scholarly journals Analysis and Study of Designs of Sensing Elements of Speed Sensors Based on the Wiegand Effect

2021 ◽  
Vol 2096 (1) ◽  
pp. 012131
Author(s):  
P G Mikhailov
Keyword(s):  
Magnetic Layer ◽  
Magnetic Domain ◽  
Hysteresis Loops ◽  
Pulse Mode ◽  
Magnetic Pulse ◽  
Space Technology ◽  
Instrument Making ◽  
Speed Sensor ◽  
Wide Range ◽  
The Wire

Abstract Speed sensors are used in various products and systems of mechanical engineering, instrument making, flight and rocket and space technology. At the same time, the main requirements for such sensors include a wide range of measured revolutions, from almost zero to several thousand revolutions per minute. Another requirement is a range of operating temperatures, ranging from cryogenic to temperatures of several hundred degrees. In this case, a prerequisite should be a generator method of conversion, in which energy is not consumed from the outside, but it is generated during the operation of the sensor. The principle of operation of the speed sensor is based on the magnetic pulse mode, in which a private hysteresis loop is formed. The generation of such a characteristic is possessed by mechanically and thermally treated wire made of cobalt-iron-vanadium alloy 52K9F of uniform composition. As a result, the wire acquires a composite magnetic structure consisting of an external hard magnetic layer - a shell, a central soft magnetic layer and an intermediate layer. The layers have different properties, due to which the hysteresis loops of the Wiegand wire have a complex shape. A distinctive feature of the loops is the presence of practically vertical sections of magnetization change - discontinuities corresponding to an abrupt change in the magnetization of the material. The large discontinuity on the loops arises due to the so-called "Barkhausen jump", caused by an almost ideal single magnetic domain stretched along the axis of the wire in its core.

scholarly journals Magnetic Structure of Ion-Beam Imprinted Stripe Domains Determined by Neutron Scattering

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 752 ◽  
Author(s):  
Thomas Saerbeck ◽  
Henning Huckfeldt ◽  
Boris P. Toperverg ◽  
Arno Ehresmann
Keyword(s):  
Magnetic Structure ◽  
Layer Structure ◽  
Ion Beam ◽  
Quantitative Description ◽  
Magnetic Layer ◽  
Magnetic Domain ◽  
Quantitative Information ◽  
Magnetic Vector ◽  
Stripe Domain ◽  
Magnetization Direction

We present a detailed analysis of the in-plane magnetic vector configuration in head-to-head/tail-to-tail stripe domain patterns of nominal 5 μm width. The patterns have been created by He-ion bombardment induced magnetic patterning of a CoFe/IrMn3 exchange bias thin-film system. Quantitative information about the chemical and magnetic structure is obtained from polarized neutron reflectometry (PNR) and off-specular scattering (OSS). The technique provides information on the magnetic vector orientation and magnitude along the lateral coordinate of the sample, as well as the chemical and magnetic layer structure as a function of depth. Additional sensitivity to magnetic features is obtained through a neutron wave field resonance, which is fully accounted for in the presented analysis. The scattering reveals a domain width imbalance of 5.3 to 3.7 μm of virgin and bombarded stripes, respectively. Further, we report that the magnetization in the bombarded stripe significantly deviates from the head-to-head arrangement. A domain wall of 0.6 μm with homogeneous magnetization direction is found to separate the two neighboring domains. The results contain detailed information on length scales and magnetization vectors provided by PNR and OSS in absolute units. We illustrate the complementarity of the technique to microscopy techniques for obtaining a quantitative description of imprinted magnetic domain patterns and illustrate its applicability to different sample systems.

