories to open-ended projects with design components17. The theme based laboratories foster a discovery learning approach, practical thinking to construct the system, and exposure to system level design concepts, which are common to all engineering disciplines17. At Iowa State University the engineering program has developed an introductory computer engineering course encouraging problem-based learning, which has been central to engineering education. It is particularly relevant to the integration of new system design concepts and technologies into introductory courses18. This adaptation allows students involved and interested in various disciplines to take the course and be able to succeed. These project experiences not only solidify scientific fundamentals, intuition of electrical concepts, and an understanding of systems-level design issues, but also better prepare students for the rest of their college experience and life in the workforce.

Like problem solving, design is a focus that can be found across all engineering disciplines. Part of Marquette University’s Department of Electrical and Computer Engineering’s mission statement reads, “it is important to note that since engineers’ problems are sometimes creative, sometimes analytic, and sometimes experimental, their educational experience must give practice in each of these areas and in all Page 26.594.4 types of problems. Significant design experience is an essential part of the engineer’s education”19. In many cases, the beginning engineering student is thrown into upper-level engineering courses without an adequate introduction to the basic material. This, at best, causes undue stress on the student as they feel unprepared when faced with unfamiliar material, and at worst, results in students dropping out of the program or changing majors when they discover that their chosen field of engineering is not what they thought it was14. Using design in electrical and computer engineering courses forces students to analyze and comprehend the material they are being taught and acts as an essential way to increase the breadth of knowledge being learned. At the U.S. Naval academy, electrical engineering courses are designed to connect concepts across the curriculum. Learning about design and its application introduces students to MATLAB and digital systems, which are then further explored in upper level courses8. These projects ended up being so successful that students would stay after their lab period to test ideas beyond what was asked for by the professor.

One engineering education survey focused on the ability to learn in groups as compared to individual work. The results indicated that, “Relative to the students who only worked individually, the students who worked in teams were significantly more likely to agree that the course had achieved its stated learning objectives”20. Working in groups allows students to collaborate and work through common issues, and results in building a support network that motivates them to succeed.

Regardless of engineering discipline, students should graduate with engineering practice experience, the ability to problem solve, and the ability to design. These three core competencies are also engineering educational objectives as dictated by ABET criteria21. Increasing the design component in the undergraduate curriculum better prepares graduates for engineering practice, the end result being a well- rounded engineer. Traditional engineering courses provided graduates with little, if any, experience in engineering application. Electrical and computer engineering courses and labs that have moved towards an active learning approach through design and open-ended projects or labs offer the greatest benefits and opportunities to students, and allow students the chance to better prepare themselves for the workforce.

Circuits and Instrumentation Course

The ENGR 313 – Circuits and Instrumentation course at James Madison University introduces students to the fundamentals of circuit analysis and instrumentation topics. The course covers fundamental DC and AC circuits and analysis techniques and instrumentation while providing exposure to common electronics equipment and laboratory tools through laboratory investigations. Specific course outcomes and the relation to ABET criteria (a, b, e, and k) are detailed below. Upon successful completion of this course, students will be able to: 1. Develop and solve mathematical models of multi-component circuits using Kirchhoff’s current law, Kirchhoff’s voltage law, and Ohm’s law (a) 2. Describe and mathematically model the characteristics and behavior of first- and second-order dynamic systems and circuits (a) 3. Understand and use terminology related to DC and AC circuits (a) 4. Use complex impedance and frequency domain analysis to mathematically model the periodic input response behavior of dynamic circuits and systems (a) 5. Understand the fundamentals of instrumentation and measurement (a) 6. Use common electronics laboratory tools and devices (b, k) 7. Design, construct, and test circuits to perform specific tasks using resistors, capacitors, diodes, transistors, operational amplifiers, etc. (a, e) 8. Work as individuals and as team members to design and conduct laboratory experiments, analyze

data, and communicate results (k) Page 26.594.5

An overarching goal of the course is to provide students with the skills necessary to design and analyze multidisciplinary systems that include electrical components and make informed decisions regarding data collection using instrumentation. Our world is increasingly becoming data driven and integrated, thus as an engineer is it crucial to understand the fundamentals of electrical circuits in order to tackle the interesting and challenging problems of the future. Another objective for the course within the James Madison University engineering curriculum is to prepare students for the electrical portion of the Fundamentals of Engineering Exam.

To achieve these objectives, the 4-credit (5 contact hour) course is designed as a combined lecture and laboratory experience. The primary lecture and laboratory topics used throughout the course are outlined in Table 1. Since the course’s inception, an open ended design, build, and test project has been incorporated as a culminating element to reinforce the course concepts, encourage integration with engineering design principles, and develop practical experience with development and troubleshooting. During more recent offerings, two open ended projects have been incorporated, approximately at mid- semester and end-of-semester. This paper investigates the impact of such open-ended projects on the student perceptions of applying and integrating engineering design with engineering science concepts to develop and implement an effective design that appropriately addresses requirements and constraints.

