• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.28 no.3
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• pp.274-285
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• 1992

Among various Power converters, a variable voltage variable frequency (VVVF) three-phase PWM inverter is regarded as most promising power converter due to its capabilities, which permits the control of voltage, frequency and harmonic contents in a single power stage employing only on DC source. As a modulating technique of the PWM inverter, the regular sampling technique has rendered possible the on-line computation and generation of PWM control waveforms with a reasonably high switching frequencies. In this paper, microprocessor based three-phase regular samping PWM inverter with real-time control algorithm and control circuits for driving three phase AC motor has been developed. Harmocic components of PWM waveform were analized theoretically in terms of Bessel function series and then calculated by digital computer and observed with spectrum analyzer.

• Journal of ILASS-Korea
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• v.15 no.4
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• pp.163-169
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• 2010

Jetting stability is the most important factors in inkjet printing because printing quality is totally determined by shape of the droplets on the substrate. In order to acquire stable jet, viscosity and dynamic behavior of the ink must be considered. In addition, waveform to drive the inkjet printhead is also to be controlled. In this study, the driving waveform composed of rising time, dwell time and falling time is optimized to obtain a stable jetting using drop watcher system. Also, effect of ink viscosity on jetting is experimentally investigated by changing the temperature of ink cartridge. As a result, jetted drop having uniform velocity is acquired.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.95-96
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• 2009

It is analyzed how the Plasma - MgO surface interaction, driving waveform and their inter-relation can cause misfiring. Developing of glow discharge mode during the ramp reset due to lack of priming particles was suggested as one of the important misfiring sources. It is also shown that simple modification of reset waveform can considerably reduce misfiring probability.

• Current Optics and Photonics
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• v.7 no.1
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• pp.28-32
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• 2023

Frequency characteristics of gain-saturated erbium-doped fiber amplifier (EDFA) are experimentally evaluated to mitigate the optical signal fluctuation induced by atmospheric turbulence in terrestrial freespace optical communication systems. Here, an acousto-optic modulator (AOM) is used to emulate optical signal fluctuations induced by atmospheric turbulence. The waveform which is generated in proportion to the refractive-index structural parameters is used to drive the AOM at various periodic frequencies. Thus, the dependence of the signal fluctuation suppression on the frequency is evaluated. The experiment is conducted using a periodic frequency sweep of the AOM driving voltage waveform and signal input power variation of the amplifier. It is observed that a low periodic frequency and high input signal power effectively suppress the optical signal fluctuation. This study evaluates the experimental results from the high-pass filter and gain-saturation characteristics of the EDFA.

• Journal of Korea Society of Industrial Information Systems
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• v.18 no.3
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• pp.1-8
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• 2013

Plasma display panel (PDP) televisions are facing to have a new chance to receive attention along with a boom in 3-D software and contents because PDP can provide the comfortable and realistic 3-D images. The PDP has three driving circuit boards such as X, Y and addressing boards. Cost effective driving waveform has already been reported to decrease the number of driving circuit board. Half bridge based sustaining driver can remove a sustaining driver in the X board. However, the biasing circuit in the X driving boards cannot be reduced because there are some drawbacks such as unstable gas discharge condition and unreliability of an address driver IC. In this paper, the half bridge based sustaining driver is considered and a simple address driver is proposed to remove one driving board, X driving board. The stable gas discharge condition, reliability of the address driver IC and the low cost can be obtained by the proposed circuit.

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

• The Transactions of the Korean Institute of Electrical Engineers
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• v.38 no.11
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• pp.896-904
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• 1989

PWM techniques which eliminate and reduce harmonics of output voltage in PWM Inverter driving System with fluctuating input volotage are described. First, harmonic factors are analyzed from harmonic equation of general PWM waveform and by examination of control possiblity of each factor, controllable factor is selected. Applying controllable factor to NPWM, PWM techniques using reference wave and carrier wave modulation are introduced. Actually, by the experiment applied with this strategy, the reduction of harmonics of output voltage is confirmed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.6
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• pp.521-521
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• 2020

• Journal of Power Electronics
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• v.4 no.1
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• pp.56-63
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• 2004

A new driving circuit for the SPSS (Single-Pulse Soft-Switching) PFC converter is proposed. The switching device of a SPSS converter switches once in every half cycle of an AC commercial power source. Therefore, it can be solved many problems caused by the high frequency operation. The proposed SPSS converter achieves the soft-switching operation and the EMI noise can be reduced. The resonant capacitor voltage supplies to the resonant inductor even if the input AC voltage is the vicinity of zero cross voltage. Then, the power factor and input current waveform can be improved without delay time. A new driving circuit achieves the operation of SPSS converter by one switching drive circuit. The proposed converter can be satisfied the IEC standard sufficiently

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.950-951
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• 2006

This paper proposed a new driving method for the stable lighting of CDM lamps. To avoid the acoustic resonance in the proposed method, the inverter output voltage will be a low frequency rectangular waveform containing a sinusoidal voltage ripple with high frequency. Moreover, the realtime power control of the inverter can be achieved by the control of switching currents. To verify the validity of tile proposed method, a prototype set-up was build and the experimental results are presented in this paper.