• Journal of Institute of Control, Robotics and Systems
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• 제10권2호
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• pp.164-170
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• 2004

Recently, the demand for micro hard disk drive that provides high-capacity removable storage for handhold electronic devices is growing very rapidly Reducing power consumption is one of the primary control objectives in micro disk drives. The input power delivered to the seek servo system is consumed as heat by the transistors of power amplifier and motor coil resistance. In this paper, we present a new seek servo controller for minimizing the power consumption. We use a Fourier decomposition and nonlinear programming to determine the optimum seek profile that minimizes the power consumption. Also, the trajectory tracking controller is developed for exact tracking of the optimum seek profile. Finally, we present some experimental results using a commercially available micro disk drive in order to demonstrate the superior performance of the proposed controller.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.592-597
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• 2003

To solve a problem of micro drive due to small size and portability, it is necessary to understand and to investigate micro drive widely ,deeply. So, we performed modal analysis of suspension of micro drive, and load/unload experiment for Input current to VCM coil and disk speed. To determine the effect of ramp profile, curve fitting of lateral speed is performed with equation of speed. The results indicate that small load/unload speeds decrease the number of head/disk contacts, and during unloading process, low disk speed increase the number of head/disk contacts.

• Progress in Superconductivity
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• 제14권2호
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• pp.102-105
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• 2012

We are developing meander-shaped metallic magnetic calorimeters using micro-fabrication methods. A planar Nb coil in a meander shape was fabricated on a Si substrate. The coil was designed to have a persistent current using a metal heater evaporated on a part of the coil. A paramagnetic sensor, $5{\mu}m$ thick Au:Er foil, was glued on top of the meander structure with epoxy. The magnetization and heat capacity were measured at different temperatures, and applied field currents matched well with expected values. The detector showed an energy resolution of 4 keV FWHM for the 5.5 MeV alpha particles.

• Proceedings of the KIEE Conference
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.3295-3297
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• 1999

This paper presents the fabrication of an electromagnetic micro actuator consisting of a Parylene diaphragm with a spiral copper coil and a permanent magnet. The copper coil is fabricated by electroplating and patterning. The frequency response of the actuator are obtained using a laser vibrometer. When the input voltage is 3 V, the DC deflection is 5 ${\mu}m$, and the resonance frequency is about 35 Hz. Also, the mechanical sensitivity of the actuator diaphragm is 69 ${\mu}m/V$.

• Journal of the Korean Society for Precision Engineering
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• 제27권9호
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• pp.43-51
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• 2010

Speed, accuracy and smoothness are the important properties of pan-tilt camera. In the case of a high ratio zoom lens system, low vibration characteristic is a crucial point in driving pan-tilt mechanism. In this paper, a novel micro-stepping controller with a function of reducing vibration was designed using field programmable gate arrays (FPGA) technology for high zoom ratio pan-tilt camera. The proposed variable reference current (VRC) control scheme reduces vibration decently and optimizing coil current in order to prevent the step motor from occurring missing steps. By employing VRC control scheme, the vibration in low speed could be significantly minimized. The proposed controller can also make very high speed of 378kpps micro-step driving, and increase maximum acceleration in motion profiles.

• Proceedings of the Korean Magnestics Society Conference
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• 한국자기학회 2007년도 The 1st International Symposium on Advanced Magnetic Materials
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• pp.253.1-253.1
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• 2007

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2009년도 Korea Superconductivity Society Meeting 2009
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• pp.65-65
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• 2009

• Journal of the Korean Vacuum Society
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• 제21권1호
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• pp.48-54
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• 2012

Carbon coils could be synthesized on nickel catalyst layer-deposited silicon oxide substrate using $C_2H_2$ and $H_2$ as source gases and SF6 as an additive gas under thermal chemical vapor deposition system. The geometries of as-grown carbon materials were investigated with increasing the reaction temperature as the increment of $25^{\circ}C$ from $650^{\circ}C$ up to $800^{\circ}C$. At $650^{\circ}C$, the embryos for carbon coils were formed. With increasing the reaction temperature to $700^{\circ}C$, the coil-type geometries were developed. Further increasing the reaction temperature to $775^{\circ}C$, the development of wave-like nano-sized coils, instead of nano-sized coils, and occasional appearance of micro-sized carbon coils could be observed. Fluorine in $SF_6$ additive may shrink the micro-sized coil diameter via the reduction of Ni catalyst size by fluorine's etching role. Finally, the preparation of the micro-sized carbon coils having the smaller coil diameters, compared with the previously reported ones, could be possible using $SF_6$ additive.

• Proceedings of the KIEE Conference
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1925-1926
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• 2008

본 논문에서는 UHF TV방송 전 대역 Ch.14(473MHz)$\sim$Ch.69(803MHz)까지의 모든 채널에서 동작하는 유도결합구조의 RF동조회로를 설계하였다. 기존 자기결합구조의 RF동조회로는 PCB 양면을 사용하여야 하고 수작업으로 Air Coil 간격을 조절해야만 한다. 부품의 집적화와 양산 효율성 측면에서 자기결합구조의 단점을 해결할 수 있도록 하기 위해 본 논문에서 제안한 유도결합구조는 수동부품인 칩인덕터와 칩커패시터 및 가변용량 다이오드만을 사용하여 RF동조회로를 설계하였다. 칩인덕터는 Air Coil에 비해 낮은 소자 Q값을 가진다. 상대적으로 낮은 Q값을 갖는 칩인덕터를 사용하기 때문에 이를 보완하기 위해 Peaking용 칩인덕터를 설계 디자인에 적용하였다. 가변형 대역통과필터로 동작하기 위해 자기결합구조와 동일하게 가변용량 다이오드를 이용하였다. UHF TV방송 전 대역(470$\sim$806MHz)에서 -2.88 $\sim$ -3.97dB의 삽입손실 특성 및 -8dB 이상의 반사손실 특성과 330MHz의 중심주파수 변화 범위를 갖는다. 현재 상용중인 지상파 튜너에 적용되고 있는 자기결합구조의 RF동조회로를 대치하여 적용될 수 있을 것이다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1060-1065
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• 2003

This paper contributes to development of a new chip mounting head system for flip chip. Recently, the LDM(Linear DC Motor) has been widely used, because it has particular merits than the rotary type motors. In this paper, we proposed a macro/micro positioning system for force control of a chip mounting system. In the proposed macro/micro system, the macro actuator provide the system with a gross motion while the micro device yields fine tuned motion to reduce the harmful impact force that occurs between very small sized electronic parts and PCB surface. In order to prove the effectiveness of the proposed macro/micro chip mounting system, we compared the proposed chip mounting head with the conventional chip mounting head equipped with a macro actuator only. A series of experiments were executed under the mounting conditions of various access velocities and PCB stiffness. As a result of this study, a satisfactory voice coil actuator as the micro actuator has been developed, and its performance meet well the specifications desired for the design of the chip mounting head system and show good correspondence between theoretical analysis and experimental results.