Physics 3364 : Laboratory Electronics

University of Pennsylvania — Fall 2023

Contact info

  • Bill Ashmanskas — ashmansk@hep.upenn.edu — instructor
  • Jose Vithayathil — vithayat@physics.upenn.edu — lab instructor
  • Jackson Powell — jrp24@sas.upenn.edu — teaching assistant
  • Harish Bayana — hbayana@sas.upenn.edu — teaching assistant

Handouts / PDFs

Prospectus items

Course ID : PHYS 3364-401 2023C (2023-03)

Course description and level

A laboratory-intensive survey of analog and digital electronics, intended to teach students of physics or related fields enough electronics to be effective in experimental research and to be comfortable learning additional topics from reference textbooks. Analog topics include voltage dividers, impedance, filters, operational amplifier circuits, and transistor circuits. Digital topics may include logic gates, finite-state machines, programmable logic devices, digital-to-analog and analog-to-digital conversion, and microcomputer concepts. Recommended for students planning to do experimental work in physical science. Prerequisite: Familiarity with electricity and magnetism at the level of PHYS 102, 141, 151, 171.

Class structure for Fall 2023

We meet TR 1:45–4:45pm in DRL 2N25 (map). Attendance is required, as most of your learning will happen while you work through and discuss each day’s lab exercises with your lab partner and the instructors. For rare unavoidable absences due to illness, family obligation, etc, we will try to arrange a mutually convenient make-up time in the lab. Friday afternoons usually work well.

The overall course format is somewhat reversed from a typical physics course. You spend 6 hours/week in the lab, briefly jotting down your findings as you go along, so no out-of-class time is needed to write up your labs. To prepare for lab, you spend about 2 hours each weekend reading our notes or a textbook chapter. To help you to assimilate past weeks’ lab material, the weekend reading assignment will often contain a single practice problem, which should take under an hour to complete. We will have a final exam, but no midterm exams or quizzes.

[In one recent semester, we did implement quizzes, as well as substantially increase the difficulty of the final exam, as a mid-course correction in response to a significant number of students’ submitting copied work, going through the motions mindlessly in class, and (from my perspective) lying to me about the time they spent preparing for class. For the moment, I will assume that was a one-time anomaly! Our somewhat relaxed format for this course only works when everyone acts in good faith to prepare for class, to make good use of the time we spend together, and to represent honestly what is or is not one’s own work. If you see your peers acting in bad faith, be aware that their actions affect how we administer the course not only for them but for everyone. Let that embolden you to be a positive influence on your peers’ behavior! Social norms and our ability to trust one another’s integrity have a huge impact on a group of people’s ability to work together effectively: in science, in medicine, and in courses as I prefer to structure them. If, on occasion, your own work does not live up to your standards, don’t lie about it or copy someone else’s work; own up to what you were in fact able to do, and we can discuss how best to move forward.]

Also see workload below.

Schedule

(The schedule below is a work in progress. I am working on splitting past semesters’ weekly reading assignments in half, so that there is one shorter thing to read/do before each lab, instead of one long thing to read/do each weekend.)

(One schedule change we hope to implement before the end of the term is to replace/augment the last few days’ labs with a menu of options. If you love digital logic as much as I do, you could learn about serial I/O and register files. If you’re feeling creative, you could work on an individual project. If you like E&M, you could build and study an LC transmission line inspired by two chapters of the Feynman Lectures. If you love analog electronics, you could do Tom Hayes’s lab on parasitic oscillations.)

We meet TR 1:45–4:45pm in DRL 2N25 (map).

Monday Tuesday Wednesday Thursday

Aug 28

Reading 1 due:
video intro illustrating lab01

Aug 29

Lab 1:
introduce lab & equipment;
build first circuits;
measure some V-vs-I curves

Aug 30

Reading 2 due:
my intro notes

Aug 31

Lab 2:
voltage divider,
meter imperfections,
Thevenin equivalents

Sep 4

Reading 3 due:
Eggleston chapter 1

Also do Lab 1x in CircuitLab

Sep 5

Lab 3:
Thevenin, scope intro,
AC voltage divider

Sep 6

Reading 4 due:
my impedance notes

Sep 7

Lab 4:
scope probe,
RC circuits

(include mini lecture)

