This book covers many important topics in the basics and principles of electrical engineering, from bachelor's to master's and doctorate levels. Initially, DC machines were covered. In this part, we covered definition, principle, characteristics, speed, types, advantages and disadvantages, motor operating method and operating point. In the second axis, asynchronous machines were studied, focusing on the operating principle, characteristics, operating point and power diagram. In the third section, we looked at single-phase transformers, discussing the power supply and the ideal and real transformer, as well as calculating efficiency and characteristics. In the fourth axis, three-phase transformers were studied through analysis of installation, nameplate, connection methods, equivalent model for each phase, wiring diagram and efficiency. At the end of each section, a series of exercises with typical solutions was proposed.