Absorption and Scatter Corrections for Transflectance Measurements in Nonhomogeneous Fiber Samples

1998 ◽  
Vol 6 (A) ◽  
pp. A35-A44 ◽  
Author(s):  
R.A. Taylor
Keyword(s):  
High Speed ◽  
Near Infrared ◽  
Light Transmission ◽  
Accurate Determination ◽  
Fiber Optic Sensor ◽  
Infrared Light ◽  
Specimen Preparation ◽  
Absorption Bands ◽  
Speed Sensor ◽  
Wide Range

A new fiber optic sensor was developed to measure the mass of optically thin cotton samples by integrating light transmission and reflectance signals. High speed measurements of cotton strength requires an accurate determination of the specimen mass without use of laborious cut-and-weigh methods. A previous high speed sensor measured changes in visible light transmission which required secondary measurements of fiber fineness to adjust the data for light scattering. Fiber orientation also affected scattering which required a precise control on specimen preparation. The new sensor measures fiber specimen transflectance using near infrared light. Because cellulose (the basic compound in cotton) exhibits strong absorption bands, its concentration can be accurately measured using near infrared absorbance. In this report we show that an integratinq sensor gave the best measurement of cotton fiber mass. Additionally, we demonstrated its accuracy over a wide range of fiber orientations using a novel fiber specimen tension experiment.

ACHIEVING A LINEAR DOSE RATE RESPONSE IN PULSE-MODE SILICON PHOTODIODE SCINTILLATION DETECTORS OVER A WIDE RANGE OF EXCITATIONS

2014 ◽  
Vol 27 ◽  
pp. 1460136
Author(s):  
LEWIS CARROLL
Keyword(s):  
Signal Processing ◽  
Dose Rate ◽  
Pulse Generator ◽  
Current Mode ◽  
Pulse Mode ◽  
Radioactive Material ◽  
Activity Levels ◽  
Silicon Photodiode ◽  
Processing Scheme ◽  
Wide Range

We are developing a new dose calibrator for nuclear pharmacies that can measure radioactivity in a vial or syringe without handling it directly or removing it from its transport shield “pig”. The calibrator's detector comprises twin opposing scintillating crystals coupled to Si photodiodes and current-amplifying trans-resistance amplifiers. Such a scheme is inherently linear with respect to dose rate over a wide range of radiation intensities, but accuracy at low activity levels may be impaired, beyond the effects of meager photon statistics, by baseline fluctuation and drift inevitably present in high-gain, current-mode photodiode amplifiers. The work described here is motivated by our desire to enhance accuracy at low excitations while maintaining linearity at high excitations. Thus, we are also evaluating a novel “pulse-mode” analog signal processing scheme that employs a linear threshold discriminator to virtually eliminate baseline fluctuation and drift. We will show the results of a side-by-side comparison of current-mode versus pulse-mode signal processing schemes, including perturbing factors affecting linearity and accuracy at very low and very high excitations. Bench testing over a wide range of excitations is done using a Poisson random pulse generator plus an LED light source to simulate excitations up to ∼106 detected counts per second without the need to handle and store large amounts of radioactive material.

scholarly journals The deformation rate, atomic mobility and mechanical properties of metals

2021 ◽  
Vol 97 (1) ◽  
pp. 28-37
Author(s):  
D.S. Gertsriken ◽  
◽  
A.M. Husak ◽  
V.F. Mazanko ◽  
S. Ye. Bogdanov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Diffusion Coefficients ◽  
Mechanical Characteristics ◽  
Radioactive Isotopes ◽  
Diffusion Welding ◽  
Magnetic Pulse ◽  
Layer By Layer ◽  
Self Diffusion ◽  
Wide Range ◽  
The Difference