Sep 11

Reading 5 due:
skim Eggleston ch2

Includes hw01 problem
for Thevenin practice

Sep 12

Lab 5:
RC integrator,
RC differentiator,
resonant RLC,
(LR optional)

(include mini lecture)

Sep 13

Reading 6 due:
Tom Hayes’s diode notes

Includes RC transient step response HW Q

Sep 14

Lab 6:
diodes 1

(Bill away at UT Arlington)

Sep 18

Reading 7 due:
skim Eggleston ch3

Sep 19

Lab 7:
diodes 2

Sep 20

Reading 8 due:
my opamp notes (I)

Sep 21

Lab 8:
opamp 1: golden rules

Sep 25

Reading 9 due:
Eggleston §6.1–6.3

Sep 26

Lab 9:
opamp 2:
more golden rules

Sep 27

Reading 10 due:
my opamp notes (II)

Sep 28

Lab 10:
opamp 3:
imperfections

Oct 2

Reading 11 due:
comparators

Oct 3

Lab 11:
opamp 4:
comparators

Oct 4

Reading 12 due:
AM radio lab

Oct 5

Lab 12:
opamp 5: (fun!)
AM radio

Oct 9

Reading 13 due:
BJT intro

Oct 10

Lab 13:
BJT 1:
emitter follower

Oct 11

no reading

Oct 12

fall break

Oct 16

Reading 14 due:
common-emitter amp,
Eggleston BJT

Oct 17

Lab 14:
BJT 2: follower,
common-emitter amp

Oct 18

Reading 15 due:
push-pull, mirror,
current source

Oct 19

Lab 15:
BJT 3: common-emitter
amp, current source,
push-pull, (switch)

Oct 23

Reading 16 due:
home-made opamp

Oct 24

Lab 16:
BJT 4 (new): build up
diff amp & opamp in
circuitlab in class; start lab17 if time

Oct 25

Reading 17 due:
design a common-emitter
amplifier in CircuitLab;
no actual reading

Oct 26

Lab 17:
BJT 5: home-made opamp, (switch)

Oct 30

Reading 18 due:
PID + group audio proj

Oct 31

Lab 18:
group audio project;
start PID controller

Nov 1

 

Nov 2

Lab 19:
PID controller

Nov 6

Reading 20 due:
FETs, digital intro

(DG403 video?)

Nov 7

Lab 20:
FETs

Bill at IEEE NSS/MIC

Nov 8

 

Nov 9

Lab 21:
digital intro

Bill at IEEE NSS/MIC

Nov 13

Reading 22 due:
mainly arduino

Nov 14

Lab 22:
arduino 1
CircuitPython version
Lab 22p

Nov 15

 

Nov 16

Lab 23:
arduino 2
CircuitPython version
Lab 23p

Nov 20

Reading 24 due:
logic, counters,
FPGA intro

Nov 21

Lab 24:
flip flop intro

Nov 22

 

Nov 23

Thanksgiving

Nov 27

Reading 25 due:
more FPGA/Verilog

Nov 28

Lab 25:
FPGA 1

Nov 29

 

Nov 30

Lab 26:
FPGA 2

Dec 4

Reading 27 due:
FPGA, FSM

Dec 5

Lab 27:
FPGA 3

Dec 6

 

Dec 7

Lab 28:
FPGA 4
last class meeting

Dec 11

last day of fall classes*

Dec 12

reading days

Dec 13

reading days

Dec 14

exam period Dec 14–21

Dec 18

exam Mon Dec 18
12pm-2pm @ PCPE200
(note weird location!)

Dec 21

fall term ends
first day of term Aug 29 (Tuesday)
our first class day Aug 29 (Tuesday)
last day to add Sep 12 (Tuesday)
last day to drop Oct 9 (Monday)
fall break Oct 12-15
last day to withdraw Nov 6 (Monday)
reading days Dec 12–13
[exams][exams] Dec 14–21
fall term ends Dec 21 (Tuesday)
authoritative source Penn academic calendar

Course policies

Why take this course?

