scholarly journals Wireless power transfer to a micro implant device from outside of human body

2019 ◽  
Vol 9 (3) ◽  
pp. 1541
Author(s):  
Kazuya Yamaguchi ◽  
Kazuma Onishi ◽  
Kenichi Iida
Keyword(s):  
Human Body ◽  
Power Supply ◽  
Calculated Result ◽  
Wireless Power Transfer ◽  
Load Resistance ◽  
State Equation ◽  
Power Transfer ◽  
Wireless Power ◽  
Ac Power ◽  
Parasitic Components

<pre>This paper states wireless power transfer (WPT) from an AC power supply to a micro implant device in human body. At first, an equivalent circuit of WPT which contains biomedical tissue is constructed with an AC power supply, parasitic components, load resistance, and inductances. Then a state equation which stands for the behavior of circuit is found, and the expression of efficiency is derived as the ratio of the power of power supply and load. Finally an experiment is conducted based on the theoretical calculation, and the error between experimental and calculated result is computed and examined.</pre>

scholarly journals The Interaction between Load Circuits and Decision of Frequency for Efficient Wireless Power Transfer

2018 ◽  
Vol 8 (3) ◽  
pp. 1331
Author(s):  
Kazuya Yamaguchi
Keyword(s):  
Power Supply ◽  
Natural Frequencies ◽  
Wireless Power Transfer ◽  
Transfer System ◽  
Power Transfer ◽  
Wireless Power ◽  
Ac Power ◽  
Wireless Power Transfer System ◽  
Efficient Transfer ◽  
The Ideal

<pre>This paper derives an expression of efficiency of wireless power transfer on a situation that there are two devices towards one AC power supply. The interaction between a power supply and load is paid attention on a conventional wireless power transfer system, in contrast, the interaction between loads must be taken account of on the situation too. This is attributed to a possibility that a load disturbs the energy transmitted from a power supply to another load. Moreover each load needs different frequency of power supply for the ideal transfer since they have different natural frequencies on many situations. This paper models a circumstance that there are a power supply and two loads with a state space equation, and proposes how to decide a frequency of power supply to realize efficient transfer for each load.</pre>

Using Square Wave Input for Wireless Power Transfer

2016 ◽  
Vol 6 (1) ◽  
pp. 431 ◽  
Author(s):  
Kazuya Yamaguchi ◽  
Takuya Hirata ◽  
Ichijo Hodaka
Keyword(s):  
Resonant Frequency ◽  
High Power ◽  
Power Supply ◽  
Wireless Power Transfer ◽  
Wave Form ◽  
Power Transfer ◽  
Wireless Power ◽  
Sinusoidal Wave ◽  
Square Wave ◽  
Ac Power

A wireless power transfer (WPT) circuit is composed of a transmitting circuit with an AC power supply and a receiving circuit with a load, and the circuits are wirelessly connected each other. Then a designer chooses the wave form of the AC power supply. Many papers about WPT adopt a sinusoidal wave as the input. The frequency of the sinusoidal wave is generally determined to the resonant frequency of the circuit for high power transfer. Since the number of circuit elements in the power supply to generate a square wave is much less than that of a sinusoidal wave, WPT with a square wave input should be treated. In fact, some papers about WPT adopt a square wave as the input, and adjust the frequency of the square wave to the resonant frequency of the circuit. In this paper, we examine how the frequency of a square wave input affects power and efficiency of WPT circuits, and propose a procedure how to determine the frequency of the input to improve power and efficiency. Finally we discuss which wave should be adopted as an input and how the frequency of the input should be determined, regardless of whether resonant phenomena occur or not.

scholarly journals Using Square Wave Input for Wireless Power Transfer

2016 ◽  
Vol 6 (1) ◽  
pp. 431
Author(s):  
Kazuya Yamaguchi ◽  
Takuya Hirata ◽  
Ichijo Hodaka
Keyword(s):  
Resonant Frequency ◽  
High Power ◽  
Power Supply ◽  
Wireless Power Transfer ◽  
Wave Form ◽  
Power Transfer ◽  
Wireless Power ◽  
Sinusoidal Wave ◽  
Square Wave ◽  
Ac Power

