The textbook was created in accordance with the Federal State Educational Standard for Non-Electrotechnical Areas of Training (qualification "bachelor"). The basic concepts of the theory of electricity are considered. Analysis and calculation methods of single-phase and three-phase electric circuits are given; transients in electrical circuits, nonlinear and magnetic circuits. The basics of the theory of electric transformers and electric machines, their main characteristics, as well as the basics of electric drive and power supply are given. Element base of modern electronic devices, amplifiers of electric signals, sources of secondary power supply, pulse and automatic generating devices are considered.