• Journal of IKEEE
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• v.19 no.2
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• pp.260-264
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• 2015

In this paper, we propose mode selector for operating a switching system and regulator of linear system to detect the load current. The proposed mode selector can be a mode switching of linear system and switching system, and it has been proposed to compensate for the disadvantages of regulator of switching system with low efficiency in light load conditions. At light load conditions, the mode selector is possible to provide a high efficiency in light load condition by switching the mode to the regulator of linear system. The mode selector was designed to using a Dongbu Hitek $0.18{\mu}m$ CMOS process.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.212-216
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• 2001

Because conventional switching converters have been usually using unbalanced circuit topologies, parasitic capacitance between the drain/collector of an active switch and the frame ground through its heat sink may generate the common-mode conducted noise. We have proposed a balanced switching converter circuit, which is an effective way to reduce the common-mode conducted noise. As an example, a boost converter version of the balanced switching converter was presented and the mechanism of the common-mode noise reduction was explained using equivalent circuits. This paper extends the concept of the balanced switching converter circuit and presents a buck-boost converter version of the balanced switching converter. The feature of common-mode noise reduction is confirmed by experimental results and the mechanism of the common-mode noise reduction is explained using equivalent circuits.

• Journal of Power Electronics
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• v.2 no.2
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• pp.139-145
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• 2002

Because conventional switching converters have been usually using unbalanced circuit topologies, parasitice between the drain/collertor of an active switch and frame ground through its heat sink may generate the commom-mode conducted noise. We have proposed a balanced switching converter circuit, whitch is an effective way to reduce the commom-mode converter version of the balanced switching converter was presented and the mechanism of the commom-mode noise reduction was explained using equivalent circuits. This paper extends the concept of the balanced switch converter circuit and presents a buck-boost converter version of the blanced switching converter. The feature of common-mode niose reduction is confirmed by experimental resuits and the mechanisem of the commom-mode niose reduction is explained using equivalent circuits.

• Proceedings of the KIPE Conference
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• 1998.11a
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• pp.44-48
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• 1998

In the buck-boost DC-DC converter which is used at a certain situation such as in factories where loads often change a lot, the switches in the device make big energy loss in operating at Buck-Boost Mode due to hard switching and are affected by lots of stresses which decrease the efficiency rate of the converter. In order to improve this problem, to decrease the loss of snubber and switching, it has been investigated that zero voltage switching mode and zero current switching mode which make the operation of switches with soft switching. For the more sophisticated and advanced device, this paper is presented the Partial Resonant Soft Switching Mode Power Converter which is adapted the power converter having the partial resonant soft switching mode, that makes switches operate when the resonant current or voltage becomes zero by making the resonant circuit partially at turning on and off of the switches with suitable layout of the resonant elements and switch elements in the converter. Also, this paper includes the analysis and simulation of the Partial Resonant type Buck-Boost Chopper.

• Journal of the Korean Society of Combustion
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• v.16 no.3
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• pp.12-20
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• 2011

Oxy-coal combustion for $CO_2$ capture in coal power plants entails a mode switching from air-firing to oxyfiring. In this study, procedure of the mode switching was investigated and discussed through experiments in pilot scale facilities: (1) a 0.3 $MW_{th}$ furnace with a vertical single burner and a FGR(Flue Gas Recirculation) system (2) a 1 $MW_{th}$ furnace with horizontal 4 burners and a FGR system. Principle of the mode switching was established and performed with control of FD fan, FGR fan, ID fan and oxygen flow rates. We have found that equivalence ratio in the oxy-firing mode should be increased more than that in the air-firing to achieve stable mode switching. Control of FD, ID and FGR fans should be performed carefully in the mode switching, in the sense of complete combustion and flame attachment. Moisture contents in the ash and the flue gas recycled to the primary oxidizer stream should be removed to prevent condensation, corrosion and duct clogging.

• Journal of Biomedical Engineering Research
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• v.16 no.3
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• pp.265-270
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• 1995

An implementation scheme of the magnetic nerve stimulator using a switching mode power supply is proposed. By using a switching mode power supply rather than a conventional linear power supply for chArging high voltage cApacitors, the weight and size of the magnetic net've stimulator can be considerably reduced. Maximum output voltage of the developed magnetic nerve stimulator using the switching mode power supply is 3,000 volts and switching time is about 100 msec Experimental results of human nerve stimulations using the developed stimulator are presented.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.735-737
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• 2004

This paper proposes a method of fault diagnostics on switching mode power supply. When the error of switching mode power supply cannot be found when the conventional diagnostics is performed, this proposed method first performs diagnosis on the switching mode power supply strictly to judge the operating condition. This method analyzes the PWM wave which depends on the load change, to make sure the feedback control of the power supply to diagnosis the operation of the power supply system.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.1092-1095
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• 2003

A driving mechanism and excellent features for an in-plane switching twisted nematic liquid crystal mode (IT mode) that could possibly improve the viewing-angle and color shift characteristics and the cell gap error tolerance is proposed. .It is important that the surface azimuthal anchoring strength of the liquid crystal cell differs at the upper and lower substrates. Furthermore. as a rubbing-free LCD. amorphously aligned in-plane switching twisted nematic mode (a-IT mode) is also demonstrated.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.8
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• pp.59-65
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• 2004

In this paper, we propose Pseudo-TN IPS mde(Pseudo-Twisted Nematic In-Plane Switching mode) based on IT(In-plane switching Twisted nematic) mode that increase contrast ratio from improving optical characteristics and analyze the characteristics of Pseudo-TN IPS uude. Optical transmittance is 25% higher for the PTN-IPS mode than for the IT mode. Because aperture ratio of the PIN-IPS is increased. And the control of Liquid Crystal for adjusting optical transmittance is more easier than IT mode, because optical transmittance variation is linear with applying voltage. Contrast ratio is 8% lower for the PTN-IPS mode than for the IT mode in the horizontal direction. But, Contrast ratio is 20% higher for the PTN-IPS mode than for the IT mode in the vertical direction. It has also cell gap margin and many benefits of IT mode, this may be used very well in the future LC Cell design.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.2036-2038
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• 1998

In the buck-boost DC-DC chopper which is used at a certain situation such as in factories where loads often change a lot, the switches in the device make big energy loss in operating at Buck-Boost Mode due to hard switching and are affected by lots of stresses which decrease the efficiency rate of the converter. In order to improve this problem, to decrease the loss of snubber and switching, it has been investigated that zero voltage switching mode and zero current switching mode which make the operation of switches with soft switching. For the more sophisticated and advanced device, this paper is presented the Partial Resonant Soft Switching Mode Power Converter which is adapted the power converter having the partial resonant soft switching mode, that makes switches operate when the resonant current or voltage becomes zero by making the resonant circuit partially at turning on and off of the switches with suitable layout of the resonant elements and switch elements in the converter. Also, this paper includes the analysis and simulation of the Partial Resonant type Buck-Boost Chopper.