This book features a compilation of applicable and insightful engineering notes extracted from the author's multi-decade career in industry and academia. The book includes a plethora of modern engineering tools, including simulators and platforms like Matlab and LabVIEWTM that have been utilized to support the topics. The book is organized into four parts: Riddles, Simulations, Projects, and Math. The Riddles include puzzling issues encountered in the basic concepts and their various solutions. The Simulations section presents examples of challenging simulations, such as an ECG telemetry system, a software timer IC, and a random number generator. The section also addresses the weak points of simulators that must be considered. The Projects part comprises hardware and software projects from real life, including a DTMF pager and a barcode reader. The Math part aims to underline the importance of mathematics in engineering. For example, complex numbers are employed to show how to generate rotating magnetic fields and explain the backward-rotating wheels of carts in movies. A project exploiting vector algebra calculates the distance and heading between two points on the earth. The part is concluded with a Sudoku generator. This toolbox of solutions is intended for researchers, academics, students and professionals in electrical engineering.