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The results of the analysis of the features of the power exchange process in switched capacitors are presented. The methods are outlined to ensure high efficiency of charge pumping. The features of switching processes in transient operation modes are investigated. Circuit modeling made it possible to establish the sources of losses accompanying power conversion and heat release. The recommendations are made to optimize parameters of converter components and generate control signals.

The paper presents the results of a study of a combined DC input-to-bipolar output pulse converter using the single-ended primary inductor converter SEPIC/CuK buck-boost topology and features of switching processes in transient operating modes. Circuit modeling made it possible to specify the characteristics of switching processes, evaluate the parameters of the input current ripple, formulate recommendations for the selection of transducer elements, and form the control signals.

To solve an important problem associated with the provision of technological processes with modern temperature measurement tools, specific requirements were formulated with respect to the optical part of a pyrometer intended for measuring temperature in the measurement cavity of the tungsten–rhenium thermocouple calibration setup (up to 2200°С). In accordance with these requirements, the optical part of a commercial Termokont pyrometer has been reworked and experimentally tested.

The paper presents the results of studies of the operation of the inverting DC–DC converter with charge pump and LDO, which are part of the combined bipolar secondary power supply LM27762, at the near to maximum input voltage of 5.5 V and an output voltage of –4.9 V. The ripple voltages were measured at various load currents from 10 to 250 mA at the positive pole of the flying capacitor, at the output of the charge pump system and at the output of the microcircuit. It was shown for the first time on the basis of the obtained information that at low load currents up to about 107 mA the charge pump system operates in the burst mode, and at currents greater than 109 mA – in the charge pump mode with a constant frequency. The results do not confirm the information in the documentation on the microcircuit that, at themaximum input voltage of 5.5 V, the charge pump can enter the PWM mode in hot conditions. When working in burst mode, the presence of LDO in the LM27762 chip reduces the ripples of the negative voltage at the output. However, they significantly exceed the values given in the documentation on the chip. During switching to the constant–frequency mode, the level of negative voltage ripples at the output of the microcircuit decreases sharply, but it increases with further increase of the load current and exceeds the values given in the documentation.

The principle of recognition based on the use of the properties of a thin gas layer and the supporting surface of equipment, which provided the creation of a number of universal devices capable of solving the problem of sorting and culling piece parts by weight. A promising method of recognition by the generalized criterion (specific load) is presented on the basis of which two new orientation criteria were obtained (the area of the support surface of the product and its mass) are obtained on the basis of this method. It is proved that the gas layer has a high sensitivity to changes in the characteristic parameters of products, i. e. is able to recognize them. There is a need to develop automatic sorting and rejection devices for a class of small piece products with implicit design features and having understated physical and mechanical properties, as they can not apply to traditional means of automation, loading and orientation operations with mechanical grips, weighing in the stream. There are significant difficulties in the culling of piece products with bevels, shells, etc., which led to the creation of devices that provide manipulation of a wide variety of sizes of specific products with a decrease in dry mechanical friction between the product and the bearing parts of the equipment. Classification of specific product types and configurations of circuits pneumatic devices that use the effects in the thin gas bearing strata (the working surfaces and air chambers, view their movements, technological capabilities). The bases of recognition of products by mass on a gas layer with the use of various working surfaces, which formed the basis for the creation of a number of new sorting devices with a high level of flexibility, are proposed..

A non-contact method is proposed for measuring the surface temperature of an object using a standard radiator and standard object having optico-physical properties identical to those of the monitored object. Placed co-planarly with the monitored object in the field of view of an optoelectronic system (OES) is a standard object, the temperature of which is regulated and measured, and a standard radiator, whose normal spectral emissivity and temperature are known. In addition, the OES has its three fixed points, at which it registers the normal emissivity of the standard object, monitored object, and standard radiator (SR). The main distinction of the proposed method from the known ones is that the limits or tolerances for the nature of reflection and the quantitative parameters of reflection of the monitored object make no difference. The obtained analytical expression is an equation of the non-contact method of measuring the surface temperature of the monitored object, which can be applied for any spectral range of operation of the OES. A metrological analysis of the proposed method is made using a monochromatic optoelectronic system working at wavelengths of 0.65, 2.0, 5.0, 14.0, and 50.0 p,m for the temperature of the monitored object, T, equals to 400, 700, and 1000 K. Based on the analysis of the results the requirement for the implementation of the proposed method of measuring the surface temperature has been formulated, which says that the choice of an optoelectronic system for measuring the surface temperature of objects should be preceded by a methodological and metrological analysis of the optico-physical properties of the monitored object, the surrounding background, and the OES itself.