Table 1: Circuits and Instrumentation Lecture and Laboratory Topics

Lecture Topics: Lab Topics: 1. Basic laws (Ohm’s Law, Kirchhoff’s Laws) 1. Common laboratory equipment (Multimeters, 2. Circuit Analysis Techniques and Theorems solderless breadboards, function generators, 3. First and Second Order System response oscilloscopes, soldering irons, etc.) modeling using differential equations 2. Resistors and Diodes (non-ohmic devices) 4. Frequency Analysis and Bode Plots 3. Solar Cells and i-v characteristic curves 5. Operational Amplifiers 4. Strain Gauges and Wheatstone Bridge circuits 6. Measurement uncertainty 5. First and Second Order System response 7. Sample Aliasing and Nyquist Sampling 6. Operational Amplifier circuits Theorem 7. Filter circuits 8. AC Power analysis 8. Design/Build projects 9. Complex Impedance Analysis

Circuits Laboratory Design Projects

The design projects for the ENGR 313 course were developed to provide relatively undirected experiences to compliment the directed experiences in the lecture and lab. Formal instruction on project completion was not provided to students; rather, a set of design requirements, a recommended timetable, and supplemental materials (e.g., data sheets, vendor design briefs, past labs relevant to the design requirements) were provided. Students were challenged to synthesize multiple weeks of course content into a single design project, and engage in self-directed learning. Two design projects were given in one semester, one at week 5 to be completed by mid-term, and one at week 10 to be completed during finals week. The following subsections describe the two lab projects.

Lab Design Project 1 - Designing a Calibrated Instrument

The first project posed to the students was intended to reinforce DC circuit and instrumentation concepts. These concepts included linear calibration and uncertainty, resistive circuit networks, and design of operational amplifier circuits. In this project, student teams were provided aluminum cantilever beams Page 26.594.6 of varying length and thickness with a pre-mounted, 120 Ω, F = 2.1, three-wire strain gage bonded to the top surface. Each team was challenged to design and prototype an analog circuit that would transform the beam and strain gage into a weight measurement device. Students were instructed that the device should have subsystems as illustrated in Figure 1. Additionally, vendor specification sheets and application notes for the three-wire strain gage and the provided operational amplifiers were provided. Brief introductions to strain gages, Wheatsone bridges, and operational amplifiers were also provided as supplementary documents for student self-learning. Prior to and during this project, no direct instruction on Wheatstone bridge design was covered in the class or laboratory component of the course. Each student team, comprised of three or four students, was responsible for constructing and integrating all of the sub-systems to meet the project requirements, as outlined below.

At the end of the project period, each team was required to meet with the instructor to demonstrate the operation of the circuit. During this demonstration, the instructor was to hang an unknown weight (between 0.1 N and 3.0 N) from the end of the cantilever beam and the student team was challenged to report the weight back to the instructor. In order to expose students to additional laboratory and prototyping equipment, a requirement of the project was for students to receive soldering training and to solder the designed Wheatstone bridge on a copper clad prototyping board. In addition to the completed prototype, students were also required to prepare a brief technical report, codifying the final design (through the use of schematics), the instrument calibration data (sensitivity and uncertainty), and recommendations for design improvements. A full description of the project, as provided from the students, can be found in the appendix.

Figure 1: Block diagram of the conceptualized instrument.

Lab Design Project 2 - Designing An LED Audio Frequency Indicator Project

The second laboratory design project was selected to reinforce the concepts of frequency dependent AC circuit responses and filtering circuits, which was covered during the second half of the semester. To accomplish this, students were challenged to design an audio frequency filtering circuit coupled to LED lights. Essentially, the project requested the design of a three-band audio crossover filter, wherein specific frequencies of input would result in different colored LEDs being lit. The input of this prototype circuit was specified to be a portable media/music player and, for testing and verification purposes, a laboratory function generator with a defined output amplitude. No requirements were placed on the method of filtering (i.e., active vs. passive); however, each project was required to have the subsystems as defined in Figure 2.

At the conclusion of the laboratory project period, teams presented their designs and prototype to the instructor. As part of the presentation, students were required to demonstrate operability of the circuit with both the function generator and the portable media player input. During this time, students were also questioned about the frequency dead-band and/or overlap regions of the LED outputs and other challenging points as identified during the presentation. In addition to this presentation, teams were also required to submit a design brief, clearly indicating their design (via schematic), predicted (theoretical) frequency response behavior, and comparison to observed behavior, as well as suggestions for improving the design. A complete description of the project, as provided to the students, can be found in Page 26.594.7 the Appendix.

Figure 2: Block diagram of the conceptualized audio frequency sensitive led circuit.

Circuits Laboratory Design Project Assessment

The delivery of the course laboratory design projects was comprised of two course sections, totaling n = 45 students. The student population across the two sections included 15 (33%) female and 31 (67%) male students. Each author was responsible for one class section. Topics and laboratory pacing between course sections was similar throughout the semester and the two course projects occurred simultaneously.

Quantitative Assessment

One measure of success for the design project experiences was the number of successful project completions. Out of 12 teams, 10 demonstrated a working prototype for the first project and 10 teams developed and demonstrated a successful prototype for the second design project.

To assess student perceptions about the learning goals for these project assignments, post-project surveys were administered to the students. The ten questions posed on each survey were: Q1. Rate how this project helped to meet the following course outcome: Design, construct, and test circuits to perform specific tasks using resistors, capacitors, diodes, transistors, operational amplifiers, etc. Q2. Rate how this project helped to meet the following course outcome: Use common electronics laboratory tools and devices (multimeters, solderless breadboards, function generators, oscilloscopes, soldering irons, etc.). Q3. Rate how this project helped you to meet the following course outcome: Understand the fundamentals of instrumentation and measurement. Q4. Rate how this project reinforced your understanding of the course concepts related to the project. Q5. Rate how this project improved your understanding of circuits used for instrumentation. Q6. Rate how this project improved your understanding of designing to a set of requirements. Q7. Rate how this project improved your understanding of subsystems within an instrument and how they interact. Q8. Rate your agreement with the following statement: Because of this laboratory project, I am more interested and excited about electrical circuits. Q9. Rate your agreement with the following statement: Because of this laboratory project, I feel more Page 26.594.8 confident in my ability to design and build electrical circuits. Q10. Rate your agreement with the following statement: Because of this laboratory project, I recognize the need for and an ability to engage in lifelong learning.

