1.3 Book organization and approach
This book is organized differently from most textbooks written for the Intro-to-EE-for-non-EE-majors course. Most texts focus substantial time on the theory and analysis of linear circuits, i.e., circuits comprised of components such as voltage and current sources, resistors, capacitors and inductors. The treatment typically evolves from mathematical analysis starting with algebra, then moving to matrices (solving systems of linear algebraic equations), then moving on to setting up and solving first and second order differential equations. Standard treatment then moves on to the Laplace transform as a way to study the frequency behavior of linear systems. The study of electronic devices, such as diodes and transistors comes next, followed by digital circuits and, in some cases, the behavior of motors. Intro-to-EE-courses-for-non-EE’s based on such texts rarely have a lab component.
In my own experience learning electronics, both as an EE student several decades ago, and when self-teaching in areas where I needed to learn something new, I have found that I rely on a combination of theory and hands-on practice to understand new concepts. I need the theory in order to form some kind of concept in my head. And I need the practice in order to both make sense of the theory and to test and validate my understanding of it. Some of my best, most satisfying learning has taken place when I was able to study the theory, practice it by working through pencil-and-paper problems, and then build something tangible to test things out. It is in this sprint that I have written this book. Theoretical concepts are introduced, pencil and paper problems are assigned, and lab experiments are conducted. The lab experiments involve circuits that do things: glow and blink lights in different colors, spin motors, sense room variables such as light level and temperature, measure medical vital signs like temperature and heart rate, etc…
This theory plus hands-on agenda necessitates changing the order and flow of this course compared to the traditional theory-only Intro-to-EE course-for-non-EE majors. Some of the bells and whistles of electronic circuits come from electronic devices such as LED’s, transistors and microcontrollers. Rather than waiting till near the end of the course to introduce these devices, we introduce them from the get-go. We alternate between theory and practice and assign pencil-and-paper problems along with hands-on circuit building and design problems beginning on day 1. Is this the correct pedagogy? That’s a difficult question to answer, but experience suggests it works. I’ve taught this course this way since 2013, to nearly 1500 students during 2013, 2014, 2015, 2016, 2017, 2018, 2019 and 2020. Most students indicate they appreciate the approach. Many students have reported they initially approached the course with trepidation, fear, and a nagging uncertainty about electronics; but they gained confidence as they progressed through and successfully built a series of increasingly complex circuits. Let’s see how it works for you. Don’t hesitate to let me know: write me at dmclaugh@umass.edu
My experience: while I was in graduate school, I studied microwave radars and in particular, how microwave radar signals interact with, or bounce off of, the ocean surface. A microwave radar transmitter generates a short pulse of microwave energy that is emitted into space by an antenna; that pulse of energy travels away from the antenna at the speed of light, then it reflects or bounces off targets in its path, and some of the energy is reflected back to the antenna, where it is measured by a sensitive receiver. When the wind blowing over the ocean is very calm, the ocean surface is smooth, and it reflects microwave energy like a mirror. When the wind speed increases, it creates a spectrum of waves of various lengths that serve to roughen the ocean surface; the rough surface tends to scatter the microwave energy in all directions, and less is reflected back to the radar antenna. So a microwave radar can be used to infer the intensity of the wind blowing over the surface by looking at the intensity of the echo signal scattered back to the antenna. A radar installed on an aircraft or satellite can then be used to infer the ocean surface wind speed, and this is the basis for microwave radar remote sensing of hurricanes. In graduate school in the 1980’s, I studied applied electromagnetics, and I learned the theory for how electromagnetic waves are generated and radiated by an antenna. I also studied how all the different components of a radar — amplifiers, mixers, filters, etc… go together. I understood the theory, sort-of, although to be truthful, it seemed like magic (or “mathemagic”) when I studied it. I could solve most pencil and paper problems, but it wasn’t intuitive for me. And, frankly, I was afraid, or insecure, about my understanding. Doing theory homework problems was one thing, but building a radar was another thing altogether. I had to deal with dozens of practical problems that weren’t addressed by the theory: block diagrams that couldn’t be realized in hardware; software that had endless bugs (real bugs, like insects crawling inside waveguides); components overheating and coming apart due to vibrations in an aircraft, etc. But I eventually got my radar built and installed on a NASA C-130 aircraft, and I had the chance to fly the radar over the ocean, from Hilo, HI to Moffet Field, CA in 1988. (I was literally still debugging code as we were taxiing down the runway). Airborne, we knew roughly what the wind speed was blowing over the surface below, and my radar, in real-time, showed the intensity of the reflected radar echo. And the real data signals actually correlated with model predictions! There I was, flying at 8000′ over the ocean, my radar in an equipment rack before me, my antenna poking out of the fuselage below the belly of the aircraft, beaming microwaves down onto the surface below, and theory and real data were lining up. At that point, something clicked: the hardware and software that I had built using my own hands, combined with my sort-of understanding of all the theory allowed me to relate to electromagnetic waves in a more visceral, more intuitive way. Whether or not, or how well, I understood all the “mathemagic” was beside the point, because my creation, and the data it generated, was an empirical fact. This fact did wonders for my confidence: it led me to realize that I could really do this stuff. So it has been the case dozens of times since: I study the theory, form a concept in my head, do some pencil and paper, write some code, build and test the thing (and test and debug and test and debug) and when it works, it all comes together. It’s hard work, to be sure, but when the experiments line up with the theory, the resulting fact it is a sweet reward that represents something learned, understood, and put into practice.