By Yicheng Zhu, Electrical Engineering and Computer Sciences
Teaching Effectiveness Award Essay, 2024
How can we enhance student engagement and cultivate genuine interest? I asked myself this question before serving as a Graduate Student Instructor (GSI) for EE 113/213A: Power Electronics, an upper-division/graduate-level course centered around circuit analysis and design. Circuits, as abstractions of physical electric systems, can seem intangible to students, particularly when introduced solely through textbooks and lectures. Adding to this challenge, the course begins with basic circuit theories familiar to students from prerequisite courses, but it quickly progresses to the specialized realm of periodic steady-state analysis for power electronic circuits. This transition requires students to shift their mindset and approach circuit analysis from a new angle. As a GSI, I believe that an effective strategy for guiding students on this intellectual journey is to bring the circuit diagrams found in textbooks and lecture notes to life in a more vibrant and engaging manner.
Fortunately, the field of power electronics naturally captivates students with its extensive applications in everyday life, such as smartphone chargers, electric vehicles, and photovoltaic generation. Under the valuable guidance of Professors Robert Pilawa-Podgurski and Jessica Boles, I organized five live demonstrations on practical power converters during lectures, each designed to underscore the key concepts discussed in class. I set up a class demonstration cart equipped with a comprehensive laboratory platform, including a camera and an oscilloscope, to display the experimental apparatus and the real-time voltage and current waveforms through the classroom’s projector. One demonstration compared incandescent, fluorescent, and LED light bulbs, illustrating the role of power electronic converters in enhancing the energy efficiency and quality of modern lighting systems. The students’ excitement was palpable when the incandescent bulb was powered on, emitting bright light and intense heat. Many were surprised at the unanticipated waveforms of the currents drawn by the fluorescent and LED bulbs, which challenged their preconceptions about these common light sources. We also took apart a ‘wall wart’ adapter to demonstrate the internal structure and workings of an actual switched-mode power supply. While some demonstrations confirmed theoretical predictions with expected waveforms, others were intentionally designed to exhibit unexpected phenomena due to parasitic circuit elements, showcasing the complexity of practical semiconductor switches and passive components. These class demonstrations were aimed at bridging the gap between theory and practice, enriching students’ understanding and sparking their curiosity. I noticed the students’ increased class engagement as they began to appreciate the practical relevance of the course content.
Beyond observing the impact of the live demonstrations on student engagement, I also gathered feedback during my GSI office hours. Many students said the live demonstrations were intriguing and added an enjoyable element to the lectures. Some told me that exploring the practical, non-ideal phenomena helped prepare them for future engineering challenges in real-world scenarios. A few mentioned that the live demonstrations made me more approachable as a GSI, which encouraged them to attend my office hours. Benefiting from the increased engagement, my office hours often evolved into collaborative group study sessions with students staying extra hours to assist each other with coursework, which promoted a supportive and interactive learning environment. The live class demonstrations, by fostering meaningful interactions and collective problem-solving, effectively enhanced student engagement and interest. They became the most memorable aspect of my experience as a GSI.