Electronic devices are all around us. A smartphone lets you walk around an unfamiliar city without fear of getting lost, of missing an important message from a friend, or of making the wrong subway connection. Somehow the phone can detect the sound of your voice, can produce both speech and music, can sense Earth’s magnetic and gravitational fields, can respond to the swipe of your finger, can record and display images, can exchange radio signals with a distant cell tower, can receive and decode GPS signals from orbiting satellites, and more. Learning a bit of hands-on electronics will give you some intuition for what goes on (at least in principle, if not in detail) inside those electronic gadgets that enrich our lives. So even if you have no practical reason for doing so, spending one semester learning electronics may broaden your view of the world, and thus can be a worthwhile part of your liberal-arts education.

If you work in experimental science, it is likely that some part of your research will involve instruments that turn real-world physical quantities (temperature, pressure, acceleration, light intensity, chemical concentration) into electrical signals that can be measured, recorded, or maybe used in some sort of process control (e.g. turning on and off a laser or a vacuum pump). While many labs primarily use commercial electronics modules for data collection, you may still need to amplify or filter a signal before connecting it to a commercial data-acquisition module. Or perhaps your lab’s existing commercial module has a spare output that can be switched on or off under computer control, but you need to amplify that output with a circuit that can provide enough current to drive the stepper motor that moves your experiment back and forth on the tabletop. Understanding the building blocks of electronics can give you more flexibility in how you carry out experiments in your own research.

In some fields of research, experiments require huge numbers of custom-designed electronics modules. The High-Energy Physics group here at Penn has designed key parts of the readout electronics for the CDF experiment at Fermilab (e.g. discovery of top quark), the ATLAS experiment at CERN (discovery of Higgs boson), and the SNO experiment in Sudbury, Canada (resolution of solar neutrino puzzle). These experiments could not be done without teams of scientists who understand electronics (and the associated particle-detection instruments, which are also custom-designed). So knowing something about electronics can be pretty handy if you work in experimental particle physics, radio astronomy, etc.

Synopsis of course content

In the first few weeks, we will become familiar with the lab equipment as we study circuits built entirely from passive two-terminal components: resistors, capacitors, inductors, diodes, and LEDs. Then we will study opamps (operational amplifiers), which are essentially the Swiss-army-knife of analog electronics. Opamps will allow us to accomplish so many useful tasks (including mathematical “operations”) that we will find them almost magical. To show off our new skills for an afternoon, we will combine these quasi-magical components into a simple home-made AM radio receiver.

Having seen how handy opamps can be, we will then learn just enough about Bipolar Junction Transistors (BJTs) to be able to see how, in principle, an opamp is implemented — and we’ll test this understanding by building our own simplified opamp. We will also apply our opamp and transistor skills to make an analog P-I-D controller (“proportional, integral, derivative”), as shown in this Phys364 video.

Then we will study Field-Effect Transistors (FETs) as a segue between analog and digital electronics. From there, we will study digital logic gates and Arduino microcontrollers (tiny computers that interact with their surroundings). After seeing how handy it is to be able to program a little computer to be able to interact with the world, we will briefly study Field Programmable Gate Arrays (FPGAs) as a mechanism for building up more complicated digital circuits, such as arithmetic operations, memories, and Finite State Machines. Finally, we will see that the microprocessor that powers a computer is, in principle, just a Finite State Machine with attached memory.

In summary, we will learn to use the magic of opamps to solve useful problems in analog electronics — then learn how opamps are built up out of transistors (BJTs). Then we will build up digital logic gates out of transistors (FETs) and learn to use logic gates and tiny Arduino computers to carry out useful tasks in digital electronics — then learn how a simple computer can be built up (inside an FPGA) out of logic gates. Our hope is that this process will both leave you with useful skills and help to demystify the electronic devices that power our modern world.

