• Title, Summary, Keyword: 더블브리지회로

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A Study on Minimize Method of EPIRB's Error Operation by Improve the Seawater Sensing (해수센싱 방법의 개선에 의한 EPIRB오동작의 최소화방안 연구)

  • Lee, Young-Soo;Choi, Jo-Cheon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.11
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    • pp.1978-1982
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    • 2006
  • The EPIRB overcame the limitations of the conventional marine communication systems, the false distress calls by EPIRB systems internationally account for about 94 percent of the total calls because of the different usages of EPIRB systems with manufacturers, users' errors, and systems' faults. To resolve these problems, international bodies and manufacturers are developing many measures to reduce those error emissions. In conventional systems, the distress call was sent immediately after the EPIRB is removed from the automatic release system. Taking into account the properties of the system, however manufacturers improved the operation so that the distress call is sent only when the EPIRB is released and then immersed into water. In spite of these efforts, the error emissions have not significantly reduced. In this study, the domestic and international technical regulations and standards for the COSPAS-SARSAT and satellite EPIRB systems were reviewed, and a bridge-type water detection sensor was developed to minimize the error emission from EPIRB.

Three-Phase ZVS DC-DC Converter with Low Transformer Turn Ratio for High Step-up and High Power Applications (낮은 변압기 턴비를 갖는 고승압.대전력용 3상 ZVS DC-DC컨버터)

  • Kim, Joon-Geun;Park, Chan-Soo;Choi, Se-Wan;Park, Ga-Woo
    • The Transactions of the Korean Institute of Power Electronics
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    • v.16 no.3
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    • pp.242-249
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    • 2011
  • The proposed converter has easy device selection for high step-up and high power applications since boost half bridge and voltage doubler cells are connected, respectively, in parallel and series in order to increase output power and voltage. Especially, optimized design of high frequency transformers is possible owing to reduced turn ratio and eliminated dc offset, and distributed power through three cores is beneficial to low profile and thermal distribution. The proposed converter does not necessitate start-up circuit and additional clamp circuit due to the use of whole duty range between 0 and 1 and is suitable for applications with wide input voltage range. Also, high efficiency can be achieved since ZVS turn on of switches are achieved in wide duty cycle range and ZCS turn on and off of diodes are achieved. The proposed converter was validated through 5 kW prototype.