In communication and communication devices, power equipment, relay protection and automation terminals, in the electric power industry of smart cities and homes, in industry, in railway transport, microprocessor-based relay protection and automation devices, distributed generation installations, including renewable energy sources, and electricity storage, as well as intelligent automated information and measurement systems are beginning to be used. Contactless converters of direct and alternating currents of control and control systems are widely used in them. Their disadvantages are a narrow range of controlled currents, large dimensions and weight. Therefore, it is important to eliminate them. The paper discusses the general principles of construction of contactless converters of large direct currents, the main requirements for them, and shows the results of the development of one of the options proposed by us, universal contactless magneto-modulation converters of large direct currents with an extended range for various control and control systems. They differ from the known ones by an extended controlled range with small dimensions and weight, and increased accuracy and sensitivity. The converter has a simple and technological design with low material consumption and cost, and can control large direct currents, as well as alternating currents, without contact. The paper considers the errors from external magnetic fields of universal contactless converters of control and control systems. It is shown that the error from the external magnetic field does not exceed 0.08% if the number of sections of the measuring winding is even and with their symmetrical arrangement, and with their even increase-the error decreases. At the same time, the developed contactless converters can be widely used in industry, metallurgy, railway transport, agriculture, water and farming, as well as in the electric power industry of “smart” cities and homes and for checking electric meters at the place of their installation
