Design of a digital control system of disk gyroscope with orthogonal control circuit

This paper introduces a gyro control system with the quadrature control circuit. The control system realizes the automatic decoupling of driving mode and sensing mode. The quadrature control circuit eliminates the quadrature signal in the sensitive mode by applying a voltage to the quadrature control electrode. The time needed to adjust the voltage can be changed by adjusting the parameters of the controller. The control system is realized by a digital circuit. The feasibility of the design is verified by the test.

DESIGN FEATURES AND THE TIME CHARACTERISTICS OF THE RAIL FOUR-CHANNEL SPARK GAP WITH FIELD DISTORTION

The article discusses the design features of a four-channel rail arrester with field distortion and the results of the study of its time characteristics. The need for this work related to the development of such dischargers due to the lack of their analogues is due to the widespread use of capacitive energy storage devices as power sources for electrodynamics mass accelerators. At the present stage of development of science and technology, the use of such accelerators is the most promising for creating experimental stands for modeling in laboratory conditions the processes of high-speed interaction of aircraft structural elements with particles of different masses and different origins. According to the operating conditions of the experimental stands and a wide range of changes in both particle masses and interaction velocities, the amplitude values of currents through the low-inductive load of the mass accelerator vary from hundreds of kilo amperes to several million amperes at acceleration times from units to hundreds of microseconds. With this in mind, capacitive energy storage devices are made in a multi-module design. Each module is switched to the load by its own switch. To extend the range of operation of the drive, provide the required erosion resistance of the electrodes of the switch, the stability of the discharge formation at parallel operation of switches developed construction of a rail four-channel spark gap with the distortion field, experimental and theoretical study of the effect of the ratio of the geometric dimensions of the inter electrode gap for obtaining small values for the delay time of the discharge. As a result of the research, it is shown that the value of the delay time tzap depends on the shape and diameter of the main electrodes, the material of the electrodes, the distance between the main and the control electrode, the threshold voltage, as well as the degree of inhomogeneity of the field in the inter electrode gap. The obtained analytical expressions allow us to determine the values of threshold stresses and delay times, taking into account the statistical delay time and the time of discharge formation. It is established that the value of the delay time is significantly affected by the field inhomogeneity coefficient and the configuration of the control electrode. It is noted that when the operating voltage on the arrester exceeds the threshold voltage, the delay time of the switch lies in the nanosecond region. The value of the threshold voltage Upor, at which the process of direct transformation of the streamer into a spark discharge with high conductivity, followed by a breakdown of the inter electrode gap, is determined.

Оптимизация анодной мембраны с прострельной мишенью в системе источников мягкого рентгеновского излучения для проведения процессов рентгеновской нанолитографии

In this paper, we propose a method for optimizing the design and composition of the anode membrane with a transmission-type target as part of a system of soft X-ray sources based on field-emission triodes for performing tasks in the field of X-ray nanolithography. It allows to prevent the degradation of the operating characteristics of the system when significant electrostatic deformation of the anode occurs under the influence of a control electric field in the inter-electrode space of the triodes. For this purpose, the inclusion of an additional control electrode in the system design is considered, which makes it possible to compensate for the deformation of the anode membrane to an acceptable level and thereby stabilize the operation of X-ray sources. A numerical model of the electrostatic deflection of the anode assembly in a modified design is developed, based on which the optimal composition and geometric parameters of the anode membrane with a compensating electrode are determined. In particular, the optimal distance between the anode membrane in the initial (undeformed) state and the compensating electrode was found (equal to 5 μm), at which a minimum voltage difference (about 1.15 kV) should be applied to these electrodes to prevent critical deflection of the membrane (0.72 μm with a membrane radius of 750 µm). It is also shown that, due to their extremely high hardness (>80 GPa), diamond-like films are the most promising material for the anode electrode. The results obtained can also be useful for the development of miniature X-ray generation devices for various applications.

