• Title/Summary/Keyword: Cold Restart

Search Result 5, Processing Time 0.019 seconds

Core Technology for Ultra Low Power Using Cold Restart in Wearable Devices (Cold Restart를 이용한 웨어러블 디바이스의 초저전력 핵심 기술)

  • Kim, Seon-Tae;Park, Hyoung Jun;Park, Ho-Jun;Woo, Duk-Kyun
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.54 no.4
    • /
    • pp.44-49
    • /
    • 2017
  • There are many battery-based wearable devices for healthcare and medical applications, but there is a user's inconvenience to charge battery frequently due to insufficient power management. In this paper, we propose a tickless-based operating system and power management algorithm that can effectively utilize the power management provided by HW, and propose a cold restart method that consumes the minimum power at the board level. The operating system of the proposed technique has reduced the power consumption from 2 times to 33 times in the four scenarios modeling the wearable device application compared to the existing operating system.

The Development of Electric Ballast for a Instant Restart of Metalhalide Lamp (메탈헬라이드램프용 순시재점등 전자식안정기 개발)

  • 김수경;장우진
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
    • /
    • 2003.11a
    • /
    • pp.185-190
    • /
    • 2003
  • The most shortcoming of metalhalide lamps is what the instant restarting cannot be realized when the arc tube is in the hot condition. The discharge starting voltage of arc tube in the hot condition is much higher than in the cold condition. Therefore it takes about five minutes to restart the metalhalide lamps, that is to say, it is possible to start when the pressure and the temperature are decreased. But, if the lamp is restarted in the hot condition, we must supply the high voltage pulse with 20kV at the both sides of lamp. The proposed electronic ballast is consist of a electromagnetic interference (EMI) filter, a power factor correction (PFC) circuit, a flyback converter, a half-bridge inverter, and a high voltage igniter circuit. By this composition we can restart the lamp with the voltage 20kV, even if the lamp is in the hot condition.

  • PDF

DEVELOPMENT ON ENHANCED LEAKED FUEL RECIRCULATION DEVICE OF LPLi ENGINE TO SATISFY SULEV STANDARD

  • Myung, C.L.;Kwak, H.;Park, S.
    • International Journal of Automotive Technology
    • /
    • v.7 no.4
    • /
    • pp.407-413
    • /
    • 2006
  • The liquefied petroleum gas(LPG), mixture of propane and butane, has the potential to reduce toxic hydrocarbon emissions and inhibit ozone formation due to its chemical composition. Conventional mixer systems, however, have problems in meeting the future lower emission standards because of the difficulty in controlling air-fuel ratio precisely according to mileage tar accumulation. Liquid Phase LPG injection(LPLi) system has several advantages in more precise fuel metering and higher engine performance than those of the conventional mixer type. On the other hands, leakage problem of LPLi system at the injector tip is a main obstacle for meeting more stringent future emission regulations because these phenomena might cause excessive amount of THC emission during cold and hot restart phase. The main focus of this paper is the development of a leaked fuel recirculation system, which can eliminate the leaked fuel at the intake system with the activated carbon canister. Leaked fuel level was evaluated by using a fast response THC analyzer and gas chromatography. The result shows that THC concentration during cold and hot restart stage decreases by over 60%, and recirculation system is an effective method to meet the SULEV standard of the LPLi engine.

The Ignitor Development for Momentary Restarting of Metal Halide Lamps (메탈 핼라이드 램프의 순시 재점등을 위한 점화기 개발)

  • Park, Chong-Yeun;Bae, Su-Ho
    • Journal of Industrial Technology
    • /
    • v.20 no.B
    • /
    • pp.169-174
    • /
    • 2000
  • The most of metalhalide lamps is what the momentary restarting cannot be realized when the arc tube is in the hot condition. The discharge starting voltage of arc tube in the hot condition is much higher than in the cold condition in proportion to the gaseous pressure. Therefore it takes about ten minutes to restart the metal Halide lamps, that is to say, it is possible to start when the pressure and the temperature are decreased. But, if the lamp is restarted in the hot condition, we must supply the high voltage pulse with 15kV between the both electrodes of lamp. The proposed ignitor has two ignitors. If we connect each ignitor at the both sides, the high voltages of two different frequencies are generated. If so, when the one of the ignitor generates the highest voltage and the other applied to elecrodes of the lamp. In this way, we can restart the lamp with the voltage 15kV, even if the lamp is in the hot condition.

  • PDF

The Development of Electric Ballast for a Instant Start/Restart of Metalhalide Lamp (메탈핼라이드램프용 순시점등/재점등 전자식안정기 개발)

  • Kim, Su-Kyoung;Jang, Woo-Jin
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.18 no.5
    • /
    • pp.9-15
    • /
    • 2004
  • The most shortcoming of metalhalide lamps is what the instant restarting cannot be realized when the arc tube is in the hot condition. The discharge starting voltage of arc tube in the hot condition is much higher than in the cold condition. Therefore it takes about five minutes to restart the metalhalide lamps, that is to say, it is possible to start when the pressure and the temperature are decreased. But, if the lamp is restarted in the hot condition, we must supply the high voltage pulse with 20[kV] at the both electrode of lamp. The proposed electronic ballast is consist of a electromagnetic interference(EMI) filter, a power factor correction(PFC) circuit, a flyback converter, a half-bridge inverter, and a high voltage igniter circuit. By this composition we can start/restart the lamp with the voltage 20[kV], even if the lamp is in the hot condition.