In spectroscopy, hollow cathode lamps are subject to increased requirements for radiation parameters. To check spectrometric equipment, it is necessary to create a highly stable source of spectral lines, the intensity of which on the given spectral lines will remain unchanged (≤1%) for a long time. A solution to this problem is proposed, and a scheme of an experimental test bench for a hollow cathode lamp with an optical-electronic negative feedback loop is presented. The feedback signal controls the current source, which is a functional unit of a specialized power supply unit and generates an electric current flowing through the lamp. The results of an experimental study with an appropriate metrological analysis are presented. The proposed technical solution to build a stable source of spectral lines allowed us to obtain a high level of stability of spectral lines in both the short and long term.

It is shown that the Electronics Workbench (EWB) software can be used to analyze working regimes of a high-power device and minimize switching loss. Problems of measurement of parameters of high-power devices based on FETs from the EWB library needed for development of control circuits are considered.

One of the topical areas of theoretical and experimental research is the analysis, modeling and synthesis of technical systems with probabilistic interactions of elements. The work is devoted to the development of simulation models for the study of one class of such systems - network management systems. As data transmission channels, such systems use industrial or public digital computer networks. The use of computer networks in control systems leads to new problems: random time delay in the transmission process, the likely loss of the data packet, the possibility of asynchronous operation of the elements of the system. Not taking these factors into account can lead to a loss of sustainability of the management system. To study these problems, it is proposed to use simulation models of appropriate control systems. In the work, simulation models for a digital control system without delay in the transmission channel, a network management system with a network communication channel between the sensor and the controller have been developed. In this case, cases are considered where the transmission time on the network channel does not exceed the quantization clock time and when the transmission time over the network channel may exceed the quantization clock time. For the cases considered, appropriate simulation models have been developed. When simulating a network management system in which the transmission time of a data packet over a network channel could exceed the time of a quantization clock, it was assumed that the sensor and the controller have an infinitely large buffer. For simplicity of modeling, it was assumed that if a data packet from a digital sensor is not transmitted in one clock cycle to the controller, it is placed in the sensor buffer. With the possible transfer of data over the channel, all packets from the sensor buffer are transferred to the controller buffer. It was assumed that the controller processes incoming data from the buffer sequentially – one packet per quantization cycle. To simulate such situations it was suggested to use the corresponding developed random processes. Simulation of the functioning of digital and network control systems was carried out in the Simulink environment of the Matlab system.

Catalytic dehydrogenation of ethylbenzene charge in a two-stage continuous-action adiabatic reactor is the main stage of the styrene production process. The analysis of this technological process existing automated control systems revealed the following main drawback, that these systems require great efforts from production personnel to ensure a change of the reactor temperature regime in the stages of the reactor in accordance with styrene concentration drop, which is caused by deactivation catalytic layer deactivation. Therefore, the synthesis of the target product concentration at the reactor outlet predictive control system is actual task in the field of technical cybernetics. This article presents the system analysis results of the dehydrogenation reactor as a control object. The main research result is a method choice for controlling of the chemical transformations temperature regime in the reactor, using that, it is possible to increase the energy efficiency and productivity of this device. The general and specific tasks of the control system synthesis are formulated on the basis of the system analysis, the information and functional synthesis of the temperature regime ACS is produced, the information and functional schemes of the reactor unit process equipment control subsystems are developed. As an operating system ACS is selected, which realizes of steam-ethylbenzene mixture temperature change at the reaction zones entrances of the 1st and 2nd reactor sections in accordance with the program control algorithm on the basis of predicting models, describing the heat exchange processes occurring inside the reactor stages as well as the dynamics of changes in such parameters as the concentration of coke deposits, catalyst activity, the basic and by- products concentration of chemical reactions.

The world of Internet globally is changing communication in the information environment of companies. Nearly every educational organization currently has a formal the Internet site. In recent years began to develop industry site building. However, it should be noted that the development of sites, in many cases, bases on personal views and emotions of the customer and the developer. The use of this approach works well when creating simple sites. In this connection it is necessary to use when you design educational organization (EO) site fundamentals and concepts of the theory of semantic information systems. In this article presents the main provisions and concepts of the semantic information systems. On the basis of that educational organization is considered as a semantic information system and its official web-resource is presented in the form of a complex multi-level information system, which consists of information objects sets and semantic chains. The target environment of educational organization information objects in the form of the main enlarged groups. The analysis of the semantic target information at groups of users. The main homogeneous and complex forms of semantic information are listed and proposed concept of semantic chains. Following is an example of the process of informing the applicant on the website EO. The time diagram of site visits by main users subgroups is given, by means of which substantiated the basic principles of development of the menu and site navigation. It identifies directions of development of educational organization as part of the electronic information educational environment.

