Implementation of variable frequency current meter by means of microcontroller

The article describes the stages of development of a variable-frequency current meter using a microprocessor based on STM32 for measurement tasks and subsequent analysis of the output current of the frequency converter.В статье описываются этапы разработки измерителя тока переменной частоты средствами микропроцессора на базе STM32 для задач измерения и последующего анализа тока на выходе преобразователя частоты

Micro-relief and roughness of the surface of the profiled sulfocation-exchange membrane after its contact with phenylalanine solution

The work was conducted under financial support of RFBR (project N 18-08-01260)

Study of strong photon-magnon coupling in a YIG-film split-ring resonant system

By using the stripline Microwave Vector Network Analyzer Ferromagnetic Resonance and Pulsed Inductive Microwave Magnetometry spectroscopy techniques, we study a strong coupling regime of magnons to microwave photons in the planar geometry of a lithographically formed split-ring resonator (SRR) loaded by a single-crystal epitaxial yttrium-iron garnet (YIG) film. Strong anti-crossing of the photon modes of SRR and of the magnon modes of the YIG film is observed in the applied-magnetic-field resolved measurements. The coupling strength extracted from the experimental data reaches 9 percent at 3 GHz. Theoretically, we propose an equivalent circuit model of an SRR loaded by a magnetic film. This model follows from the results of our numerical simulations of the microwave field structure of the SRR and of the magnetization dynamics in the YIG film driven by the microwave currents in the SRR. The equivalent circuit model is in good agreement with the experiment. It provides a simple physical explanation of the process of mode anti-crossing. Our findings are important for future applications in microwave quantum photonic devices as well as in magnetically tunable metamaterials exploiting the strong coupling of magnons to microwave photons

Toward the evaluation of the influence of temperature fluctuations on the durability of the stator winding insulation of asynchronous motors in random mode loading

В статье обсуждается влияние колебаний температуры обмотки электродвигателя на скорость старения изоляции обмотки статора асинхронного двигателя при работе в случайных режимах нагружения. Показано, что при определенных параметрах случайного режима работы срок службы изоляции может существенно снижаться, при этом широко используемый для оценки теплового состояния двигателя метод средних потерь дает оценку теплового состояния двигателя с существенной ошибкой.The influence of the stator winding temperature oscillation on the insulation-aging rate of the asynchronous motors stator winding in random mode loading. It is shown that under certain parameters of the random mode insulation durability can significantly decrease, wherein the widely used average loss method gives the evaluation of the motor thermal state with a substantial error.дна строка 10 pt

Direct Hopf Bifurcation in Parametric Resonance of Hybridized Waves

We study parametric resonance of interacting waves having the same wave vector and frequency. In addition to the well-known period-doubling instability we show that under certain conditions the instability is caused by a Hopf bifurcation leading to quasiperiodic traveling waves. It occurs, for example, if the group velocities of both waves have different signs and the damping is weak. The dynamics above the threshold is briefly discussed. Examples concerning ferromagnetic spin waves and surface waves of ferro fluids are discussed.Comment: Appears in Phys. Rev. Lett., RevTeX file and three postscript figures. Packaged using the 'uufiles' utility, 33 k

Clustering of 4A Type Induction Motors

Method of «4A» type induction motors clustering via k-means algorithm is proposed in this paper. Analysis of transient processes in the current loop for induction motors in one cluster, when the current regulator is tuned to the center of the cluster is carried out.В данной статье предложен вариант разбития двигателей серии 4А на кластеры с помощью алгоритма k-means (k -средних). Проведен анализ переходных процессов в контуре тока для двигателей, находящихся в одном кластере, при настройке регулятора тока на центр кластера

Resonant scattering of spin waves from a region of inhomogeneous magnetic field in a ferromagnetic film

The transmission of a dipole-dominated spin wave in a ferromagnetic film through a localised inhomogeneity in the form of a magnetic field produced by a dc current through a wire placed on the film surface was studied experimentally and theoretically. It was shown that the amplitude and phase of the transmitted wave can be simultaneously affected by the current induced field, a feature that will be relevant for logic based on spin wave transport. The direction of the current creates either a barrier or well for spin wave transmission. The main observation is that the current dependence of the amplitude of the spin wave transmitted through the well inhomogeneity is non-monotonic. The dependence has a minimum and an additional maximum. A theory was constructed to clarify the nature of the maximum. It shows that the transmission of spin waves through the inhomogeneity can be considered as a scattering process and that the additional maximum is a scattering resonance