The dependences of diffusion coefficients in metals with different crystal lattice (b.c.c., f.c.c., h.c.p., b.c.t.), subjected to pulse effects by different types of processing in a wide range of strain rates (10-2 - 106 s-1) without heating and at T < 0,5 Tpl. studied by m ethods based on the use of radioactive indicators 55Fe, 95Nb, 60Co, 65Zn, 63Ni, 26Al, 44Ti (layer-by-layer radiometric analysis of residual integral activity, macro- and microautoradiography). Used such types of processing as ultrasonic shock treatment, diffusion welding, shock load, magnetic pulse processing, etc. On the same materials subjected to the same types of processing, mechanical characteristics (impact strength, microhardness, tensile strength, etc.) were determined. In addition, literature data related to the determination of some mechanical characteristics in the deformation of metals at different speeds were used. It turned out that with increasing the rate of plastic deformation there is not only an increase in the mobility of atoms, but also a decrease in differences in the values of the diffusion coefficients of intrinsic atoms and other diffusers in different metals. Despite the large difference in melting temperatures, in particular zinc and niobium, their self-diffusion coefficients in the migration of atoms without heating at a rate of 106 s-1 differ only 1.5 times, while at 1 s-1 the difference in the mobility of atoms is 4 orders of magnitude. It is shown that the velocity dependences of diffusion and mechanical characteristics can be rectilinear, have extremum or inflection, but they will be approximately the same for diffusion coefficients and parameters that characterize the mechanical properties of metals under impulse loads. Establishing the type of velocity dependences for diffusion and mechanical characteristics makes it possible to determine intermediate and extrapolated values for both characteristics, as well as on the schedule of one dependence to predict the shape of the other with a certain accuracy. Keywords: radioactive isotopes, self- and heterodiffusion, pulse loads, strain rate, mechanical characteristic.

scholarly journals POWER SUPPLY FOR THE INVESTIGATION OF PULSE ELECTROCHEMICAL PROCESSES

2018 ◽  
Vol 61 (3) ◽  
pp. 246-257 ◽  
Author(s):  
Yu. G. Aliakseyeu ◽  
A. Yu. Korolyov ◽  
V. S. Niss ◽  
A. E. Parshuto ◽  
E. V. Soroka ◽  
...  
Keyword(s):  
Direct Current ◽  
Power Supply ◽  
Environmental Safety ◽  
Pulse Mode ◽  
Electrochemical Process ◽  
Process Efficiency ◽  
Metallic Materials ◽  
Current Pulses ◽  
Wide Range ◽  
Processing Modes

Recently, there has been a tendency in the industry to use electrochemical processing methods based on the use of milli- and microsecond pulses of different polarity and amplitude instead of a direct current. The use of a pulsed current in many cases makes it possible to obtain the desired effect by cheaper means and to provide additional controllability of the electrochemical process by adjusting the time parameters of the current pulses. This also ensures reduction of the energy costs of the polishing and cleaning process of surfaces as compared to direct current processing and increasing the efficiency of processing when the rate of smoothing the surface microroughness referred to the total removal of the metal rises significantly. For example, the application of bipolar pulses in polishing of many metallic materials eliminates the use of expensive and hazardous chromium electrolytes. The use of pulse mode during electrolyte-plasma polishing makes it possible to achieve the reduction of energy consumption and to increase of process efficiency while maintaining high intensity, processing quality and environmental safety. In order to study the effect of pulses parameters and the duration of a pause between them on the characteristics of the surface of parts made of various metallic materials in electrochemical and electrolyte-plasma processing modes the special power supply was modeled, designed and manufactured. The power supply provides the possibility of regulation frequency, the duration of the positive and negative pulses and the duration of the pauses between them a wide range. It makes it possible to generate current pulses up to 50 A at a voltage of 0 to 400 V of positive and negative polarities and is able to regulate their duration in the range from 10.0 μs to 8.1 s with the possibility of changing the ratio of the pulse duration and pauses from 1:1 to 1:9.

scholarly journals Micromagnetic Simulation of L10-FePt-Based Exchange-Coupled-Composite-Bit-Patterned Media with Microwave-Assisted Magnetic Recording at Ultrahigh Areal Density

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1264
Author(s):  
Pirat Khunkitti ◽  
Naruemon Wannawong ◽  
Chavakon Jongjaihan ◽  
Apirat Siritaratiwat ◽  
Anan Kruesubthaworn ◽  
...  
Keyword(s):  
Magnetic Recording ◽  
Magnetic Domain ◽  
Hysteresis Loops ◽  
Areal Density ◽  
Bit Patterned Media ◽  
Patterned Media ◽  
Microwave Assisted ◽  
The Media ◽  
5 Ghz ◽  
Exchange Coupled Composite

