사전충전모드를 통한 SCALDO 레귤레이터의 초기 동작특성 개선

권오순(O-Soon Kwon),손준배(Joon-Bae Son),송종규(Jong-Gyu Song) 한국전기전자학회 2016 전기전자학회논문지 Vol.20 No.3

SCALDO(Supercapacitor Assisted LDO) 레귤레이터는 기존 LDO(Low Drop-out) 레귤레이터(이하 LDO)의 낮은 효율을 개선하기 위해 연구되고 있는 회로로서, 회로의 입력단과 LDO사이에 슈퍼커패시터를 부착하여 입력과 출력전압의 차이에 의해 발생하는 불필요한 전력손실을 재사용함으로써 LDO의 효율을 향상시킬 수 있다. 하지만 SCALDO 레귤레이터는 현재 연구 중에 있는 회로로 몇 가지 개선되어야 할 사항들이 남아있다. 그 중 한 가지는 회로의 최초동작 시 LDO에 인가되는 과전압문제이다. 회로의 최초동작 시 슈퍼커패시터가 완전히 방전되어 있어 충전모드 시 입력과 슈퍼커패시터, LDO가 직렬로 연결되는 SCALDO 레귤레이터 특성 상 입력전압이 LDO에 짧은 시간동안 그대로 인가되는데, 입력전압이 출력전압보다 최소 2배 이상 크기 때문에 이는 LDO에 상당히 큰 부담이 될 수 있다. 본 논문에서는 이러한 과전압 문제를 해소하기 위해 회로 동작 전 슈퍼커패시터를 충전시킬 수 있는 사전충전부가 포함된 새로운 SCALDO 레귤레이터를 제안하였으며, 실험을 통해 동작 초기 LDO에 인가되는 과전압이 상당부분 감소됨을 확인하였다. A SCALDO(Supercapacitor Assisted LDO) regulator is a newly studied regulator to improve the efficiency of a LDO regulator. Commonly a LDO regulator has very low efficiency and a SCALDO regulator can improve it considerably because this regulator can reuse meaninglessly wasted energy at the LDO regulator by a supercapacitor witch is attached between input and a LDO regulator. However this regulator has several challenges because it is a being studied regulator. One of them is an overvoltage issue. At initial operating of this regulator, a supercapacior is totally discharged and input is connected with a supercapacitor and a LDO regulator in series. Thus, input voltage is enabled to a LDO regulator and this input voltage is a significant value to a LDO regulator because commonly input voltage is bigger than twice output voltage. In this paper, to solve this overvoltage issue, we proposed a new SCALDO regulator that has a pre-charger for charging a supercapacitor before starting operation. And we found that a proposed SCALDO regulator can properly reduce overvoltage of a LDO regulator through experiments.

DC정합회로를 갖는 능동 Replica LDO 레귤레이터

유인호(Ryu, In-Ho),방준호(Bang, Jun-Ho),유재영(Yu, Jae-Young) 한국산학기술학회 2011 한국산학기술학회논문지 Vol.12 No.6

본 논문에서는 DC 정합회로를 갖는 능동 Replica LDO 레귤레이터에 대하여 나타내었다. Replica단과 출력 단의 DC전압을 정합하기 위하여 DC정합회로를 설계하였다. 능동 Replica LDO 레귤레이터의 PSR특성은 일반적인 레귤레이터 보다 큰 값을 가질 수 있다. 설계된 DC정합회로는 Replica 레귤레이터에서 발생할 수 있는 단점을 줄여 준다. 또한 전체회로를 능동회로로 설계함으로써 칩면적을 줄이고 수동저항을 사용할 때 발생하는 열잡음을 제거할 수 있다. 0.35um CMOS 파라미터를 사용하여 HSPICE 시뮬레이션한 결과, DC정합회로를 이용하여 설계된 레귤레이 터의 PSR특성은 -28dB@10Hz로써 DC정합회로를 사용하지 않는 일반적인 레귤레이터의 -17dB@10Hz보다 개선될 수 있음을 확인하였다. 레귤레이터의 DC출력 전압은 3V이다. In this paper, an active replica Low-dropout(LDO) regulator with DC voltage matching circuit is presented. In order to match the voltage between replica and output of regulator, DC voltage matching circuit is designed. The active replica low dropout regulator has higher Power Supply Rejection(PSR) than that of conventional regulator. The designed DC voltage matching circuit can reduce the drawback that may be occurred in replica regulator. And using fully active element in regulator can reduce the chip area and heat noise with resistor. As results of HSPICE simulation with 0.35um CMOS parameter, the designed active replica LDO regulator achieves Power Supply Rejection, -28@10Hz better than -17@10Hz of conventional replica regulator without DC matching circuit. And the output voltage is 3V.

