• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2017년도 전력전자학술대회
• /
• pp.138-139
• /
• 2017

This paper describes the design and implementation of a trigger circuit which can be series connected with main pulse circuit for a xenon flash lamp driver. For generating high voltage, the trigger circuit is designed as an inductive energy storage pulsed power modulator with 2 state step-up circuit consisting of a boost converter and a flyback circuit. In order to guarantee pulse width, a resonant capacitor on the output side of the flyback circuit is designed. This capacitor limits the output voltage to protect the flyback switch. In addition, to protect another power supply of xenon flash lamp driver from trigger pulse, the high voltage transformer which can carry the full current of main pulse is designed. To verify the proposed design, the trigger circuit is developed with the specification of maximum 23 kV, 0.6 J/pulse output and tested with a xenon flash lamp driver consisting of a main pulse circuit and a simmer circuit.

• 비파괴검사학회지
• /
• 제37권2호
• /
• pp.91-98
• /
• 2017

Recently, composite materials have been mainly used in the main wings, ailerons, and fuselages of aircraft and rotor blades of helicopters. Composite materials used in rapid moving structures are subject to impact by hail, lightning, and bird strike. Such an impact can destroy fiber tissues in the composite materials as well as deform the composite materials, resulting in various problems such as weakened rigidity of the composite structure and penetration of water into tiny cracks. In this study, experiments were conducted using a 2 kW halogen lamp which is most frequently used as a light source, a 2 kW near-infrared lamp, which is used for heating to a high temperature, and a 6 kW xenon flash lamp which emits a large amount of energy for a moment. CFRP composite sandwich panels using Nomex honeycomb core were used as the specimens. Experiments were carried out under impact damages of 1, 4 and 8 J. It was found that the detection of defects was fast when the xenon flash lamp was used. The detection of damaged regions was excellent when the halogen lamp was used. Furthermore, the near-infrared lamp is an effective technology for showing the surface of a test object.

• 대한기계학회논문집B
• /
• 제36권10호
• /
• pp.1025-1032
• /
• 2012

플래시 램프 열처리(Flash lamp annealing, FLA) 공정은 저온폴리실리콘의 생산을 위한 기술로써 대면적 기판용 실리콘 결정화 기술로 기대 받고 있는 기술이다. 본 연구에서는 FLA 공정 중 기판에 발생하는 변형의 원인에 대하여 이론적인 해석과 이를 토대로 시뮬레이션을 수행하였다. 상용 FEM 해석프로그램에 고온에서의 유리의 점성에 대한 모델을 적용하여, 고온에서 유리의 구조적인 수축과 응력이완으로 인한 영구변형을 수치적으로 재현하였다. 0 세대 실험시편($2cm{\times}2cm$)의 경우 중력의 영향이 미미하여서, 실험 결과와 일치하는 'U'모양의 변형이 남는 것을 확인하였고, 4 세대 기판($74cm{\times}94cm$)의 경우 중력으로 인하여 'M'모양의 변형이 발생하는 것을 시뮬레이션하였다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
• /
• pp.296-299
• /
• 1987

The purpose of this paper is to increase the lamp efficacy by filling the optimal Nitrogen gas pressure in the outer enclosure of metal halide lamp. This study presents a new model of Langmuir in the outer enclosure of discharge lamp. In this paper, in the first place, the diameter of Langmuir sheath and the total gab loss were calculated. Secondly, the each gas loss was computed if the arbitrary gas pressure is filled, With the calculated data, flash over which affects the lamp efficacy, lamp life and color rendering was considered. In case of the established discharge lamp, the gab pressure has been filled by experience only roughly. The gas loss is converted into the radiation output. Therefore, the lamp efficacy is improved by reducing the gas loss.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2017년도 전력전자학술대회
• /
• pp.231-232
• /
• 2017

This paper describes the design and implementation of a 2.5kW (500V, 5A) simmer circuit that maintains the ionization of xenon gas inside the lamp. The design is based on a LCC resonant converter in continuous conduction mode (CCM) with above resonant frequency to take advantage of high power density from using parasitic elements such as the leakage inductance in a power transformer. In addition, since the converter has current source output characteristics, it is suitable for maintaining ionization of the lamp having the negative resistance load characteristic. To verify this converter design, PSpice modeling was performed. Finally, the developed simmer circuit is verified by a resistive load of rated performance and the Ionization maintenance operation of the xenon flash lamp.