Survey questions 1-3 map directly to the course outcomes 5-7. Survey question 4 indirectly maps to course outcomes 1-4, depending on the project, and was worded such that it can be applied to both projects. The course concepts involved in the project are given in the project descriptions. Survey question 5 is not linked to course outcome 5; rather, its purpose is to gage the students’ system perspective of circuits and their use. We do not expect our students to become practicing electrical engineers, but we do expect our students to use instrumentation to take measurements in order to tackle the interesting and challenging problems of the future. Survey questions 6 and 7 are aimed at understanding students’ perception of how engineering analysis techniques learned in engineering science courses inform the process of design learned in engineering design courses. Authentic design projects across the curriculum lead students to break down the mental barriers that design is different in engineering science courses, and work toward an integrated perspective of engineering. Furthermore, understanding subsystems and how they interact is a qualitative reasoning skill that is often introduced in engineering design and plays a significant role in developing a system perspective of circuits. Survey questions 8 and 9 were given to understand students’ interest and confidence in working with circuits. Because the engineering program at James Madison University is non-discipline specific we would like to understand student interest and motivation. Survey question 10 maps directly to ABET criteria j and is aimed at gaging the students’ perception of engaging in self-directed learning.

Students evaluated each question on a scale of 0-3 (0 – Strongly Disagree, 1 – Disagree, 2 – Agree, 3- Strongly Agree). The average and standard deviation of the n = 45 responses to the project 1 and project 2 survey questions are shown in Figure 3. It is noted that, with few exceptions, the average and standard deviation scores for each question remained consistent between the project surveys. Questions 6 and 7 showed a slight improvement in the perceived understanding of designing to requirements and the understanding of subsystem interactions.

Figure 3 – Results of post-project survey response scores, including error bars representing the ±1 standard deviation estimate from the responses.

Table 2 provides a tally of the responses received by question for each project. Notably, for Q6 and Q7, Page 26.594.9 a larger number of students indicated that the projects contributed to their understanding of requirements and subsystem interactions. The largest number of students did not feel that the laboratory projects added to their interests in electrical circuits (Q8) or to their ability to design and build circuits (Q9) after the projects.

Table 2: Tally of responses per question and post project survey. Degree of shading represents the frequency of responses (dark shading indicating a more frequent response). Project 1 Project 2 Question 3 – 2 – 1 – 0 – 3 – 2 – 1 – 0 – Strongly Agree Disagree Strongly Strongly Agree Disagree Strongly Agree Disagree Agree Disagree Q1 20 24 1 0 22 22 1 0 Q2 24 21 0 0 27 18 0 0 Q3 14 27 4 0 16 25 4 0 Q4 16 24 5 0 17 24 4 0 Q5 15 26 4 0 16 26 3 0 Q6 9 33 3 0 16 28 1 0 Q7 17 24 3 1 20 24 1 0 Q8 9 22 11 3 9 22 12 2 Q9 13 21 9 2 12 23 10 0 Q10 15 24 6 0 13 30 2 0

Student Feedback and Comments

The intention of the laboratory design projects was to reinforce the learning of the theoretical concepts required in the course in a student- or learner-centered manner. As such, the laboratory projects include multiple aspects of an authentic design and build experience, including designing to set of requirements, sub-system integration, bridging theory and practice, qualitative and quantitative reasoning, and practical applications. There are multiple ways to meet the set of requirements, thus students needed to engage their engineering science and design skills. To assess student perceptions about the project assignments and their educational value, the following open-ended questions were asked in the post- project surveys: Q11. What was the most valuable aspect of lab project #? Q12. What was the least valuable aspect of lab project #? Q13. Use the space below to add any additional comments.

The following student comments are grouped based on the educational aspects of the projects, and provide insight on what the students’ valued. The responses and feedback were positive and in favor of the projects educational value. Negative comments reflected the perceived difficulty of the projects. The majority of the negative comments related to the lack of procedures and instructions.

1) Aspect of Lab Design Project: As a complementary experience to the course and lab directed instruction, the laboratory design projects aimed to reinforce the theoretical concepts learned in the course and provide context for how they can be applied. Student Feedback – Example #1: “The most valuable aspect of the lab project was probably being able to design, build, and test a circuit that allowed for a practical application of the material learned in class. It was not only a strong example of applying that information, but the project enhanced my understanding of the material greatly. It was also insightful realizing how important it is to Page 26.594.10 understand the interactions between subsystems.“

Student Feedback – Example #2: “The most valuable aspect of the first lab project for me was the process of having to work through the initial confusion and frustration of a novel system to learn, then apply, then address problems (bound to occur), and ultimately find functional success.”

2) Aspect of Lab Design Project: Projects in industry do not have a right answer; rather, they have a set of requirements to meet. This was emulated by providing a general framework for the project through block diagrams and a set of requirements to design for. Student Feedback – Example #1: “Being able to actually design, build, and solder our own circuits to meet specific criteria and goals.”