쌍봉형(Twin Peaks) 금융감독기구 체제 도입 논의 검토

고동원(Dong Won Ko) 성균관대학교 법학연구소 2013 성균관법학 Vol.25 No.1

Recently, in relation to reforming the financial regulatory organizations in Korea, the issue of introducing a "twin peaks" financial regulator model is actively being discussed among scholars and practitioners. The "twin peaks" model refers to the model where a prudential regulator and a business conduct regulator are separately established and operated. While an integrated financial regulator supervises and regulates all financial institutions in all matters, the twin peaks regulators supervise financial institutions according to their respective objectives, I.e. a prudential supervisor focusing on prudential matters of financial institutions, and a business conduct regulator being involved in regulating business conduct of financial institutions in selling their financial products. This twin peaks model is currently adopted in the countries such as Australia, Netherlands, and New Zealand, and recently the United Kingdom is scheduled to implement this model in April 2013. This article intends to analyze the advantages and drawbacks of the twin peaks model, in particular based on the cases of operating in Australia and New Zealand, by interviewing the relevant officials of the regulators in those two countries. As a result, it is assessed that the twin peaks model has more or less advantages of specializing in each operation and contributing to the efficiency of the regulation and supervision (e.g, the business conduct regulator is specializing in legal matters and so is more effective with regard to protecting financial consumers.) On the contrary, it is revealed that the twin peaks model demonstrates drawbacks in the matters of (i) "underlap regulation", i.e., certain financial institutions (e.g. non-bank financial companies, securities firms and fund managers in Australia) are not actually regulated by either financial regulator in the matter of the prudential supervision, (ii) "overlap regulation", i.e., certain financial institutions are regulated by both regulators in the area of their certain businesses, (iii) the possibility of non-cooperation or non-exchange of financial information between the two regulators, in which case it may lead to the inefficiency of financial regulation, and (iv) "commercial imbalance" regulation, i.e., a prudential regulator may engage in an excessive or over-prudential regulation disregarding the demand or environment of financial markets. This article is cautious about introducing the twin peaks model in Korea, because the drawbacks rather than the advantages are highly likely to happen in Korea and in particular the two regulators are not likely to cooperate each other or exchange information between them well, taking into account the situations of conflicts and non-cooperation between the current two regulators (i.e., the Financial Services Commission, the financial regulation policy decision-making agency, and the Financial Supervisory Service, the financial regulation execution agency).

Simulation on Hydraulic Control Characteristics of Regulator System in Bent-Axis Type Piston Pump

Kim, Jong Ki,Oh, Seok Hyung,Jung, Jae Youn Korean Tribology Society 2000 KSTLE International Journal Vol.1 No.2

Variable displacement axial piston pumps are widely used for raising the energy level of the fluid in hydraulic systems. And the regulator is the device which regulates the discharge flow of the piston pump by controlling the swivel angle. The regulator receives the hydraulic pilot pressure and controls the pump output flow depending on the machine load and engine speed. This work deals with constant power control (horsepower control) in the design of a regulator by using a bent-axis type piston pump. In order to effectively use engine power, we must keep the horsepower from the engine to the pump constant. Therefore the regulator operates the constant power control. As a result, optimum power usage is obtained by accurately following the power hyperbola. This study focused on developing a simulation model of a regulator. First, the governing equations of the regulator are derived, and analysis is performed by computer simulation, which can identify significant parameters of regulator. As a result, the variation of the swivel angle, flow rate, hyperbolic curve, inner leakage and responsibility are simulated, and significant parameters of a regulator are identified.

