scholarly journals Coupling Coefficient Measurement Method with Simple Procedures Using a Two-Port Network Analyzer for a Multi-Coil WPT System

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3950
Author(s):  
Seon-Jae Jeon ◽  
Dong-Wook Seo
Keyword(s):  
Coupling Coefficient ◽  
Measurement Method ◽  
Simple Procedure ◽  
Measurement Procedure ◽  
Network Analyzer ◽  
Wireless Power ◽  
S Parameter ◽  
Coefficient Measurement ◽  
Simple Measurement ◽  
Definition Of

In this paper, we propose a measurement method with a simple procedure based on the definition of the impedance parameter using a two-port network analyzer. The main advantage of the proposed measurement method is that there is no limit on the number of measuring coils, and the method has a simple measurement procedure. To verify the proposed method, we measured the coupling coefficient among three coils with respect to the distance between the two farthest coils at 6.78 and 13.56 MHz, which are frequencies most common for a wireless power transfer (WPT) system in high-frequency band. As a result, the proposed method showed good agreement with results of the conventional S-parameter measurement methods.

scholarly journals Thermoelectric Properties of n-Type Molybdenum Disulfide (MoS2) Thin Film by Using a Simple Measurement Method

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3521 ◽  
Author(s):  
Ashraf ◽  
Forsberg ◽  
Mattsson ◽  
Thungström
Keyword(s):  
Thin Film ◽  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Molybdenum Disulfide ◽  
Thermoelectric Properties ◽  
Temperature Difference ◽  
Measurement Method ◽  
Figure Of Merit ◽  
Coefficient Measurement ◽  
Simple Measurement

In this paper, a micrometre thin film of molybdenum disulfide (MoS2) is characterized for thermoelectric properties. The sample was prepared through mechanical exfoliation of a molybdenite crystal. The Seebeck coefficient measurement was performed by generating a temperature gradient across the sample and recording the induced electrical voltage, and for this purpose a simple measurement setup was developed. In the measurement, platinum was utilized as reference material in the electrodes. The Seebeck value of MoS2 was estimated to be approximately −600 µV/K at a temperature difference of 40 °C. The negative sign indicates that the polarity of the material is n-type. For measurement of the thermal conductivity, the sample was sandwiched between the heat source and the heat sink, and a steady-state power of 1.42 W was provided while monitoring the temperature difference across the sample. Based on Fourier’s law of conduction, the thermal conductivity of the sample was estimated to be approximately 0.26 Wm-1 K-1. The electrical resistivity was estimated to be 29 Ω cm. The figure of merit of MoS2 was estimated to be 1.99 × 10-4.

Scaling Law of Coupling Coefficient and Coil Size in Wireless Power Transfer Design via Magnetic Coupling

2017 ◽  
Vol 137 (4) ◽  
pp. 326-333
Author(s):  
Chiaki Nagai ◽  
Kenji Inukai ◽  
Masato Kobayashi ◽  
Tatsuya Tanaka ◽  
Kensho Abumi ◽  
...  
Keyword(s):  
Coupling Coefficient ◽  
Scaling Law ◽  
Magnetic Coupling ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power ◽  
Coil Size

Measurement of Angular Acceleration of a Rigid Body Using Linear Accelerometers

1975 ◽  
Vol 42 (3) ◽  
pp. 552-556 ◽  
Author(s):  
A. J. Padgaonkar ◽  
K. W. Krieger ◽  
A. I. King
Keyword(s):  
Experimental Data ◽  
Rigid Body ◽  
Simple Procedure ◽  
Three Dimensional ◽  
Angular Acceleration ◽  
Theory And Practice ◽  
Body Segments ◽  
Impact Biomechanics ◽  
The Stability ◽  
Definition Of

The computation of angular acceleration of a rigid body from measured linear accelerations is a simple procedure, based on well-known kinematic principles. It can be shown that, in theory, a minimum of six linear accelerometers are required for a complete definition of the kinematics of a rigid body. However, recent attempts in impact biomechanics to determine general three-dimensional motion of body segments were unsuccessful when only six accelerometers were used. This paper demonstrates the cause for this inconsistency between theory and practice and specifies the conditions under which the method fails. In addition, an alternate method based on a special nine-accelerometer configuration is proposed. The stability and superiority of this approach are shown by the use of hypothetical as well as experimental data.

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