• ETRI Journal
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• v.35 no.2
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• pp.226-233
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• 2013

This paper presents a two-stage power-efficient class-AB operational transconductance amplifier (OTA) based on an adaptive biasing circuit suited to low-power dissipation and low-voltage operation. The OTA shows significant improvements in driving capability and power dissipation owing to the novel adaptive biasing circuit. The OTA dissipates only $0.4{\mu}W$ from a supply voltage of ${\pm}0.6V$ and exhibits excellent high driving, which results in a slew rate improvement of more than 250 times that of the conventional class-AB amplifier. The design is fabricated using $0.18-{\mu}m$ CMOS technology.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.11
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• pp.37-46
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• 2013

This paper proposes the boost type bidirectional zero current switching(ZCS) DC/DC converter of transformer series construction for electric vehicle operation using low voltage battery. This converter can high boost through the double voltage circuit and series construction of output part using two converters. This converter system has the advantages that bidirectional power transfer is excellent, size and making of transformer because of this converter keeps the transformation ratio to 1:1. Proposed DC/DC converter uses the ZCS method to decrease the switching loss. By replacing reactance ingredients of L-C resonance circuit for ZCS with leakage inductance ingredients of high frequency transformer and half-bridge capacitor it reduces system size and expense because of not add special reactor. It can confirm to output of high voltage to operate the electric vehicle with low voltage of input and operation of ZCS in all load region through the result of PSIM simulation and experiment.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1038-1041
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• 2006

We report low operating voltage and long lifetime organic light-emitting diodes (OLEDs) with a vanadium oxide $(V_2O_5)-doped$ N,N'-di(1-naphthyl)- N,N'-diphenylbenzidine $({\alpha}-NPD)$ layer between indium tin oxide and ${\alpha}-NPD$. At a luminance of $1000\;cd/m^2$, $V_2O_5$ doped ${\alpha}-NPD$ device shows a operation voltage of 5.1V, while the device without $V_2O_5$ shows 5.8V. The $V_2O_5$ doped $({\alpha}-NPD)$ device also shows a longer lifetime and smaller operation voltage variation over time. It is suggested that the improved device performance can be attributed to the higher hole-injection efficiency and stability of the $V_2O_5$ doped $({\alpha}-NPD)$ layer.

• Journal of Sensor Science and Technology
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• v.18 no.1
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• pp.95-101
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• 2009

A simple and new CMOS potentiostat circuit for amperometric sensor is described. To maintain a constant potential between the reference and working electrodes, only one differential difference amplifier (DDA) is needed in proposed design, while conventional potentiosatat requires at least 2 operational amplifiers and 2 resistors, or more than 3 operational amplifiers and 4 resistors for low voltage CMOS integrated potentiostat. The DDA with rail-to-rail design not only enables the full range operation to supply voltage but also provides simple potentiostat system with small hardwares and low power consumption.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.1150-1153
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• 1992

A new soft-switching resonant type inverter is proposed to obtain the low voltage stress. In this proposed inverter, only one additional switch is used for the soft commutation. Therefore, a simple structure and a easy control can be available. Moreover, the PWM capability can be highly improved due to tile convenient choice of switching condition. Based on the operational principle, analysis and design procedures are described. Through the simulation, the operation of the proposed invertor is verified.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.179-182
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• 2006

This paper introduce a different-type voltage-controlled oscillator (VCO) for PLL frequency synthesizer, And also the architecture of a high speed low-power-consumption CMOS dual-modulus frequency divider is presented. It provides a new approach to high speed operation and low power consumption. The proposed circuits simulate in 0.35 um CMOS standard technology.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1333-1335
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• 2005

STATCOM has many advantages rather tan SVC at a view point of a continuous controllability of reactive power and response time of reactive power compensation In this paper, 30kVA STATCOM for compensation of low voltage industrial loads is designed and its operation characteristics is analyzed and verified by simulation.

• Applied Science and Convergence Technology
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• v.27 no.2
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• pp.23-25
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• 2018

With respect to the electrode structure and the discharge characteristics, the atmospheric pressure plasma sheet of a thin polyimide film is introduced in this study; here, the flexible plasma device of a dielectric-barrier discharge with the ground electrode and the high-voltage electrode formulated on each surface of a polyimide film whose thickness is approximately $100{\mu}m$, that is operated with a sinusoidal voltage at a frequency of 25 kHz and a low voltage from 1 kV to 2 kV is used. The streamer discharge is appeared along the cross-sectional boundary line between two electrodes at the ignition stage, and the plasma is diffused on the dielectric-layer surface over the high-voltage electrode. In the development of a plasma sheet with thin dielectric films, the avoidance of the insulation breakdown and the reduction of the leakage current have a direct influence on the low-voltage operation.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.280-282
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• 2011

This paper presents a development of voltage compensation dc/dc converter to decrease fuel consumption of RTGC system. We used 3-phase interleaved converter, which has the same structure as the commercially available three-phase inverter, is used. RTGC system is supplied the power from diesel-engine generator. According to power demand, engine speed is varying 20~60Hz, and voltage is varying 210Vac ~ 480Vac. When idle mode or low power operation dc/dc converter operates by constant output voltage control. The perpormance of converter is evaluated through several experiments with a real RTGC. Proposed system can cut down fuel consumption by 36% at idle mode operation.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.592-596
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• 2004

This paper deals with the operation of a flywheel energy storage UPS. The ups has good features such as long life-time, improved efficiency, no environment problems, reduced size and space, and low maintenance cost compared with the conventional UPS using battery. The operating principle of the UPS is analysed in each mode including charging, voltage compensation, discharging, and voltage unbalance compensation. Especially, the tracking characteristic of the disturbed phase of the source voltage after outage is analysed. The usefulness of the operation is proved through simulations.