This book covers Direct Current (DC) circuit theory and is broken up into three modules. Module 1 covers the basics for circuits that include DC sources (voltage or current) and resistors. Even though Module 1 is not very difficult, it forms the foundation for more complicated topics in Module 2 and 3 so it is important to have a firm grasp of all Module 1 topics before moving on. Module 2 covers more difficult problem solving techniques for circuits that include only DC sources and resistors. Module 3 introduces capacitors and inductors. These non-linear reactive components are analyzed in the transient and steady state regions in circuits with DC sources in Module 3. There are two follow-on eBooks in this 3-part series. They are AC Circuits and Electromechanical Systems.
The circuits in this book are created in a user friendly circuit drawing and simulation tool called Multisim. Creating new circuits and simulating them to verify your calculations are correct is a good way to hone your skills. While it is a luxury to have a program like Multisim that you can use to check your answers, a word of caution is in order. Sometimes people will become so dependent on Multisim that they have no confidence that they can get the correct answer without it. Additionally, learning to solve the circuit problems helps prepare you for the variety of different problems you will solve in the future. By learning how to solve new types of problems you become a better problem solver, which is what the world desperately needs. Engineers that have become adept at solving complicated problems in many different areas are desperately needed to help solve the challenges we face. So focus on learning to become a better problem solver instead of becoming a master in simulating circuits in Multisim.
One goal of this book is to provide practical information so that you are better equipped to put circuit theory into practice. The picture on the cover of this book shows an example of the early stages of a student’s attempt to build the circuitry for an analog robot. It is my hope that as you master circuit theory you will also be empowered to build something of your own with the knowledge you gain. While providing practical information, the book tries to avoid going into too many tangents that result in numerous pages being skipped over by the reader. Links are provided throughout the book where more background information is available when I felt the temptation to depart from the main point. Many of the links come from allaboutcircuits.com, which is a very good open educational resource. The primary goal of this book is to explain how to solve a variety of DC circuit problems in a more efficient and simple manner than you normally see in circuits books. Over the years I have developed many shortcuts, solving methods, and procedures that greatly simplify the most difficult circuit problems.
When I took my first introductory circuit course, I was overwhelmed by all of the confusing problem solving techniques and quickly got behind and buried in confusion. I still have nightmares about the terms super-node and super-mesh! I promise you will not see those horrible methods covered in this book, but instead easier methods that don’t end in confusion and madness will be shown. After that experience I made it my mission to learn circuits on my own and figure out ways to make the problems easier to solve. I was fortunate to have some amazing professors along the way that helped me in my quest for knowledge. I am especially grateful to a legendary OU professor named John Fagan, who served as my mentor and advisor during my graduate studies and inspired me to pursue a career in academia. He first introduced me to the idea of the “Matrix Method” and instilled in me the importance of hands-on projects in engineering education.