A wireless power transfer (WPT) circuit is composed of a transmitting circuit with an AC power supply and a receiving circuit with a load, and the circuits are wirelessly connected each other. Then a designer chooses the wave form of the AC power supply. Many papers about WPT adopt a sinusoidal wave as the input. The frequency of the sinusoidal wave is generally determined to the resonant frequency of the circuit for high power transfer. Since the number of circuit elements in the power supply to generate a square wave is much less than that of a sinusoidal wave, WPT with a square wave input should be treated. In fact, some papers about WPT adopt a square wave as the input, and adjust the frequency of the square wave to the resonant frequency of the circuit. In this paper, we examine how the frequency of a square wave input affects power and efficiency of WPT circuits, and propose a procedure how to determine the frequency of the input to improve power and efficiency. Finally we discuss which wave should be adopted as an input and how the frequency of the input should be determined, regardless of whether resonant phenomena occur or not.

scholarly journals A Study of Wearable Wireless Power Transfer Systems on the Human Body

2020 ◽  
pp. 1-1
Author(s):  
Juan Barreto ◽  
Gianfranco Perez ◽  
Abdul-Sattar Kaddour ◽  
Stavros V. Georgakopoulos
Keyword(s):  
Human Body ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power

Thin Film Coil Design Considerations for Wireless Power Transfer in Flat Panel Display

2012 ◽  
Vol 1388 ◽  
Author(s):  
Jun Yu ◽  
Kai Ying ◽  
David Hasko ◽  
Sungsik Lee ◽  
Arman Ahnood ◽  
...  
Keyword(s):  
Thin Film ◽  
Metal Layer ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Flat Panel Display ◽  
Wireless Power ◽  
Flat Panel ◽  
Resonant Coupling ◽  
Ac Power ◽  
Spiral Coils

AbstractWireless power transfer is experimentally demonstrated by transmission between an AC power transmitter and receiver, both realised using thin film technology. The transmitter and receiver thin film coils are chosen to be identical in order to promote resonant coupling. Planar spiral coils are used because of the ease of fabrication and to reduce the metal layer thickness. The energy transfer efficiency as a function of transfer distance is analysed along with a comparison between the theoretical and the experimental results.

scholarly journals Comparison of the Efficiency and Load Power in Periodic Wireless Power Transfer Systems with Circular and Square Planar Coils

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4975
Author(s):  
Jacek Maciej Stankiewicz ◽  
Agnieszka Choroszucho
Keyword(s):  
Power Transmission ◽  
Wireless Power Transfer ◽  
Load Resistance ◽  
Numerical Approach ◽  
Maximum Efficiency ◽  
Power Transfer ◽  
Wireless Power ◽  
Load Power ◽  
Coil Geometry ◽  
Square Planar

In the article, a wireless charging system with the use of periodically arranged planar coils is presented. The efficiency of two wireless power transfer (WPT) systems with different types of inductors, i.e., circular and square planar coils is compared, and two models are proposed: analytical and numerical. With the appropriate selection of a load resistance, it is possible to obtain either the maximum efficiency or the maximum power of a receiver. Therefore, the system is analyzed at two optimum modes of operation: with the maximum possible efficiency and with the highest power transmitted to the load. The analysis of many variants of the proposed wireless power transfer solution was performed. The aim was to check the influence of the geometry of the coils and their type (circular or square) on the efficiency of the system. Changes in the number of turns, the distance between the coils (transmit and receive) as well as frequency are also taken into account. The results obtained from analytical and numerical analysis were consistent; thus, the correctness of the adopted circuit and numerical model (with periodic boundary conditions) was confirmed. The proposed circuit model and the presented numerical approach allow for a quick estimate of the electrical parameters of the wireless power transmission system. The proposed system can be used to charge many receivers, e.g., electrical cars on a parking or several electronic devices. Based on the results, it was found that the square coils provide lower load power and efficiency than compared to circular coils in the entire frequency range and regardless of the analyzed geometry variants. The results and discussion of the multivariate analysis allow for a better understanding of the influence of the coil geometry on the charging effectiveness. They can also be valuable knowledge when designing this type of system.

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