Student Feedback – Example #2: “Employing the design process to a circuits project was a good experience because it was a novel application that broadened my awareness of the capacity of the design techniques we have learned.”

3) Aspect of Lab Design Project: Many engineered products are designed at the subsystem level and teams work together to integrate them into the final product. Understanding the interdependencies of sub-systems that are integrated together to create a system is key for design, analysis, testing, and troubleshooting. Student Feedback – Example #1: “The most valuable aspect of Project 1 was being able to put together the sub-systems of the design and when they were not working well together we had to figure out how to troubleshoot the issues. This made us really understand what was happening in the circuit design. “

Student Feedback – Example #2: “The most valuable aspect of lab project 1 for me was discovering the roles of different circuit subsystems and how they all interact to accomplish a goal. Since many practical applications involve the interaction of different electrical subsystems, I think that the hands-on experience through this lab helped enhance our understanding of integration of subsystems. I also think this lab enhanced problem solving skills and application of knowledge because there was not a procedure or specific set of instructions to follow; this approach is similar to how actual engineering problems should be addressed outside of a classroom setting.”

4) Aspect of Lab Design Project: Building connections between theory and practice are important for problem solving and developing an engineering intuition. Practicing the theory engages other modes of learning and provides a stimulus for learning. Student Feedback – Example #1: “The most valuable aspect of this project was seeing how these components interact together in a real world circuit. Schematics are drawn in a way that is easy to understand, but being able to practice actually putting these things together is also very important.”

Student Feedback – Example #2: “Getting to actually build the circuit and test it out made me realize how the slightest errors can cause problems. Building the circuit also made me understand how it worked because I had to make it with my own hands and double check each others work.”

5) Aspect of Lab Design Project: Qualitative and quantitative reasoning A complete education in engineering design must not only focus on the numbers and calculations, or quantitative reasoning. Qualitative reasoning through understanding the requirements and developing representations (i.e. schematics) must also take place as it enables a true understanding of the system Page 26.594.11 being designed. Student Feedback – Example #1: “The most valuable aspect of this lab was being able to put two "lessons from class" (the Wheatstone bridge and the Op-Amp) together for a real application: to calibrate a strain gauge. It was very satisfying to see four weeks of hard work demonstrating the predicted behaviors. Even though the calibration did not lead us to predict the mystery mass within a 95% confidence interval, we were able to verify that our system behaved as desired, just without the accuracy required. Going through the process of drawing a schematic, simulating the circuit, building the circuit, testing the circuit, troubleshooting, and verifying a successful circuit is very helpful. I will be using these methodical steps for future projects.”

Student Feedback – Example #2: “The importance of researching and designing before you dive into something complicated such as this project and also how methodical you must be when building a circuit as complicated and with as many places to make mistakes as this project had.”

6) Aspect of Lab Design Project: The projects provide an opportunity for designing and building circuits that have practical applications both in engineering and non-engineering fields. The projects also provide exposure to what is likely inside devices they have already used, seen on a website, or can purchase. Student Feedback – Example #1: “The most valuable aspect of lab project 2 was how each subcomponent had a purpose and aided in the success of the system as a whole. The iteration that took place between designing each subcomponent led to a deeper understanding of the system as a whole. I liked how the system we were designing is similar to LED speaker systems that you can buy. It gave me a better understanding of how to approach real circuit systems.”

Student Feedback – Example #2: “It was really cool to create something that actually did something. It has so many different applications.”

Feedback on what was least valuable in the project: Student Feedback – Example #1: “Overall it was a good lab, but it came too soon. I did not know how to successfully build a circuit on a breadboard or a circuit board before that lab. I would have liked it if we did those labs separately and then did a cohesive project after we got a better understanding of how each of the circuits worked.

Student Feedback – Example #2: “Even though we were given a blackbox schematic of the different components, it was very difficult to determine how to design the components. It would have helped if we had briefly discussed how an attenuator, a buffer, and a comparator can be implemented. I do agree that because we had to research on our own, we experienced what it is like to be a practicing engineer that is given a problem and expected a solution with little guidance.”

Student Feedback – Example #3: “Not being able to troubleshoot the system effectively caused a lot of frustration and led to me feeling like the project was not worth my time.”

Student Feedback – Example #4: “Would have liked more help on certain aspects of the project; felt totally lost and helpless a lot.”

Discussion and Observations

From a student perception perspective, the circuits design projects strongly met the course outcomes of (1) Design, construct, and test circuits to perform specific tasks using resistors, capacitors, diodes, Page 26.594.12 transistors, operational amplifiers, etc.; (2) Use common electronics laboratory tools and devices (Multimeters, solderless breadboards, function generators, oscilloscopes, soldering irons, etc.); and (3) Understand the fundamentals of instrumentation and measurement. Further, it appears from responses to survey questions 6, 7, 11, and 12 that the repeated project exposure reinforced the importance of designing to requirements as well as the importance of understanding subsystem interactions during design. Additional research is needed, however, to fully understand the influencing factors. Unfortunately, the projects did not appear to increase motivation or interest in the subject matter at hand.

