In contrast to available undergraduate textbooks at this level which take a bottom up approach that is forty years old, this book follows a top down approach that takes the role and system context of power conversion functions as the starting point. It presents a compact treatment of magnetic circuits, sufficient to gain a good quantitative understanding. A modern simple approach to machines is introduced, which makes the principles of field oriented control and space vector theory approachable to undergraduate students. Power electronics focuses on simple dC supply topologies that use a parallel transistor and diode switches. Following the top down approach, the building blocks of the system are defined, and the theory of how they exchange power with each other is described. Then the building blocks are opened, and the principles of static and electromechanical power conversion are treated.