BYOE: Improving Experience with a Metal Detector Project for Electromagnetics
Harold R. Underwood · 2020
Abstract BYOE: Improving Experience with a Metal Detector Project for Electromagnetics For the seemingly abstract concepts of electromagnetics that remain central to the electrical engineering curriculum, many students in a non-lab theory-oriented first course on the subject need the motivation of more active and applied learning than traditional methods can provide. In-class graphical illustrations of applications help visual learners see the “big picture” better, and concept questions foster peer-instruction to facilitate self-assessment, but a hands-on project for Electromagnetics more fully engages tactile learners providing a wider range of experimental and creative design activities. To reap the benefits of project-based learning while minimizing its drawbacks, this work-in-progress focuses on a single inductive metal detector (IMD) project first employed with Electromagnetics students at Messiah College during the Fall 2018 semester, as a supplemental course activity. Students built an Arduino-based self-inductance type IMD prototype developed from an idea in the literature, with modifications to maximize use of components already available in the Arduino Starter Kit. The initial base-line prototype of this directed project allows students to see how elements of other courses in electrical engineering such as circuits, analog electronics, and embedded systems connect with Electromagnetics, particularly in the coil inductance as the sensitive metal detector. To facilitate further student learning, a procedure leads students through assembly of the baseline prototype, highlights key issues of interest via pointed questions for students to answer through experimentation, and prompts them to develop a creative extension. Key investigations include 1) having students measure the coil inductance to compare it against the predicted value of a standard solenoid or an improved model and 2) hypothesizing why certain metallic objects shift the audible output frequency up, while other objects shift it down. The initial experience with this project work has been assessed at the end of the Fall 2018 semester in the form of 1) student grades based on rubric-specified evaluation of their project report, and 2) results of a satisfaction survey administered to students about their project activity. Some suggestions on improving the educational experience with this project with the results reported in this paper should be beneficial to any engineering educators seeking to introduce directed project work into their course, but especially those seeking to address unique challenges that educators of Electromagnetics face.