Physics 321 – Electronics Laboratory – Fall 2015
Instructor:
Office:
Office hours:
Email:
Asst. Prof. Erik Henriksen
Compton 377
by email appointment
henriksen@wustl.edu
Graduate TA & Grader Jordan Russell
Office
Crow 123
Office hours
by email appointment
Email
j.russell@wustl.edu
Lab Coordinator
Office
Office hours
Email
Scott Handley
Compton 167
by email appointment
smh@wuphys.wustl.edu
Textbooks: there is no required text for this class. However, it may be extremely useful
to refer to some standard electronics texts, so the following have been placed on reserve in
the physics library: Simpson, Introductory electronics for scientists and engineers; Sedra &
Smith, Microelectronic circuits; and the classic Horowitz & Hill, The art of electronics.
Website: there is a website at https://physics.wustl.edu/classinfo/321/Docs/intro.php from
which you can download the lab writeups and other relevant information. I highly recommend reading the primer on using oscilloscopes. To access the website, use Name: phys321
and Password: advlab.
The course: This course will serve as an introduction to practical laboratory electronics
by way of covering the application of analog, digital, radio frequency, and mixed signal
electronics to experiments in the physical sciences. No prior experience with electronics is
assumed.
Key concepts you will learn include: how some common circuits work, some neat mathematical techniques for solving differential equations, hands-on debugging procedures, how to
interface electronics to other things, safety considerations, sources of noise in circuits, stray
capacitance, shielding, positive and negative feedback, bandwidth, impedance matching, and
a number of other concepts important to master for any good experimental physicist and
generally useful for developing problem solving skills.
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The topics to be covered will vary with the professor’s (and students’ !) interests, but
will usually include:
- Passive circuit elements: resistors, capacitors, and inductors.
- Voltage dividers, input & output impedances, and Thevenin equivalent circuits.
- Basic circuit analysis.
- The oscilloscope.
- The many uses of operational amplifiers: opamps as amplifiers, integrators, summers,
buffers, and oscillators.
- Complex impedances, passive & active filters, Fourier transforms, power.
- Circuit design and simulation using Multisim.
- Diodes as rectifiers, mixers, and building blocks for DC power supplies.
- Radio transmitters and receivers, mixers, and detectors.
- Transistors as amplifiers, buffers, and switches.
- Oscillators, one-shots, flip-flops.
- Counters, timers, pulse width modulation and the 555 counter.
- Digital to analog, and analog to digital, conversion.
- Transmission lines and antennas.
- Electronic music.
- Arduino microcontrollers.
- Phase-locked loops.
It is impossible to teach both a lecture course and lab course covering all of electronics
in a one semester course but hey!– it’s worth a shot. I’ll attempt to teach you how to make
a number of practical circuits, while yet understanding the fundamental behavior of circuit
components, with a physicist’s approach to “the way things work.” Initially you will be
assigned some simple labs, building quickly to more complicated circuits. Although I do not
assume any prior electronics knowledge on your part, I’ll expect you to learn quickly in a
hands-on atmosphere. The lecture component will be used to prepare you for each lab and
supply some of the underlying concepts. There is no assigned reading, so it is incumbent
upon you to closely follow the lectures and supplement this on your own outside of class with
reference to the reserve textbooks. You will need to complete portions of the labs outside of
class, in particular the writeups and possibly some calculations.
Homework I will occasionally assign problems for you to work on outside of class. These
will be based on material contained in the lectures. I will expect you to work alone on these
problems. I have no way of keeping track of whether you do, so this is entirely on your honor.
Office hours As we will spend several hours together in lab each week and you are of
course free– nay, encouraged!– to ask all kinds of questions during this time, I will not have
regular office hours. If you must find me outside of the lab, you may either rely on chance
meetings or else contact me by email to schedule an appointment.
Grading You are required to keep a well organized laboratory notebook as described
below. Notebooks will generally be collected on the Friday following the completion of a lab,
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to be graded over the weekend and returned at the start of the following class. If you need
information from your lab over that weekend, make a copy or take a picture.
Your grade will be based 25% on your lab notebook grades, 45% on lab completion,
participation, and effort, and 30% on the final project. Except for “completion,” these are
fairly subjective rubrics, so it is in your interest to work hard and impress me! I expect you
to be fully engaged during class and make use of the resources available. If we lack resources,
let me know and together we will improve this class.
Attendance is mandatory. There are three reasons you may miss a class on a given day:
you’re at death’s door, you’re off to visit grad/medical schools (for seniors only), and WU
requests that I allow for holidays. However, you are required to make up the work on your
own time, and are responsible for arranging a time to access the lab, complete the circuit,
and demonstrate to me that you’ve finished.
Lab notebook I recommend that you obtain a “computation notebook” from the bookstore–
these have brown cardboard covers and numbered, graph-paper pages. While somewhat expensive (yet far cheaper than textbooks!), these are particularly useful since they have pages
slightly larger than 81/2×11 in2 , allowing you to cut and paste pages into the notebook (e.g.
data sheets, figures, &c.). While the entries of a lab notebook are more free-form than a
final report or paper, you should largely follow these guidelines:
1. Introduction: Each lab should start with an introduction including the lab number,
title, and a concise description of the experiment. It is usually a good idea to include
a drawing of the circuit under investigation. You should begin writing this introduction before starting the experiment since it will help you collect and organize your
thoughts. Date all entries, and be sure to include the name of your lab partner for
that experiment. Use a pen! NO pencil!
2. Data: Record all raw data as it is taken, without being overly concerned with anything
other than a chronological organization until later. Here you should include data in
all forms that you think appropriate, including sketches of the lab setup, oscilloscope
traces, computer tables and plots, &c. Record any modifications to the circuits you’ve
made, and any circuit analysis including even scratch calculations.
3. Results: Summarize key data in neat tables and graphs, and include any calculations
done in analyzing the circuit. If you try different methods along the way to getting
the correct answer, it is important to restate the final, correct methods so we can tell
what you did!
4. Conclusions: When you have completed the lab work, finish your lab notebook entry
with a summary including a qualitative and/or quantitative analysis of the circuit,
describing in words and equations how it worked (or didn’t), what you learned, and
what you might have tried given more time. You should also include the answers to
any explicit, quantitative questions in the lab. Note, you are expected to do some
circuit analysis even if not explicitly called for.
5. Neatness = success I can’t overstate the importance of neatness in building circuits.
Messy circuits will fail, and messy notes will make it hard to tell what you did. Points
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will be deducted for messy or unreadable lab notebooks. Take your time!
Each lab bench should be cleaned up after the completion of an experiment, unless noted
otherwise. Points will be deducted from your grade if we have to clean up after you.
Final project During the last three weeks of class you will be responsible for coming up
with a novel final project to be built utilizing the accumulated knowledge of the semester.
Let the sky be the limit here, so long as the project can be completed within six lab sessions
(minus the lecture component, so there’ll be a bit more time available). I will work with you
to come up with fun ideas to pursue, and if we lack necessary parts/components/materials,
we will order these.
Your lasting contribution I want this class to be fun, useful, and most importantly,
relevant to your lives and education. Electronics are a fundamental part of our modern
society, and this class should give you a head start on understanding and being able to
utilize this fascinating field. To this end, I am more than happy to alter the syllabus to
accommodate new interests and directions, so long as we continue to also cover the basics.
If you have an idea of something to explore in lab or lecture, let’s talk about it!
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