• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.59-60
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• 2014

In this paper, development of laser diode driver with 2.5kW rating is presented. The driver is configured with interleaved PFC converter, high frequency full bridge DC-DC converter, two laser diode drivers and ${\mu}$-processor based controller. The system has two laser diode drivers for providing high current and low current. High current driver delivers normal output power of diode; low current driver is for providing critical current of diode for long lifetime. Computer simulation and experiment was performed for verification, as the results, developed driver performs well.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.4
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• pp.377-383
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• 1999

A new soft switching single stage AC-DC full bridge boost converter with unit input power factor and isolated output i is presented in this paper. Due to the use of a non-dissipative snubber on the primary side, a single stage high-power f factor isolated full bridge boost converter has a significant reduction of switching losses in the main switching devices. The non-dissipative snubber adopted in this study consists of a snubber capacitor Cr, a snubber inductor Cr, a fast r recovery snubber diode Dr' and a commutation diode Dp. This paper presents the complete operating principles, t theoretical analysis and experimental results.

• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.3
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• pp.237-240
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• 2021

This research proposes a new rectifier circuit to reduce the circulating current of a phase-shifted full bridge converter. The proposed circuit is a structure in which the output inductor of the secondary rectifier circuit is changed to a coupled inductor in the phase-shifted full bridge with the existing center-tapped rectifier. The parts are rearranged after adding a diode. After applying the proposed circuit, the circulating current to the primary current of the transformer and the voltage stress of the rectifier diode on the secondary side of the transformer are reduced. Accordingly, the snubber loss of the rectifier is improved. By reducing the circulating current and snubber loss, the circuit achieves higher efficiency than conventional circuits. In this research, we present the structure of the proposed circuit, its strengths, and the analysis results from experiments. Furthermore, its effectiveness is verified through the experimental results of a prototype converter with an input of 300-400 V and an output of 50 V/1 kW.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.144.1-144.1
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• 2016

We fabricate organic single crystal nanowire heterojunction p-n diode poly(3-hexylthiophene)(P3HT) and from Phenyl-C61-butyric acid methyl ester(PCBM) using by liquid-bridge mediated nanotransfer molding(LB-nTM) method. LB-nTM has been reported an one step direct printing method for making well-aligned nanowire arrays. Moreover, multi-patterning nanostructures can be fabricated with the consecutive printing process. As a result, it is possible to make simple and basic concept of heterojunction devices such as lateral organic p-n nanojunction diode. P3HT/PCBM nanowires heterojunction diode has rectifying behavior with on/off ratios of ~20.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.289-291
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• 2005

In this paper results of the experiment which used LLC resonant half bridge DC-DC converter to a portable electrical equipment. LLC resonance Half Bridge DC-DC converter which was used in this experiment improved an efficiency because it reduced switching, conduction losses and with synchronous rectifier. As a result of the experiment, this proposed converter could verified an increase of 2% to the efficiency more than diode rectifier.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1392-1394
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• 2005

In this paper results of the experiment which used LLC resonant Half Bridge DC-DC converter to a portable electrical equipment. LLC resonant Half Bridge DC-DC converter which was used in this experiment improved an efficiency because it reduced switching, conduction losses and with synchronous rectifier. As a result of the experiment, this proposed converter could verified an increase of 2% to the efficiency more than diode rectifier.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.3
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• pp.293-301
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• 2011

This paper proposes a bridgeless half-bridge AC-DC converter with high-efficiency. The proposed converter integrates the bridgeless power factor correction (PFC) circuit with the asymmetrical pulse-width modulated (APWM) half-bridge DC-DC converter. It provides the isolated DC output voltage from the AC line voltage without using any full-bridge diode rectifier. Conduction losses are lowered with a simple circuit structure. Switching losses are also reduced by achieving zero-voltage switching (ZVS) of the power switches. By using series-connected two transformers, the proposed converter provides a low-profile and high power density for AC-DC converters. The performance of the proposed converter is verified from a 250 W (48 V / 5.2 A) experimental prototype circuit at $90 \;V_{rms}$ line voltage.

• Proceedings of the KIPE Conference
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• 2001.12a
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• pp.149-152
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• 2001

A Single-phase bi-directional inverter Using a diode bridge-type resonant circuit to implement ZVT(Zero Voltage Transition) switching is Presented. It is shown that the ZACE(Zero Average Current Error) algorithm based polarized ramptime current control can provide a suitable interface between diode bridge-type resonant circuit DC link and the inverter. The current control algorithm is analyzed about how to design the circuit with analyzed switch which m ZVT operation for the main power switch The simulation and experimental results would be shown to verify the proposed current algorithm, because the main power switch is turn on with ZVT and the bi-directional inverter is operated.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.179-185
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• 2005

This paper presents a novel circuit topology of a high efficiency single-phase power conditioner. This power conditioner is composed of time-sharing sinewave absolute pulse width modulated boost chopper with a bypass diode in the first power processing stage and time-sharing sinewave pulse width modulated full-bridge inverter in the second power processing stage operated by time-sharing dual mode pulse pattern control scheme. The unique operating principle of the two power processing stage with time-sharing dual mode sinewave modulation scheme is described with a design example. This paper proposes also a sinewave tracking voltage controlled soft switching PWM boost chopper with a passive auxiliary edge-resonant snubber. The new conceptual operating principle of this novel power conditioner related to new energy utilization system is presented and discussed through the experimental results.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.295-298
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• 1999

In this paper, the diode bridge-type ZVT(Zero-Voltage Transition) inverter is proposed. It consists of one auxiliary switch, three resonant inductors and six blocking diodes. So, the advantage of the proposed topology is the reduction of the auxiliary switch. The topology of the proposed ZVT inverter is analyzed with a description of the control conditions based on the load current. Therefore, this paper two control algorithms were discussed. A variable resonant pattern control algorithm by using load current feedback and a resonant period control algorithm by using resonant inductor current feedback is proposed in order to achieve the ZVT switching condition in full control range and the reducing current spike main switches cause by reverse recovery problem.