• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.55-57
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• 2000

This paper presents the measurement of phasor angle of power system using Synchronized Phasor Measurement System(SPMS). SPMS includes the GPS receiver, so it can add the exact time information to the data acquired from the power system by SPMS. Using that data, we can compare the difference of phasor angles of voltages currents acquired at the exactly same time, and monitor the RMS values of voltage and current. In this paper, we present the difference of voltage angles between 345kV Sinjechon S/S and 345kV Asan S/S, where two SPMS were installed separately, and prove their performance by comparing to simulation result of PSS/E.

• JSTS:Journal of Semiconductor Technology and Science
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• v.2 no.3
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• pp.173-179
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• 2002

We propose a novel sensing circuit for 2T-2MTJ MRAM that can be used for high speed synchronous operation. Proposed bit-line sense amplifier detects small voltage difference in bit-lines and develops it into rail-to-rail swing while maintaining small voltage difference on TMR cells. It is small enough to fit into each column that the whole data array on selected word line are activated as in DRAMs for high-speed read-out by changing column addresses only. We designed a 256Kb read-only MRAM in a $0.35\mu\textrm{m}$ logic technology to verify the new sensing scheme. Simulation result shows a 25ns RAS access time and a cycle time shorter than 10 ns.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.4 s.97
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• pp.213-219
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• 1999

Piezoelectric element is deformed by driving voltage pattern. We developed a device of moving LD(laser disk) to use the rapid deformation of piezoelectric element. If driving voltage is changed very rapidly, the difference of acceleration is accurred between spindle motor and LD. To move LD on turn table is attained by utilizing difference of acceleration. This paper describes theoretical and experimental results about the movement of LD and presents to measure the center of mass LD with unbalance force.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1988.10a
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• pp.95-97
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• 1988

The instability of MOS devices is mainly caused by the oxide charges, and as the need to develop the gate metal grows researches for various new metal gate have been performed, and in these researches, the difference work function existing between the metal and the semiconductor should be considered. Here int his paper, the device is made by the sputtering and the LPCVD method using pure Al, compound metal. poly-si, as a gate metal, the result of the research was shown that the work function difference from using different gate metals effects on the flatband voltage shift. This means we can infer that the threshold voltage adjustment is possible by using different gate metals and this whole mechanism makes the devices behavior more stable.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.6
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• pp.609-613
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• 2023

In this paper, a 1,200 V Si-based IGBT used in electric vehicles and new energy industries was designed. A field stop IGBT with a separate gate structure, which is the proposed structure, was designed to change trench depth and split gate width variables. Then, the general trench structure and electrical characteristics were compared and analyzed. As a result of conducting the trench depth experiment, it was confirmed that the breakdown voltage was the highest at 6 ㎛, and the on-state voltage drop was the lowest at 3.5 ㎛. In the separate gate width experiment, it was confirmed that the breakdown voltage decreased as the variable increased, and the on-state voltage drop increased. Therefore, it may be seen that it is preferable not to change the width of the separate gate. In addition, experiments show that there is no difference in on-state voltage drop compared to a structure in which a general field stop structure has a separate gate structure. In other words, it is determined that adding a dummy gate with a separate gate structure to the active cell will significantly improve the on-voltage drop characteristics, while confirming that the on-voltage drop does not change, and while having excellent characteristics in terms of breakdown voltage.

• 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.

• Journal of the Korean Vacuum Society
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• v.3 no.1
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• pp.71-76
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• 1994

The electrical characteristics of the capacitor dielectric films of amorphous silicon-nit-ride-oxide(ANO) structures are compared with the capacitor dielectric films of oxide-nitride-oxide (ONO) structrues The electrical characteristics of ONO and ANO films were evaluated by high frequency(1 MHz) C-V high frequency C-V after constant voltage stree I-V TDDB and refresh time measurements. ANO films shows good electrical characteristics such as higher total charge to breakdown storage capacitance and longer refresh time than ONO films. Also it makes little difference that leakage current and flat band voltage shyift(ΔVfb)of ANO ana ONO films.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2001.02a
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• pp.176-177
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• 2001

Three nearly identical superconducting fault current limiters (SFCLs) were connected in series to increase the voltage ratings. A slight difference in the quench starting point of individual SFCL units produced significantly imbalanced power distribution when connected in series. The imbalance was successfully removed by connecting a shunt resistor to one SFCL in parallel. 1.2 kV SFCL was designed with five current limiting elements and two or three shunt resistors.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.847-850
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• 1998

This paper proposes a new scheme of FLR for improving corner breakdown voltage. The major difference from the conventional FLR is to build extra rings and floating field plates in the corner region. In this structure the additional field plate and ring have reduced th electric field at the junction in the corner region. Thus it improves the breakdown characteristics which are critical for obtaining high breakdown voltage.

• Journal of Welding and Joining
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• v.14 no.6
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• pp.131-139
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• 1996

The response of the arc sensor using the welding current and/or welding voltage as its outputs has been obtained by the analysis and/or experiments of the static characteristics of arc sensor. But in order to improve the reliability of arc sensor, it is necessary to know its dynamic characteristics. So in this paper, it is presented the dynamic model of arc sensor including the power source, arc voltage, electrode burnoff rate, and wire feed rate. A numerical simulation of the dynamic model of arc sensor was implemented, computing the welding current with input of CTWD. The results of computer simulations and experiments of $CO_2$arc welding showed that a linear relationship between weaving center - weld line distance and current area difference was established. Additionally, a real-time weld seam tracking system interfaced with industrial welding robot was constructed, the result of the weld seam tracking experiment for weld line with an initial offset error of 5$^{\circ}$was good.