Asee peer logo

Electrical Fundamentals Make Them Come Alive For Students

Download Paper |


2005 Annual Conference


Portland, Oregon

Publication Date

June 12, 2005

Start Date

June 12, 2005

End Date

June 15, 2005



Conference Session

Curriculum Development in Electrical ET

Page Count


Page Numbers

10.520.1 - 10.520.11

Permanent URL

Download Count


Request a correction

Paper Authors

author page

Walter Banzhaf

Download Paper |

NOTE: The first page of text has been automatically extracted and included below in lieu of an abstract

Session 3247

Electrical Fundamentals - Make Them Come Alive for Students

Walter Banzhaf, P.E.

College of Engineering, Technology, and Architecture University of Hartford, West Hartford, CT 06117

Introduction Many laboratory experiments we ask students to perform in electrical fundamentals laboratory classes are unnecessarily unexciting. Such tasks as determining the current through R7 of a ladder network with eight resistors (does a first-semester student really care about R7, or its current?), or verifying Kirchhoff's Voltage Law in a circuit with only resistors, are all too often devoid of interest to the average student. Nothing in the experiment makes noise, or gives off light, or moves. This paper describes three innovative experiments (constructing a thin-film resistor, constructing a capacitor using a piece of window glass and aluminum foil, and a practical DC constant current source) for a first course in electrical fundamentals which give the student the intended knowledge and practical experience, and, the author feels, have stimulated students' interest in and understanding of the topics they cover.

Construction and Test of a Thin-Film Resistor Resistors are basic circuit elements found in all electronic circuits and come in all manner of formats (cylindrical, SMT, thin- and thick-film), yet students often are exposed only to small cylindrical resistors with values that can range from 0.1 ohm to 22M ohm. The physical parameters that determine resistance are often an unclear and abstract concept, and students have little understanding of the basic formula for a resistor with uniform cross-sectional area: R = ρL/A, where R is the resistance (in Ω), ρ is the resistivity (in Ω-cm), L is the length (in cm), and A is the cross-sectional area (in cm2).

Having each student use the graphite of a pencil to make a "thin film" resistor, and learn by direct and easily understood measurements the effect of length, area and resistivity on resistance, gives a student the kind of understanding of resistance that results from an easy, enjoyable "hands-on" experience. After construction, the student's resistor is used as a rheostat, and then a potentiometer, and as a volume control. Finally each student learns, by experimenting with audio from a CD player, that a tapered resistance works better as a volume control than a linear potentiometer.

How the Resistors are Constructed Students are given a template (see Figure 1 below) and told to use a soft graphite pencil to completely shade in the areas inside the dotted lines, making each area as dark as possible. By doing this they are constructing three thin-film resistors: two are rectangular solids, one is Proceedings of the 2005 American Society for Engineering Education Annual Conference & Exposition Copyright  2005, American Society for Engineering Education

Banzhaf, W. (2005, June), Electrical Fundamentals Make Them Come Alive For Students Paper presented at 2005 Annual Conference, Portland, Oregon.

ASEE holds the copyright on this document. It may be read by the public free of charge. Authors may archive their work on personal websites or in institutional repositories with the following citation: © 2005 American Society for Engineering Education. Other scholars may excerpt or quote from these materials with the same citation. When excerpting or quoting from Conference Proceedings, authors should, in addition to noting the ASEE copyright, list all the original authors and their institutions and name the host city of the conference. - Last updated April 1, 2015