James G. Harris
Computer Engineering Program
Cal Poly, San Luis Obispo, CA 93407
(805)756-5708, jharris@ohm.elee.calpoly.edu
Bruce Black
Electrical and Computer Engineering
Rose-Hulman Institute of Technology
5500 Wabash Avenue, Terra Haute, IN 47803
(812)877-8226, black@nextwork.rose-hulman.edu
This work has been supported in part by the National Science Foundation with awards from the Division of Undergraduate Education within Education and Human Resources Directorate and the Division of Engineering Education and Centers within the Engineering Directorate under the auspices of the Engineering Education Coalition Program. There have been other faculty that have contributed to this work including Mahmood Nahvi and Emile Attala at Cal Poly and Dave Voltmer at Rose-Hulman.
A group of faculty at four universities over the last eight years have been developing technology assisted instruction to enhance the learning of the fundamentals of electrical engineering [1, 2]. Two of those faculty have been involved in developing a set of modules to assist the students in learning the analysis of circuits using pn junction diodes and the bipolar junction transistor. A total of six modules have been developed, three addressing the diodes and three addressing the transistor. These six modules now constitute a package that can introduce the student to the analysis of circuits with non-linear elements, the diode set introducing the student to non-linear two terminal, or one port, devices, and three terminal. or two port, devices. This package can assist the faculty by using it for demonstrations in the classroom, and the students by providing them interactive computer-based tutorial exercises. The modules are available over the Internet through a number of access methods described below.
The original intent for the development of each of the modules was to provide a standalone topic addressing the fundamentals of electrical engineering. The concepts of the pn diode and the bjt transistor were each addressed separately. The pn diode modules were developed at Rose-Hulman and the bjt transistor modules were developed at Cal Poly. As time progressed and because of the design constraint that each module should not take more then one hour for a student to perform, the original modules were extended into additional modules until now there is a total of three in each area. Table I presents the lists of modules.
All the modules run on a PC under DOS 3.0 or higher. The first module in each set introduces the student to the non-linear port equations, a one-port model for the diode and a two-port model for the transistor, treating one of the three terminals (the emitter) as a common node. This module also presents the concept of a dc operating point. The second module extents the model, adding junction capacitance for the PN diode and introducing the concept of small signal analysis around an operating point for the BJT transistor. The third module in the set enhances these concepts with more interactive features and applications.
These six modules are standalone, and therefore can be operated independent of each other. It is suggested that the faculty use the modules for demonstrations in their classroom, starting with the pn diode modules in order and then the bjt transistor. These demonstrations have been performed with a notebook computer and an overhead projector with LCD display. This overhead projector should be ``high power,'' at least 3000 lumens; but, it can be adequate to use a standard projector with the lights turned out and the shades closed.
Students can be assigned homework activities that require them to perform the tutorials, i.e., to run each module at the appropriate time in the courses. Typically, these modules are available through the Internet, but we have loaded them on machines available to students in open labs. Students are encouraged to download the modules for their own personal use. Experience has indicated that the students find the modules valuable, and a culture is developed that considers using the modules ``cool.''
These six modules taken as a set can be use in the introduction to electrical engineering courses, as well as the major courses in electronics, to assist the students in learning the principles of non-linear circuit analysis. Using the diode modules first should allow the students assistance in the non-linear modeling of one port devices, its analysis, and application for design. The same sequence of principles can be introduced in the context of two-port devices using the three transistor modules. The intent is to introduce the concepts using techniques that are not available through the medium of a textbook, lecture or chalkboard description. Faculty are encouraged to download the modules, review them, and then use them as they see fit.
The modules can be accessed through two basic methods: local Cal Poly Internet and NEEDS database. The user can use two alternate methods via Cal Poly's local version of NEEDS to obtain the modules [3]. The ``readme'' file associated with the relevant directory should be read so that the user will know of any modifications incorporated into the access procedure being followed. All use the Internet, primarily the ftp capability:
login ``anonymous''
password ``your email address''
``cd tai''
use ``readme'' file to get further instructions
follow instructions on gopher menu
In addition to the Cal Poly access, the modules have been cataloged within the NEEDS database, an Internet accessible library of electronic material [4]. Material is submitted to NEEDS and cataloged using a MARC record, which is a computer readable file reference used by the library science community to catalog electronic media. The user can obtain the material by accessing the NEEDS database via the Internet using the telnet capability. The sequence of actions on the Internet:
or, via the world wide web, use URL:
Thus, either through direct access to Cal Poly or via NEEDS, the modules can be obtained by any engineering program that has access to the Internet. Hence, there has been established a convenient, cost-effective mechanism for the faculty and students to obtain the six modules.
These six modules are still undergoing evaluation and development. Their use as a package to introduce the student to non-linear circuit analysis has not been assessed. The purpose of this paper is to present a status of the development, and to encourage faculty to use this new resource in their introduction to electrical engineering courses, and provide us feedback on its utility and value in instruction. This feedback will be used to evolve the modules into a more sophisticated set of modules.
James G. Harris received his BS and MS in EE from UC-Berkeley and the PhD in EE from Syracuse University. He was an Assistant Professor at Howard U niversity, and an Associate Professor at the University of the District of Columbia, both in Washington, D.C. He is a Professor of Electrical Engineering at Cal Poly in San Luis Obispo, CA, where he served as a department head for seven years, and is currently Director of the Computer Engineering Program. Previously, he served as a program director at the NSF during 1990-92 in the Division of Undergraduate Education. He worked for TRW for 11 years, and has taught for a total of 18 years. He is a member of IEEE, SIAM, ASEE, AAAS, SHOT, and ACM.
Bruce A Black received a B.S.E.E. from Columbia University, a M.S.E.E. from MIT, and a Ph.D. E.E. from the University of California, Berkeley. He was an Associate Professor at the University of Toronto, an Associate Professor at Clarkson College of Technology, and is currently an Associate Professor at Rose-Hulman Institute of technology. He is a member of ASEE and IEEE as well as a member of Honor Societies including Sigma Xi, Eta Kappa Nu, and Tau Beta PI.