In this work, we propose exchange-coupled-composite-bit-patterned media (ECC-BPM) with microwave-assisted magnetic recording (MAMR) to improve the writability of the magnetic media at a 4 Tb/in2 recording density. The suitable values of the applied microwave field’s frequency and the exchange coupling between magnetic dots, Adot, of the proposed media were evaluated. It was found that the magnitude of the switching field, Hsw, of the bilayer ECC-BPM is significantly lower than that of a conventional BPM. Additionally, using the MAMR enables further reduction of Hsw of the ECC-BPM. The suitable frequency of the applied microwave field for the proposed media is 5 GHz. The dependence of Adot on the Hsw was additionally examined, showing that the Adot of 0.14 pJ/m is the most suitable value for the proposed bilayer ECC-BPM. The physical explanation of the Hsw of the media under a variation of MAMR and Adot was given. Hysteresis loops and the magnetic domain of the media were characterized to provide further details on the results. The lowest Hsw found in our proposed media is 12.2 kOe, achieved by the bilayer ECC-BPM with an Adot of 0.14 pJ/m using a 5 GHz MAMR.

scholarly journals ELECTROMAGNETIC PROCESSES IN A FLAT RECTANGULAR SYSTEM WITH AN INDUCTOR BETWEEN THIN BIFILAR COILS

2021 ◽  
Vol 2021 (1) ◽  
pp. 3-9
Author(s):  
Yu.V. Batygin ◽  
◽  
S.O. Shinderuk ◽  
O.F. Yeryomina ◽  
E.A. Chaplygin ◽  
...  
Keyword(s):  
Magnetic Pulse ◽  
Induced Current ◽  
Analysis And Evaluation ◽  
Electromagnetic Processes ◽  
Time Shape ◽  
Wide Range ◽  
Induced Currents ◽  
Metal Processing ◽  
Induced Signal ◽  
Practical Recommendations

The aim of the research is the analysis and evaluation of the electromagnetic processes characteristics in the proposed flat rectangular system consisting of a thin solenoid-inductor located between the branches of the bifilar, thin-walled multi-turn coils. The analysis of electromagnetic processes and the obtained estimates of the excited currents are carried out. It is shown that with a minimum gap between the windings of the solenoid-inductor and the bifilar, the time functions of the exciting current and the current induced in the bifilar windings are the same, and the amplitude of the latter is maximum and equal to half the current amplitude in the inductor. It was found that the proposed system has a practical invariance of the time shape and amplitude of the induced current in a wide range of variable geometric parameters. The minimal effect of the fields of induced currents on the processes in the solenoid-inductor and the minimum losses when removing the induced signal from the bifilar windings are noted. Physically, the first is due to the asymmetry of the excited magnetic field relative to the plane of the solenoid-inductor, the second is due to a significant decrease in spurious inter-turn capacitance due to the thinness of the bifilar windings. The obtained results allow us to give practical recommendations when choosing design solutions for elements of new circuits of equipment for magnetic pulse metal processing. References 14, figures 2.

scholarly journals GNSS Interference Environment in Malaysia: A Case Study

2021 ◽  
Vol 3 (1) ◽  
pp. 13-16
Author(s):  
Ooi Wei Han ◽  
Shahrizal Ide Moslin ◽  
Wan Aminullah
Keyword(s):  
Public Awareness ◽  
Essential Element ◽  
Global Navigation Satellite Systems ◽  
Space Technology ◽  
Local Study ◽  
Satellite Systems ◽  
Wide Range ◽  
Global Navigation Satellite ◽  
Significant Interference

