Resonant configuration topology exploration for inductive link power transfer

This paper investigates the performance of circuit topology used in wireless power applications to optimize the level of maximum efficiency. We analyse the series and the parallel resonant topologies for use in an inductive coupling link to derive power transfer efficiency expressions verified using MATLAB. We look into the two topologies into the link under resonant conditions for selectively supplying the device with power. The results are obtained analytically which are verified subsequently by MATLAB simulation. We then analyse the links to see how maximum power transfer efficiency for a given pair of coils can be achieved. The topology at a given tuning frequency is used for powering a selected resistive load. The method is presented using a given pair of coils simulated and the results agree well with the theoretical explanation and derivations

Inter-digital sensor for non-invasive blood glucose monitoring

This paper is to describe a contemporary approach of microwave spectroscopy by adapting the interdigital capacitor sensor in estimating the glucose levels in blood through the electromagnetic properties change. Interdigital capacitor configuration has been implemented in various field of applications nowadays such surface acoustic wave (SAW) equipment, microwave devices, chemical and biological sensors. Such a wide area of applications has proven it to be a reliable device, which can be applied in non-invasive blood glucose monitoring system. Focus of this ongoing work is to study the analytical expression for calculating the capacitance and electric field changes of the suggested inter-digital capacitor structure. This also involves the study of parameters, which affect the frequency response changes in the proposed configuration and to present a model of biological tissue. Moreover, the dependency of the capacitance on the geometrical properties of interdigital capacitor structure, electrical properties of the structure as well as those of the human biological tissue are being examined in this project. Production of a sensor based on capacitive sensing, which can be used for the non-invasive approach of blood glucose monitoring is the main target of this paper. The results include reporting changes in parameters such as relative permittivity because of blood suga

Resonant configuration topology exploration for inductive link power transfer

This paper investigates the performance of circuit topology used in wireless power applications to optimize the level of maximum efficiency. We analyse the series and the parallel resonant topologies for use in an inductive coupling link to derive power transfer efficiency expressions verified using MATLAB. We look into the two topologies into the link under resonant conditions for selectively supplying the device with power. The results are obtained analytically which are verified subsequently by MATLAB simulation. We then analyse the links to see how maximum power transfer efficiency for a given pair of coils can be achieved. The topology at a given tuning frequency is used for powering a selected resistive load. The method is presented using a given pair of coils simulated and the results agree well with the theoretical explanation and derivations

An estimation of the coupling coefficient of the series inductive resonant wireless power transfer coils

Though the power transfer efficiency of the inductive resonant wireless power transfer is relatively high, the power transfer efficiency of the inductive resonant wireless power transfer is undoubtedly depending on the coupling coefficient. Coupled with the coupling coefficient, the highest possible power transfer efficiency can be achieved by controlling the operating frequency with impedance matching. Therefore, the relationship of the input impedance to the variation of the coupling coefficient is of paramount importance in maintaining the highest possible power transfer efficiency for a given coupling coefficient. This paper presents the relationship of the input impedance of the series-to-series inductive resonant wireless power transfer to the variations of the coupling coefficient. The analysis is carried out by using the T-equivalent circuit, producing analytical results for comparison and validation by equivalently obtained simulation results, guarantying the maximum power transfer efficiency for a typical series-to-series inductive resonant link. The modeling validity is shown by percentage error in between the analytical and simulation results. The novelty of this paper is in the simplicity of the coupling coefficient estimation by reference to the input impedanc

The load reliant power transfer of the series-to-series inductive resonant wireless power transfer

In this paper, the effect of the output impedance to the power transfer efficiency of the series-to-series inductive resonant wireless power transfer at the resonance frequency is reviewed in details. The analysis is carried out by utilizing the theoretical inductive resonance wireless power transfer model using the MATLAB ® package. In this paper, the experiment is designed to confirm the highest power transfer efficiency is obtained at the resonance frequency for the given value of the coupling coefficient. Besides that, the experiment is also conducted to find the optimum load impedance for all given value of coupling coefficient. The analysis shows that the maximum wireless power transfer efficiency for series-to-series inductive resonant wireless power transfer is at the maximum peak when operational at the resonance frequency. In addition, the power transfer efficiency is improved by working at the optimum load impedance. The experimental set up is presented and the analytical results are reported

The load reliant power transfer of the series-to-series inductive resonant wireless power transfer

In this paper, the effect of the output impedance to the power transfer efficiency of the series-to-series inductive resonant wireless power transfer at the resonance frequency is reviewed in details. The analysis is carried out by utilizing the theoretical inductive resonance wireless power transfer model using the MATLAB ® package. In this paper, the experiment is designed to confirm the highest power transfer efficiency is obtained at the resonance frequency for the given value of the coupling coefficient. Besides that, the experiment is also conducted to find the optimum load impedance for all given value of coupling coefficient. The analysis shows that the maximum wireless power transfer efficiency for series-to-series inductive resonant wireless power transfer is at the maximum peak when operational at the resonance frequency. In addition, the power transfer efficiency is improved by working at the optimum load impedance. The experimental set up is presented and the analytical results are reported

Frequency reliant wireless power transfer link for a applications of mWatts devices

In general, the resonant inductive wireless power transfer is superior in power efficiency consequently provides longer transfer range over inductive or capacitive wireless power transfer. For that reason, the theoretical analysis and simulation results of the series-to-series wireless power transfer topology were discussed in this paper. The study is conducted to analyze the effect of the coupling coefficient (k) of the coupling coils to the resonant frequency and input impedance of the transmitting circuit. The analysis is conducted by analyzing the equivalent circuit model by using circuit theory. The equivalent circuit model is developed by using the T-equivalent circuit. Further, the result is validated with the circuit simulation using the ISIS Proteus simulation package. The results of the analysis used in developing the highly efficient series-to-series wireless power transfer

Optimized RC timing technique for accurate measurement of minute capacitance changes

This paper presents a technique for accurate measurement of small capacitive changes. This is based on selecting the most linear part of the curve obtained by charging the capacitor undergoing changes through a known resistor value. This measurement is part of the design of a system for measuring blood glucose content non-invasively. The technique is based on measuring ultra-low low glucose levels in the blood as capacitive changes converted into RC timing constant optimized using a circuit set to trigger at an appropriate time activating a counter. The measured data is captured instant later, selecting the most linear part of the charging curve. The results so obtained are compared with the ones obtained through RC-timing standard procedure. The technique reported is with a remarkable low error of about 2.25% as against 11.78% by the standard RC-timing technique

The load reliant power transfer of the series-to-series inductive resonant wireless power transfer

In this paper, the effect of the output impedance to the power transfer efficiency of the series-to-series inductive resonant wireless power transfer at the resonance frequency is reviewed in details. The analysis is carried out by utilizing the theoretical inductive resonance wireless power transfer model using the MATLAB ® package. In this paper, the experiment is designed to confirm the highest power transfer efficiency is obtained at the resonance frequency for the given value of the coupling coefficient. Besides that, the experiment is also conducted to find the optimum load impedance for all given value of coupling coefficient. The analysis shows that the maximum wireless power transfer efficiency for seriesto-series inductive resonant wireless power transfer is at the maximum peak when operational at the resonance frequency. In addition, the power transfer efficiency is improved by working at the optimum load impedance. The experimental set up is presented and the analytical results are reported