For many of the students the circuits design projects were the first experience they had with designing, prototyping, and troubleshooting a circuit to meet a certain goal. Having the entire process left open- ended was a bit daunting to many of the students. This, however, reinforced life-long learning, teamwork, and being resourceful. Another observation was with regard to subsystem design and testing, and system integration. Students would often construct the entire system before testing and would get frustrated when trying to troubleshoot the circuit. Teams that could not identify the source of error within their circuit were encouraged to test subsystems first before integrating. With coaching, the student teams were able to understand the systems perspective of the circuit design and how outputs of one subsystem became inputs to another.

In both of the circuits projects a recommended timeline was provided for each that clearly articulated what needed to be accomplished each week to ensure a successful project. It was observed that most students did not follow the timeline in the first project and spent many hours in the days leading up to the deadline. Teams that drastically underestimated the time requirements did not complete the project and presented a partially working design. As a result of this experience, during the second project, the majority of students took full advantage of open lab and instructor consultation hours, knowing that refinements and testing would take up much more time than they previously estimated. By having two projects in the circuits course, students had a better idea of what to expect in a circuits design project as well as learned from past mistakes. Instructors noted that teams devoted more up-front time to understand the project requirements, research the subsystems and components of the system, consider the input-output relationships of the subsystems, and carefully consider methods for implementing solutions.

Recommendations and Future Work

The curriculum of our non-discipline specific engineering program combines a campus-wide, liberal arts general educational core with courses in math, science, engineering design, engineering science, business, systems analysis, and sustainability. Thus, design projects are integrated throughout the curriculum to help tie together fundamental concepts. Furthermore, the projects are emphasized as a learning opportunity where the end result (whether it was fully functional or not) was not quite as important as the lessons learned during the course of the project. This makes it a more enjoyable environment focused on experimentation, discovery, and improvement. One recommended change is to add slightly more structure to the first design project, to better model the thought processes of designing a circuit to meet a set of requirements. Additional research is also needed to verify if the importance of designing to requirements as well as the understanding subsystem interactions during design was attributed to the repeated project exposure in a single course, other factors, or some combination. Overall, the laboratory design projects were successful at motivating the students to learn the course concepts as well as fundamental engineering skills, and will continued to be offered in some capacity.

References

1. National Academy of Engineering. The Engineer of 2020: Visions of Engineering in the New Century. Washington DC: Page 26.594.13 National Academies Press; 2004. 2. National Academy of Engineering. Educating the Engineer of 2020: Adapting Engineering Education to the New Century. Washington D.C.: The National Academies Press; 2005. 3. Nagel RL, Pappas EC, Pierrakos O. On a Vision to Educating Students in Sustainability and Design—The James Madison University School of Engineering Approach. Sustainability. 2012;4(1):72-91.

4. Nagel RL, Pierrakos O, Pappas EC, Ogundipe A. The Integration of Sustainability, Systems, and Engineering Design in the Engineering Curriculum at James Madison University. ASME 2011 International Design Engineering Technical Conferences (IDETC). Vol DECT2011. Washington, DC: ASME; 2011. 5. Pierrakos O, Nagel RL, Pappas E, Nagel JK. A New Vision for Engineering Design Instruction: On the Innovative Six Course Design Sequence of James Madison University. 119th ASEE Annual Conference & Exposition. San Antonio, TX2012. 6. Sterian, A., Adamczyk, B., & Rahman, A. A Project-Based Approach to Teaching Introductory Circuit Analysis. 38th ASEE/IEEE Frontiers in Education Conference, pp. 1-6, 2008. 7. Macias-Guarasa, J., Montero, J., San-Segundo, R., Araujo, A., & Nieto-Taldriz, O. A Project-Based Learning Approach to Design Electronics Systems Curricula. IEEE Transactions on Education, 49(3), 389-397, 2006. 8. Jenkins, B., Field, C.T. Practical Circuit Design in an Elementary Circuit Theory Lab. Proceedings of American Society for Engineering Education Conference, St. Louis, MO, USA, 2000. 9. Firebaugh, S., Jenkins, B., Ciezki, J. A Comprehensive Laboratory Design Project for Teaching Advanced Circuit Analysis. Proceedings of American Society for Engineering Education Conference, Salt Lake City, Utah, USA, 2004. 10. Michaud, Francois, et al. "Designing toy robots to help autistic children-an open design project for electrical and computer engineering education." Proc. American Society for Engineering Education, 2000. 11. Smith, K.A., Shepard, S.D., Johnson, D.W., Johnson, R.T. Pedagogies of Engagement: Classroom-Based Practices. Journal of Engineering Education, 94(1), 87-101, 2005. 12. Freeman, S., Eddy, S.L., McDonough, M., Smith, M.K., Okoroafor, N., Jordt, H., Wenderoth, M.P. Active learning increases student performance in science, engineering, and mathematics. PNAS 111 (23) 8410-8415, 2014. doi:10.1073/pnas.1319030111 13. Dutson, A.J., Todd, R.H., Magleby, S.P., Sorensen, C.D. A Review of Literature on Teaching Engineering Design Through Project-Oriented Capstone Courses. Journal of Engineering Education, 86(1), pp. 17-28, 1997. 14. Adhami, R., Meenen, P.M., Wayne, D. Fundamental Concepts in Electrical and Computer Engineering with Practical Design Problems. 2nd ed. Boca Raton, FL: Universal, 2007. 15. Carlson, L.E., Sullivan, J.F. Hands-on engineering: learning by doing in the integrated teaching and learning program. International Journal of Engineering Education, 15(1), pp. 20-31, 1991. 16. Uribe, R.b., L. Haken, and M.c. Loui. A Design Laboratory in Electrical and Computer Engineering for Freshmen. IEEE Transactions on Education, 37(2), pp.194-202, 1994. 17. Shafai, C., and Kordi, B. A Laboratory-Centered Approach to Introducing Engineering Students to Electric Circuit and Electric Systems Concepts. Proceedings of the Canadian Engineering Education Association, Winnipeg, Manitoba, Canada, 2012. 18. Striegel, A. Problem-based Learning in an Introductory Computer Engineering Course. 32nd Annual Frontiers in Education Conference, pp. 7-12, 2002. 19. Yaz, Edwin E. "Department of Electrical and Computer Engineering." Marquette University Bulletin. Marquette University. 20. Oakley, B.A., Hanna, D.M., Kuzmyn, Z., Felder, R.M. Best Practices Involving Teamwork in the Classroom: Results From a Survey of 6435 Engineering Student Respondents. IEEE Transactions on Education, 50(3), pp. 266-72, 2007. 21. ABET, Criteria for Accrediting Engineering Programs, 2012 - 2013. ABET Board of Directors, 2011.

