Magnetic circuits. Single-phase transformers: principles, analysis and performance characteristics. Three-phase transformers: construction, connections and vector groups. Single-phase and three-phase transformer testing. Electromechanical energy conversion. Basic principles of DC mechanics. Principles and classification of DC generators. DC motors: analysis, performance characteristics, starting and speed control. DC machines testing. Rotating field. Synchronous generators: classification, analysis, performance characteristics, synchronization process and parallel operation.