• Title/Summary/Keyword: Low acceleration voltage

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Walking Pattern Analysis Using an Acceleration Sensor Device

  • Hong, Ju-Hee;Han, Kap-Soo;Kim, Kyungho
    • Journal of Electrical Engineering and Technology
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    • v.12 no.1
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    • pp.396-401
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    • 2017
  • In this paper, a device to analyze gait pattern was developed by using a 2-axis acceleration sensor attached to the foot. The 1st low-pass filter was adapted to limit the frequency band up to 5 Hz. An algorithm to detect the peak value exceeding the threshold voltage of an X-axis acceleration sensor and a Z-axis acceleration sensor was developed and normal and abnormal walking patterns were thus differentiated. Also, MCU and Bluetooth were combined to transfer the data to other MCUs to display on an LCD; the size of the device could then be reduced. The new algorithm and the device allowed the individual walking patterns to be easily measured at a low cost and with less restriction on activities compared to conventional multiple pressure sensors or motion camera system.

Optimal Design of Power Loss for 3 Phase Voltage Source Inverter by using Thermal Management (써멀 메니지먼트(Thermal Management)에 의한 3상 전압형 인버터의 전력손실 최적화 설계)

  • Cho, S.E.;Park, S.J.
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.10
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    • pp.1757-1762
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    • 2007
  • Recently, the demand for the low cost power conversion equipment is rapidly increased. To develop this three phase voltage source inverter, optimum power conversion equipment to system is designed. The optimum operation method to minimize the power loss also satisfy the life time of the power electronics that is request in the present industry. In this paper, the efficient operating method to change of the acceleration, jerk, and switching frequency in the interval of acceleration is selected to optimize the power loss and life time of the power electronics by using the elevator model. So, we proposed the method that 50[A] rating power electronics is adopted in 9[kW] load.

Control and Design of a Arc Power Supply for KSTAR's the Neutral Beam Injection

  • Ryu, Dong-Kyun;Lee, Hee-Jun;Lee, Jung-Hyo;Won, Chung-Yuen
    • Journal of Electrical Engineering and Technology
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    • v.10 no.1
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    • pp.216-226
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    • 2015
  • The neutral beam injection generate ultra-high temperature energy in the tokamak of nuclear fusion. The neutral beam injection make up arc power supply, filament power supply and acceleration & deceleration power supply. The arc power supply has characteristics of low voltage and high current. Arc power supply generate arc through constant output of voltage and current. So this paper proposed suitable buck converter for low voltage and high current. The proposed buck converter used parallel switch because it can be increased capacity and decrease conduction loss. When an arc generated, the neutral beam injection chamber occur high voltage. And it will break output capacitor of buck converter. Therefore the output capacitor was removed in the proposed converter. Thus the proposed converter should be designed for the characteristics of low voltage and high current. Also, the arc power supply should be guaranteed for system stability. The proposed parallel buck converter enables the system stability of the divided low output voltage and high current. The proposed converter with constant output be the most important design of the output inductor. In this paper, designed arc power supply verified operation of system and stability through simulation and prototype. After it is applied to the 288[kW] arc power supply for neutral beam injection.

Design Considerations for Low Voltage Claw Pole Type Integrated Starter Generator (ISG) Systems

  • Lee, Geun-Ho;Choi, Geo-Seung;Choi, Woong-Chul
    • Journal of Power Electronics
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    • v.11 no.4
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    • pp.527-532
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    • 2011
  • Due to the need for improved fuel consumption and the trend towards increasing the electrical content in automobiles, integrated starter generator (ISG) systems are being considered by the automotive industry. In this paper, in order to change the conventional generator of a vehicle, a belt driven integrated starter generator is considered. The overall ISG system, the design considerations for the claw pole type AC electric machine and a low voltage very high current power stage implementation are discussed. Test data on the low voltage claw pole type machine is presented, and a large current voltage source DC/AC inverter suitable for low voltage integrated starter generator operation is also presented. A metal based PCB (Printed Circuit Board) power unit to attach the 4-parallel MOS-FETs is used to achieve extremely high current capability. Furthermore, issues related to the torque assistance during vehicle acceleration and the generation/regeneration characteristics are discussed. A prototype with the capability of up to 1000 A and 27 V is designed and built to validate the kilo-amp inverter.