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ENGR 313—CIRCUITS AND INSTRUMENTATION

Lab Project #1 —Designing a Calibrated Instrument

INTRODUCTION

This lab project is a 3-week project for teams of four students. Throughout this project, you will need to use the knowledge and experience that you gained in class and lab to design, build, test, and calibrate a functional weight measurement device based on a strain gage mounted to a cantilevered beam. Each team is required to design, build, demonstrate, and report their design. This document outlines the requirements for this project. This first lab project will be weighted as 7.5% towards your final grade in the course.

PROJECT DESCRIPTION

Students will form their own project teams comprised of four students. Each team must meet the weekly deliverables, and give a demonstration of their design in lab during the week of October 13th.

Each team must: • Derive appropriate equations to model the system and inform the circuit design process • Create a schematic of the final circuit design • Include a Wheatstone bridge and instrumentation amplifier in the design • Construct and test the designed circuit • Calibrate the instrument and provide a calibration plot with uncertainty • Measure (using LabVIEW, multimeters, etc.) and provide ample documentation to prove that the designed circuit meets the project criteria • Sign up for and attend solder training • Solder the Wheatstone bridge portion of the circuit design • Each individual must complete weekly progress reports detailing their individual contributions to the project during the previous week • Give a demonstration of the working design • Write a report that explains the design, analysis, testing, and calibration of the instrument, as well as how modeling assisted with the design, deviations of the performance from expectations based on mathematical modeling, and how the limitations were overcome

Demonstrations of the calibrated instrument will occur in lab during the week of October 13th.

Your instructor will be available during normal class laboratory times to answer questions and assist teams. Evening laboratory hours (5 pm – 8 pm) are also available for teams to work on the project.

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PROJECT REQUIREMENTS

Design, build, and test a calibrated instrument to measure and report the weight of mass attached to the device. This instrument must have the subsystems defined in Figure 1.

Figure 2: Required Subsystems of Instrument

A pre-mounted 120 Ω, F = 2.1, three wire strain gage will be provided to each team.

Your team will be required to research the principles of strain gage operation and how strain measurements are performed using a Wheatstone Bridge. Each team must then design and implement a Wheatstone Bridge circuit to measure the strain induced on an aluminum bar fitted with a strain gauge having a gauge factor of F = 2.1. The bridge circuit must be adjustable so that an output of 0 V can be achieved in the no-strain condition. The input voltage to the Wheatstone bridge must be 1.5 V. Further, the Wheatstone Bridge circuit components must be soldered.

To measure the voltage difference across the Wheatstone Bridge, each team must research, design, and implement an instrumentation amplifier using the LM 324N op-amp that improves the sensitivity of the Wheatstone bridge output voltage. Bonus points opportunity: The teams that solder this instrumentation amplifier circuit in addition to the Wheatstone bridge circuit will receive bonus points.

Finally, design and implement an interface that reports the output of the instrument. The interface must convert the instrumentation amplifier output value to the value of weight applied to the end of the cantilever beam. This interface can be a manual or automated design. Bonus points opportunity: The teams that build a LabVIEW interface that will automatically convert the amplifier output value to a weight value in real-time will receive bonus points.

The calibrated instrument must be able to accept an input within the range of 10-300 grams.

Your team’s instrument will be validated by placing an unknown (to your team) weight on the instrument. Based on your circuit output, your team should be able to determine the value of the weight applied, including the uncertainty in the measurement.

PROJECT TIMELINE

All project teams will follow the timeline given in Table 1. Demonstrations of the calibrated instrument will occur in lab during the week of October 13th.

Table 2: Lab Project 1 Timeline

Week Pre-lab During Lab September Learning about strain gages, and 22 open lab time to explore Wheatstone bridges or amplifiers September Simulated Wheatstone bridge and Prototyping the Wheatstone 29 instrumentation amplifier designs; bridge and instrumentation Page 26.594.16 Discussion post on Canvas of individual amplifier contribution October 6 Functioning and soldered Wheatstone Calibration of instrument design bridge circuit; functioning instrumentation

amplifier circuit on breadboard; Discussion post on Canvas of individual contribution October 13 Calibration and uncertainty data; Demo final design with unknown Discussion post on Canvas of individual weight contribution

DEMONSTRATION OF CALIBRATED INSTRUMENT

During the final week of lab project #1, each project team will demonstrate their calibrated instrument using the apparatus shown in Figure 2. A randomly chosen weight between 10-300 g will be placed on the end of the beam with the pre-mounted strain gage. The interface of the designed circuit will report the weight applied to the end of the beam. (Note that the beam deflection, and hence, the resulting strain, will depend upon the moment generated by the weight. Be sure that your group has a pre-defined method for ensuring that the applied load will be placed at the same distance from the point of attachment during instrument testing and calibration.)

