• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2008.04a
• /
• pp.373-376
• /
• 2008

본 논문은 퍼지 펄스 폭 변조 (Pulse-width-modulation: PWM) 시스템의 안정도에 대해 다루게 된다. 복잡성을 가진 비선형 시스템은 Takagi-Sugeno (T-S) 퍼지 모델에 의해 효율적으로 논의될 수 있다. 본 논문에서는 기존의 LTI 시스템에서 논의 되었던 PWM 제어기 설계 문제를 퍼지 시스템으로 확장시킴으로써 PWM 제어기에 대한 논의의 저변을 확대시키고자 한다. 또한, 리아푸노프 (Lyapunov) 안정도에 기반 한 안정도 증명을 통해 퍼지 PWM 시스템의 안정도를 분석하고자 한다.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.9 no.3
• /
• pp.1-8
• /
• 1972

The characteristics of tunnel diode pair circuit biased within the negative resistance region has also the voltage-control type negative resistance region, and the voltage at the center point of negative resistance region is described as the square-wave relaxation oscillation. In this paper, the period T, positive duration T1, negative duration T2 of the pulse are obatined from the characteristic curve T, positive duration T1, negative duration T2 of the pulse are obtained from the characteristic curve and observed actually, considring the fact that the pulse width and the period of square-wave at the center point of the negative resistance region is able to be controlle dby the blas volgate. Mereover, the relationship between T, T1 or T2 and circuit parameters is searched for and the Circuit parameters that satisfy the conditions of T1-T2 being proportional to the variation of bias voltage with Teonstant are determined. Thereafter, the bias voltage and the signal voltage are inserted serially to the PWM circuit and the characteristics of that circuit is analyzed.

• Proceedings of the KIPE Conference
• /
• 2008.06a
• /
• pp.367-369
• /
• 2008

본 논문은 중용량에 적합한 새로운 이중출력 LLC 공진형 DC/DC 컨버터에 관한 것으로써, 별도의 Post-regulator및 추가되는 제어 IC 없이 정밀한 이중출력이 가능한 새로운 방식의 컨버터를 제안한다. 제안된 컨버터의 제어방식은 펄스폭 변조(PWM)와 동시에 주파수 변조(PFM)를 통해 이루어지며 Master 와 Slave 출력을 각각 주파수, 듀티로 제어함으로써 Slave 출력을 위한 별도의 Post-Regulator 및 제어 IC가 필요 없기 때문에, 저가의 컨버터 구현이 가능하다. 또한 기존 LLC 공진형 DC/DC 컨버터와 같이 스위칭 소자의 영전압 스위칭이 보장되는 동시에, Post-Regulator 로 인한 손실이 없기 때문에 효율 및 발열 특성이 매우 우수하다. 본 논문에서는 제안된 컨버터의 우수성과 신뢰성 검증을 위해, 실제로 50" FHD급 PDP용 전원회로를 위한 시작품을 제작하고 이를 이용한 실험결과를 바탕으로 제안된 컨버터의 타당성을 검증한다.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.53 no.9
• /
• pp.129-134
• /
• 2016

This paper studies the high frequency PWM (pulse width modulation) driving technique to increase an optical efficiency and to prevent an optical color quenching of blue laser for head up display on vehicles using digital micro mirror device (DMD) panel and yellow phosphor wheel. The proposed approach adaptively drives the current pulse width modulated signals of high optical power of blue laser to increase the lifetime and to decrease the stem temperature of laser. This method stabilizes the temperature of laser according to the driving environment and the forward current capacity. By the proposed method, the brightness of blue laser is improved by about 37% compared to the continuous waveform current driving method.

• Journal of the Korean Society of Radiology
• /
• v.11 no.3
• /
• pp.101-108
• /
• 2017

DC/DC switching power converters are commonly used to generate a regulated DC output voltage with high efficiency. The advanced DC/DC converter uses a PWM-IC with OP-Amp. (Operational Amplifier) to control a MOSFET (metal-oxide semiconductor field effect transistor), which is a switching component, efficiently. In this paper, it is shown that the electrical characteristics of OP-Amp. are affected by radiations of ${\gamma}$ rays using $^{60}Co$ for TID (Total Ionizing Dose) testing and 5 heavy ions for SEL (Single Event Latch-up) testing. TID testing on OP-Amp. is accomplished up to the total dose of 30 krad, and the cross section($cm^2$) versus LET($MeV/mg/cm^2$) in the OP-Amp. operation is evaluated SEL testing after implementation of the controller board.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.45 no.10
• /
• pp.872-880
• /
• 2017

Usually, on/off control method is a way to control the thruster. Bang-Bang Control, PWM(Pulse Width Modulator) and PWPF(Pulse Width Pulse Frequency) are widely used as a typical way. When we are designing PWPF, the incorrectly designed parameters($K_m$, ${\tau}$, $U_{on}$, $U_{off}$, $U_m$) make trouble, such as the phase lag, the wasted fuel, the reduced system life. Therefore, the effect of parameters on the system performance should be analyzed before the proper parameters are selected. In this paper, we suggest the PWPF parameters design method by performing a static analysis, and analyze the interactive effects on design parameters by performing a dynamic analysis and simulation.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.8 no.2
• /
• pp.43-49
• /
• 1998

This paper describes a phase-shift pulse-width modulation and pulse-frequency modulation seriesresonant high-frequency inverter using IGBT for the power control of high-frequency inductionheating using fuzzy, which is practically applied for 2 0- 5~0 0~~ ~in 1d uction-heating and meltingpov~er supply in industrial fields. The adaptive frequency tracking based phase-shifting PWMregillation scheme is presented in order to minimize switching losses. The trially-producedbreadboards using IGBT are succesfully demostrated and discussed.discussed.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.227-233
• /
• 2010

This paper treats the method to build up Motor drive-circuit using semi-conduct control part like power transistor, MOSEFT and refers to the operation theory, forward, reverse rotation control and speed control method which is changed by PWM. And also, this paper mention to the basic principle of DC Motor and various Motor control method using micro-processor.

• Journal of Industrial Technology
• /
• v.30 no.B
• /
• pp.109-112
• /
• 2010

Unlike the general lighting systems, stage lighting system requires accurate dimming control and reduction of flicker phenomenon. In this paper, we studied PWM dimming control and linear voltage level control methods. PWM Dimming is easy control and flicker phenomenon of linear voltage level dimming does not happen by experiment result. We concluded that stage lighting dimming system required to combine two techniques of the PWM and linear voltage level dimming control method.

• The Journal of the Korea Contents Association
• /
• v.10 no.2
• /
• pp.72-80
• /
• 2010

The 1Gbps clock and data recovery (CDR) circuit using the proposed multi-point phase detector (PD) is presented. The proposed phase detector generates up/down signals comparing 3-point that is data transition point and clock rising/falling edge. The conventional PD uses the pulse width modulation (PWM) that controls the voltage controlled oscillator (VCO) using the width of a pulse period's multiple. However, the proposed PD uses the pulse number modulation (PNM) that regulates the VCO with the number of half clock cycle pulse. Therefore the proposed PD can controls VCO preciously and reduces the jitter. The CDR circuit is tested using 1Gbps $2^{31}-1$ pseudo random bit sequence (PRBS) input data. The designed CDR circuit shows that is capable of recovering clock and data at rates of 1Gbps. The recovered clock jitter is 7.36ps at 1GHz and the total power consumption is about 12mW. The proposed circuit is implemented using a 0.18um CMOS process under 1.8V supply.