This book brings together 28 records as follows: 2 records methods 1) motorized chain (study of the training of a machine by an electric motor) 2) power electronics. 9 records tools (from No. 3 to No. 11) 3) Circuit variable speed 4) Circuit sinusoidal regime 5) circuit periodic conditions 6) Three-phase 7) Energy 8) About power 9) magnetic elements 10) Fluid Dynamics 11) Transitional arrangements; and course summaries, ranging from sheet No. 12 to No. 28; 12) The DC machine 13) The constant flux motor 14) Chopper 15) uncontrolled rectifier 16) controlled rectifier 17) Harmonic pollution 18) Single-phase transformer 19) Three-phase transformer 20) Inverter: control strategy 21) 22 Three-phase UPS ) Alternator 23) The synchronous motor 24) The asynchronous machine 25) Speed variation 26) Regulation and enslavement 27) Dimmer 28) Electrothermics. The mathematical formulation is level scientific bac bac + 2; numerous drawings and sketches, legible, are made with a word processor, to note the presence of Fresnel diagrams that are quite explicit. two pages are devoted to the study of a wind turbine (35 m blades), about the record 7) on energy. For the teacher as for the student, this book is an opportunity to revise their knowledge, as it is presented synthetically. Numerical examples are studied and corrected following the course of related contents. In the appendix, we find an analogy between electrical and thermal energy.