ElectroSim 2.0
Interactive Simulations
of Basic Electronic and Operational Amplifier Circuits
Tom O'Haver
Department of Chemistry and Biochemistry
The University of Maryland at College Park
http://www.wam.umd.edu/~toh/electrosim/
Last updated March, 2003
A Links2Go Key Resource Award in the Simulation Models topic.
A StudyWeb 4-star site.
This is a collection of real-time, theory-based interactive simulations
of some simple electronic circuits for use by students in
my course in "Electronics for Chemists", basically a course in
elementary practical instrumentation electronics. I use them
after the students have constructed and studied these circuits in the
laboratory, in an effort to deepen their conceptual understanding.
One of the problems in teaching electronics is the difficulty students
have in moving back and forth between the static, two-dimensional symbolic representations
of traditional schematic diagrams and the real, 3-dimensional circuits in the
laboratory. My simulations help to bridge this gap by allowing the
student to work with representations that look just like the
schematic diagrams in their textbooks, yet actually work and respond
to changes just like the real circuits. Using the mouse, you can drag sliders
to control voltages and resistances, open and close switches, and type in the
values of various components. Changes to voltages and currents throughout the circuit
are displayed dynamically in real time as the sliders are moved.
Another problem is that so much is invisible. The actual laboratory experiments
show only the outer, macro-level effects, leaving the student to imagine
the inner workings such as current flows and voltages changing at multiple
points in a circuit. Computer simulations can sometimes
show these inner workings in a way that real experiments can not. Still, these
computer simulations were not intended to replace laboratory experiments
and real-world experience, but rather to extend and augment textbook treatments.
Click to view a screen shot of the first simulation.
These simulations do not run on the Web; they are self-contained programs that
can be downloaded and run on stand-alone machines. They were developed
in HyperCard for the Macintosh. If you have a Macintosh (or a
Windows machine with Macintosh emulator software) you can download and run these
simulations immediately. They are very small and require little
computer power or screen space; you can have several of the simulations open at the same time in separate windows. They'll even run on the old monochrome "toaster" Macs
such as the SE or Classic.
Click here to download the complete set of ElectroSim 2.0 modules in ".sit" compressed format (570 KBytes).
Stuffit Expander will automatically decode and decompress the downloaded
file into a folder containing the full set of ElectroSim modules. Double-click on a module to launch it, or drag and drop it onto the Hypercard Player.
PC users can run these simulations via the
ARDI Executor Macintosh Simulator (minimum system requirements: 90 MHz P5 processor; 8MB of hard disk space for installation; 32MB RAM). A
free demo can be downloaded from ARDI.
The demo is good for 30 days and the only limitation is that print output
has DEMO written on it and the Apple function key is disabled. Other than this,
the ElectroSim modules run perfectly on the Executor. To download the
complete set of ElectroSim modules on a Windows PC, right-click on
this link and select "Save Target As..." to begin the download (570 KBytes). If you are using the ARDI Executor Mac simulator,
download this file to your C drive, launch
Executor, then open the downloaded ".sit" file with Stuffit Expander, which is
pre-loaded into the Executor Macintosh environment. Stuffit Expander will decode and decompress the downloaded
file into a folder containing the full set of ElectroSim simulations. Double-click on a module to launch it, or drag and drop it onto the Hypercard Player.
On the left side of each simulation module is a panel with several icons: click on "What
do I do?" for quick instruction for that module; click on "Explain" to pop up a series of text boxes that explain the circuit operation (click again to hide the boxes); click on "Show current flow" to see an animation of current flowing; click on "Show specs" to inspect and edit the transistor's characteristics.
Unsolicided Comments from Users
" ... a fantastic website that reinforces the theory that we are studying by actually letting a beginner see what is actually happening."
"WOW! It is a GREAT pleasure to find such content on the WWW."
"I found your site last week and have already started using it in two of my classes."
"Very nice! I think I can find good use for this at work, in some
basic electronic demonstrations during staff training."
" ... lots of useful stuff."
" ... your pages really helped."
"Just wanted to say how very useful they were to me."
"I have found your interactive simulations of basic electronics extremly
interesting."
This page was created by Prof. T. C. O'Haver , Department of Chemistry and
Biochemistry, The University of Maryland at College Park.
Comments, suggestions and questions should be directed to
Prof. O'Haver at to2@umail.umd.edu.
Last updated June 5, 2001.