• 한국전기전자재료학회논문지
• /
• 제37권4호
• /
• pp.427-432
• /
• 2024

The polymer crystallization process, promoting the formation of ferroelectric β-phase, is essential for developing polyvinylidene fluoride (PVDF)-based high-performance piezoelectric energy harvesters. However, traditional high-temperature annealing is unsuitable for the manufacture of flexible piezoelectric devices due to the thermal damage to plastic components that occurs during the long processing times. In this study, we investigated the feasibility of introducing a flash lamp annealing that can rapidly induce the β-phase in the PVDF layer while avoiding device damage through selective heating. The flash light-irradiated PVDF films achieved a maximum β-phase content of 76.52% under an applied voltage of 300 V and an on-time of 1.5 ms, a higher fraction than that obtained through thermal annealing. The PVDF-based piezoelectric energy harvester with the optimized irradiation condition generates a stable output voltage of 0.23 V and a current of 102 nA under repeated bendings. These results demonstrate that flash lamp annealing can be an effective process for realizing the mass production of PVDF-based flexible electronics.

• 한국광학회지
• /
• 제14권5호
• /
• pp.515-520
• /
• 2003

수 KHz의 반복율로 발진하는 레이저광을 증폭하는 증폭기를 제작하고, 특성을 조사하였다. 증폭기로는 연속 방전하는 섬광등으로 펌핑되는 Nd:YAG 헤드를 사용하였고, 레이저 매질에서 발생하는 열 복굴절을 보상하여 이중통과 증폭기를 구성한 경우, 복굴절에 의한 레이저광 손실을 5%로 감소시켰다. 4 중통과 증폭기를 구성을 하였을 때, 반복율 5-10 KHz에서 이득은 약 3.2이었고, 펄스폭은 40 ns에서 48 ns로. 20%증가하였다.

• 한국광학회지
• /
• 제30권5호
• /
• pp.197-203
• /
• 2019

본 논문은 광 소결 공정에 쓰이는 제논 플래시 램프 사용 시 조도 균일도를 개선시킬 수 있는 반사경 설계에 대한 연구를 진행하였다. 조사 영역에서 기판의 완전한 소결이 이루어지기 위해서 광효율과 조도 균일도를 목표 성능으로 설정하였다. 기존의 타원 반사경 또는 포물 반사경을 이용한 방식은 광효율을 만족하기 용이하지만 조도 균일도를 만족하는데 어려움이 있다. 따라서 본 논문에서는 조도 균일도를 만족시키기 위해 포물경의 중앙부에 쌍오목 형상을 추가하였다. 이러한 쌍오목 형태의 중앙부 형상을 갖는 포물 반사경의 조도 균일도가 기존의 반사경에 비해 향상됨을 확인하였다.

• 한국정보통신학회논문지
• /
• 제25권1호
• /
• pp.81-87
• /
• 2021

본 연구에서는 다양하게 피부치료가 가능한 V-IPL 방식을 도입하여 피부치료 시스템을 설계하여 실험하였고, 또한 병변에 따라 플래쉬 램프를 순차적으로 점등시키는 새로운 방식인 방전 방식을 이용하였으며, 기존의 LC 가변방식과 스위칭소자의 스위칭모드 제어방식을 활용하여 펄스 형상제어를 시스템에 구성하였다. 그 결과 마이크로프로세서를 이용하여 펄스폭이 1[㎛]까지 가변이 가능하였고, 깊이와 넓이에 따른 병변에 플래쉬 램프를 순차 점등시키므로써 펄스형상 및 펄스모양을 보다 다양하게 할 수 있었다. 그리고 펄스폭을 약 1~100[ms]까지 다양하게 긴 펄스를 만들 수 있었으며, 기존의 제품은 One pulse(pulse width : 1~40ms)이지만 제안한 제품은 Three pulse(pulse width : 1~100ms)로 특별한 차이가 있었다.

• 전기학회논문지
• /
• 제56권7호
• /
• pp.1261-1267
• /
• 2007

Although LEDs have been used in various applications with improving the brightness and luminous efficacy, the electrical and optical characteristics of high power LED varies at different temperature and starting time. In this paper, optimal heat sink and apparatus design were conducted using IR camera and ICEPAK on the LED bulb consisting with fourteen LED array. The temperatures of heat sink and LED device of the designed LED bulb without cooling pan were $74^{\circ}C\;and\;96.8^{\circ}C$, respectively, showing in good themal characteristics. For high efficiency driving circuit of LED array adopted optimal heat sink design, driving circuits of constant voltage and current circuits were suggested and fabricated. As a result the efficacy of all driving circuits showed more than 20 lm/W. Also, the constant current circuits are suitable for signal lamp, hallway lamp, and flash lamp having short operating time(about 30 min). On the other hand, a reading light and indoor lamp having long operating time can be controlled by constant voltage circuit.