• Journal of IKEEE
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• v.25 no.3
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• pp.517-527
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• 2021

This paper presents the phase-shift full-bridge DC-DC converter using the one-chip micom. The proposed converter primary is the full-bridge power topology that operates with the unipolar pulse-width modulation (PWM) by the phase-shift method, and the secondary is the full-bridge full-wave rectifier composed of four diodes. The control of proposed converter is performed by the one-chip micom and its MOSFET switches are driven by the bootstrap circuit. Thus the total system of proposed converter is simple. The proposed converter achieves high-efficiency using the resonant circuit and blocking capacitor. In this paper, first, the power-circuit operation of proposed converter is explained according to each operation mode. And the power-circuit design method of proposed converter is shown, and the software control algorithm on the micom and the feedback and switch drive circuits operating the proposed converter are described, briefly. Then, the operation characteristics of proposed converter are validated through the experimental results of a designed and implemented prototype converter by the shown design and implementation method in this paper. The highest efficiency in the results was about 92%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.2
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• pp.333-338
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• 2008

In this paper, a new NMOS current-mirror type bridge rectifier for driving RFID chips, whose minimum input voltage required to obtain the effective DC output voltage is low enough and whose power dissipation can be reduced than that of conventional one, is proposed. The designed rectifier is able to supply high enough and well-rectified DC voltages to drive RFID transponder chips for the frequency range of 13.56 MHz HF(for ISO 18000-3), 915 MHz UHF(fur ISO 18000-6), and 2.45 GHz microwave(for ISO 18000-4). Output characteristics of the proposed rectifier are analyzed with the high frequency equivalent circuit. And the circuitry method for effective reducing of the gate leakage current due to the increasing of operating frequency is also proposed theoretically. Using this method, the power consumption of $100\;{\mu}W$ and the DC output voltage of 2.13V for 3V peak-to-peak input voltage and $45\;K{\Omega}$ load resistance are obtained. Compared to conventional one, the proposed rectifier operates in more stable and shows superior characteristics in UHF and microwave frequencies.

• Journal of Power Electronics
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• v.8 no.3
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• pp.239-247
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• 2008

This paper presents the design of 1 kW prototype high frequency link boost half bridge inverter-fed DC-DC power converters with bridge voltage-doublers suitable for small scale PEM fuel cell systems and associated control schemes. The operation principle of this converter is described using fuel cell modeling and some operating waveforms. The switching mode equivalent circuits are based on simulation results and a detailed circuit operation analysis at soft-switching conditions.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.86-89
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• 2000

The rectifier circuit has been used in the various fields of inverter progress. This is simple and low price. Otherwise it has many problems in harmonic low power factor and etc. This paper use the twin converter of two jewel booster. It doesn't need the detection of voltage current and control PWM. The twin converter has stably the rectification source. Also the circuit is used a half-bridge inverter in the electronic ballast for lighting. Therefore this method is confirmed in high efficiency.

• ETRI Journal
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• v.31 no.3
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• pp.298-303
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• 2009

A single-switch parallel resonant converter for induction heating is implemented. The circuit consists of an input LC-filter, a bridge rectifier, and a controlled power switch. The switch operates in soft commutation mode and serves as a high frequency generator. The output power is controlled via the switching frequency. A steady state analysis of the converter operation is presented. A closed-loop circuit model is also presented, and the experimental results are compared with the simulation results.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.150-152
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• 1998

ZVS Half-Bridge converter is proposed. This converter is operating in fixed switching frequency to regulate output voltage. The ZVS is maintained by Partial resonance during the OFF interval of both switches. Using self-driven synchronous rectifier, this circuit minimizes the Power loss in the rectification circuit. 50[W] ZVS Half-Bridge converter is simulated and built. Two results has been compared.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.355-357
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• 1996

With the wide-spread use of rectifier in electronic equipments, such problems as electronic components failures or equipment disorders have been occurred due to current harmonics. To overcome these problems, power factor correction circuits employing boost converter have been used. The switching stress of boost converter can be reduced by snubber circuit. Recently, research activities in snubber circuits have been directed to energy recovery snubber for improving the efficiency of power converter. In this study, a new passive snubber circuit which can recover trapped snubber energy without added control is proposed for boost converter The control of boost converter with proposed snubber is the same as the conventional one. In addition, the energy recovery circuit can be implemented with a few passive components. The circuit operation is confirmed through simulation.

• Journal of information and communication convergence engineering
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• v.7 no.1
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• pp.52-56
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• 2009

In this research, we have studied the development of dc-dc converter suitable for the driving of mobile instruments by using a dye-sensitized solar cell(DSC). We also have designed a interlocking circuit. The circuit makes power generation be saved in one battery and concurrently be discharged in the other battery. As this application, mobile devices such as MP3, cellular phone are operated by using power generator from DSC during the daytime and they can be operated by using the saving energy of the daytime during the night. Consequently, it has a simple and robust circuit configuration. Besides, we designed dc-dc converter circuit to drive low power instruments by using NMOS switch and PMOS rectifier. Operational modes are analysed, and then validity of the proposed interface circuit is verified through DCS.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1044-1048
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• 2001

This paper proposes a nonlinear impedance circuit composed by diodes and inductors or capacitors. This circuit needs no control circuits and switches, and the impedance value is changed by the polarity of current or voltage. This paper presents one of these applications to improve the input current of capacitor input diode rectifiers. The rectifier using the nonlinear impedance circuit id constructed with four diodes and four capacitors in addition to the conventional rectifiers, that is, it has eight diodes and five capacitors, including a DC link capacitor. It makes harmonic components of the input current reduce and the power factor improve. A circuit design method is shown by experimentation and confirmed simulation. It explained that compared conventional pulse-width modulated (PWM)inverter with half pulse-width modulated (HPWM) inverter proposed HPWM inverter eliminated dead-time by lowering switching loss and holding over-shooting.

• Journal of Power Electronics
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• v.18 no.3
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• pp.902-909
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• 2018

This study investigates the influences of different core parameters on the dynamic performances, such as rise time and overshoot, in pulse transformers for the triggering circuit of SCRs. First, a simplified transformer equivalent circuit, which emerges from a standard transformer equivalent circuit, is developed to analyze the step response. Second, the relations between the dynamic performances and the parasitic parameters are calculated by the simplified equivalent circuit. Third, the variations of rise time and overshoot, which are vital to the stability of triggering SCRs, with different core parameters, such as mechanic dimensions and topologies, are comprehensively investigated by analyzing the parasitic parameters. Finally, prototype transformers are fabricated to experimentally validate the analysis. The presented method can practically instruct the design of a pulse transformer for triggering SCRs.