The Stefan–Boltzmann law for the integral radiation flux was analytically and mathematically exactly derived based on Planck’s law for the spectral radiation flux of an object.

A contactless method is presented for measuring the surface temperature of radioelectronics objects from their own infrared radiation. Metrological analysis of the contactless method was executed using the small perturbations method.

A mathematical description of the time dependence of the technological properties (Mooney viscosity, processability factor) and structural characteristics (molecular weight and molecular weight distribution parameters) based experimental study of the degradation of polymer in bulk, has been developed. Samples of a butadiene-styrene copolymer with different contents of a high-molecular fraction introduced for varying initial Mooney viscosity have been studied. The processing properties of the polymer have been monitored using rotational viscosimetry. The rate constants of degradation have been estimated. The obtained dependences can be used both to create polymer compositions with controlled properties and to develop process control systems. The developed mathematical description is based on both controllable and control parameters (initial, current and limit viscosity, temperature, concentration of the macroradicals, the activation energy, and the constants of the degradation rate at different stages of the process, etc.).

A procedure for calculating thermophysical parameters of vulcanizable mixtures from experimental data obtained by a laboratory unit developed by us is discussed. The procedure is based on a mathematical model in the form of a heat conduction equation that takes account of the dependence of heat capacity and heat conductivity coefficients of the medium on the temperature. The values of thermophysical parameters are determined by minimizing the functional discrepancy between measured and calculated temperatures with a ±2°C standard deviation.

Mathematical models relating ultrasonically measured velocities and attenuation coefficients of sound to the basic physical and mechanical properties of rubbers were considered. The models were used for the development of methods for express quality assessment of rubber wastes. A compact universal minilaboratory for express analysis of rubber properties based on ultrasonic non-destructive control methods was offered.

The study tested output voltage pulsations and pulsations of voltage on a flying capacitor when MAX 1759 integrated circuit of DC-DC converter is pumped in a voltage boost mode with an output voltage of 3.6V and 5.2V at an input voltage of 3.2V and a load current in the range of 5...100 mA. The analysis of the results obtained shows that the hysteresis comparator is the basis for the charge pump control. The algorithm for operating the charge pump system is described for the first time in detail

Measurement of the frequency dependence of the fluctuation rejection ratio produced by the microcircuits of linear voltage stabilizers by means of a modern oscillograph and generator without the use of special expensive equipment is investigated. The effect of the amplitude of the sinusoidal probe voltage to induce distortion of the form of the output signal of the stabilizer at different frequencies is studied. Questions related to the possible influence of the automatic scanning options and the lay-out and configuration of the printed board as well as the types, ratings, and assembly of the capacitors on the measurement results are considered.

The work focuses on analyzing the modern process control systems in the food and agricultural industries for improving management quality. Computer simulation of the control systems with a network channel for transmitting information was carried out for various volumes of data buffers for system elements. The subject of the investigation is to study the effect of data buffering on the quality of process control for systems with a limited buffer volume for data packets. It is assumed that the transmission of a data packet over a network channel during the quantization period is carried out with a given probability. If the data packet from the digital sensor is not transmitted in one quantization cycle to the controller, then it is placed in the sensor buffer. When data is transmitted over the channel, all packets from the sensor buffer are transferred to the controller buffer. The controller processes the incoming data from the buffer sequentially–one packet per quantization cycle. For simulate such situations, it was proposed to use the corresponding developed random processes. The innovation of the developed simulation models is in the fact that the development of the simulation models is based on modelling the time gap of the information data stream. Modelling the functioning of the network control system was carried out in the Simulink environment of the Matlab system.

A mathematical model of the process of extraction of vegetable oil by an organic solvent for a separate section of the extractor with irrigation has been developed. The model is intended for the synthesis of an automatic control system. A description of the change in the oil concentration in the oilcake along the length of the extraction section and in the miscella for a steady-state operation is obtained. And a system of independent differential equations with a delayed argument is obtained that connects deviations from the nominal oil concentrations in the oilcake and miscella at the outlet of the section with flow deviations and oil concentrations at the inlet of the section. The transition from partial differential equations to equations with a delayed argument will reduce the time spent on calculating the adjustable parameters of the control system during its synthesis.

