• Title/Summary/Keyword: drive

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Study on vibration characteristic of NFR Disc Drive (NFR Disc Drive 진동 특성에 관한 연구)

  • Jeong, Mi-Hyeon;Song, In-Sang;Seo, Jeong-Kyo;Choi, In-Ho;Min, Byung-Hoon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.04a
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    • pp.874-875
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    • 2008
  • Gap servo NFR (Near Field Recording) system is one of technologies to reduce beam spot size by increasing NA (Numerical Aperture) of lens. To achieve high NA, SIL (Solid Immersion Lens) is used. In case of using a blue LD (405 nm) as the light source the gap distance should be controlled under 100 nm with much tighter margin. To develop NFR disc drive with very small gap distance between SIL bottom and the surface of media, we need to research for the vibration characteristics and design considerations. This paper deals with a study on vibration characteristic of NFR disc drive.

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Displacements of the helical stator tooth for an electromechanical integrated toroidal drive

  • Xu, Lizhong;Zheng, Dazhou
    • Interaction and multiscale mechanics
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    • v.2 no.4
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    • pp.413-430
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    • 2009
  • The stator tooth is a key component of the electromechanical integrated toroidal drive system. The stator tooth is spiral in shape and the calculation of its displacements is difficult. In this paper, using the coordinate transformation method, the displacements of the stator tooth in the local coordinate system are expressed as the function of the variable in the drive coordinate system. Using the minimum potential energy principle, the equations of the displacements of the stator tooth under the loads are deduced. The displacement distributions within the stator tooth are investigated and the changes of the displacement distributions along with the main parameters are analyzed. This research can offer the basis for the strength and stiffness design of the drive system.

Study of Lower Hybrid Current Drive for the Demonstration Reactor

  • Molavi-Choobini, Ali Asghar;Naghidokht, Ahmad;Karami, Zahra
    • Nuclear Engineering and Technology
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    • v.48 no.3
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    • pp.711-718
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    • 2016
  • Steady-state operation of a fusion power plant requires external current drive to minimize the power requirements, and a high fraction of bootstrap current is required. One of the external sources for current drive is lower hybrid current drive, which has been widely applied in many tokamaks. Here, using lower hybrid simulation code, we calculate electron distribution function, electron currents and phase velocity changes for two options of demonstration reactor at the launched lower hybrid wave frequency 5 GHz. Two plasma scenarios pertaining to two different demonstration reactor options, known as pulsed (Option 1) and steady-state (Option 2) models, have been analyzed. We perceive that electron currents have major peaks near the edge of plasma for both options but with higher efficiency for Option 1, although we have access to wider, more peripheral regions for Option 2. Regarding the electron distribution function, major perturbations are at positive velocities for both options for flux surface 16 and at negative velocities for both options for flux surface 64.

A High-voltage LED Drive IC Using a Voltage Clamp Bias (Voltage Clamp Bias를 사용한 고전압 LED Drive IC)

  • Kim, Seong-Nam;Park, Shi-Hong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.04b
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    • pp.85-87
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    • 2009
  • Due to the enormous progress in light emitting diodes (LEDs), LEDs have been become a good solution for lightings. In LED driver for lighting applications, it is required a high input voltage to drive more LEDs. Therefore, a high-voltage should be changed to low-voltage to supply power for drive IC. In this paper, a LED drive IC with hysteretic-buck converter topology using a voltage clamp bias circuit was proposed and verified through simulations.

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A Gate Drive IC for Power Modules with Shoot-Through Immunity (상단락 방지용 모듈을 구동하기 위한 게이트 구동 IC)

  • Seo, Dae-Won;Kim, Jun-Sik;Park, Shi-Hong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.04b
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    • pp.81-82
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    • 2009
  • This paper introduces a gate drive IC for power modules with shoot-through immunity. A new approach uses a bootstrap diode as a high-side voltage bias and a level shift function at the same time. Therefore, the gate drive circuit becomes a simple and low-cost without conventional level shift functions such as HVIC(High-Voltage IC), optocoupler and transformer. The proposed gate drive IC is designed and fabricated using the Dongbu-Hitek's 0.35um BD350BA process. It has been tested and verified with IGBT modules.

