Yazar "Eguchi, K." seçeneğine göre listele

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    Design of an Inductor-less Step-Down AC/AC Converter Combined with a Symmetrical-Type Converter and Ladder-Type Converters
    (Institute of Electrical and Electronics Engineers Inc., 2020) Eguchi, K.; Asadi, Farzin; Ishibashi, T.; Oota, I.
    In this paper, a new inductor-less step-down ac/ac converter is designed by using switched-capacitor (SC) techniques. Unlike existing inductor-less ac/ac converters, the proposed ac/ac converter consists of ladder-type converters nested in a symmetrical-type converter. In the proposed ac/ac converter, the $1/4\times$ voltage gain is achieved by converting an ac input twice by the symmetrical-type converter and the ladder-type converters. The proposed new topology enables to reach not only high power efficiency but also high input power factor. To evaluate the characteristics of the proposed ac/ac inverter realizing the $1/4\times$ voltage gain, we conducted theoretical analysis and simulation program with integrated circuit emphasis (SPICE) simulations. The SPICE simulation results demonstrated that the proposed ac/ac converter can achieve about 84% power efficiency and 0.88 input power factor when the output power is 200W. © 2020 IEEE.
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    Design of an LED sink driver using a switched-inductor and switched-capacitor buck-boost converter with high voltage gains
    (Institute of Electrical and Electronics Engineers Inc., 2020) Eguchi, K.; Shibata, A.; Asadi, Farzin; Ishibashi, T.; Harada, Y.; Oota, I.
    A novel light emitting diode (LED) sink driver using a switched-inductor and switched capacitor (SISC) buck-boost converter is proposed in this paper. The proposed LED driver can achieve a high voltage gain by cascading the SI buck-boost block and the SC doubler block with a flying capacitor. The proposed negative SISC topology can provide not only high voltage gain but also flexible controllability of LED currents. The performance of the proposed SISC buck-boost converter was clarified by simulation program with integrated circuit emphasis (SPICE) simulations. In the performed simulations, the proposed SISC buck-boost converter can improve power efficiency about 6% from the conventional hybrid buck-boost converter when the duty factor D is 0.5 and the output power is 500mW. Furthermore, the feasibility of the proposed SISC topology was confirmed by breadboard experiments. © 2020 IEEE.
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    A high voltage multiplier using stacked hybrid Cockcroft–Walton/Dickson multipliers
    (IOP Publishing Ltd, 2021) Eguchi, K.; Nakashima, D.; Ishibashi, T.; Asadi, Farzin
    A high voltage multiplier is one of the most important components for shockwave non-thermal food processing systems. In the design of the high voltage multiplier for shockwave non-thermal food processing systems, not only high voltage gain but also high speed operation and low voltage stress of circuit components are required. In this paper, a novel high voltage multiplier with stacked topology is proposed for shockwave non-thermal food processing systems. Unlike conventional high voltage multipliers, the proposed multiplier is designed by stacking hybrid Cockcroft-Walton/Dickson multipliers (HCWDMs). In the proposed multiplier, high speed operation is achieved, because the stacked topology can reduce the number of multiplier stages. Furthermore, voltage drop of higher multiplier stages and voltage stress are mitigated by the stacked topology using HCWDMs. The validity of the circuit design is confirmed by the laboratory experiments regarding the prototype of the shockwave non-thermal food processing system. The experimental results demonstrate that the proposed multiplier can generate about 3.9 kV within 113 s by converting the ac input 100 V at 60 Hz. © 2021 Institute of Physics Publishing. All rights reserved.
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    A Hybrid LED Sink Driver Combining a Buck-Boost Converter and a Switched-Capacitor Step-Up Converter with Nested Topology
    (IOP Publishing Ltd, 2021) Eguchi, K.; Shibata, A.; Do, W.; Asadi, Farzin
    For LED lighting applications, this paper presents a novel light emitting diode (LED) sink driver with high voltage gains. Unlike traditional LED sink drivers, the proposed LED sink driver consists of a buck-boost converter and a switched-capacitor (SC) step-up converter with nested topology, where an input voltage is converted twice by cascading these two converter blocks. Therefore, theproposed hybrid topology enables the LED sink driver to achieve not only flexible control of an output voltage but also high voltage gains and few passive components. The characteristics of the proposed LED sink driver are investigated by theoretical analysis, simulation program with integrated circuit emphasis (SPICE) simulations, and breadboard experiments. In the performed simulations, the power efficiency of the proposed driver reaches about 80 % at 500 mW when the duty factor is 0.5. Furthermore, the experiment demonstrates high voltage gains and flexible controllability of an output voltage. © Published under licence by IOP Publishing Ltd.
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    An LED Driver Connecting a Nested-Type SC Converter and an SI Buck-Boost Converter in Parallel
    (Institute of Electrical and Electronics Engineers Inc., 2021) Eguchi, K.; Shibata, A.; Do, W.; Asadi, Farzin
    For light emitting diode (LED) lighting applications, a novel hybrid LED driver with high voltage gains is proposed in this paper. Unlike existing LED sink drivers with series-connected structure, the proposed driver has the switched-inductor and switched capacitor (SISC) topology combining with an SI buck-boost converter and a nested-type SC converter in parallel. In the proposed topology, the LED cathode and anode are connected to the SI buck-boost converter and the nested-type SC converter, respectively. The characteristics of the proposed topology are analyzed theoretically. Furthermore, the validity of the proposed topology is confirmed by simulation program with integrated circuit emphasis (SPICE) simulations and breadboard experiments. The SPICE simulations and experiments reveal that the proposed driver can achieve high voltage gains and flexible controllability of outputs. © 2021 IEEE.