• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권11호
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• pp.566-571
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• 2004

Pulse modulation technique provide additional controling method for electron temperature and density in rf and microwave processing plasma. Transient characteristics of electron density and temperature have been measured in pulse modulated rf inductively coupled argon plasma using simple probe circuit. Electron temperature relaxation is clearly identified in the after glow stage. Controllability of average electron temperature and density depends on the modulation frequency and duty ratio. Numerical calculation of time-dependent electron density and temperature have been performed based on the global model. It has been shown that simple langmuir probe measurement method used for continuous plasma is also applicable to time-dependent measurement of pulse modulated plasma.

• 전자공학회논문지
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• 제50권6호
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• pp.138-144
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• 2013

XRF 시스템에서 디지털 방식으로 펄스를 합성하는 기술은 현재 다양하게 발전 되면서 기존의 아날로그 방식을 대신하고 있다. XRF 시스템에서는 펄스의 높이를 분석하기 위해 주로 trapezoidal 필터를 사용한다. 본 논문에서는 trapezoidal 필터의 하드웨어 구현을 위한 효율적인 구조를 제안한다. 또한 측정 오차가 기존 알고리즘에 의한 오차의 절반으로 감소되면서 효율적인 하드웨어 구현이 가능한 최대값 검출 알고리즘을 제안한다. 제안한 알고리즘은 하드웨어 언어인 Verilog HDL로 설계하고 FPGA로 구현하였으며 테스트보드를 제작하여 성능을 검증하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1852-1854
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• 2003

In manufacturing processes, various and suitable pulse shapes are required for the purpose of material processing. In order to make various pulse shapes with variable pulse length and high duty cycle, We have fabricated the power supply consisting 6 SCRs and the Pulse Forming Network(PFN) with the precise delay time control. So our control system has three switching circuits, 3 mesh PFN, and simmer circuit. In addition, we have designed and fabricated the PIC one-chip microprocessor(16F877) to control the delay time of sequential switching.

• 센서학회지
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• 제15권2호
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• pp.77-83
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• 2006

A monitoring apparatus for pulse shapes of human heartbeats has been developed using an amorphous MI(Magnetic Impedance) sensor. The pulse shapes are successfully obtained from voltage signals due to the variations of magnetic impedance in the amorphous MI sensor, which is attached to a patient's wrist. This voltage signal was fed into a signal processing module to extract the pulse shapes of heartbeats. The signal processing module, which is proposed to detect a weak variations of impedance in MI sensor under a noisy measurement environment, consists of a high frequency current source, an amplifier stage and a synchronous detection circuit. To evaluate the characteristics of a newly developed apparatus, various experiments were performed. The experimental results show that the developed apparatus could be used as a diagnosis tool for traditional Korean medicine with further systematic clinical studies.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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• pp.74-77
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• 2000

A pulsed Nd:YAG laser has been used in a wide variety of fields : measuring, material processing and so on. In a material processing, it is very important to control the laser energy density. A pulse repetition rate and a pulse width are regarded as the most dominant factors to control the energy density of laser beam. In this study, pulsed Nd:YAG laser system was designed and manufactured to control the laser output usefully and easily. This system adopted the sequential charge and discharge circuit is controlled by 80196 micro- processor. As a result, it is found that laser output is controlled minutely by changing laser input and pulse repetition rate, and usefully by using 80196 microprocessor.

• KIEE International Transactions on Electrophysics and Applications
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• 제3C권4호
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• pp.155-160
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• 2003

In this study, an Alexandrite laser system for hair removal adopting a multi-discharge method in which three flash lamps are turned on consecutively was designed and fabricated to examine the pulse width and the pulse shape of the laser beams depending upon the changes in the lamp turn-on time. Specifically, this study demonstrates a technology that makes it possible to formulate various pulse shapes by turning on three flashlamps consecutively on a real-time basis with the aid of a PIC (program integrated circuit) one-chip microprocessor. With this technique, the lamp turn-on delay time can be varied more diversely from 0 to 10 ms and real-time control is possible with an external keyboard, enabling an assortment of pulse shapes. In addition, longer pulses can be more widely used for industrial processing as well as for numerous medical purposes.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 E
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• pp.2035-2037
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• 1999

This paper describes an ASM(All Solid-state Modulator) pulsed power generator for non-thermal plasma applications. The proposed generator can produce 20kV, 500A, 100ns pulses at repetition rates up to 10kHz, and it is composed of 30 series connections of power circuit card assembly which contains paralleled MOSFETs, MOSFET drivers, energy storage capacitors and specially designed 1:1 pulse transformer. Higher pulse voltages and currents can easily be obtained by increasing the numbers of series and parallel connections of power circuit card and MOSFETs, respectively. Component layouts are optimized to minimize the leakage inductance and the voltage spikes across switching devices. Especially it put emphasis on the over-current protection (including short circuit) for the reliable operation in real situations. Experimental results show that the proposed pulser is very efficient in air pollution control application and could be useful for other applications such as synthesis of nanosize powders and non-thermal food processing.

• 한국전기전자재료학회논문지
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• 제33권5호
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• pp.350-354
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• 2020

In this study, a pressure sensor for each displacement was fabricated based on the silicon-based pressure sensor obtained through simulation results. Wires were bonded to the pressure sensor, and a piezoresistive pressure sensor was inserted into the printed circuit board (PCB) base by directly connecting a micro-electro-mechanical system (MEMS) sensor and a readout integrated circuit (ROIC) for signal processing. In addition, to prevent exposure, a non-conductive liquid silicone was injected into the sensor and the entire ROIC using a pipette. The packaging proceeded to block from the outside. Performing such packaging, comparing simple contact with strong contact, and confirming that the measured pulse wavelength appears accurately.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(5)
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• pp.215-218
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• 2001

A pulsed Nd:YAG laser is used widely for materials processing and medical instrument. It's very important to control the laser energy density in those fields using a pulsed Nd:YAG laser. A pulse repetition rate and a pulse width are regarded as the most dominant factors to control the energy density of laser beam. In this paper, the alternating charge and discharge system was designed to adjust a pulse repetition rate. This system is controlled by microprocessor and allows to frequence an expensive condenser for high frequency to cheap one for low frequency. In addtion, The microcontroller monitors the flow of cooling water, short circuit, and miss firing and so on. We designed Nd:YAG laser firmware with smart microcontroller, and want to explain general matters about the firmware from now.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -2
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• pp.615-618
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• 2000

A number of studies have recently been made on hardware for a biological neuron f3r application with information processing functions of neural networks. We have been trying to produce hardware from the viewpoint that development of a new hardware neuron model is one of the important problems in the study of neural networks. In this paper, we first discuss the circuit structure of a pulse-type hardware neuron model with the enhancement-mode MOSFETs (E-MOSFETs). And we construct a pulse-type hardware neuron model using I-MOSFETs. As a result, it is shown that our proposed new model can exhibit firing phenomena even if the power supply voltage becomes less than 1.5[V]. So it is verified that our model is profitable for IC.