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Article
Publication date: 3 July 2017

Yusmarnita Yusop, Mohd. Shakir Md. Saat, Siti Huzaimah Husin, Sing Kiong Nguang and Imran Hindustan

This paper aims to present a new wireless power transfer technique using capacitive coupling. The capacitive power transfer (CPT) system has been introduced as an…

Abstract

Purpose

This paper aims to present a new wireless power transfer technique using capacitive coupling. The capacitive power transfer (CPT) system has been introduced as an attractive alternative to the traditional inductive coupling method. The CPT offers benefits such as simple topology, fewer components, better electromagnetic interference (EMI) performance and robustness to surrounding metallic elements.

Design/methodology/approach

A class-E inverter together with and without inductor capacitor (LC) matching circuit has been utilised in this work because of its ability to perform the DC-to-AC inversion efficiently with significant reduction in switching losses. The validity of the proposed concept has been verified by conducting a laboratory experiment of the CPT system.

Findings

The performances for both systems are analysed and evaluated. A 9.7 W output power is generated through a combined interface [printed circuit board (PCB) plate] capacitance of 2.82 nF at an operating frequency of 1 MHz, with 97 per cent efficiency for 0.25 mm coupling gap distance.

Originality value

An efficient CPT system with class-E LC matching topology is proposed in this paper. With this topology, the zero-voltage switching can be achieved even if the load is different by properly designing the LC matching transformation circuit.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 36 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 2 November 2015

Julian Veitengruber, Frank Rinderknecht and Horst E. Friedrich

The purpose of this paper is to devote the optimal substitution of slip rings through an inductive power transfer system for field winding supply of generators or motors…

Abstract

Purpose

The purpose of this paper is to devote the optimal substitution of slip rings through an inductive power transfer system for field winding supply of generators or motors with a wound rotor. By a rotational pot-core transformer approach, the rotor-side energizing of the excitation windings can be provided isolated and free of wear.

Design/methodology/approach

For design purpose, an analytical model of the inductive link and the compensation network elements is shown. Based on a pot-core transformer approach, possible types of compensation networks regarding motor-specific constraints were carried out and compared among themselves by parameter studies. The analytical parts of the model were subsequently validated with measured data of an appropriate core and accompanying FEM calculations. On the basis of an experimental prototype system, the approach has been tested both stationary and transient.

Findings

The publication exemplifies how a brushless excitation system for generators and motors can be inexpensively designed and implemented.

Originality/value

This paper systematically presents a comprehensive analytical approach for brushless excitation systems as well as a prototypical system. Compensation network elements regarding motor-specific constraints were carried out and compared among themselves by parameter studies.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 34 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

Content available
Article
Publication date: 3 May 2021

Habeeba Khan, Sayyed Arif Ali, Mohd Wajid and Muhammad Shah Alam

In this work, a microstrip antenna array for wireless power transfer (WPT) application is reported. The proposed 4 × 4 antenna array operating at 16 GHz is designed using…

Abstract

Purpose

In this work, a microstrip antenna array for wireless power transfer (WPT) application is reported. The proposed 4 × 4 antenna array operating at 16 GHz is designed using a flexible Kapton polyimide substrate for a far-field charging unit (FFCU).

Design/methodology/approach

The proposed antenna is designed using the transmission line model on a flexible Kapton polyimide substrate. The finite element method (FEM) is used to perform the full-wave electromagnetic analysis of the proposed design.

Findings

The antenna offers −10 dB bandwidth of 240 MHz with beam width and broadside gain found to be 29.4° and 16.38 dB, respectively. Also, a very low cross-polarization level of −34.23 dB is achieved with a radiation efficiency of 36.67%. The array is capable of scanning −15° to +15° in both the elevation and azimuth planes.

Originality/value

The radiation characteristics achieved suggest that the flexible substrate antenna is suitable for wireless charging purposes.

Details

Frontiers in Engineering and Built Environment, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2634-2499

Keywords

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Article
Publication date: 7 March 2016

Jing Zhou, Yuqing Gao, Xiaoyan Huang and Youtong Fang

Consider the mutual coupling between loads, the purpose of this paper is to study the total transmission efficiency based on different load coil positions relative to the…

Abstract

Purpose

Consider the mutual coupling between loads, the purpose of this paper is to study the total transmission efficiency based on different load coil positions relative to the charging platform, to provide the theoretical basis for the design and parameter optimization of one-to-multiple wireless charging platform.

Design/methodology/approach

Based on the dual-load series-resonant wireless power transfer system, the expression of system efficiency and its calculation model is achieved using the equivalent circuit theory. Finally, a 96 kHz magnetic resonance wireless power transmission test platform is built up to verify the theoretical analysis given in this paper.

Findings

For the completely resonant circuit, the transmission efficiency can be improved by increasing the transmitter-receiver coupling and reducing the coupling between receivers. The total transmission efficiency achieves its lowest value when two loads are with equal competitive capability.

