• Proceedings of the KIPE Conference
• /
• 1996.06a
• /
• pp.80-84
• /
• 1996

A Switched Reluctance Motor(SRM) has a torque pulsating inherently due to characteristics of pulse driving. A torque pulsating causes noise and sound vibration. To reduce a noise, a torque pulsating shall be controlled. Many efforts to make flat-topped current has been proposed to minimize a torque pulsating up to now. This paper proposed a control scheme to minimize the vibration of SRM by controlling the vibration directly by using of self-turning technique. The experimental results show that the proposed control scheme is effective in reducing the torque ripple and noise.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1996.04a
• /
• pp.95-99
• /
• 1996

In this paper, we proposed a method to measure the gap between the magnetic pole and the levitated object applying the inductance characteristic which vary according to gap. We made a driving circuit which supply the control input PWM(Pulse Width Modulation) signal and the carrier PWM signal to estimate the gap. Because the inductance is a function of gap, and the current of the carrier signal is a function of the inductance. We investigated the validity of the proposed method through the experimental results.

• Journal of Advanced Marine Engineering and Technology
• /
• v.22 no.6
• /
• pp.928-934
• /
• 1998

This paper describes a fully digitalized driver for BLDC motors which is realized by a single chip microprocessor. The speed change can be done by using the signal obtained from the position detecting sensor and adjusting the pulse width at the input channel of power module. In order to establish a speed control system a repetitive control method is adopted to track a periodic refer-ence change in the BLDC motor system. The experimental results show accurate reference track-ing performance under the given periodic reference in the repetitive controller design.

• Proceedings of the KIPE Conference
• /
• 1998.10a
• /
• pp.1024-1029
• /
• 1998

In this paper, the voltage-fed series compensated inductor type load-resonant high-frequency inverter is originally presented for driving a newly-developed silent discharge ozone generating tube. The effective power regulation scheme of this ozonizer is proposed, which is based on PDM (Pulse Density Modulation) related PWM strategy due to DSP implementation. The effectiveness of this inverter type ozonizer is proved in simulation and experiment.

• Proceedings of the KIPE Conference
• /
• 2002.07a
• /
• pp.278-280
• /
• 2002

Microstep driving method is adopted to reduce the thrust ripple of LPM(Linear Pulse Motor). It controls each phase current to improve the resolution of position. Therefore, the phase current waveform affects the characteristics of LPM in microstep drive. In this paper, the characteristics of LPM was investigated in accordance with phase current waveform.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.25 no.2
• /
• pp.176-181
• /
• 1988

In this paper, the LPC speech synthesizer with Multipulsse excitation is implemented using general-purpose DSP \ulcornerD7720. As the driving function for synthesis filter is used in the amplitude and position of pulse, the Voice/Unvoice decision and pitch period detectioncan be excluded. The synthesizer is implemented with DSP device which is operated on the interrupt mehtod with main computer and on the DMA mehtod with D/A converter. The comparision of synthetic and original waveform, alogn with the listening test, proves the validity of this system.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.14 no.6
• /
• pp.728-732
• /
• 2014

Macro-model of magnetic tunnel junction (MTJ) for spin transfer torque magnetic random access memory (STT-MRAM) has been developed. The macro-model can describe the dynamic behavior such as the state change of MTJ as a function of the pulse width of driving current and voltage. The statistical behavior has been included in the model to represent the variation of the MTJ characteristic due to process variation. The macro-model has been developed in Verilog-A.

• Proceedings of the KIEE Conference
• /
• 2001.10a
• /
• pp.33-35
• /
• 2001

Linear Pulse Motor(LPM) has a thrust ripple which is causing vibration. To reduce the vibration, Microstep driving method is adopted. We manufactured Microstep drive, and drove LPM with that, and then investigated the characteristics of thrust force.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2000.02a
• /
• pp.199-199
• /
• 2000

본 실험은 궁극적으로 coplanar AC-PDP 구동의 고효율(η)과 고화질을 목표로 두고 있는 기초 물리실험이다. AC-PDP의 최적화는 이 외에 많은 요소를 가지고 있으므로 다각도로 고찰하여야 한다. 이번 연구에서는 VDS(versatile driving simulator)를 이용하여 ramp resets pulses에서의 addressibility를 dynamic margin의 관점에서 조사하였다. AC-PDP panel의 구조는 R,G,B 3개의 cell이 모여 한 개의 화소를 이루고 있으며, R,G,B 각각의 Vf가 다르게 Va가 각각 다르다. 그러므로 실험을 통해 panel에서 R,G,B의 Vf-Va 공통 영역을 최적화하려는데 의미를 두고 있다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.5
• /
• pp.587-592
• /
• 2018

Because the brightness of an AMOLED is determined by the flowing current, each pixel of AMOLED operates via A current driving method. Therefore, it is necessary to supply power to adjust the amount of current according to THE user's requirement for AMOLED driving. In this study, an IP driver block was designed and a simulation was conducted for an AMOLED display, which supplies power as selected by users. The IP driver design focused on regulating the output power due to the OLED characteristics for the diode electric current according to the voltage to be activated by pulse-skipping mode (PSM) under low loads, and 1.5 MHz pulse-width modulation (PWM) for medium/high loads. The IP driver was designed to eliminate the ringing effects appearing from the dis-continue mode (DCM) of the step-up converter. The ringing effects destroy the power switch within the IC, or increase the EMI to the surrounding elements. The IP driver design minimized this through a ringing killer circuit. Mobile applications were considered to enable true shut-down capability by designing the standby current to fall below $1{\mu}A$ to disable it. The driver proposed in this paper can be applied effectively to the same system as the AMOLED display dual power management circuit.