• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.278-281
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• 2006

A Hybrid type LPM(Linear Pulse Motor) is designed as single side stator structure. Experimental results are shown that the static and dynamic characteristics. By the computer simulation, the permanent magnet design method is also clarified to desired thrust force. And microstep driver is adopted to the position controller to the designed LPM. The driver suppressed position errors within ${\pm}1501{\mu}m$.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1503-1505
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• 2005

The Cold cathode fluorescent lamp(CCFL) are widely used to illuminate the liquid crystal display(LCD). Ballasts are required for CCFL because the lamp need high starting voltage and behave negative dynamic resistant characteristics in the desired region of operation. Dimming methods of CCFL are used to pulse frequency modulation(PFM) or pulse width modulation(PWM). In this paper, CCFL driving and control circuit is designed by half-bridge type series and parallel resonant inverter that variable frequency modulation method to control the output voltage current. The validity of this study is confirmed from the simulation and experimental results.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.5
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• pp.215-219
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• 2004

The effects of ambient temperature on the discharge characteristics of Ne-Xe based micro discharge cells for ac-PDP (plasma display panel) have been studied. In ramp voltage driving, which is generally used as a reset method of PDP, two dissimilar modes of strong and weak discharge were found. As the interval between the former sustaining discharge and ramp voltage discharge becomes greater, the probability of a strong discharge increases. This suggests that a sufficient number of priming particles is necessary for initiating weak mode (Townsend discharge). It was discovered that under higher ambient temperatures, weak discharge occurs more frequently. The discharge time lag observed in square pulse driving of single cells becomes surprisingly smaller under higher ambient temperatures for the constant gas number density condition.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.358-360
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• 1996

LPM(Linear pulse motor) has made linear motions by itself. And the LPM has higher thrust force ratio to mass and more wide driving speed lunges comparing with the conventional rotating type motors. However, there are the thrust force ripples in the LPM, which are produced by the mechanical structures and nonlinear back emf. It makes to hesitate the practical applications of LPM. Especially, it becomes needed to reduce the thrust force ripples for practical, which needs relative low driving speeds. For reducing the thrust force ripples, in the first place, it was built a new nonlinear linkage flux equations of the LPM. In these equations, the influence of permanent magnetic and variable reluctance thrust force components were considered. In this paper, some experimental results in the modeling of LPM are shown and detent lone and holding force characteristics of LPM are measured.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.5
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• pp.44-52
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• 2007

In this study, design and control method using low cost Micro-controller(MCU) for inverter driving circuit in fluorescence lamp is presented. Soft starting technique is adopted to reduce switching loss and moment deterioration which are induced by high speed switching frequency in inverter ballast. Performance of the ballast stabilizer and the lighting characteristic of the fluorescence lamp have been improved by stabilizing switching pulses through the Pulse Width Modulation control.

• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.258-260
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• 2003

In this paper, we study the reduction of the Dynamic False Contour in a new driving method. This method divides scan lines into Multi Blocks, and drives both selective write and selective erase address. Because of the characteristic of proposed waveform, each scan line has a different sustain pulse weight. Therefore, the Dynamic False Contour occurs seriously in the boundary of each Block. Finally, if scan-lines tie several lines, the Dynamic False Contour can reduce in the boundary of each Block.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1487-1490
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• 2006

One of the factors deteriorating PDP image quality is the nonlinearity and nonuniform of output luminance as a function of input gray level. A novel method using modified ADS driving scheme is proposed to decrease this nonlinearity. It optimizes the reset pulse and adjusts the subfields, makes the relation of output luminance and input gray level almost linear. This method can be applied to general commercial PDPs.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.279-284
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• 1999

Although the switched reluctance motor (SRM) has a several advantages such as simple magnetic structure, robustness, wide range of speed characteristics and simple driving, it has a considerable inherent torque ripple and speed variation duet to the driving characteristics of pulse current waveform and the nonlinear inductance profile. The high torque ripple and speed variation inhibits wide application. The minimization of the torque ripple is very important in high performance servo drive applications, which require smooth operation with minimum torque pulsations. This paper presents the new SRM torque modeling technique for the control of instantaneous torque. The SRM is modeled by the database of torque profiles for every small variation in currents and rotor angles, which is inferred from the several measured data by the adaptive neuro-fuzzy inference technique. Simulation results demonstrating the effectiveness of proposed torque modeling technique are presented.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.9
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• pp.1579-1583
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• 2008

We proposed the new structure of ac plasma display panel(PDP) to improve the luminous efficacy and driving voltage characteristics. Through two-dimensional numerical simulations, we analyzed the effects of new counter discharge type, which consists of counter sustain electrodes and auxiliary electrodes. Generally, an advantage of AC PDP with the counter sustain electrodes has been known for the driving characteristics of the low voltage. In this work, the new counter structure using the ignition discharge by the auxiliary pulse applied to the address electrode showed the result of the increased luminous efficacy. The short gap discharge between two auxiliary electrodes on the front plate could intensity the long gap discharge between counter electrodes. The reliability of simulation result could be confirmed by the experimental result in the test panel.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.11
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• pp.33-38
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• 2011

In this paper, the effect of pulse current and generated heat on characteristics of the LED is measured and evaluated. For experiments, the LED driving circuit and digital logic which determines period and duty ratio of lighting are designed. At rated current, the temperature and optical characteristics of the LED with change in duty ratio and period are compared, and those of the LED with change in duty ratio and existence of cooling fan are also compared at constant average current. As a result, frequency does not affect device temperature and optical characteristic of the LED but duty ratio does. Also, the cooling fan is less effective on those of the LED at rated current.