The book (a work that complements the classics in a way that the reader understands, the application of theory in practice by means of tables, figures and graphs) contains summarized material for the disciplines of Energy Conversion and Electrical Machines. The texts are didactic, so that the reader will understand the theory and how to connect an electric machine with laboratory results (advantages and disadvantages). understanding its full operation in stationary and permanent regime. This book aims to talk about transformers, motor and Continuous Current Generator (DC), single-phase motor, synchronous machine and three-phase induction motor with winding rotor and squirrel cage. In addition, it provides a description of its construction characteristics; the concepts of excitation currents; synchronous speed and slippage; the starting characteristics, observing the rotor and stator currents at different speeds; the vacuum characteristics; the full load and speed control using external variable resistors. Finally, a conclusion will be made by analysing and verifying the main particularities of the laboratory tests.