• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.62-65
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• 2003

We considered of the efficiency for the Buck+Half bridge converter This converter has advantages of applications for a low output voltage, a high output current and a wide input voltage. Developed the Buck converter ratings and the Half Bridge converter ratings are 36$\~$72V Input and 22V/5A output, 19$\~$24v input and 3.3V/30A output, respectively. Buck converter is operated with zero voltage switching process to reduce the switching losses. The 80.1 $\~$97.6$\%$ of the efficiency is measured at 18.4 $\mu$H output filter inductance of Buck convertor. In Half Bridge convertor, the 86$\~$96.4$\%$ of the efficiency is measured at 100kHz switching frequency with PQI core.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.9
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• pp.62-71
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• 2002

An intergral C-V converter is proposed to solve the nonlinearity problem of capacitive pressure sensors. The integral C-V converter consists of a switched-capacitor integrator and a switched-capacitor differential amplifier. It converts the sensor capacitance change which is inversely proportional to an applied pressure into a linear voltage output. Various PSPICE simulations prove that the convertor has excellent characteristics, such as low nonlinearity less than 0.01%/FS and low sensitivity to parallel offset capacitance and parasitic capacitance for the displacement range of sensor diaphragm set to 0 ${\sim}$ 90% of the initial distance between the electrodes in the simulation. We also show that the offset compensation and the gain trimming are easily achieved with the integral C-V converter.

• Journal of the Semiconductor & Display Technology
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• v.21 no.2
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• pp.107-111
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• 2022

In this paper, a plastic film type submersion sensor capable of measuring submersion speed was developed. This submersion sensor is designed as a capacitive type, and it is a sensor that outputs the change in capacitance between the electrode of the submersion sensor and the grounded body as a voltage through a C-V(capacitance-voltage) converter. We developed an submersion sensor in which two electrodes of different lengths are connected in parallel to measure the submersion speed accurately by minimizing the influence of noise such as contamination. When both electrodes of the submersion sensor are exposed to water, the rate of change of water level suddenly increases, so the submersion speed is measured by measuring the time to this point. Since the difference in length between the two electrodes of the submersion sensor does not change in any case, it is possible to accurately measure the submersion speed.

• 전자공학회논문지 IE
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• v.47 no.3
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• pp.14-18
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• 2010

In this paper, we describe a CMOS DC-DC converter with a variable output voltage(5-7V @100mA) for a portable battery-operated system applications. The proposed DC-DC converter is used along with a Pulse-Frequency Modulation (PFM) method and consists of reference circuit, a feedback resistor, a controller, and an internal oscillator. The integrated DC-DC converter with two external passive components(L,C) has been designed and fabricated on a 0.5um 2-poly 3-metal CMOS process and could be applied to the Personal Digital Assistants(PDA), cellular Phone, Laptop Computer, etc.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.465-468
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• 2001

An objection of this study is to develop a high stable analytic system of radioactive pulses. The proposed system consists of an amplifying circuit with 60dB gain, a programmable power supply unit which can generate DC voltage up to 1, 500V, and a digital signal processor. Pulse height distribution in accordance with pulse counts is important data in analyzing radioactive pulses. In this study, AD convertor (12bit, l00ns) and DSP (TMS 320C31-60) are used to analyze the pulse height, and the analytic system is designed to be operated in PC-networking.

• Journal of Power Electronics
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• v.1 no.2
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• pp.65-70
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• 2001

Transmission System Operators are governed by operational security standards that are applied in real time. During system disturbances, the System Operators must rely on the installed protection and control equipment, prior to human intervention. New power electronic solutions bring rapid and repeatable responses to disturbances, which will help System Operators to guarantee a stable system. Last year, Alstom completed the world's first competitively bid STATCOM to support the voltage on National Grid's 400kV network that supplies London and the Southeast from the north of the UK. It is rated ${\pm}75MVAr$ and forms part of a Static Var System (SVS) with a total rating of 0 to 225MVAr. This paper will describe the reasons for its size, location, its chain-link configuration and give examples of its operating performance. The paper will also describe the features that allow this STATCOM to deliver much more than reactive compensation in support of a wider transmission service objective, as system conditions require.

• Journal of Advanced Navigation Technology
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• v.21 no.3
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• pp.220-229
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• 2017

In this paper, To take advantage a variety of DC power as the boost DC-DC converter design specifications through the inductor L and capacitor C through PSPICE to calculate the best estimate of the value. Boost DC-DC converter with a switch device using IRF840 and reverse recovery time Schottky diodes with excellent with constant current controller using D10SC6M and resistance can be configured to considering the Power LED Module was driven by the production. Converter's switching frequency is 50 kHz, the first Duty Rate was made to increase gradually depending on the value of the detection were, 10 % in the output voltage. As a result, the simulated Boost Power LED driver characteristics is in comparison with the design specifications, 5% or less as the error was approximated. Finally, when input 15 V were offered, a stable output 24 V were obtained. and Dimming Control through the adjustment of brightness and current consumption were possible.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.2
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• pp.303-308
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• 2001

An objection of this study is to develop a high stable measuring circuits and a analytic system for radioactive pulses. The proposed system consists of a pulse detection units for neutrons and gamma-rays a programmable high voltage supply unit and a digital signal processor. The programmable high voltage supply unit designed can generate DC voltage up to 1,500 V at 5 V input and have a series voltage regulator to maintain the output voltage constantly, resulting in less than 1.63% of voltage regulation. The pulse detection parts consists of an active integrator, a pole-zero circuit, and a 3-stage amplifier of 60 dB, and its frequency bandwidth is from 37 Hz to 300 kHzAlso, pulse height distribution in accordance with pulse counts is important data in analyzing radioactive pulses. In this study, A/D convertor (12bit, 100ms) and DSP (TMS320C31-60) are used to analyze the pulse height, and the analytic system is designed to be operated in PC-base.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.7
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• pp.665-671
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• 2017

The alkali-Metal Thermal-to-electric Converter (AMTEC) is one of the promising static energy conversion technologies for the direct conversion of thermal energy to electrical energy. The advantages over a conventional energy converter are its high theoretical conversion efficiency of 40% and power density of 500 W/kg. The working principle of an AMTEC battery is the electrochemical reaction of the sodium through an ion conducting electrolyte. Sodium ion pass through the hot side of the beta"-alumina solid electrolyte (BASE) primarily as a result of the pressure difference. This pressure difference across the BASE has a significant effect on the overall performance of the AMTEC system. In order to build the high pressure difference across the BASE, hermeticity is required for each joined components for high temperature range of $900^{\circ}C$. The AMTEC battery was manufactured by utilizing robust joining technology of BASE/insulator/metal flange interfaces of the system for both structural and electrical stability. The electrical potential difference between the anode and cathode sides, where the electrons emitted from sodium ionization and recombined into sodium, was characterized as the open-circuit voltage. The efforts of technological improvement were concentrated on a high-power output and conversion efficiency. This paper discusses about the joining and performance of the AMTEC systems.