Grading

  • Notes to add to this section:
    • Because exams make such a small part of the course grade, the cutoff for a straight A is often 94 or 95%.
    • In spring 2023, for the first time ever in this course, I observed rampant of shared answers copied from other people, accompanied by people basically lying to me about how much time they had spent preparing for class. They knew that the “right” answer for time spent on each weekend’s reading was 2 or 3 hours, so that’s what they told me, even when they had in fact simply submitted copy-pasted answers from a shared document and had in fact spent no more than 10 or 15 minutes preparing for class. I really deeply resent when students lie to me. Lying and dishonesty bother me far more than truthfully telling me that one ran out of time.
    • I responded mid-semester to this highly disappointing breach of trust by adding (a) quizzes and (b) an unusually difficult final exam. The way that I really strongly prefer to administer this course (minimizing exams) depends completely on my being able to trust you to come to class prepared and to spend the classroom time earnestly engaging your own brain with the material.
    • If you (and your classmates — ethical norms are most effectively promoted through social influence) consistently demonstrate that you are prepared for class and are applying your own brain to each day’s lab work, I will continue my traditional “chill” approach to grading. If I notice even a few people making a habit of arriving unprepared, doomscrolling their smartphones, letting their lab partners do all of the work, and making no serious effort to debug their own circuits, I’ll be forced to use exams to separate free-riders from students who earnestly do the work.
    • In this course, as in life, please hold yourself to standards of personal integrity such that if everyone behaved as you do, everyone’s experience in the course would be improved: for example, maximal learning for a reasonable investment of time each week.
  • 50% — lab write-ups (work in class & submit scanned PDF on Canvas at end of each day that we meet)
    • Don’t spend time at home making your lab look good. Just scan it right away to a PDF and upload it to Canvas.
    • Most labs contain some “optional/extra-credit” material, which you are not required to do. But your doing some of the optional parts of the labs will earn you “free points” (in proportion the the total number of optional lab exercises you complete) that will reduce the weight of any points that you may lose on the final exam.
    • So if you don’t have time for the optional parts of the labs, don’t let them worry you. But to the extent that your time and interest allow, you can use the optional lab material as insurance against possible future mistakes made on exam problems.
  • 25% — in-person final exam — (May 3, at 9am, ANNS 111)
    • Note that points earned by completing “optional/extra-credit” lab exercises (usually at the end of each lab) will proportionally reduce the weight of any mistakes you may make on the final exam.
  • 15% — email/online responses to weekly reading assignments
    • Most questions will simply be to motivate you to think about the reading that you just did, and to demonstrate to me that you read it carefully.
  • 10% — one (!) homework problem a week, which you will turn in with your weekly reading assignment
  • up to 5% extra credit — final project, if you choose to do it
    • Main reason to do a project is if you think you’ll enjoy the challenge of making your own idea work in the lab.
    • Your having done an interesting project provides me with good material if you later ask me for a letter of recommendation.
  • If you finish the course with a cumulative score of 80% or more, your letter grade will be no lower than a straight B.
  • If your cumulative score is 90% or more, then your letter grade will be no lower than an A–.
  • If your cumulative score exceeds 100% (which requires doing some sort of final project as well as doing an excellent job on all of your regular work) you can earn an A+. Penn only counts it as 4.0, but it will still make you smile every time you see it.
  • Final grades from fall 2023: 3 A+, 8 A, 5 A-, 2 B+, 4 B, 1 C, one incomplete.
    • Final exam median 77.5%, mean 72.5%.
    • Total score without XC median 89.5%, mean 84.1%.
    • Total score with XC median 91.6%, mean 86.8%.

Textbook

  • Required text: Basic Electronics for Scientists and Engineers, by D. Eggleston
    • https://www.amazon.com/Electronics-Scientists-Engineers-Dennis-Eggleston/dp/0521154308
    • available in Penn bookstore and on amazon (about $55 new, about $40 used, or $33 for the Kindle edition)
    • If you prefer not to own your own textbook, our classroom (DRL 2N25) has several reserve copies that can be signed out. (Beware: we won’t give you a grade for the course until you return or replace any books you borrow! But so far nobody has ever failed to return a book.)
    • We will provide the first 1 or 2 chapters on Canvas so that you have time to order your own copy of the book.
  • We will supplement Eggleston’s textbook with our own written notes.

