scholarly journals Interlaboratory comparisons of calibration results of a multifunctional calibrator of electrical quantities

2021 ◽  
Vol 1 ◽  
pp. 1-4
Author(s):  
Vasyl Dovhan ◽  
Denys Nikitenko ◽  
Dmytro Shynder
Keyword(s):  
Interlaboratory Comparisons ◽  
Measurement Instruments ◽  
Dc Voltage ◽  
Laboratory Calibration ◽  
Ac Current ◽  
Dc Current ◽  
Criterion Analysis

Article is dedicated to organization and conduct of the calibration results of reciprocal interlaboratory comparisons for the multifunctional calibrator of electric quantities: DC voltage, AC voltage, DC current and AC current. The interlaboratory comparisons of electric quantities measurement instruments calibration results are represented. Evaluation of the laboratory calibration results bias is provided using the modified criterion. Analysis and conclusions concerning participating laboratory competence are provided.

scholarly journals A Sliding Surface for Controlling a Semi-Bridgeless Boost Converter with Power Factor Correction and Adaptive Hysteresis Band

2021 ◽  
Vol 11 (4) ◽  
pp. 1873
Author(s):  
José Robinson Ortiz-Castrillón ◽  
Gabriel Eduardo Mejía-Ruiz ◽  
Nicolás Muñoz-Galeano ◽  
Jesús María López-Lezama ◽  
Juan Bernardo Cano-Quintero
Keyword(s):  
Sliding Mode Control ◽  
Power Factor ◽  
Error Term ◽  
Sliding Mode ◽  
Power Factor Correction ◽  
Sliding Surface ◽  
Dc Voltage ◽  
Start Up ◽  
Ac Current ◽  
Current Error

This paper proposes a new sliding surface for controlling a Semi-Bridgeless Boost Converter (SBBC) which simultaneously performs Power Factor Correction (PFC) and DC bus regulation. The proposed sliding surface is composed of three terms: First, a normalized DC voltage error term controls the DC bus and rejects DC voltage disturbances. In this case, the normalization was performed for increasing system robustness during start-up and large disturbances. Second, an AC current error term implements a PFC scheme and guarantees fast current stabilization during disturbances. Third, an integral of the AC current error term increases stability of the overall system. In addition, an Adaptive Hysteresis Band (AHB) is implemented for keeping the switching frequency constant and reducing the distortion in zero crossings. Previous papers usually include the first and/or the second terms of the proposed sliding surface, and none consider the AHB. To be best of the author’s knowledge, the proposed Sliding Mode Control (SMC) is the first control strategy for SBBCs that does not require a cascade PI or a hybrid PI-Sliding Mode Control (PI-SMC) for simultaneously controlling AC voltage and DC current, which gives the best dynamic behavior removing DC overvoltages and responding fast to DC voltage changes or DC load current perturbations. Several simulations were carried out to compare the performance of the proposed surface with a cascade PI control, a hybrid PI-SMC and the proposed SMC. Furthermore, a stability analysis of the proposed surface in start-up and under large perturbations was performed. Experimental results for PI-SMC and SMC implemented in a SBBC prototype are also presented.

scholarly journals PENGEMBANGAN ALAT UKUR BATAS KAPASITAS TAS SEKOLAH ANAK BERBASIS MIKROKONTROLER

2020 ◽  
Vol 1 (1) ◽  
pp. 14-22
Author(s):  
Novia Utamu Putri ◽  
Putri Oktarin ◽  
Risky Setiawan
Keyword(s):  
Elementary School ◽  
Elementary School Students ◽  
School Children ◽  
Input Voltage ◽  
Wearable Device ◽  
School Students ◽  
Ac Current ◽  
Safe Limit ◽  
Dc Current ◽  
Made In

Backpacks are often used by school children as a container or a place to carry their school materials and equipment, so these types of backpacks are very popular with school children. The large number of students wearing backpacks to school can be proven from the results of a survey conducted at SD N Bumisari, Natar District, South Lampung. Of the total number of subjects, 456 elementary school students carried 404 students (88.6%), and 52 students (11.4%) carried sling bags. But they rarely pay attention to the weight of the burden on the bag he carries everyday which turns out to cause injury to back pain.The tool is made in the form of a wearable device where the tool is in the form of a backpack that can be carried anywhere without having to require AC current as input voltage to the tool, because the power uses DC current with a voltage of 5V, the device is made using a microcontroller supported by a 10 kg loadcell sensor, modules HX711, keypad, plus an indicator component in the form of a buzzer. If the bag load exceeds the safe limit, the buzzer indicator will sound.