Originality/value

Through the simulation analysis of efficiency formula, the selection principle of impact factors can be applied to the optimization analysis of the transmission efficiency.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 35 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 6 November 2017

Xian Zhang, Zhaoyang Yuan, Yang Qingxin, Zhaohui Wang, Hao Meng and Yao Jin

The purpose of the paper is to analyze the impact of coupling on the distribution of the magnetic field and study the characteristics of the magnetic flux density in the…

Abstract

Purpose

The purpose of the paper is to analyze the impact of coupling on the distribution of the magnetic field and study the characteristics of the magnetic flux density in the transmission process of the magnetic coupling resonant wireless power transmission (MCR-WPT) system, which provides guidance on the design of the WPT system.

Design/methodology/approach

In this study, a finite element simulation analysis was conducted and a three-dimensional (3D) electromagnetic field measurement platform was used.

Findings

It is shown that the distribution of the magnetic field, as well as the position of maximum magnetic flux density, will change when the coils are coupled. The simulation results of the magnetic field distribution, as well as the transmission performance, are different from those in practice. It cannot describe the actual performance of WPT system.

Originality/value

A 3D electromagnetic field measurement system and the host computer software are designed to help optimize the simulation and carry out more accurate and efficient research. The 3D electromagnetic field measurement system can be used to study the distribution of the spatial electromagnetic field, influencing factor, exposure and interoperability between different coils.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 36 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 1 January 2008

K. Arshak, A. Arshak, E. Jafer, D. Waldern and J. Harris

To develop a wireless sensor micro‐systems containing all the components of data acquisition system, such as sensors, signal‐conditioning circuits, analog‐digital…

Abstract

Purpose

To develop a wireless sensor micro‐systems containing all the components of data acquisition system, such as sensors, signal‐conditioning circuits, analog‐digital converter, embedded microcontroller unit (MCU), and RF communication modules. This has now become the focus of attention in many biomedical applications.

Design/methodology/approach

The system prototype consists of miniature FSK transceiver integrated with MCU in one small package, chip antenna, and capacitive interface circuitry based on Delta‐sigma modulator. At the base station side, an FSK receiver/transmitter is connected to another MCU unit, which send the received data or received instructions from a PC through a graphical user interface GUI. Industrial, scientific and medical band RF (433 MHz) was used to achieve half duplex communication between the two sides. A digital filtering has been used in the capacitive interface to reduce noise effects forming capacitance to digital converter. All the modules of the mixed signal system are integrated in a printed circuit board of size 22.46 × 20.168 mm.

Findings

An innovation circuits and system techniques for building advanced smart medical devices have been discussed. Low‐power consumption and high reliability are among the main criteria that must be given priority when designing such wirelessly powered microsystems. Switched capacitors readout circuits have been found to be suitable for pressure sensing low‐power applications.

Research limitations/implications

The presented wireless prototype needs a second phase of development that will lead to a further reduction in both size and power consumption. Currently, the main limitation of the RF system is the number of working hours according to the selected battery.

Practical implications

The developed system was found to be useful in terms of measuring pressure and temperature in a system of either slow or fast physical change. It would be a good idea to explore the system performance in human or animal trials.

Originality/value

This paper fulfils useful information for capacitive interface circuitries and presents a new short‐range wireless system that has different design features.

Details

Microelectronics International, vol. 25 no. 1
Type: Research Article
ISSN: 1356-5362

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Article
Publication date: 26 August 2014

Damir Krklješ, Dragana Vasiljević and Goran Stojanović

This paper aims to present a prototype of a capacitive angular-position sensor which exploits advantages of flexible/printed electronics. The novelty of the sensor is that…

Abstract

Purpose

This paper aims to present a prototype of a capacitive angular-position sensor which exploits advantages of flexible/printed electronics. The novelty of the sensor is that the capacitor structure is placed at the circumference of the rotor and stator, that it posses two channels (capacitor structures) electrically shifted for p/4 and that the rotor is common for both channels. The electrodes of the sensing capacitor are digitated, providing a triangular transfer function.

Design/methodology/approach

This sensor prototype consists of two flexible inkjet-printed silver electrodes forming a cylindrical capacitor structure. One of them is wrapped around the stator and another is wrapped around the rotor part of a simple mechanical platform used to precisely adjust the angular displacement.

Findings

The capacitance as a function of angular position was measured using an inductance capacitance impedance (LCZ) Meter, and results are presented for a full-turn measurement range. The experimental results are compared with analytical ones and very good agreement has been achieved.

Originality/value

The proposed capacitive sensor structure can be used as an absolute or an incremental encoder with different resolutions, and it can be applied in automotive industry or robotics.

Details

Sensor Review, vol. 34 no. 4
Type: Research Article
ISSN: 0260-2288

Keywords

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Article
Publication date: 2 November 2015

Fulian Qiu and David Harrison

Wearable electronic devices have emerged which require compact, flexible power storage devices such as batteries and supercapacitors. Recently, energy storage devices have…

Abstract

Purpose

Wearable electronic devices have emerged which require compact, flexible power storage devices such as batteries and supercapacitors. Recently, energy storage devices have been developed based on supercapacitor threads. However, current supercapacitor energy storage threads which use electrolytes based on aqueous gels have a 1 V potential window. This is much lower than the voltage required by most electronic devices. This current contribution presents an approach for fabricating a multilayer supercapacitor working as a circuit unit, in which series combinations of the multiple layer structures can achieve a higher potential window, which can better meet the needs of wearable electronic devices.

