• Journal of the Korean Society for Precision Engineering
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• v.19 no.8
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• pp.155-160
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• 2002

In this paper, a controller design for brushless linear motor is implemented. The designed controller is mainly composed of current, speed and position controller, which are carried out by the high-speed digital signal processor (DSP). In addition the PWM inverter is controlled by space voltage PWM method. This system is implemented by using 32-bit DSP (TMS320C31), a high-integrated logic device (EPM7192), and IPM (Intelligent Power Module) for compact and powerful system design. The experimental results show the effective performance of controller for the brushless linear motor.

• KIEE International Transactions on Electrophysics and Applications
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• v.5C no.2
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• pp.49-53
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• 2005

The current drive in a MOSFET is limited by the intrinsic channel resistance. All other parasitic elements in a device structure perform significant functions leading to degradation in the device performance. These other resistances must be less than 10$\%$-20$\%$ of the channel resistance. To meet the necessary requirements, the methodology of separation and quantification of those resistances should be investigated. In this paper, we developed an extraction method for the resistances using calibrated TCAD simulation. The resistance of the extension region is also partially determined by the formation of a surface accumulation region that gathers below the gate in the tail region of the extension profile. This resistance is strongly affected by the abruptness of the extension profile because the steeper the profile is, the shorter this accumulation region will be.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.970-973
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• 2008

For commercial vehicles with a manual transmission, the pneumatic and fluid pressure servo-device is widely used for transmitting large torque. However, the pneumatic and fluid pressure servo-device usually results in non-linear variation of foot-efforts, also such characteristics tend to increase physical fatigue of drivers who drive commercial vehicles for a long time. Thus, vehicle manufacturers consider the hysteresis loops in the Clutch Actuation System (CAS) design when a new vehicle model is being developed. In this study, we numerically simulate the hysteresis loops for predictable CAS design, and the experimental results confirm the simulation results.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.4
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• pp.87-93
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• 1997

An electro-optic polymer digital optical switch with a coupling region modified for optimum mode coupling is proposed, and it is analyzed by using the beam propagation method combined with the effective index method. Its modified coupling region is adiabatically introduced along the propagation direction from the branching point of the two waveguides. The structure of the modified coupling region and its refractive index profiles are designed to optimize the mode coupling in the Y-branch waveguide. Therefor, the switching performance of the device may be enhanced with a fixed device length. It is confirmed from the numerical calculation that the drive voltage is reduced by more than 30 percents and te crosstalk is improved by about 8dB.

• Journal of the Semiconductor & Display Technology
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• v.2 no.2
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• pp.17-20
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• 2003

The current drive in an MOSFET is limited by the intrinsic channel resistance. All the other parasitic elements in a device structure playa significant role and degrade the device performance. These other resistances need to be less than 10%-20% of the channel resistance. To achieve the requirements, we should investigate a methodology of separation and quantification of those resistances. In this paper, we developed the extraction method of resistances using calibrated TCAD simulation. The resistance of the extension region is also partially determined by the formation of a surface accumulation region that forms under the gate in the tail region of the extension profile.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.464-469
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• 1998

In the conventional wire feeder drives of welding machine, one thyristor or MOSFET device was used for half-wave phase control circuit and direct EMF measurement was used for sensing the wire feed rate. But the method using one switching device has poor response for sudden disturbance and it has latent speed ripple. It can affect some welding performance such as spatter generation and irregular bead formming. Therefore, the welding performance using full-bridge PWM speed control scheme was compared with conventional driving scheme was compared with conventional driving scheme and experimented in this paper. The results of experiment confirm the posibility of welding performance improvement by proposed constant speed control scheme in wire feeding drive of welding machine.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.2
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• pp.73-77
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• 2000

A dual-gate SOI SA-LIGBT (shorted-anode lateral insulated gate bipolar transistor) which eliminates the snapback effectively is proposed and verified by numerical simulation. The elimination of the snapback in I-V characteristics is obtained by initiating the hole injection at low anode voltage by employing a dual gate and a floating electrode in the proposed device. For the proposed device, the snapback phenomenon is completely eliminate, while snapback of conventional SA-LIGBT occurs at anode voltage of 11 V. Also, the drive signals of two gates have same polarity by employing the floating electrode, thereby requiring no additional power supply.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.6
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• pp.266-271
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• 2001

In this paper, a controller design for coreless linear synchronous motor is proposed. The designed controller is mainly composed of speed and current control, which are carried out by the high-speed digital signal processor(DSP). In addition the PWM inverter is controlled by space voltage PWM method. This system is implemented using by 32-bit DSP(TMS320C31), a high-integrated logic device(EPM940), and IPM(Intelligent Power Modules) for compact and powerful system design. The experimental results show the effective performance of controller for coreless linear synchronous motor.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.452-456
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• 2009

This paper presents a method for precisely localizing and parking of bimodal trams. In order to gam an automatically driving system for bimodal trams, precise up-to-date localization, velocity recognition, distance to next station and precise parking location estimation functions are required. This paper proposes a system consisting of control device, steering device, sensor input equipment, driving system, tachometer, vehicle-side sensors, magnetic markers and magnetic sensors. The tram recognizes the precise location via magnetic markers containing information. Parking position and precise distance calculation is embodied by a tachometer. The vehicle-side sensors are used to assure safe station approaching and parking magnetic markers provide improvement of precision while tram parking. This paper provides a system realizing localization and precise parking and afterwards the automatic drive test results are reported and analyzed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.12
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• pp.1843-1847
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• 2012

Piezo devices have large power density and simple structure. They can generate larger force than the conventional actuators. It has also wide bandwidth with fast response in a compact size. Thus the piezo devices are expected to be used widely in the future for small actuators with fast response time and large actuating force. However, the piezo actuators need high voltage with high driving current due to their large capacitive property. In this paper, we propose a simple method to drive piezo devices using voltage inversion circuit with coil inductance. Experiments with real circuit demonstrates that the proposed scheme can improve the energy efficiency very much.