Low Frequency Measurements in Amorphous Wire for Studying GMI Effect

2011 ◽  
Vol 495 ◽  
pp. 201-204
Author(s):  
Polykseni Vourna
Keyword(s):  
Magnetic Field ◽  
Low Frequency ◽  
Major Change ◽  
Wheatstone Bridge ◽  
Amorphous Wire ◽  
Dc Voltage ◽  
Gmi Effect ◽  
Offset Voltage ◽  
Ac Current ◽  
The Magnetic Field

When a soft ferromagnetic material is flown by an ac current and a magnetic field is applied at the same time, a major change of its impedance is occurred. The aim of this paper is to investigate the influence of low frequency (1KHz-12KHz) ac current and the applied magnetic field on an amorphous magnetic wire (Co68Fe4.35Si12.5B15) without glass coating. For this purpose an experimental configuration has been setup, based on a Wheatstone bridge which receives an ac input signal from a frequency generator. The output is connected to the amorphous wire wrapped with a coil supplied by a dc voltage for the generation of the magnetic field. The output voltage pulse is measured for two cases a) The value of ac frequency is changing while the value of dc voltage applied to the coil remains constant (the magnetic field remains unchanged) and b) the magnetic field is changing while the ac frequency remains constant to a predefined value. Experimental results of the first scenario showed that when the frequency is altered a non-linear increase of the ac signal is observed at the output which shows an increase of the GMI effect and is related to the non-linearity of the wire’s permeability. For the second scenario the results showed an increase of the output signal offset (voltage) which also indicates an increase of the GMI effect.

New Cathodic Protection Criteria Based on Direct and Alternating Current Densities Measured Using Coupons and Their Application to Modern Steel Pipelines

CORROSION ◽  
2004 ◽  
Vol 60 (3) ◽  
pp. 304-312 ◽  
Author(s):  
Y. Hosokawa ◽  
F. Kajiyama ◽  
Y. Nakamura
Keyword(s):  
Cathodic Protection ◽  
Field Tests ◽  
Alternating Current ◽  
Pipe Material ◽  
Review Of The Literature ◽  
Density Measurements ◽  
Corrosion Risk ◽  
Ac Current ◽  
Current Densities ◽  
Dc Current

Abstract The risks of alternating current (AC) corrosion, overprotection, and stray direct current (DC) corrosion are increasing on cathodically protected buried steel pipelines due to the recent changes in factors such as burial conditions, the characteristics of coatings, and pipe material. In the present study, field tests as well as a review of the literature on these risks were conducted. As a result, it has been revealed that there is a certain limitation to assess these risks with respect to conventional cathodic protection (CP) criteria based on pipe-to-soil potential. Therefore, new CP criteria for the elimination of these risks have been developed based on DC and AC current density measurements on coupons. The effectiveness of the new CP criteria was evaluated through the design of CP systems on newly constructed pipelines subject to the risks of AC corrosion, overprotection, and stray DC corrosion. Using these new CP criteria, the design and installation of CP systems as well as the elimination of these risks were completed successfully. The risks of overprotection as well as stray DC corrosion were eliminated by providing an appropriate level of DC current from CP rectifiers. The elimination of the AC corrosion risk was accomplished using distributed magnesium anodes and solid-state DC decoupling devices. Finally, the new CP criteria were proven to be effective in eliminating the risks of AC corrosion, overprotection, and stray DC corrosion on buried steel pipelines.

Study on Electrical Automation with Design of Programmable Control Voltage/Current Source

2013 ◽  
Vol 703 ◽  
pp. 273-277
Author(s):  
Yu Wen Zhai ◽  
Wei Liu ◽  
Xiao Yang
Keyword(s):  
Current Source ◽  
Control Voltage ◽  
Signal Source ◽  
Digital Display ◽  
Dc Voltage ◽  
Standard Signal ◽  
Signal Amplifier ◽  
Dc Current

The design of programmable control voltage/current source based on MCU C8051F410 is introduced. The system mainly consists of D/A converter with PWM, voltage/current conversion circuit and digital display circuit. It can provide with DC voltage within the ranges of 0 to 200mV, 0 to 2V, -10V to +10V; and provide with DC current within the range of 4 to 20 mA. The programmable control voltage/current source can be used as the standard signal source for thermodynamic instrumentation, especially for the adjusting and testing for ADC or precise litter signal amplifier in the field of electrical automation.

