scholarly journals Low-cost teslameter based on hall effect sensor MLX90242

2018 ◽  
Vol 15 (2) ◽  
pp. 225-232 ◽  
Author(s):  
Ugljesa Jovanovic ◽  
Igor Jovanovic ◽  
Marjan Blagojevic ◽  
Dejan Krstic ◽  
Dragan Mancic
Keyword(s):  
Magnetic Flux ◽  
Hall Effect ◽  
Flux Density ◽  
Low Cost ◽  
Temperature Stability ◽  
Calibration Procedure ◽  
Magnetic Flux Density ◽  
High Quality ◽  
Hall Effect Sensor ◽  
Usb Communication

A low-cost teslameter based on a Hall effect sensor MLX90242 is proposed in this paper. The proposed teslameter is built around a PIC18F4550 microcontroller and it can measure magnetic flux density in the range between -55 mT and 55 mT. Temperature stability of measurements originates from the MLX90242 sensor itself. In order for the proposed transducer to be accurate, it has undergone a calibration procedure using a highly accurate teslameter employed as reference instruments and high-quality variable-field electromagnet. The proposed teslameter can store measurements on a PC via built-in USB communication.

scholarly journals FFC NMR Relaxometer with Magnetic Flux Density Control

2019 ◽  
Vol 9 (3) ◽  
pp. 22
Author(s):  
António Roque ◽  
Duarte M. Sousa ◽  
Pedro Sebastião ◽  
Elmano Margato ◽  
Gil Marques
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Flux Density ◽  
Low Cost ◽  
Current Control ◽  
Magnetic Flux Density ◽  
Density Control ◽  
Earth Magnetic Field ◽  
Innovative Solution ◽  
Field Cycling

This paper describes an innovative solution for the power supply of a fast field cycling (FFC) nuclear magnetic resonance (NMR) spectrometer considering its low power consumption, portability and low cost. In FFC cores, the magnetic flux density must be controlled in order to perform magnetic flux density cycles with short transients, while maintaining the magnetic flux density levels with high accuracy and homogeneity. Typical solutions in the FFC NMR literature use current control to get the required magnetic flux density cycles, which correspond to an indirect magnetic flux density control. The main feature of this new relaxometer is the direct control of the magnetic flux density instead of the magnet current, in contrast with other equipment available in the market. This feature is a great progress because it improves the performance. With this solution it is possible to compensate magnetic field disturbances and parasitic magnetic fields guaranteeing, among other possibilities, a field control below the earth magnetic field. Experimental results validating the developed solution and illustrating the real operation of this type of equipment are shown.

Study of EPS Hall-Effect Torque Sensor Technology

2011 ◽  
Vol 422 ◽  
pp. 107-112
Author(s):  
Tan Li ◽  
Guo Biao Shi
Keyword(s):  
Magnetic Flux ◽  
Hall Effect ◽  
Low Cost ◽  
Sensor Technology ◽  
Steering Wheel ◽  
Magnetic Flux Density ◽  
Torque Sensor ◽  
Power Steering ◽  
Working Principle ◽  
Flux Path

In an electric power steering (EPS) system, it is important to make a precise and reliable measurement of the torque on the steering wheel. A non-contact torque sensor has been developed for EPS system. The sensor is based on a magnetic principle that the magnetic flux path is changed with the torsion of a torsion bar which is placed in the steering shaft. The change of magnetic flux density in the working airgap is detected by a standard Hall-effect IC. The sensor has broad prospects for its good performance, simple structure and low cost. This paper introduces the torque sensor’s working principle, analyzes the magnetic circuit by 3D simulation, and concludes its key technologies and development trends.

Influence of magnetic concentrator on Hall effect based current sensor

2018 ◽  
Vol 37 (4) ◽  
pp. 1481-1488
Author(s):  
Ivan Yatchev ◽  
Mehmet Sen ◽  
Iosko Balabozov ◽  
Ivan Kostov
Keyword(s):  
Magnetic Flux ◽  
Hall Effect ◽  
Flux Density ◽  
Output Signal ◽  
Air Gap ◽  
Current Sensor ◽  
Magnetic Flux Density ◽  
Content Type ◽  
Hall Plate ◽  
Open Core

Purpose The purpose of the paper is to clarify the influence of introducing magnetic concentrators on the performance of Hall effect based current sensors and to obtain dependencies of the sensor characteristics on the conductor position. Design/methodology/approach The finite element method and Comsol software are used for analysis of the three-dimensional magnetic field of the constructions of Hall effect based current sensor with different types of magnetic concentrators – closed-core (of rectangular and toroidal type) and open-core of toroidal type – with additional larger air gap. The Hall plate is also included in the model with its real dimensions and the magnetic flux density is obtained by integrating over its volume. Findings It has been found that there is dependence of the output signal (proportional to the magnetic flux density) of Hall effect based current sensor with both closed- and open-core magnetic concentrators on the position of the current carrying conductor. Distribution of the magnetic flux density and dependencies of its value in the Hall plate on the conductor position and on the additional air gap have been obtained. Optimization is carried out with respect to the additional air gap and cross-section dimensions of the concentrator. Originality/value Estimation of the influence of the introducing magnetic concentrators is made with respect to relationships between the output signal and conductor position for different constructions of the magnetic core of the concentrators.

scholarly journals Design of a New 1D Halbach Magnet Array with Good Sinusoidal Magnetic Field by Analyzing the Curved Surface

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2522
Author(s):  
Guangdou Liu ◽  
Shiqin Hou ◽  
Xingping Xu ◽  
Wensheng Xiao
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Permanent Magnet ◽  
Flux Density ◽  
Permanent Magnets ◽  
Air Gap ◽  
Curved Surface ◽  
Magnetic Flux Density ◽  
Sinusoidal Magnetic Field ◽  
The Magnetic Field

In the linear and planar motors, the 1D Halbach magnet array is extensively used. The sinusoidal property of the magnetic field deteriorates by analyzing the magnetic field at a small air gap. Therefore, a new 1D Halbach magnet array is proposed, in which the permanent magnet with a curved surface is applied. Based on the superposition of principle and Fourier series, the magnetic flux density distribution is derived. The optimized curved surface is obtained and fitted by a polynomial. The sinusoidal magnetic field is verified by comparing it with the magnetic flux density of the finite element model. Through the analysis of different dimensions of the permanent magnet array, the optimization result has good applicability. The force ripple can be significantly reduced by the new magnet array. The effect on the mass and air gap is investigated compared with a conventional magnet array with rectangular permanent magnets. In conclusion, the new magnet array design has the scalability to be extended to various sizes of motor and is especially suitable for small air gap applications.

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