Figure 3: (Left) Example Pre-mounted Strain Gage on Beam (Right) Instrument Test Apparatus

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PROJECT DELIVERABLES

All project teams will work toward the following two deliverables: • A fully functioning instrument with the subsystems of Wheatstone bridge, instrumentation amplifier, and interface. Wheatstone bridge must be soldered. • A professional, type-written project report that details the design, analysis, testing and calibration of the instrument. All reports must have the following sections: o Introduction – includes an overview of the project and explains what is included in the document o Design Team – includes a description of team member roles, who worked on each subsystem of the design, and explains how work was assigned. All the weekly individual contribution reports should be placed in an Appendix. o Design & Analysis – includes the methods of design and analysis, descriptions, schematics, simulations, and equations relevant to each subsystem listed in Figure 1, the overall system schematic, equations used by the interface, and how the design meets the given requirements. Include images of the subsystems and overall design. Should be organized into subsections. o Calibration – includes the method of calibration, and calibration information including a plot with uncertainty. All the raw information should be placed in an Appendix. o Testing – includes methods of testing the design, preliminary testing results, and results from the demo testing during the week of Oct. 13th. Include images of testing. o Discussion – includes what was observed during testing, how mathematical analysis informed the design, why deviations of performance from expectations based on mathematical modeling occurred, how the limitations were overcome o Conclusion – summarize the project, results, and key take-aways of the design o References – follow APA format o Appendices – should include at least two appendices: compiled weekly individual contributions, and raw data from calibration.

The professionalism of the report will also be graded. This includes appearance, organization, graphics, grammar, tone, and clarity of writing.

The due dates for the project deliverables are given in Table 2.

Table 3: Due Dates for Deliverables

Week Due Deliverable October 13 Fully working design October 20 Project report

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ENGR 313—CIRCUITS AND INSTRUMENTATION

Laboratory Project 2 — LED Audio Frequency Indicator

INTRODUCTION

This laboratory project will require you to use and integrate concepts from class and previous labs, as well as research new topics, to complete the design of an audio frequency LED indicator circuit. Self-selected project groups of 3 or 4 students must design, build, test, and present the final design, justifying technical decisions with appropriate research and calculations. The remaining laboratory periods will be “open lab” periods devoted to this project work.

PROJECT DESCRIPTION

Your engineering team has been approached by a company that wishes to include audio frequency sensitive LED lighting into clothing and electronic devices. The company has asked you to devise a proof-of- concept prototype to demonstrate how LED lights can be made sensitive to audio frequencies from a portable music player (iPod, etc.). For this project you will need to design and demonstrate a circuit capable of providing audio frequency selective lighting response.

Audio or sound is the result of air compression waves that occur at different frequencies. These slight pressure variations in the air are detected by our ears and interpreted as sound by our brains. Recording equipment captures these air pressure variations and stores the time-history of these pressure variations. These signals can then be reproduced (re-played) at a later time. The recorded pressure variations are reproduced by sending an electrical signal that represents the recorded information to a speaker, which in turn cause air compression waves.

Therefore, recorded audio (music) signals are comprised of many different frequencies of sinusoidal waves that are all combined together (recall that a pure tone is a sinusoidal wave at a single frequency). The volume of the audio is determined by the amplitude of the sinusoidal waves while the tone or pitch is determined by the frequency of the waves.

In many audio playback and speaker systems, it is customary (for sound quality reasons) to “divide” the audio frequencies among multiple speakers. Low frequency signals, which result in low, bass tones, are sent to a large speaker element, often called the bass speaker or subwoofer. Midrange frequencies, which are typical of many musical instruments and the human voice, are sent to a smaller, midrange speaker. Finally, high-frequency signals, associated with instrument overtones and high pitch instruments are directed to a small speaker, often referred to as the tweeter. The frequencies associated with each ranges is given in Table 1.

Table 1: Frequency ranges and audio classifications Frequency Category Audio Classification Frequency Range (Speaker) Low Range (Woofer) Sub Bass Less than 60 Hz Bass 60 Hz – 250 Hz Midrange (Midrange) Midrange 250 Hz – 2 kHz High Frequency (Tweeter) High Midrange 2 kHz – 6 kHz

High Frequencies Larger than 6 kHz Page 26.594.19

An electronic circuit, known as an audio crossover filter or network is usually used to accomplish this frequency selection and direction process for speakers.

For this project, your team will design, construct, test, and demonstrate a crossover filter. However, instead of driving speakers with your audio filter, you will drive LEDs. In this manner, the LEDs will light up when the circuit is provided with an input signal at a particular frequency.