Design/methodology/approach

Two-capacitive layer thread supercapacitors were fabricated using a semi-automatic dip coating method by coating two capacitive layers sequentially on a 50 μm stainless steel core wire, each capacitive layer includes ink, aqueous-based gel electrolyte and silver conductive paint layers.

Findings

Two capacitive layers of the single thread supercapacitor can work independently, or as combination circuits – parallel and series. Cyclic voltammograms showed that all flexible circuits have high electrochemical stability. For the case of series circuit configuration, with H3PO-polyvinyl alcohol (PVA) gel electrolyte, a working potential window of 2 V was achieved.

Originality/value

A flexible single thread supercapacitor of multilayer structure, with working voltage above 1 V in H3PO4-PVA gel electrolyte, has not been reported before. A semi-automatic dip coating setup used to process the thread supercapacitor has high potential for transfer to an industrial environment for mass production.

Details

Circuit World, vol. 41 no. 4
Type: Research Article
ISSN: 0305-6120

Keywords

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Article
Publication date: 1 December 2005

A. Arshak, K. Arshak, G. Lyons, D. Waldron, D. Morris, O. Korostynska and E. Jafer

Telemetry capsules have existed since the 1950s and were used to measure temperature, pH or pressure inside the gastrointestinal (GI) tract. It was hoped that these…

Abstract

Purpose

Telemetry capsules have existed since the 1950s and were used to measure temperature, pH or pressure inside the gastrointestinal (GI) tract. It was hoped that these capsules would replace invasive techniques in the diagnosis of function disorders in the GI tract. However, problems such as signal loss and uncertainty of the pills position limited their use in a clinical setting. In this paper, a review of the capabilities of microelectromechanical systems (MEMS) for the fabrication of a wireless pressure sensor microsystem is presented.

Design/methodology/approach

The circuit requirements and methods of data transfer are examined. The available fabrication methods for MEMS sensors are also discussed and examples of wireless sensors are given. Finally, the drawbacks of using this technology are examined.

Findings

MEMS for use in wireless monitoring of pressure in the GI tract have been investigated. It has been shown that capacitive pressure sensors are particularly suitable for this purpose. Sensors fabricated for wireless continuous monitoring of pressure have been reviewed. Great progress, especially using surface micromachining, has been made in recent years. However, despite these advances, some challenges remain.

Originality/value

Provides a review of the capabilities of MEMS.

Details

Sensor Review, vol. 25 no. 4
Type: Research Article
ISSN: 0260-2288

Keywords

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Article
Publication date: 27 February 2020

Kong Dejun and Chen Haixiang

The purpose of this paper is to investigate the effects of laser power on the electrochemical corrosion performance in 3.5% NaCl, 0.1 M H2SO4 and 0.1 M NaOH solutions…

Abstract

Purpose

The purpose of this paper is to investigate the effects of laser power on the electrochemical corrosion performance in 3.5% NaCl, 0.1 M H2SO4 and 0.1 M NaOH solutions, which provided an experimental basis for the application of Al–Ti–Ni amorphous coating in marine environment.

Design/methodology/approach

Amorphous Al–Ti–Ni coatings were fabricated on S355 structural steel by laser thermal spraying (LTS) at different laser powers. The surface and cross-section morphologies, chemical element distribution, phases and crystallization behaviors of obtained coatings were analyzed using a scanning electron microscope, energy-dispersive X-ray spectroscope, X-ray diffraction and differential scanning calorimetry, respectively. The effects of laser power on the electrochemical corrosion performances of Al–Ti–Ni coatings in 3.5% NaCl, 0.1 M H2SO4 and 0.1 M NaOH solutions were investigated using an electrochemical workstation.

Findings

The crystallization temperature of Al–Ti–Ni coatings fabricated at the laser power of 1,300 and 1,700 W is ∼520°C, whereas that fabricated at the laser power of 1,500 W is ∼310°C. The coatings display excellent corrosion resistance in 3.5% NaCl and 0.1 M NaOH solutions, while a faster dissolution rate in 0.1 M H2SO4 solution. The coatings fabricated at the laser power of 1,300 and 1,700 W present the better electrochemical corrosion resistance in 3.5% NaCl and 0.1 M NaOH solutions, whereas that fabricated at the laser power of 1,500 W exhibits the better electrochemical corrosion resistance in 0.1 M H2SO4 solution.

Originality/value

In this work, Al-wire-cored Ti–Ni powder was first on S355 steel with the laser power of 1,300, 1,500 and 1,700 W, and the effects of laser power on the electrochemical corrosion performance in 3.5% NaCl, 0.1 M H2SO4 and 0.1 M NaOH solutions were investigated using an electrochemical workstation.

1 – 10 of 342