Styrene synthesis process occurring in a two-stage continuous adiabatic reactor is a complex chemical engineering system. It is characterized by indeterminacy, nonstationarity and occurs in permanent uncontrolled disturbances. Therefore, the task of developing the predictive control system of the main product concentration of the dehydrogenation reaction - styrene to maintain this value within a predetermined range throughout the period of operation is important. This solution is impossible without the development of the process model on the basis of the kinetic revised scheme, taking into account the drop of the reactor catalytic bed activity due to coke formation on the surface. The article justifies and proposes: the drop changes dependence of catalyst bed activity as a time of reactor block operation function and improved model of chemical reactions kinetics. The synthesized mathematical model of the process is a system of ordinary differential equations and allows you: to calculate the concentration profiles of reaction mixture components during the passage of the charge through the adiabatic reactor stage, to determine the contact gas composition at the outlet of the reactor stages throughout the cycle of catalytic system, taking into account temperature changes and drop of the catalyst bed activity. The compensation of the decreased catalyst bed activity is carried out by raising the temperature in the reactor block for the duration of the operation. The estimation of the values of chemical reactions rate constants, as well as the calculation and analysis of the main and by-products concentrations of dehydrogenation reactions at the outlet of the reactor plant is curried out. Simulation results show that the change of temperature of the reactor, carried out by the exponential law considering deactivation of the catalyst bed allows the yield in a given range of technological regulations throughout the operation cycle of the reactor block.

The paper deals with the problem of mathematical modeling of thermochemical destruction process. The apparatus of Markov's chains is used to synthesize a mathematical model. The authors of the study suggest to consider the destruction process as a random one, where the system state changes, which is characterized by the proportion of macromolecules in each fraction of the molecular- and weight distribution. The intensities of transitions from one state to another characterize the corresponding rates of destruction processes for each fraction of the molecular- and weight distribution. The processes of crosslinking and polymerization in this work were neglected, and it was accepted that there is a probability of transition from any state with a lower order index (corresponding to fractions with higher molecular weights) to any state with a higher index (corresponding to fractions with lower molecular weights). Markov's chain with discrete states and continuous time was taken as the mathematical model basis. Interactive graphical simulation environment MathWorksSimulink was used as a simulation environment. Experimental studies of polybutadiene destruction in solution were carried out to evaluate the mathematical model parameters. The GPC (gel-penetration chromatography) data of the polybutadiene solution were used as the initial (starting) data for estimating the polymer WMD (molecular weight distribution). Mean-square deviation of the calculated data from the experimental data for each fraction and at specified times was minimized for the numerical search of parameter values. The results of comparison of experimental and calculated on mathematical model data showed an error of calculations on the average about 5%, which indicates an acceptable error in estimating of polymer fractions proportions change during the process of destruction for the process under consideration and conditions.

Analytical study of the processes of heat conduction is one of the main topics of modern engineering research in engineering, energy, nuclear industry, process chemical, construction, textile, food, geological and other industries. Suffice to say that almost all processes in one degree or another are related to change in the temperature condition and the transfer of warmth. It should also be noted that engineering studies of the kinetics of a range of physical and chemical processes are similar to the problems of stationary and nonstationary heat transfer. These include the processes of diffusions, sedimentation, viscous flow, slowing down the neutrons, flow of fluids through a porous medium, electric fluctuations, adsorption, drying, burning, etc. There are various methods for solving the classical boundary value problems of nonstationary heat conduction and problems of the generalized type: the method of separation of variables (Fourier method) method; the continuation method; the works solutions; the Duhamel's method; the integral transformations method; the operating method; the method of green's functions (stationary and non-stationary thermal conductivity); the reflection method (method source). In this paper, based on the consistent application of the Laplace transform on the dimensionless time θ and finite sine integral transformation in the spatial coordinates X and Y solves the problem of unsteady temperature distribution on the mechanism of heat conduction in a parallelepiped with boundary conditions of first kind. As a result we have the analytical solution of the temperature distribution in the parallelepiped to a conductive mode free convection, when one of the side faces of the parallelepiped is maintained at a constant temperature, and the others with the another same constant temperature.

Summary. Control systems using a network channel for communication between the elements are called network management systems. Using networks to connect geographically distributed components of the system has a number of advantages, such as reducing the cost of system installation, compact size and weight, ease of diagnostics and system maintenance, and increased flexibility. Nevertheless, the use of networks has also created new problems that did not exist in conventional control systems. These issues should include a random time transmission over the network from one device to another network device, possible loss of data packets during transmission, an asynchronous mode of operation control system components. Network features make analysis, modeling, and management of network management systems more complex and difficult task. This complexity is due primarily to the fact that such systems require complex research, including research on the theory of communication and control theory. One of the challenges in the modeling of management systems, is a simulation of the transmission channel. In this paper we propose an approach for modeling the particular case of the transfer process. Considered a network channel with a random delay and packet loss. It is assumed that the channel can simultaneously transmit multiple data packets. Time delay is modeled random distribution law Erlang appropriate order. The probability of packet loss depends on the arrival rate of data packets in the channel transmission and the parameters of the law Erlang distribution. A model of the channel as a series connection of discrete elements. Discrete produce independent quantization of the input signal. This representation allows to model the random data. The formula for determining the probability of packet loss during transmission.