The requirements for this prototype are: • The circuit must accept audio input (voltage) from a portable audio device. For this proof of concept prototype, we will use a mono, or single channel output, as opposed to traditional stereo playback. • To demonstrate the single frequency filtering capabilities, your team must devise a method for mimicking the audio device output using a laboratory function generator. • The audio filter will distinguish at least three frequency ranges, corresponding to the low-range, midrange, and high frequency ranges shown in Table 1. • When a low frequency signal (less than 250 Hz) has a peak-to-peak voltage that is larger than 3 dB below the maximum amplitude output of the audio device output, a red LED must be lit. • When a midrange frequency signal (between 250 Hz and 2 kHz) has a peak-to-peak voltage that is greater than 3 dB below the maximum amplitude output of the audio device, a yellow LED will be lit. • When a high frequency signal (greater than 2 kHz) has a peak-to-peak voltage that is greater than 3 dB below the maximum amplitude output of the audio device, a green LED will be lit.

This design may be accomplished using active filters (i.e., op-amps) and/or passive filters (i.e., inductors).

Your designed circuit will be tested by your instructor using a function generator and must also be demonstrated using the selected audio device and group selected audio tracks. The output amplitude of the function generator will be set to the maximum output amplitude for these tests. The function generator will then be attached to your circuit, including the circuit required to reduce or amplify the function generator output to match that of the expected output of the audio device. The frequency of the function generator output will then be varied (set to different frequencies) to verify that the circuit meets the design requirements.

MATERIALS PROVIDED

Each group may use the following equipment and/or components within their electronics design: • A maximum of two (2) DC power supplies • One (1) solderless electronics breadboard • A maximum of two (2) LM324N Quad Op-Amp integrated circuits (ICs) • Common circuit components (resistors, capacitors, inductors, LEDs, jumper wire kits, etc.) • Access to standard 3.5 mm audio (mono channel) jacks with pigtail (wire leads) for integration with portable audio player devices.

Note that your group is not required to use all of these components for the final design.

ADDITIONAL INFORMATION AND SUGGESTED APPROACH

Most portable audio players are designed to reproduce audio by driving “earbud” style speakers with a typical resistance of 32 Ω. To evaluate the output of the audio player, you will need to mimic these conditions and measure the typical output voltage of the device (using an oscilloscope) across such a load (i.e., earbuds). Also, remember that the amplitude of the output will vary based upon the setpoint “volume” of the audio player, so it will be advantageous to select a consistent volume level for the design. To be able to accurately test your circuit at precise audio frequencies, it will be necessary to interface your design with a function generator. The function generator’s output (when the amplitude output is set to its maximum value) will most likely not produce the same voltage as the audio player; therefore, it will be Page 26.594.20 necessary for your team to devise a resistive circuit that will either attenuate or amplify the signal provided by the function generator to a level that mimics the voltage input provided by the audio player.

Because there is a desire to not disturb the quality of the audio signal input into the speakers, your circuit will need to include a circuit that “buffers” the frequency selective LED circuit from the audio signal. Amplification of the audio signal may be necessary. For reference, the signal model for the desired circuit can be represented by the block diagram in Figure 1.

Figure 1 – Block diagram of the conceptualized audio frequency sensitive LED circuit.

A recommended timeline for development of this proof-of-concept prototype is suggested in Table 1. Note that the final prototype must be demonstrated to the client (your instructor) during the week of December 8th (Finals Week). 30 min. timeslots will be made available as the date gets closer.

Table 1 – Suggested timeline for project implementation. Week of… Recommended Project Tasks November 3 • Explore low-pass, high-pass, and bandpass filters to understand how they work • Characterize the output of the audio device • Characterize the output of the laboratory function generator • Design and implement a circuit to mimic the maximum amplitude output of the audio device using the function generator November 10 • Design and implement an amplifier or buffer circuit to measure the voltage across the headphone load • Identify and evaluate (using mathematical modeling and simulation) designs for low-pass, high-pass, and bandpass filters • Begin implementation of filter circuits November 17 • Complete and test filter circuits and modify individual filter circuit designs, as required, based on results • Identify methods to light LEDs when frequency input is within the desired range at the required -3 dB level • Begin integrating LEDs with filter circuits November 24 Thanksgiving Break – Enjoy! December 1 • Complete the integration of the LEDs with the filtering circuits • Test the completed prototype with the function generator and compare with expected results • Test the completed prototype with the audio player and confirm desired operation December 8 • Present the design and demonstrate desired functionality during chosen

timeslot Page 26.594.21 • Turn in lab project #2 report

DELIVERABLES AND EVALUATION

Each team will present their completed circuit to the instructor for evaluation during a 30 minute evaluation period (to be scheduled as a team with your instructor). Prepare a 10-12 minute presentation about your group’s design for presentation at the beginning of the evaluation period. This presentation should include a demonstration, technical description of the circuit’s functionality, and schematics. Following this presentation, the circuit operation will be verified and questions about the design and operation of the circuit will be asked of each team member. These sessions will be scheduled for the week of December 8th (final exams week).

In addition to your proof-of-concept prototype demonstration and presentation, each team must provide the following written technical design information in the form of a brief technical report (due at the time of the scheduled evaluation period). The report should include the following: • Full system schematic of the designed prototype circuit, including values for all components and power supplies used in the design. • Images of prototyped circuit. • Justification for the selection of components used to perform the frequency selective filtering. This should include descriptions, mathematical models and calculations. Provide citations for all references used. • Explain the performance of the designed circuit. Include Bode plots of predicted and measured frequency selectivity performance of the circuit. • A summary of “lessons learned” and suggestions for further refinement and commercial implementation of the prototype circuit.

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