Dopant-Activation and Damage-Recovery of Ion-Shower-Doped Poly-Si through $PH_3/H_2$ after Furnace Annealing

  • Kim, Dong-Min;Kim, Dae-Sup;Ro, Jae-Sang;Choi, Kyu-Hwan;Lee, Ki-Yong
    • Journal of Information Display
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    • v.5 no.1
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    • pp.1-6
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    • 2004
  • Ion shower doping with a main ion source of $P_2H_x$ using a source gas mixture of $PH_3/H_2$ was conducted on excimer-laser- annealed (ELA) poly-Si. The crystallinity of the as-implanted samples was measured using a UV-transmittance. The measured value of as-implanted damage was found to correlate well with the one calculated through/obtained from TRIM-code simulation. The sheet resistance was found to decrease as the acceleration voltage increased from 1 kV to 15 kV at a doping time of 1 min. However, it increases as the acceleration voltage increases under severe doping conditions. Uncured damage after furnace annealing is responsible for the rise in sheet resistance.

CMOS Interface Circuit for MEMS Acceleration Sensor (MEMS 가속도센서를 위한 CMOS 인터페이스 회로)

  • Jeong, Jae-hwan;Kim, Ji-yong;Jang, Jeong-eun;Shin, Hee-chan;Yu, Chong-gun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2012.10a
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    • pp.221-224
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    • 2012
  • This paper presents a CMOS interface circuit for MEMS acceleration sensor. It consists of a capacitance to voltage converter(CVC), a second-order switched-capacitor (SC) integrator and comparator. A bandgap reference(BGR) has been designed to supply a stable bias to the circuit and a ${\Sigma}{\Delta}$ Modulator with chopper - stabilization(CHS) has also been designed for more suppression of the low frequency noise and offset. As a result, the output of this ${\Sigma}{\Delta}$ Modulator increases about 10% duty cycle when the input voltage amplitude increases 100mV and the sensitivity is x, y-axis 0.45v/g, z-axis 0.28V/g. This work is designed and implemented in a 0.35um CMOS technology with a supply voltage of 3.3V and a sampling frequency of 3MHz sampling frequency. The size of the designed chip including PADs is $0.96mm{\times}0.85mm$.

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Evaluation of Performance and Reliability of a White Organic Light-Emitting Diode(WOLED) Using an Accelerated Life Test(ALT) (가속수명시험(ALT)을 이용한 WOLED의 성능 및 신뢰성 평가)

  • Moon, Jin-Chel;Park, Hyung-Ki;Choi, Chung-Seog
    • Journal of the Korean Society of Safety
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    • v.27 no.4
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    • pp.13-19
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    • 2012
  • The purpose of this study is to extract the major factors related to the deterioration mechanism of white organic light-emitting diodes(WOLED) by performing accelerated testing of temperature, voltage, time, etc., and to develop an accelerated life test(ALT) model. The measurement results of the brightness of the WOLED exhibited that their average brightness tended to increase as the operating voltage increased and that the half-life period of the brightness appeared after approximately 400 hours when the operating voltage was 20V and the ambient temperature was $85^{\circ}C$. It could be seen that although the WOLED showed comparatively the same brightness when the initial acceleration began after the operating voltage was applied to it, its brightness changed excessively after the WOLED's thermal storage had been made. In addition, it was observed that the half-life period was reduced as the ambient temperature and applied voltage increased. The strength of the WOLED which had been maintained in the range of visible light at the maximum load was reduced by the deterioration of the organic light emitting material due to the influence of the operating voltage and temperature, and the reduction of emitted light was small at low voltage and temperature. It could be seen that the failure of the WOLED during the ALT was caused by wear due to load accumulation over time, and that Weibull distribution was appropriate for the life distribution and acceleration was established between test conditions. From the WOLED analysis, it is thought that factors influencing the brightness deterioration are voltage, temperature, etc., and that comprehensive analysis considering discharge control, dielectric tangent margin, etc., would further increase the reliability.

Precise position control with a low cost BLDCM drive (저가형 BLDCM 구동장치를 이용한 정밀위치제어)

  • 강석주;김준석;설승기;김덕근
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.44 no.4
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    • pp.447-452
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    • 1995
  • In this paper a simple method of a position control for brushless DC motor is presented. For precise position control, a high performance torque controller is needed and a novel current control method is proposed. The current controller detects the uncommutating mode current for every 60.deg. (elec. angle) and controls it with PI controller. The current control loop includes the feedforward of back EMF and the feedforward of the neutral voltage between the neutral point of the inverter and the neutral point of the machine. In the position control, the acceleration pattern is calculated from the position reference. Then the speed trajectory is calculated from the acceleration pattern. The experimental results are presented to verify the proposed methods.

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