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Performance Enhancement of a Sensorless Drive for Brushless DC Motor Using Digital Filter (디지틀 필터를 이용한 브러시리스 직류 전동기용 센서리스 드라이브의 성능 향상에 관한 연구)

  • Yeo, H.G.;Lee, K.W.;Park, J.B.;Kim, T.H.;Lee, I.H.;Yoo, J.Y.
    • Proceedings of the KIEE Conference
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    • 1997.11a
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    • pp.490-492
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    • 1997
  • This paper describes a digital sensorless drive of permanent magnet brushless DC (PM BLDC) motors. The sensorless drive adopts a digital filter - moving average finite impulse response filter for accurate estimation of commutation time. Experimental results show that the performance of the proposed sensorless drive is superior to that of the sensorless drive without filtering.

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A Study of the Humanoid Eye drive System (휴머노이드 안구 구동시스템에 대한 고찰)

  • Kim, Jae-Hyeok;Kang, Dong-Woo
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.67-68
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    • 2015
  • This paper describes humanoid eye drive system. The eye drive system has been developed by using more than two motors for operating 2 degree-of-freedom. It needs to accomplish purpose for operating the robot eye like movement of the human eye. However it makes problems that it increases energy consumption and requires relatively large space of operating system. Thus it needs technology to minimize and have high efficiency. This paper introduces the adequacy of perviously eye drive system. And it shows research value of the spherical motor system.

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The Influence of Main Bearing Stiffness on the Gearbox of 3 Point Suspension Wind Turbine Drive Train (메인 베어링 강성이 풍력발전기용 3점 지지 드라이브 트레인의 기어박스에 미치는 영향)

  • Nam, Ju Seok;Nam, Yong Yun
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.24 no.3
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    • pp.278-286
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    • 2015
  • The effects of the main bearing stiffness combined with vertical non-torque force on the input load and shaft deflection of a gearbox were investigated for the three-point suspension drive train of a wind turbine. A finite element analysis model for the drive train was studied experimentally, and its applicability to the present study was verified. The results show that, as the main bearing stiffness is increased, the input load of the gearbox decreases, whereas the input shaft deflection increases. The stiffness component for the pitch moment has the largest influence on the gearbox input load. Although the gearbox life increases at a higher main bearing stiffness, the economic efficiency and durability of the entire drive train system should also be considered in the selection of the main bearing stiffness.

A Study on the One-chip Design of Low Cost for Micro-stepping Drive of 5-Phase Stepping Motor Having Pentagon Type Winding (5상 펜타곤 결선방식 스테핑 모더의 마이크로스텝 구동을 위한 저가형 전용 칩 설계에 관한 연구)

  • Kim Myung-Hyun;Ahn Ho-Kyun;Park Seung-Kyu;Son Young-chul
    • Proceedings of the KIPE Conference
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    • 2002.07a
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    • pp.451-454
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    • 2002
  • In this paper, studied on the one-chip design of low cost for the micro-stepping drive having 5-phase Pentagon Type winding. Micro-stepping method in order to eliminate effectively the resonant phenomena and to Increase the positional resolution. This paper proposed trapezoidal current wave- form for current control and provided design- method by using only one-chip of low cost. Therefore the drive will be simple and small size. Also the drive will have a lot of advantage at commercial business. Finally the above study has been implemented on the VHDL. Simulation has been performed to verify the PWM for micro-stepping drive.

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A Drive Method of SRM for EPS with High Efficiency & Low Torque Ripple (EPS용 SRM의 고효율 저토크리플 구동방식)

  • Hwang H.J.;Moon J.W.;Kim J.K.;Ahn J.W.
    • Proceedings of the KIPE Conference
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    • 2003.07b
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    • pp.832-835
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    • 2003
  • This paper presents a design and characteristics analysis of a SRM drive for EPS(Electrically Power Steering) application. A conventional driving room space and mechanical structure are suggested in design stage. In the restricted design conditions, motor parameters are determined for sufficient torque and speed. For the smooth torque generation and simple circuit of power system, 12/8 motor drive is considered. With FEM and magnetic circuit analysis, designed motor is simulated to meet the requirement of specifications. Effectiveness of the suggested SRM drive for EPS application is verified by the manufactured prototype motor drive tests.

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