Global Navigation Satellite Systems or GNSS is a space technology that has become an essential element nowadays for positioning, navigation & timing (PNT) with wide range of applications in many civilian sectors as well as across military. The reliability, accuracy and availability of GNSS are highly important especially for critical and precise positioning applications. However, the signals from space are weak and it can be easily blocked, disrupted or compromised by several other threats including intentional and unintentional interferences or jamming. GPS jammer is widely available off the shelf with an affordable price and capable of interfering the GPS signal, and many authorities worldwide have raised concerns and a lot of efforts and research have been put in place to reduce and mitigate the threats. In Malaysia, understanding and countering threats to GNSS/GPS based applications will be a new and unfamiliar discipline for public and organizations. This study intended to provide an overview of the GNSS interferences environment in a local study area, in terms of interference type and the number of activity pattern that were detected. A system called Detector V1 has been used in this study. The result showed that significant interference cases happened in the study area and some of the high power interferences may impact GNSS tracking and precision of the positioning output. The role objective of having this done is to create a public awareness regarding the threat of GNSS interferences to the local users. The content also includes the proposed initiative to overcome the issue.

scholarly journals EFFECT OF MOVING AVERAGE FILTER WITH PID CONTROLLER USING HIL TECHNIQUE

2021 ◽  
Vol 03 (03) ◽  
pp. 111-123
Author(s):  
Bilal A. MUBDIR
Keyword(s):  
Steady State ◽  
Pid Controller ◽  
Moving Average ◽  
Fast Response ◽  
Feedback Signal ◽  
Moving Average Filter ◽  
Speed Sensor ◽  
Wide Range ◽  
Control Application ◽  
Average Filter

Designing fast response controller that can achieving steady state with minimum error is big challenge in control application. Proportional Integral Derivate (PID) controllers are conventional controllers for their simplicity and wide range of applications in industrial. Many efforts have been made in improving the PID controller performance by enhancing the controller with different techniques for tuning its operation or filtering the feedback signal. In this paper, the effect of using Moving Average filter with the PID controller for controlling the speed of Permanent Magnet DC (PMDC) Motor with noisy speed sensor is discussed. PID controller and the moving average filter are modeled in MATLAB/Simulink software, where the Hardware in the Loop (HIL) technique with aid of microcontroller was used for the controlled plant which is a PMDC motor in this study. Comprehensive study on the available techniques used to modeling the PID controller is done as well. Furthermore, full practical tests prove that the controller behavior is more stable when moving average filter used and its effect minimized time needed to reach the steady state point clearly by 76%.

Thin-Film Absorbing Elements of Adapter-Attenuators for HIC

2021 ◽  
Vol 26 (6) ◽  
pp. 521-532
Author(s):  
A.V. Pilkevich ◽  
◽  
V.D. Sadkov ◽  
Keyword(s):  
Integrated Circuits ◽  
Power Density ◽  
Potential Gradient ◽  
Pulse Mode ◽  
Transformation Coefficient ◽  
Resistive Film ◽  
Input And Output ◽  
Wide Range ◽  
Film Element ◽  
Absorbing Elements

One of the urgent tasks in the design of hybrid integrated circuits (HIC) is the construction of adapter-attenuators – film absorbing elements providing a wide range of attenuations with specified values of input and output resistances. Known variants of adapter-attenuators based on a homogeneous and piecewise homogeneous resistive film provide (by introducing asymmetry in the dimensions of the input and output contacts, changing the location of a piecewise homogeneous resistive film, introducing dielectric or conductive regions) a resistance transformation coefficient of no more than 3 and 10–12, respectively. In this work, promising topologies of adapter-attenuators for HIC with a close to optimal profile of input and output contacts are proposed, which allow not only to obtain a wide range of transformation coefficients (more than 100), but also to reduce the maximum values of the potential gradient and power density by 10‒30 times. The rectangular topology calculations were made using the apparatus of the theory of functions of a complex variable. Modeling of the optimized topology of adapter-attenuators for HIC was carried out by the finite element method implemented in the Elcut software package. The calculated ratios and graphs showing the relationship of attenuation, the transformation coefficient, the gain in the value of the potential gradient and the power density, depending on the ratio of the size of the film element and the resistivity of the resistive films used, have been provided. The features of adapter-attenuators fitting have been considered. The results obtained are especially important for the pulse mode of operation of adapter-attenuators’ film element for HIC.

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