• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.636-639
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• 1996

We have developed a part of hydraulic stroke sensing cylinder using magnetic sensor that can detect each position under severe construction fields. In this paper, for evaluating the developed cylinder under various environment condition, thermal control systems and two hydraulic systems to be coupled consist of. The former is composed of an heater case, temperature sensor, and interface circuits which include SCR(silicon controlled rectifier) for the control of the voltage's phase. The latter is composed of an hydraulic cylinder for position control with solenoid valve (ON/OFF motion) and a load cylinder with proportional reducing valve. To obtain the various performance evaluation, it is carried out under high temperature condition in thermal system controlled by using Ziegler-Nichols PID tuning method and artificial disturbances such as impulse or constant force. The results show that the developed cylinder has good performance under the various environment condition.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.4
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• pp.348-352
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• 2016

This paper addresses the efficient improvement of the Switched Reluctance Motor(SRM) by the proper voltage excitation. In the case of loads with large operational motor-speed differences such as washing machine, an SRM system driven by a constant DC-link voltage is not useful for improving the efficiency. To reduce the effect of the excess DC-link voltage, AC-DC control converter that uses a silicon controlled rectifier instead of diode rectifier is employed in the SRM driver system. AC-DC control converter supplies a proper link voltage for low-speed operation. The experimental results demonstrated that the efficiency of the system was improved at low speeds.

• KIEE International Transactions on Electrophysics and Applications
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• v.2C no.6
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• pp.304-308
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• 2002

We demonstrate a simple pulsed $CO_2$ laser with millisecond long pulse duration in a tube at a low pressure of less than 30 Torr. The novel power supply for our laser system switches the voltage of the AC power line (60Hz) directly. The power supply doesn't need elements such as a rectifier bridge, energy-storage capacitors, or a current-limiting resistor in the discharge circuit. To control the laser output power, the pulse repetition rate is adjusted up to 60Hz and the firing angle of SCR(Silicon Controlled Rectifier) gate is varied from 30。 to 150。. A ZCS (Zero Crossing Switch) circuit and a PIC one-chip microprocessor are used to control precisely the gate signal of the SCR. The maximum laser output of 35 W is obtained at a total pressure of 18 Torr, a pulse repetition rate of 60 Hz, and a SCR gate firing angle of 90。 . In addition, the resulting laser pulse width is approximately 3㎳(FWHM). This is a relatively long pulse width, compared with other repetitively pulsed $CO_2$ lasers.

• 전기의세계
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• v.18 no.3
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• pp.34-39
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• 1969

종래 사용되어온 교류발전기의 자동전압조정기는 직류여자기의 계자전류를 제어함으로써 교류 발전기의 단자전압을 일정하게 유지하는 방식이었다. 이경우 정정시의 전압변동을 적게하는 것은 비교적 용이하지만 급격한 부하변동에 대해서는 불경하였다. 즉 발전기에 급히 부하가 걸리면 발전기의 특성에 의하여 결정되는 전압이 순간적으로 떨어지고 또 발전기에는 복권작용이 없고 직류여자기및 제어장치의 시정수에 의한 조정작용의 시간적 늦음이 있기때문에 발전기의 전압은 더욱 강하한다. 이 전압강하의 방지책으로 발전기를 필요이상 크게하여 단종비를 크게하고 또 속응여자를 행하고 있다. 그리고 발전기의 부하가 유도전동기이 가능한 것은 소용량에 한하고 거의 모두 감압기동을 하고 있었다. 이 난점을 보상하기 위해 주회로전류에 의한 복권특성을 갖는 자여자교류발전기가 개발되어 왔으며 근래에는 S.C.R (Silicon Controlled Rectifier)의 발달에 따라 자기증폭기식에서 Transistor-Thyristor식으로 변천하고 있다. 여기서는 자여자발전기를 이용한 정전압장치부 자려자교류벌전기 75KVA에 대한 특성을 소개하고자 한다.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.3
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• pp.339-344
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• 2014

