• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.6
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• pp.433-440
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• 2007

Recently, the reduction of standby power consumption is significantly issued in electronic and electrical industry for the conservation of environment. In the case of a switched mode power supply (SMPS), it is demanded high efficiency at extremely low output power conditions by consumers. However, it is very different from high efficiency techniques at full load conditions. In addition, many SMPSs are designed as a multi-output circuit for various loads because of cost down. This circuit is difficult to implement both high efficiency and good cross regulation performance, simultaneously. In this paper, secondary side post regulator (SSPR), current mode control method, and power sequence control technique are proposed to reduce standby power consumption and to improve cross regulation performance of the multi-output SMPSs which consist of single or multiple converter. The proposed methods are analyzed by their operational principles and optimal designs verified by experimental results with 110[W] and 270[W] SMPSs.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.1
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• pp.148-156
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• 2007

This paper explains stocker system that is operated in the long distance and linear area. The power system of stocker system uses Contactless Power Supply(CPS) to reduce problems of particle generation. The circuit configuration of CPS is simplified than the conventional ones, and the prototype is designed for commercial product. To transfer output data(information) from crane(secondary vehicle system) of the CPS to Primary system optical modem and TMS320F243(DSP, TI) are used between primary and secondary. power system are used, and the output voltage is controlled by operating frequency modulation. This paper is applied to stocker system controlled as one to one communication between the moving part(secondary system) and fixed part(primary system) of crane using optical modem. The study makes one to multi communication between fixed part and moving part for the purpose of multi crane operation of stocker system and must be done in the future.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.592-593
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• 2012

Buck converter must operate at fairly high switching frequency for miniaturizing a whole circuit and achieving a fast response. However, at the conditions of low output voltage, high output current, and high switching frequency, the influence of parasitic elements to circuit operation will become extremely obvious. In this paper, it has been shown that these parasitic elements of output capacitor link the ripple of the output voltage. The MCP capacitors and aluminum electrolytic capacitors are applied to the buck converter and observed characteristics and the experimental results were reported.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2033-2036
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• 1997

In this paper, we proposed a novel current-fed DC-DC converter with multi-output. It has two winding reactor in series with the input source of the converter. By using the 2nd winding recycling the energy stored in the reactor to the input, the double-outputs DC-DC converter can be created, which makes it a good choice for a multi-output power supply with more outputs and has savings in cost and space. The steady state and dynamic characteristics of the converter are analyzed in detail by using the state space averaging method. It is found that the maximum value of $V_{o2}$ exists in the 2nd output and also during the MOSFET off period, the energy stored in the magnetizing inductance is reset through auxiliary winding $N_3$, so the duty cycle is restricted to 50%. Theoretical and experimental results were taken from the converter rated at switching frequency 50kHz. input voltage 50V. output voltage 5V. 12V and output power 65W. As a result, both results were well consistent. Therefore, it is varified the validity of the proposed converter in this paper.

• Journal of Sensor Science and Technology
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• v.28 no.2
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• pp.121-126
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• 2019

The voltage-controlled oscillator is one of the fundamental building blocks that determine the signal quality and power consumption in RF transceivers for wireless sensor networks. Ring oscillators are attractive owing to their small form factor and multi-phase capability despite the relatively poor phase noise performance in comparison with LC oscillators. The phase noise of a ring oscillator can be improved by using a coupled structure that works at a lower frequency. This paper introduces a 2.4 GHz low-noise ring oscillator that consists of two 3-stage coupled ring oscillators. Each sub-oscillator operates at 800 MHz, and the multi-phase signals are combined to generate a 2.4 GHz quadrature output. The voltage-controlled ring oscillator designed in a 65-nm standard CMOS technology has a tuning range of 800 MHz and exhibits the phase noise of -104 dBc/Hz at 1 MHz offset. The power consumption is 13.3 mW from a 1.2 V supply voltage.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.273-274
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• 2014

다 출력 Flyback 타입 전원공급장치(Switch Mode Power Supply)에서 제어 출력단과 비 제어 출력단 부하 차이로 인하여 비 제어 출력단 전압이 크게 상승하는 현상이 발생한다. 본 논문은 전원공급장치 트랜스포머 결합도가 비 제어 출력 전압 변동 상승에 미치는 영향을 분석하기 위해 다양한 트랜스포머 권선 방법을 제시하였고, 이를 실험을 통해 검증하였다.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.5
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• pp.448-456
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• 2011

In this paper, we proposed a LED driver that allows to use a long lifetime MLCC with small voltage capacity to replace the electrolytic condenser that has been used at the output part by storing only the voltage fluctuation due to temperature variation in the output condenser. The proposed LED driver can allow to use a long lifetime MLCC with small power loss as the output condenser instead of the conventional electrolytic condenser with short lifetime because it stores only the voltage fluctuation due to the temperature variation of the LED light source in the output condenser by connecting the output condenser with the input power supply in series in the basic topology of the conventional boost DC/DC converter. In this study, we performed a simulation to verify the conventional DC/DC converter and the proposed DC/DC converter. It was shown that the DC/DC converter proposed through the experiment allows to use MLCC as the output condenser and the efficiency can be improved.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.11a
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• pp.59-62
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• 2007

In this paper, we composed solar generation system with multi-phase interleaved boost converter Solar generated voltage is low, so it has need of the boost power conversion device for supply power to normal load. The multi-phase interleaved boost converter is easy to boost voltage and it can be reduced both input current ripple and output voltage ripple because it is composed with multi-phase. We simulated and tested multi-phase interleaved boost converter applied three-phase.

• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.214-217
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• 2003

The connectorless power supply system on that multi-contact causes confidence when the wiring reconstructed in the rear. As you see above, contact points between sets and indoor space cause inferior function of audio frequency so it needs to be eliminated. This paper explains the structure of connectorless power supply to supply the system with power crossing the air gap in the part of inductively in the connectorless power supply of both magnetic and electrical model. To get maximum output of electrical load, compensating capacitor compensates to show inter-inductance, lequeage-inductance reducing the track-inductance and access the conditions for resonance. At that time it accesses the maximum electric power. The small change of the value of compensating capacitor causes the changes of maximum electric power. Here the power electronics technology is used not only in the industrial machinery but also in the home appliances so the switching power supply is used to actualize the miniaturization, lightweight, and high efficiency. Generally the condenser input methods are widely used in the rectification circuit of switching power supply, but condenser input method generate great quantity of high frequency components because with this method the current flows in the power input filtering condenser only around value of peak of ac input voltage. To solve these problems, installation of power factor improve circuit on the front of filtering capacitence was considered. Several methods were suggested regarding, but the active filter method which makes smalliging and highly power factor possible are the produce main stream. IC for power factor improvement can be utilized by CMOS process proposing low power consumption. When the high power factor is considered seriously in the power factor improvement circuit, active filter method is selected. In the active filter method, the boost converter is used. Regarding this ·the boost converter is needed.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.181-184
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• 2005

Operating conditions of photovoltaic power generator is very sensitive to the PV modules. The PV module's control is an importance issue in the removing DC ripple noise. In this paper, the phase-shifted-carrier technique, which is a new three-step dc-dc power multi-converter schemes, is applied to solar generator system to improve the output current waveform. The novel type of three-step dc-dc converter presented has many features such as the good output waveform, high efficiency, low switching losses, low acoustic noise. The circuit configuration is constructed by the conventional full-bridge type converter circuit using the isolated DC power supply for which the solar cell is very suitable. In the end, a circuit design for understanding three-step dc-dc converter and new solar power system were presented