The system of automatic control of the substrate temperature in the installation for the production of film material spray pyrolysis method

A system of automatic control of the substrate temperature is proposed, which ensures the required accuracy of temperature maintenance and its minimum gradient over the surface when obtaining transparent conductive coatings by spray pyrolysis. During pyrolysis, aerosol droplets are transferred to a heated substrate; at the right temperature, they decompose, and then synthesize or melt on a hot substrate. The ideal temperature regime for evaporation of aerosol droplets will be the mode when a drop appears at the substrate immediately after evaporation of the solvent from it. Precise control of the substrate temperature and temperature gradient ensures this mode. The functional scheme of the proposed automatic control system consists of an automatic temperature controller, a power regulator, an infrared heater on halogen lamps, and a temperature sensor. The variational problem of minimizing power consumption when the infrared heater is turned on has been solved. This activation eliminates current emissions and thereby increases the service life of the heater. It is proposed to connect the heater to a current source in order to eliminate current emissions, thereby ensuring the optimal switching mode. The synthesis and analysis of the specified automatic control system has been performed, its time and frequency parameters have been calculated. Acceptable performance, zero static control error and zero overshoot, a significant margin of stability in phase and amplitude have been confirmed. The use of such an automatic temperature control system contributes to the creation of an optimal mode of evaporation of aerosol droplets, allows you to stabilize the substrate temperature and temperature gradient, thereby ensuring the stability of the characteristics of the resulting films. The investigated transparent conductive coatings are part of glasses with adjustable transparency, and are also used as layers of solar cells.