Summary. In operation of industrial pyrolysis furnaces, the main task is the selection of the optimal mode of thermal decomposition of the feedstock, depending on the yield of the desired products under conditions of technological limitations on the process. To solve this problem for an operating reactor, this paper considers the SRT-VI Large-Capacity industrial Furnace , the mathematical model of the pyrolysis process was constructed, using a kinetic scheme which consists of primary reaction of decomposition of raw materials and secondary elementary reactions of interaction of the considered mixture components, the heat balance equation and hydrodynamics of flow in the coil. The raw material for the selected installation type is naphtha (straight-run petrol). Output parameters of the model are the molar costs of marketable hydrocarbons. The reactor is described by the equation of ideal displacement in the static mode of operation. It is assumed that all reactions have a temperature dependence that follows the Arrhenius law. The activation energies of chemical processes were estimated using the PolanyiSemenov equation and identification of pre-exponential factors was carried out using a genetic algorithm (GA). This task requires solving simultaneous system of differential equations describing the pyrolysis process and a search for a large number of unknown parameters, and therefore it is proposed to modify the GA. Optimal scheme includes Gray encoding arithmetic operators, tournament selection, with tournament ranking more than 4, crossover with partial random choice of alleys, mutations with a high probability of occurring and elitism with competitive global competition. Using the proposed approach, the parametric identification of model process is accomplished. The analysis of the simulation results with the data of operating reactor showed its suitability for use in order to control the pyrolysis process.

The article is devoted to the mathematical modeling of the kinetics of ethyl benzene dehydrogenation in a two-stage adiabatic reactor with a catalytic bed functioning on continuous technology. The analysis of chemical reactions taking place parallel to the main reaction of styrene formation has been carried out on the basis of which a number of assumptions were made proceeding from which a kinetic scheme describing the mechanism of the chemical reactions during the dehydrogenation process was developed. A mathematical model of the dehydrogenation process, describing the dynamics of chemical reactions taking place in each of the two stages of the reactor block at a constant temperature is developed. The estimation of the rate constants of direct and reverse reactions of each component, formation and exhaustion of the reacted mixture was made. The dynamics of the starting material concentration variations (ethyl benzene batch) was obtained as well as styrene formation dynamics and all byproducts of dehydrogenation (benzene, toluene, ethylene, carbon, hydrogen, ect.). The calculated the variations of the component composition of the reaction mixture during its passage through the first and second stages of the reactor showed that the proposed mathematical description adequately reproduces the kinetics of the process under investigation. This demonstrates the advantage of the developed model, as well as loyalty to the values found for the rate constants of reactions, which enable the use of models for calculating the kinetics of ethyl benzene dehydrogenation under nonisothermal mode in order to determine the optimal temperature trajectory of the reactor operation. In the future, it will reduce energy and resource consumption, increase the volume of produced styrene and improve the economic indexes of the process.

The paper deals with the possibility of determining homogenization degree of milk and dairy products using ultrasonic vibrations absorption spectra. Advantages of this method application in automated manufacturing systems were examined. Theoretical background of the method, as well as the possibility of determining the distribution of the fat globules in milk, depending on their sizes were substantiated. We derived mathematical equations, showing the relationship between the homogenization degree of dairy products and the acoustic properties of the medium, such as the propagation velocity of ultrasonic vibrations in the medium tested and the absorption coefficient in the medium at a specific frequency of the ultrasonic impact and medium temperature. It was shown that the measurement of the propagation of the milk acoustic properties in frequency, evaluation of their density function of the relaxation times spectrum, and then from the relaxation times to the particles masses allow operational control of the fat globules masses distribution in fractions. Theoretical studies were confirmed by experimental research carrying out whose results demonstrate clearly the dependence of absorption degree of ultrasonic vibrations on the degree of milk homogenization. The dependence between the estimates of the relaxation spectra and the first two moments of the statistical distribution of milk fat globules, which demonstrated their relationship was studied. Possible improvements the method under consideration to increase the reliability of the results obtained were proposed.