A Single-Stage Resonant Buck-Boost AC Voltage Regulator

Chien-Ming Wang,Chang-Hua Lin,Guan-Yu Chen 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

This paper proposed a single-stage resonant buck-boost ac voltage regulator. The proposed regulator can output a voltage which is larger or lower than the input ac one and is dependence on depending on the instantaneous duty-ratio. This property is not found in the conventional single-stage ac voltage regulator that the ac output instantaneous voltage is always lower than the input ac voltage. The proposed ac voltage regulator uses a series-resonant circuit to configure adaptively the resonant voltage pulse trains. The proposed ac voltage synthesized the resonant voltage pulse trains following the input voltage amplitude to the synthesized sinusoidal waveform (SSW) before output filter. Because the SSW very closes sinusoidal waveform, the proposed ac voltage regulator can use a simple LC filter to filter the undesired harmonics and to get the sinusoidal voltage waveform with low total harmonic distortion (THD). The proposed ac voltage regulator is controlled by constant frequency pulse width modulation technique. Its control circuit is simple. A design example of a 600W proposed ac voltage regulator is examined to assess the system performance. Under rated output power, the power efficiency is over 91% and the total harmonic distortion (THD) is within 6%.

A Modular Three-Phase Voltage Regulator With Fictitious DC-Link

Maoh-Chin Jiang,Yi-Ru Jiang,Tai-Chun Liu 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

A modular three-phase voltage regulator with a fictitious dc-link is proposed. The proposed scheme is the combination of three single-phase modules while each one of the single-phase module is a three-leg ac voltage regulator. Therefore, the proposed voltage regulator reduces the number of main switches and compensates the voltage of each phase independently. Furthermore, a small film ac capacitor is used to replace the electrolytic capacitor, which not only reduce the size of the dc link capacitor and the stress of the switches but also increase the lifetime of the voltage regulator. The proposed scheme can compensate the voltage disturbance such as under-voltage, over-voltage, voltage sag, voltage swell, three-phase voltage unbalance and three-phase load unbalance effectively. Besides, there are several advantages of this structure, for instance: simple system-configuration, rapid voltage-compensation, easy setup-maintenance and decreasing the production cost while increasing the system power density. Eventually, some experimental results are provided to illustrate the steady-state characteristics and transient responses of the proposed modular three-phase voltage regulator.

MOSFET를 이용한 고효율 SCALDO 레귤레이터 구현

권오순,손준배,김태림,송종규,Kwon, O-Soon,Son, Joon-Bae,Kim, Tea-Rim,Song, Jong-Gyu 한국전기전자학회 2015 전기전자학회논문지 Vol.19 No.3

A SCALDO(Supercapacitor Assisted LDO) regulator is a new regulator having advantages of a SMPS(Switch Mode Power Supply) which has a good efficiency and a LDO(Low Drop-out) regulator which has stable output characteristics and good EMI(Electro Magnetic Interference) characteristics. However, a conventional SCALDO regulator needs a lot of power consumption to control its switches and it drops an efficiency of the circuit. In this paper, to reduce switching power consumption and improve an efficiency of the circuit, a new SCALDO regulator adopting MOSFETs as its switching parts is proposed and it is found out that the proposed SCALDO regulator has the maximum 9.5% higher efficiency than the conventional SCALDO regulator. We also try to simplify production process of the circuit by changing switching control method of the circuit from MCU(Micro-controller unit) based firmware control to hardware control using a comparator and a T-F/F(Flip Flop).

