• Proceedings of the KIEE Conference
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• summer
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• pp.1229-1231
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• 2004

A resonant type voltage source and power device and a control method using Pulse Density Modulation(PDM) power control and Pulse Width Modulation(PWM) voltage control for plasma sterilization are described. For the stability of discharge in the generating tube

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.5
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• pp.1117-1122
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• 2005

This paper is studied the high-repetition rate optical-pulse stream generation using optical loop mirror coupler. With the recent development of the ultrahigh-speed optical time division multiplexed system, hish-repetition rate optical-pulse stream generation is necessary. This is different from conventional approaches, which use fiber or integrated waveguide delay line circuits. The high-repetition-rate optical-pulse multiplication phenomenon occurs when the optical pulse's spectral width is greater than the transfer bandwidth of the coupler used. From the analysis, the output repetition rate can be controlled by using fiber couplers with different equivalent transfer bandwidths. The pulse separation spacing is controlled by number of cascaded coupler in optical loop mirror coupler scheme.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1580-1584
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• 2010

In this paper, we made an analysis of the effective optical pulse stream generation. This is different from conventional approaches, which use fiber or waveguide delay line circuits. The optical pulse multiplication phenomenon occurs when the optical pulse's spectral width is greater than the transfer bandwidth of the coupler used. Therefore, the effective optical pulse stream generation can be controlled by using fiber couplers with different equivalent transfer bandwidths. The pulse separation spacing is controlled by number of cascaded coupler in optical loop mirror coupler scheme.

• Journal of Power Electronics
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• v.18 no.4
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• pp.1201-1210
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• 2018

The applications of thermoelectric generators (TEGs) have received a lot of attention both in terms of harvesting waste thermal energy and the need for multi-levels of power. It is critical to track the optimum electrical operating point using DC to DC converters controlled by a pulse that is generated through a maximum power point tracking algorithm (MPPT). In this paper, the hardware implementation of a short-current pulse algorithm has been demonstrated under steady stated and transient conditions. In addition, the MPPT algorithm has been proposed, which is one of the most effective and applicable algorithms for obtaining the maximum power point of TEGs. During this study, the proposed prototype has been validated both analytically and experimentally. It has also demonstrated successful performance, which highlights the claimed advantages of the proposed MPPT solution.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.3
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• pp.51-56
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• 2014

The flat power spectrum of the transmitter output signal for the desired frequency range is ideal to achieve the best performance of ultrashort pulse reflectometry. However, the power spectrum of a typical pulse generator decreases significantly as frequency increases. A configuration of three chirped waveforms was employed to improve the power spectrum of the transmitter signal at higher frequencies. To determine the amplification gain required for higher frequency components, three chirped waveforms were theoretically generated and their power spectra were measured using numerical band-pass filters. Based on the results of numerical computations, the three chirp configuration was successfully applied to the design of the transmitter for a broadband system.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1755-1757
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• 1998

Pulse transformers have been developed to apply for pulsed power technology as an alternative of a Marx generator. To obtain repetitive pulsed power generation, it is necessary to observe the rising time of output of pulse transformer. In this paper, using the equivalent circuit, The rising wave of output of pulse transformer is simulated for various input wave by using the Electromagnetic transient program(EMTP).

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.274-277
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• 1994

This paper describes a very fast rising high voltage pulse generation for studying surge phinomenon and prebreakdown of liquid dielectric by appling the traveling wave theory of the distributed circuit. This very fast rising high voltage pulse generator consists of a charging coaxial cable, a discharging switch, and a terminating resistance. As results, the rising time of pulses are about 31(nsec), which is very fast, and its duration is 950[nsec] when using 200[m] coaxial cable. The length of the coaxial cable and changing voltage can regulate the duration and the amplitude or the polarity of the pulse. When terminated the resistance, capacitor and inductor, the measured waveform corresponds with simulated waveform.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.8
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• pp.1552-1557
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• 2007

In this work, temperature stable pulse width modulation controller using bandgap reference voltage is proposed. Two bandgap reference voltages are designed by using BiCMOS technology which are temperature dependent and independent voltage references. PWM controller is designed by using 3.3 volt supply voltage and the output frequency is 1MHz. From simulation results, the variation of output pulse width is less than form +0.86% to -0.38% in the temperature range $0^{\circ}C\;to\;70^{\circ}C$.

• Journal of Sensor Science and Technology
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• v.25 no.2
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• pp.138-142
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• 2016

A pulse measurement by tonometry provides useful information for diagnosis, including not only blood pressure and heart rate but also parameters for estimating a condition of the cardiovascular system. Currently, various pulse measurement devices based on the tonometry have been developed. A reliability of these devices is determined by a positioning technic between the sensor and the blood vessel and a controlling technique of the pressurization level. An angle of the sensor for the pulse measurement seems to be highly related with a measured signal, however, the objective studies for this issue have been not published. In this paper, the variation of the pulse signals by tonometry direction was experimentally assessed according to the angle of the sensor. In order for guaranteeing the repeatability of the experiment, we used a pulse generator device, which can generate human pulse signal by using silicon tube and fluid pump, and developed a structure for precise adjustment of the angle and the pressurization level of the sensor. The angle of the sensor was acquired by an inclinometer, which was attached at the opposite side of the sensor. As results, a coefficient of variation (CV) of a maximum amplitude (MA) of the pulse wave was largely increased over the angle range of $-9{\sim}9^{\circ}$. Furthermore, the changes of the pulse shape showed different aspects according to the sign of the angle tilted along the blood vessel. It is expected that the results of this study can be helpful for developing more precise pulse measurement devices based on the tonometry and applying in clinic.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1818-1820
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• 2003

In this study, we developed friendly-environment device through various applications of pulse power system and studied research about pulse energy transfer characteristics. We have studied the mutual relation between characteristics of the load impedance and consumed power of the pulse power system. The consumed power means electrical power from the wall plug. For changing the load impedance, we could change elecrode length. As results, we can get electrical characteristics between pulse generator and load. When the pulse energy was triggered the microbes, caused waste water, they were almost removed in the waste water.