Selection of electrodes for monitoring protection systems of ships’ steel hulls and machinery

The article considers the problems of ship structures exposed to adverse conditions, which contribute to the failure of important mechanisms and reduce the service life of steel parts of machines. One of the most important reasons for the ship structures wear is corrosion. The experience of choosing the electrodes to control the sacrificial protection systems on board ships is presented. There are presented the results of measuring the potential of the hull of the boat ROOM 52-22 at a given control point, using a multimeter MASTECH MY 62 and two control electrodes. The first control electrode is of in-house design; it was made of electric carbon product for electric machines. A standard portable silver chloride reference electrode was used as a second electrode. Both electrodes have been in operation for 3 years. The vessel under consideration was in a long-term parking mode. Control measurements were performed from 23.05 - 07.07.2019, while monitoring the potential of the hull three times a day using several parallel measurements. The time interval between parallel potential measurements made ≈ 5 seconds. The potential of the hull was measured by a specially trained operator. The accuracy of measurements was estimated using the coefficient of variation. Analysis of the studies justified that the accuracy of the control results of the protective anticorrosion systems on ships depends on the choice of the type of control electrode. It has been found that the efficiency of the silver chloride electrode has a strong impact on its operation life. The results of full-scale corrosion studies can be used by ship crews to justify the selection of control electrodes.

A novel multiple-axis MEMS gyroscope-accelerometer with decoupling frames

Purpose Technological capabilities of manufacturing microelectromechanical system (MEMS) gyroscopes are still insufficient if compared to manufacturing high-efficient gyroscopes and accelerometers. This creates weaknesses in their mechanical structure and restrictions in the measurement accuracy, stability and reliability of MEMS gyroscopes and accelerometers. This paper aims to develop a new architectural solutions for optimization of MEMS gyroscopes and accelerometers and propose a multi-axis MEMS inertial module combining the functions of gyroscope and accelerometer. Design/methodology/approach The finite element modeling (FEM) and the modal analysis in FEM are used for sensing, drive and control electrode capacitances of the multi-axis MEMS inertial module with the proposed new architecture. The description is given to its step-by-step process of manufacturing. Algorithms are developed to detect its angular rates and linear acceleration along three Cartesian axes. Findings Experimental results are obtained for eigenfrequencies and capacitances of sensing, drive and control electrodes for 50 manufactured prototypes of the silicon electromechanical sensor (SES). For 42 SES prototypes, a good match is observed between the calculated and simulated capacitance values of comb electrodes. Thus, the mean-square deviation is not over 20 per cent. The maximum difference between the calculated and simulated eigenfrequencies in the drive channel of 11 SES prototypes is not over 3 per cent. The same difference is detected for eigenfrequencies in the first sensing channel of 17 SES prototypes. Originality/value This study shows a way to design and optimize the structure and theoretical background for the development of the MEMS inertial module combining the functions of gyroscope and accelerometer. The obtained results will improve and expand the manufacturing technology of MEMS gyroscopes and accelerometers.

Chemical delivery array with millisecond neurotransmitter release

Technologies that restore or augment dysfunctional neural signaling represent a promising route to deeper understanding and new therapies for neurological disorders. Because of the chemical specificity and subsecond signaling of the nervous system, these technologies should be able to release specific neurotransmitters at specific locations with millisecond resolution. We have previously demonstrated an organic electronic lateral electrophoresis technology capable of precise delivery of charged compounds, such as neurotransmitters. However, this technology, the organic electronic ion pump, has been limited to a single delivery point, or several simultaneously addressed outlets, with switch-on speeds of seconds. We report on a vertical neurotransmitter delivery device, configured as an array with individually controlled delivery points and a temporal resolution of 50 ms. This is achieved by supplementing lateral electrophoresis with a control electrode and an ion diode at each delivery point to allow addressing and limit leakage. By delivering local pulses of neurotransmitters with spatiotemporal dynamics approaching synaptic function, the high-speed delivery array promises unprecedented access to neural signaling and a path toward biochemically regulated neural prostheses.

Ceramic Materials for the Low-Temperature Synthesis of Dielectric Coatings Used in Electronics, Led Devices and Spacecraft Control Systems

The sol-gel synthesis of filled aluminosilicates (FAS) has been developed. Such FAS consist of dendrimer morphology macromolecules capable to accommodate as a filler up to 70 % wt of high-refractory nitrides and oxides of high-melting compounds. The study of the obtained ceramic coatings on the developed metal surfaces has showed their use prospects to develop an ion beam control electrode in the ion plasma machine, microelectronics, and LED technology.