Circuits for Everyone:
A Problem-Based Learning Approach
George Watson
ghw@udel.edu
Department of Physics and Astronomy
University of Delaware
Fall Meeting of the Chesapeake Section AAPT
Tidewater Community College, Virginia Beach, VA
Silicon, Circuits, and the Digital Revolution
SCEN103 at the University of Delaware
http://www.physics.udel.edu/~watson/scen103/
The course:
SCEN103 in Spring 2000 was an Honors
colloquium designed to introduce first-year
students to some of the science behind high
technology.
Designed to promote scientific and computer
literacy and awareness, SCEN103 gives students
an opportunity to leverage their interests in
everyday devices and high-tech objects into a
study of fundamental science concepts.
Live demonstrations, in-class group explorations
of technology applications, and daily work with
the Internet are essential elements of SCEN103.
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A key feature of the writing-intensive work for this colloquium was
the student’s setup and development of a personal website.
Working in small groups, students also created websites devoted
to science and technology topics.
This year’s colloquium was designed as a pilot Pathways Course
during the discussion of General Education Reform at UD.
Much of the learning in Spring 2000 SCEN103 was done with
problem-based learning.
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Broad Course Objectives:
Analyze simple electrical circuits to assess their function and
effectiveness.
State and describe fundamental scientific principles
underlying modern electronic devices.
Explain the basic operation of electrical
circuits, simple semiconductor devices, and
integrated circuits.
Identify the contributions of science
and technology to everyday life.
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Communicate technical ideas orally and in writing.
Evaluate the information content of Internet resources.
Use graphical and other multimedia elements effectively in a
webpage.
Create an informative and organized website devoted to presenting a
topic of technical interest from various perspectives.
Access timely, relevant, and authoritative information for problem
solving.
Construct technical information into a logical framework for decision
making.
Establish a frame of mind where quantitative reasoning is embraced.
Work effectively in a group to solve complex problems.
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Problem-Based Learning in SCEN103
SCEN103 relies heavily on PBL with students working
collaboratively in groups to solve real-world problems.
Students learn to apply simple scientific concepts, find and
evaluate scientific and technical information, and communicate
ideas about science and technology to others.
Discussions led by the course instructor, plus supplementary
lectures, help to give a context and conceptual framework to the
problems.
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Why PBL in SCEN103?
The rate of generation of new information in the scientific and
technical sectors is truly staggering.
Information becomes outdated rapidly and is updated constantly; much
of what will be needed to know in the workplace following graduation
has not been generated yet!
Thus identifying when new information is needed, where to find it,
how to analyze it, and how to communicate it effectively are essential
skills to learn in college.
An important result of PBL is that while problems are used to identify
what to learn, the process of learning "how to learn" is also developed.
This method of instruction has been chosen to help develop skills
important for success both in the students’ undergraduate education and
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in their professional life following graduation.
What is effective learning in SCEN103?
Effective learning is much more than memorizing information to
answer questions on examinations.
Learning is a process that culminates in the ability:
to ask the right questions and frame good problems,
to acquire information and evaluate sources of information,
to critically investigate and solve problems,
to make choices among many alternatives,
to explain concepts to others (both orally and in writing), and
to generalize to new situations.
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Problem-Based Learning helps develop these abilities!
PBL #1
Crossed Circuits
Two roommates argue about perceived use of electrical energy.
Who should pay more towards the utility bill?
Energy = power x time
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"How long does it take you to dry your hair?“ came Chris's scream from the
kitchen. "I'm trying to concentrate on my physics homework!"
"Do you want the answer as a fraction of a year?“ came Pat's retort from the
bathroom. "Then you can have fun looking up the conversion to minutes in the
back of your textbook!"
"You've been at it for at least 20 minutes. You know, you should have to pay extra
toward the electric bill. I bet you spend an hour a day drying your hair. I think $5
extra each month would be about right."
"You've gotta be kidding me. With you and your night light burning all night long, I
bet you use much more electricity than me! What are you afraid of anyway?"
"Yeah, but sometimes you fall asleep with your TV blaring. I bet that uses much
more than my little night light."
"Oh, please! That only happens once a month. Your Winnie-the-Pooh light is on
every night! Besides, how about your incessant showering. You take at least twice
as long in the shower as I do. That must cost much more than running my hair dryer.
What do you do in there anyway?"
Which roommate should pay a utility premium, Pat or Chris? How much extra?
Lab #1
Hairdryers: How much power?
Students bring in their hairdryers and test all settings. A relationship
is discovered among the three circuit quantities while checking the
manufacturers’ claims.
Power = current x voltage
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PBL #2
A San Francisco Treat
Electrical wiring plans are formulated for a building conversion
using floorplans from a “This Old House” project.
Parallel circuits
Household wiring
Power ratings of appliances
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Exercise #1
Electrical Energy Use in the World?
Student groups use the CIA’s online World Fact Book to accumulate
regional electrical energy use and investigate sources of discrepancies.
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Globalization for Pathways Course objective
PBL #3
More Power!
Mark and Tim Allen rewire a toaster for more power by using
hairdryer parts.
Resistance and Ohm’s law
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Lab #2
Resistivity and
Play-Doh
Students roll out cylinders of various diameters and find a
relationship among resistance and geometric factors.
Resistance of a cylinder (wire)
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PBL #4
Spring Break
Adventure
Students investigate the circuit concepts behind the operation of
two familiar battery testers.
Synthesis of cylinder resistance,
Ohm’s law, and
Electrical power
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Lab #3
Batteries and
Bulbs
Students work from the simplest possible circuit to the
challenging circuit on the left and its companion on the right.
Series and parallel combinations
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Exercise #3
Penetration rates of major consumer products in U.S. households
Historical aspects of electrical use
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PBL #5
Lights Out!
Students attempt to design a flashlight from a 6V lantern bulb
and two AAA cells that will last for five hours.
Batteries and internal resistance
Energy capacity
Circuit design
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Problem-Based Learning at the
University of Delaware
www.udel.edu/pbl
Institute for Transforming
Undergraduate Education
www.udel.edu/itue