This paper presents a novel bipolar junction transistor (BJT) based electrostatic discharge (ESD) protection device. This protection device was designed for 20V power clamps and fabricated by a process with Bipolar-CMOS-DMOS (BCD) $0.18{\mu}m$. The current-voltage characteristics of this protection device was verified by the transmission line pulse (TLP) system and the DC BV characteristic was verified by using a semiconductor parameter analyzer. From the experimental results, the proposed device has a trigger voltage of 29.1V, holding voltage of 22.4V and low on-resistance of approximately $1.6{\Omega}$. In addition, the test of ESD robustness showed that the ESD successfully passed through human body model (HBM) 8kV. In this paper, the operational mechanism of this protection device was investigated by structural analysis of the proposed device. In addition, the proposed device were obtained as stack structures and verified.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.589-590
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• 2006

A novel Triple-Well P-type Triggered Silicon Controlled Rectifier (TWPTSCR) for on-chip ESD protection implemented with a triple-well CMOS technology is presented. Unlike conventional SCR devices, the proposed TWPTSCR offers a reduced triggering voltage level as well as the enhanced ESD performance of the SCR devices. From the experimental results, the TWPTSCR with a device width of 20um has the triggering voltage of 1.1V.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.587-588
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• 2006

This paper presents the new structural zener triggered silicon-controlled rectifier (ZTSCR) electrostatic discharge (ESD) protection circuit. The proposed ESD protection circuit has lower triggering voltage than conventional circuits. The proposed ZTSCR has the triggering voltage of 4V. In the ESD event, this proposed novel ZTSCR ESD protection device could trigger quickly and provide an effective discharging path.

• Journal of Power Electronics
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• v.12 no.6
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• pp.947-953
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• 2012

The latch-up immunity of the high voltage power clamps used in high voltage ESD protection devices is very becoming important in high-voltage applications. In this paper, a stacking structure with a high holding voltage and a high failure current is proposed and successfully verified in 0.18um CMOS and 0.35um BCD technology to achieve the desired holding voltage and the acceptable failure current. The experimental results show that the holding voltage of the stacking structure can be larger than the operation voltage of high-voltage applications. Changes in the characteristics of the stacking structure under high temperature conditions (300K-500K) are also investigated.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1088-1090
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• 2001

In general, Power SCR(Silicon Controlled Rectifier) is most widely used in Power Plant as well as Industrial field. It has been controlled and operated according to its own control method. Especially, in case of Power plant, it plays a major role in AVR(Automatic Voltage Regulator) or electro chlorination control circuits. Generally, they used in Analog control system at above field. But each SCR current value is different because of load unbalance or switching characteristic variations, it may cause power plant unit trip or system disorder according to SCR element burn out or bad operating condition. Therefore, in this paper a development of 3 phase current balance control unit is described, it gets over the past analog control system limit, uses DSP(Digital signal processor) had high speed response, controls SCR gate firing angle for 3 phase current balance.

• Journal of IKEEE
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• v.21 no.3
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• pp.234-239
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• 2017

In this paper, we propose an ESD (Electrostatic Discharge) protection circuit based on a new structure of SCR (Silicon Controlled Rectifier) embedded with PMOS structure. The proposed ESD protection circuit has a built-in PMOS structure and has a latch-up immunity characteristic and an improved tolerance characteristic. To verify the characteristics of the proposed ESD protection circuit and to analyze its operating characteristics, we compared and analyzed the characteristics of the existing ESD protection circuit using TCAD simulation. Simulation results show that the proposed protection ESD protection circuit has superior latch-up immunity characteristics like the existing SCR-based ESD protection device HHVSCR (High Holding Voltage SCR). Also, according to the results of the HBM (Human Body Model) maximum temperature test, the proposed ESD protection circuit has a maximum temperature value of 355K, which is about 20K lower than the existing HHVSCR 373K. In addition, the proposed ESD protection circuit with improved electrical characteristics is designed by applying N-STACK technology. As a result of the simulation, the proposed ESD protection circuit has a holding voltage characteristic of 2.5V in a single structure, and the holding voltage increased to 2-STACK 4.2V, 3-STACK 6.3V, 4-STACK 9.1V.