전자제어 디젤엔진의 연료압력 레귤레이터 고장에 따른 진단 및 성능 연구

김태중(Kim, Tae-Jung),조홍현(Cho, Hong-Hyun) 한국산학기술학회 2015 한국산학기술학회논문지 Vol.16 No.3

배출가스 규제강화에 대응하기 위해 전자제어 디젤엔진의 적용으로 연료 분사량과 연료 분사시기를 정밀하게 제어하 여 연료소비율과 출력 향상 및 소음과 진동이 감소되었다. 전자제어 디젤엔진 시스템의 성능을 유지하기 위해서는 연료압력 을 정밀하게 제어하는 중요한 부품이 연료압력 레귤레이터이며 제어불량이 발생할 경우 연료압력이 정밀하게 제어되지 않아 시동불량, 시동지연, 가속불량, 엔진부조 등 이상 현상이 초래된다. 본 실험에서는 연료압력 레귤레이터의 고장에 따른 성능 변화를 고찰하기 위하여 연료압력 레귤레이터 제어율에 변화를 주어 연료압력, 회수된 연료유량과 엔진회전수에 미치는 영 향을 실험적으로 고찰하였다. 실험결과, 연료압력 레귤레이터의 제어율이 기준에서 4-6% 정도 낮아지면 엔진회전수, 회수되 는 연료유량의 변화가 크게 나타났으며 이 때 이상현상이 발생함을 확인하였다. 또한 이를 통하여 연료압력 레귤레이터의 고장 유무을 판단할 수 있다. To cope with exhaust gas regulation, Diesel engine applied to electronic control system. As it accurately regulated the injected fuel mass and the fuel efficiency and the output are increased but the noise and the vibration are decreased. In order to keep the performance of Electronic Diesel Control System, it is important to accurately control the fuel pressure. However, when the regulator of fuel pressure is not controlled properly, the failure phenomenons(starting failure, staring delay, accelerated failure, engine mismatch et al.) occur because the fuel pressure is not stabilize. In this study, effects on a fuel pressure, engine rotating speed according to the control rate of fuel-pressure regulator are investigated in order to analyzed the performance variation with failure of fuel-pressure regulator. As a result, when the control rate of a fuel-pressure regulator is 4%~6% lower than that of standard condition, the variation of engine's rpm and return fuel flow is increased, and the abnormal condition was occurred. Besides, it is possible to diagnose the failures on fuel-pressure regulator under these conditions.

Phosphorylation of A-Type ARR to function as negative regulator of cytokinin signal transduction.

Landes Bioscience 2008 Plant signaling & behavior Vol.3 No.5

<P>The plant hormone cytokinins regulate diverse aspects of plant growth and development. In Arabidopsis, a multi-step TCS system similar to bacterial and yeast TCS is used for cytokinin signaling. In a TCS system, a His sensor kinase perceives the signal by auto-phosphorylating on a His residue in response to an output signal, and the phosphate group is transferred to a conserved Asp residue in the receiver domain of the response regulator. The response regulator then modulates downstream signaling. Cytokinin multi-step TCS system utilizes an additional component, histidine-containing phosphotransfer domain protein (HPT) to transfer the phosphate group from a sensor kinase to a response regulator in the nucleus. The typical response regulators are classified into either type A or B. The type-B ARRs are transcription activators that act as positive regulators of cytokinin signaling, whereas most of the type-A ARRs are negative regulators of cytokinin signaling. Histidyl-aspartidyl phosphorelays are presumed to be essential for this cytokinin signal transduction in plants. Our studies have shown that ARR7, an A-type response regulator, negatively regulates cytokinin signaling in various aspects by acting as a transcriptional repressor and that the phosphorylation of ARR7 is required for these ARR7-regulated cytokinin-responses. Here I propose potential mechanisms by which the phosphorylation of ARRs is involved in regulating cytokinin- mediated gene expression, mainly based on biochemical and structural studies of bacterial response regulators. Protein-protein interaction and DNA-binding studies using the phosphorylated and the un-phosphorylated forms of the ARR proteins with their structural determination will provide molecular understanding of cytokinin-responsive gene regulation by ARRs.</P>

Regulation of iron-uptake systems in Vibrio vulnificus , a ferrophilic bacterium

Sung-Heui Shin 조선대학교 의학연구원 2021 Medical Bilogical Science and Engineering Vol.4 No.2

Vibrio vulnificus is a gram-negative ferrophilic bacterium that causes necrotizing wound infections and fatal septicemia, which mainly occur in patients with elevated levels of iron in serum or tissue, despite the presence of well-developed bacterial multiple iron-uptake systems (IUSs). These IUSs play important roles in the pathogenesis of V. vulnificus infections and are primarily regulated at the transcriptional level by a ferric uptake regulator called Fur responding to iron availability and their own specific regulators. Recent studies have shown that the IUSs are also controlled by other global regulators, including cyclic AMP-receptor protein responding to carbon availability and SmcR, a master regulator of the quorum-sensing system responding to bacterial density. This review presents an update on this sophisticated regulation of IUSs in V. vulnificus .