Особливості Побудови Систем Електроживлення Інверсної Магнетронної Розпорошувальної Системи Для Формування Багатокомпонентних Покриттів (Практичні Аспекти Розробки Резистивних Ланцюжків У Складі Генератора Плазми)

Abstract

The consideration of the features of constructing the power supply system of a pilot industrial-technological installation for applying multicomponent coatings by the ion-plasma method is continued. The main attention is paid to the practical aspects of developing controlled resistive circuits connected to various elements of the power supply circuit of a technological plasma generator. It is noted that the control of the operation mode of the technological installation is provided by changing the resistance of these chains by the corresponding automated system. A mathematical expression is proposed in the form of a polynomial for the resistance of chains, which meets the requirements for a research installation and the condition for minimizing the number of resistors in a separate chain. The structure of the chain is considered as a combination of the required number of cells. Each of them differs from the others not only in the connection scheme of the resistors but also in their resistance. An algorithm is proposed for determining the nominal resistance, heat loss power, the number of resistors and the circuitry for their connection. For example, a diagram and the main technical characteristics of a chain connected to a group of target cathodes from tungsten are given. Such cathodes are used in the formation of nanostructured and multifunctional coatings of tungsten carbide on the surface of metal parts. Particular attention is paid to the control elements in the individual cells of the technological plasma generator. The analysis of requirements for control elements such as semiconductor switches and electromagnetic relays is carried out. It is noted that these requirements are met by conventional (not high-voltage) electromagnetic relays of domestic production, provided that their contacts are connected in series with each other. Attention is drawn to the need to prevent the formation of an electric arc when the relay contacts open, can be achieved by including a resistor and a capacitor in series with the control element. It is also important to use means of forced air cooling of the resistive chain block.