Current Induced Spin Injection in Si-MOSFET

2012 ◽  
Vol 190 ◽  
pp. 129-132
Author(s):  
I. Shlimak ◽  
A. Butenko ◽  
D.I. Golosov ◽  
K.J. Friedland ◽  
S.V. Kravchenko
Keyword(s):  
Magnetic Fields ◽  
Spin Injection ◽  
Dynamic Resistance ◽  
Experimental Scheme ◽  
Ac Current ◽  
Sample Resistance ◽  
Pass Through ◽  
Lock In ◽  
Dc Current ◽  
Parallel Magnetic Fields

Longitudinal resistivity in strong parallel magnetic fields up to B = 14 Tesla was measured in Si-MOSFET with a narrow slot (90nm) in the upper metallic gate that allows to apply different gate voltage across the slot and, therefore, to control the electron density n1 and n2 in two parts of the sample independently. The experimental scheme allows us to pass through the source-drain channel relatively large DC current (IDC), while the dynamic resistance was measured using a standard lock-in technique with small AC current. It was shown that the sample resistance is asymmetric with respect to the direction of DC current. The asymmetry increases with increase of magnetic field, DC current, and difference between n1 and n2. Results are interpreted in terms of a current-induced spin accumulation or depletion near the slot, as described by a spin drift-diffusion equation. The effect on the sample resistance is due to the positive magnetoresistance of Si-MOSFETs in parallel magnetic fields.

Intrinsic Phase Shift and Novel Dynamic Magnetization States of a Spin Torque Oscillator under ac Current Injection

2007 ◽  
Vol 998 ◽  
Author(s):  
Yan Zhou ◽  
Johan Persson ◽  
Johan Akerman
Keyword(s):  
Phase Shift ◽  
Phase Locking ◽  
Wave Length ◽  
Anisotropy Field ◽  
Spin Torque ◽  
Demagnetizing Field ◽  
Oscillation Modes ◽  
Out Of Plane ◽  
Ac Current ◽  
Dc Current

ABSTRACTWe report on a preferred phase shift ΔΦ0 between a spin torque oscillator (STO) and an ac current (Iac) injected at the intrinsic frequency (fSTO) of the STO. In the in-plane precession mode (IP) the STO adjusts to a state where its resistance (or voltage) lags Iac about a quarter of a wave length (ΔΦ0 = 87°−94°). In the IP mode ΔΦ0 increases somewhat with the dc current. As the precession changes into the Out-Of-Plane (OOP) mode, ΔΦ0 jumps by about 180°, i.e. the STO resistance now precedes Iac by about a quarter of a wave length (|ΔΦ0| = 86°). At the IP/OOP boundary, the ac current mixes the two oscillation modes and both periodic and chaotic oscillations are observed. As a consequence of mixing, subharmonic terms appear in the STO signal. ΔΦ0 can furthermore be tuned by changing one or more of the anisotropy field, the demagnetizing field or the applied field. At the IP/OOP boundary, Iac mixes the two oscillation modes. The intrinsic ΔΦ0 will impact any circuit design based on STO technology and will e.g. have direct consequences for phase locking in networks of serially connected STOs.

scholarly journals General purpose AC current to DC voltage transducer

2018 ◽  
pp. 69-76
Author(s):  
Viša Tasić ◽  
Radoš Jeremijić ◽  
Marijana Pavlov-Kagadejev ◽  
Vladimir Despotović
Keyword(s):  
General Purpose ◽  
Dc Voltage ◽  
Voltage Transducer ◽  
Ac Current

scholarly journals A METHOD FOR CALIBRATING 10-TURN AND 50-TURN CURRENT COIL USING MULTIPRODUCT CALIBRATOR

2019 ◽  
Vol 21 (3) ◽  
pp. 171
Author(s):  
Hayati Amalia ◽  
Agah Faisal
Keyword(s):  
Measurement Method ◽  
Evaluation Methods ◽  
Uncertainty Estimation ◽  
Uncertainty Component ◽  
Evaluation Result ◽  
Current Coil ◽  
National Measurement ◽  
Ac Current ◽  
Result Analysis ◽  
Dc Current

<p>This paper presents a traceable measurement method developed in the Laboratory of National Measurement Standards for Electricity and Time (NMS Lab for Electricity and Time) - National Standardization Agency of Indonesia for calibrating current coil in order to obtain correction and uncertainty estimation of the current coil windings number (N). Current coils as objects of this research were 10-turn and 50-turn current coil. Calibration was performed using standard multiproduct calibrator (MPC) and two auxiliary devices, current coil F-5500 and clamp meter F-337. Correction and uncertainty values of N current coil were evaluated for DC and AC supplied current using formulation developed based on principle of current division between current coil output and supplied current from MPC. Based on evaluation result analysis, the expanded uncertainties of this method span from 0.47% to 1.0% (when supplied by DC current) and from 0.57% to 1.1% (when supplied by AC current) for 10-turn current coil, and span from 0.44% to 0.65% (when supplied by DC current) and from 0.54% to 0.96% (when supplied by AC current) for 50-turn current coil. Moreover, it also showed that the largest uncertainty component came from current coil F-5500. Meanwhile, the largest correction for 10-turn current coil was obtained 1.2% at 10 A DC, and for 50-turn current coil was obtained -0.47% at 700 A AC. Verification of the calibration and evaluation methods had also been carried out and it indicated that the calibration and analysis methods developed can be used to examine the performance of the current coil.</p>

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