Work load

  • 6 hours/week in lab
    • Regular class meeting time is TR 1:45-4:45pm, in DRL 2N25. If you need more time, you can stay a bit late, you can arrive a bit early, or you can schedule extra time with us.
    • You’ll turn in a scanned PDF of your written record of your lab work at the end of each class (or once you get home to your computer that evening), which will mainly consist of filling in blank spaces on the day’s lab handout.
    • Your lab write-up doesn’t need to be beautiful — it just needs to convince us that you did the work and honestly took the time to think about the questions posed in the lab handout.
  • 2 hours/week on reading textbook/notes (due each Sunday night)
    • Includes answering some straightforward questions by email, to convince me that you’ve done the reading, and to let me know what we may need to supplement in class or in future weeks’ reading.
  • 1 hour/week on a practice problem (typically a calculation or a CircuitLab simulation based on a lab you’ve recently completed) to help you to assimilate each week’s ideas.
  • So the total weekly time commitment is about the same as that of a typical physics course, but in Physics 364 you’ll spend a larger fraction of those hours in class. (We estimate that a “typical” physics course requires 3-4 hours in class plus 6-8 hours outside of class per week.)
  • There will also be one in-class final exam. (No midterm exams.)
  • Optional final project (for extra credit), if you wish.
    • A final project is a fun way to reinforce what you have learned, makes you a potential contender to distinguish yourself with an “A+” grade, and provides me with some excellent material to use if you later ask me for a letter of recommendation. But it is not necessary: you can fully meet our expectations simply by doing a good job on all of the required coursework.

Academic integrity and honesty

  • The University of Pennsylvania takes academic integrity very seriously.
    • Every member of the University community is responsible for upholding the highest standards of honesty at all times.
    • Both gaining and helping someone else to gain unfair advantage constitute academic dishonesty: Facilitating academic dishonesty: knowingly helping or attempting to help another violate any provision of the Code
  • As a bright and creative person, you too should take seriously the honest representation of what is and what is not your own work.
  • What honesty implies for this course is that we don’t want you simply to copy down other people’s answers (or our answers). But we do want you to learn from your classmates, to discuss physics together, and to work cooperatively in the lab.
  • On labs and on homework problems, work cooperatively, but what you turn in must be the product of your own mind’s reasoning. Copying someone else’s work onto your own paper without proper attribution is never acceptable. Neither is lying to me about how much time or effort you put into an assignment. If the workload is not manageable, we should discuss that, not mislead one another.

Student comments from recent years

Physics 3364, fall 2023

Here are all of the student comments, unredacted, unedited, from the fall 2023 course. (Posted Jan 2024.)

  • I absolutely LOVED this course, and it made me more excited about physics/electronics. Initially I felt a little overwhelmed having very little physics and coding background compared to my peers, but I think the course is structured in a way that I was able to succeed when putting in effort. Looking back, I am so proud about how much I learned from each of the labs. I thought the readings were very helpful in preparing me for my time in the lab, and I really liked the projects like the radio, homemade opamp, and player piano. The structure and course content are organized super well, and I am definitely going to miss it. I also like how the course is a small section of people, so we get to know each other well.

  • Excellent course, but fairly time-consuming. Most of the material is taught through physically building circuits. Ashmanskas is an excellent professor, and is very willing to take student feedback. If you have time and inclination after completing coursework, you’re able to use the lab equipment for making circuits of interest, which is very nice. Having a final exam for a course like this was probably not necessary.

  • This class was in general fun and very instructive. It is one of the few classes in the Physics department we can get really hands-on experience, and I felt I learned a lot. Professor Bill and Jose were both amazing, and the TAs were probably the best ones I had at Penn. They were both very helpful and friendly, but also made sure we tried to solve bugs on our own first. In terms of constructive feedback:

    • I think some of the readings could be shortened, and the format could be changed slightly. I think it is quite difficult to read when math is buried into a paragraph, so just using more whitespace could help. I also feel there were probably too much interjections with parentheses. Although they were helpful to learn about the nuances, it felt like too much information at once at times. I think having a lot of information is good, but when there is too much, students will learn a lot less as their brains get tired quickly.

    • For the Verilog/ Arduino, I felt the labs could be made so that we can actually take some time to do the programming. Due to limited time, we often had to rely on precompiled files, and that diminished some of the learning. I feel like reducing the number of parts in the lab and focusing on programming could be nice. But overall, the professors were amazing, the TAs were great, and the things we learned were very, very cool. It was a great class!

  • I really enjoyed this course. It gave a great intro to circuits and had a very natural progression into different and more complex topics. The labs, while long, gave a comprehensive understanding of key concepts. Prof Bill and the TAs were phenomenal in helping during lab and guiding students through questions or concepts they didn’t understand. Only thing I wasn’t a huge fan of were the readings, they felt over-complicated and tedious for the material at hand (especially later in the sem) and often you would just end up re-learning the reading material during the lab.

  • Labs are way too long and then what could be a very exciting class into a dreadful one