• Title/Summary/Keyword: low power mode

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Development of PV Module Integrated Type Low Voltage Battery Charger using Cascaded Buck-Boost Converter (Cascaded Buck-Boost 컨버터를 이용한 태양광 모듈 집적형 저전압 배터리 충전 장치 개발)

  • Kim, Dong-Hee;Lee, Hee-Seo;Lee, Young-Dal;Lee, Eun-Ju;Lee, Tae-Won;Lee, Byoung-Kuk
    • The Transactions of the Korean Institute of Power Electronics
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    • v.17 no.6
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    • pp.471-477
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    • 2012
  • In this paper, in order to use module integrated converter using cascaded buck-boost converter for a low battery charger in stand-alone system, a charging algorithm which considers photovoltaic and battery status and PWM controllers which are changed according to charging modes are proposed. The proposed algorithm consists of constant current mode, constant voltage mode and maximum power point tracking mode which enables the battery to charge with maximum power rate. This paper also presents design of cascaded buck-boost converter that is the photovoltaic charger system. A 150W prototype system is built according to verify proposed the charger system and the algorithm.

Design and Implementation of Low Power Container Security Device based on IEEE 802.15.4 (IEEE 802.15.4 기반 저전력 컨테이너 보안장치의 설계 및 구현)

  • Park, Se-Young;Kim, Taek-Hyun;Choi, Hoon;Baek, Yun-Ju
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.2B
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    • pp.215-224
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    • 2010
  • A container security device (CSD) monitors intrusions through the cargo door; it is a reduced function device that uses IEEE 802.15.4 with a beacon mode. However, in the beacon mode, the CSD consumes too much battery power in periodical idle listening and sensing trials. Moreover, the CSD cannot send the message to the CSD reader actively, and it makes big latency problem. Therefore, we propose a low-power CSD to reduce the unnecessary power consumption. The proposed CSD follows the requirements of the U.S. Department of Homeland Security, and reduces battery consumption through a power-efficient hardware design, a night-watch mechanism for low-power operation and low-power sensing to reduce unnecessary monitoring. And the CSD sends alert message to the CSD reader. Simulation results show that our CSD reduces battery consumption by over 70% through the night-watch mechanism and by approximately 80% through the low-power sensing. And the CSD can send the alert message to the remote CSD reader by over 94%.

A High-Efficiency, Robust Temperature/voltage Variation, Triple-mode DC-DC Converter (고효율, Temperature/voltage 변화에 둔감한 Triple-mode CMOS DC-DC Converter)

  • Lim, Ji-Hoon;Ha, Jong-Chan;Kim, Sang-Kook;Wee, Jae-Kyung
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.6
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    • pp.1-9
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    • 2008
  • This paper suggests the triple-mode CMOS DC-DC converter that has temperature/voltage variation compensation techniques. The proposed triple-mode CMOS DC-DC converter is used to generate constant or variable voltages of 0.6-2.2V within battery source range of 3.3-5.5V. Also, it supports triple modes, which include Pulse Width Modulator (PWM) mode, Pulse Frequency Modulator (PFM) mode and Low Drop-Out (LDO) mode. Moreover, it uses 1MHz low-power CMOS ring oscillator that will compensate malfunction of chip in temperature/voltage variation condition. The proposed triple-mode CMOS DC-DC converter, which generates output voltages of 0.6-2.2V with an input voltage sources of 3.3-5.5V, exhibits the maximum output ripple voltage of below 10mV at PWM mode, 15mV at PFM mode and 4mV at LDO mode. And the proposed converter has maximum efficiency of 93% at PWM mode. Even at $-25{\sim}80^{\circ}C$ temperature variations, it has kept the output voltage level within 0.8% at PWM/PFM/LDO modes. For the verification of proposed triple-mode CMOS DC-DC converter, the simulations are carried out with $0.35{\mu}m$ CMOS technology and chip test is carried out.

Performance study for collision in non-beacon mode and beacon mode of IEEE 802.15.4 wireless network (IEEE 802..15.4 무선 네트워크의 non-beacon 모드와 beacon 모드에서의 collision에 관한 성능 연구)

  • Lee, Yoo-Jin;Nam, Heung-Woo;An, Sun-Shin
    • Proceedings of the Korean Information Science Society Conference
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    • 2006.10d
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    • pp.616-620
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    • 2006
  • IEEE 802.15.4 is designed for low-rate wireless personal area networks (LR_WPAN) and it attempts to provide a low data rate, low power, low cost wireless networking on the device-level communication. In this paper, I have established a realistic environment for the effect of collision in nonbeacon-enabled mode and beacon enabled mode. The data throughput and delivery ratio are investigated as the performance metrics.

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Flow Actuation by DC Surface Discharge Plasma Actuator in Different Discharge Modes

  • Kim, Yeon-Sung;Shin, Jichul
    • International Journal of Aeronautical and Space Sciences
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    • v.16 no.3
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    • pp.339-346
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    • 2015
  • Aerodynamic flow control phenomena were investigated with a low-current DC surface discharge plasma actuator. The plasma actuator was found to operate in three different discharge modes with similar discharge currents of about 1 mA or less. Stable continuous DC discharge without audible noise was obtained at higher ballast resistances and lower discharge currents. However, even with continuous DC power input, a low-frequency self-pulsed discharge was obtained at lower ballast resistances, and a high-frequency self-pulsed discharge was obtained at higher set-point currents and higher ballast resistances, both with audible noise. The Schlieren image reveals that the low-frequency self-pulsed mode produces a synthetic jet-like flow implying that a gas heating effect plays a role, even though the discharge current is small. The high-frequency self-pulsed mode produces pulsed jets in a tangent direction, and the continuous DC mode produces a steady straight pressure wave. Particle image velocimetry (PIV) images reveal that the induced flow field by the low-frequency self-pulsed mode has flow propagating in the radial direction and centered between the electrodes. The high-frequency self-pulsed mode and continuous DC mode produce flow from the anode to the cathode. The perturbed region downstream of the cathode is larger in the high-frequency self-pulsed mode with similar maximum speeds.

Development of Low Power Driven Inner Tap Inspection System capable of Wireless Communication with Video Equipment (영상기기와 무선통신이 가능한 저전력 구동의 이너탭 검사시스템 개발)

  • Ahn, Sung-Su
    • Journal of Korea Multimedia Society
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    • v.21 no.6
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    • pp.649-658
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    • 2018
  • In this paper, we propose a mechanical contact inner tap inspection system that can inspect the defect of the inner tap immediately after inner tap is processed within the machining center. The inspection module has the collet chuck structure, so it can mounted on the main spindle of the machining center during inspection. It was developed with a focus on inspection for tap having 20 mm depth which is primarily fabricated in automotive parts and has a double sided PCB-type control system including sensing function based on Zigbee module, micom and IR sensor for wireless transmission of measured data with low power operation, and also a battery for supplying electric power. The current consumption is 46.8mA in the inspection operation mode and 0.0268mA in the power saving mode for 3.7V of the applied power source, so that 30,000 times or more inspection can be performed with assumed 5 seconds inspection time for one tap. Experiments in test jig system and actual machining center confirm that the proposed inner tap inspection system can be applied to the batch process of simultaneous inspection after tapping in the machining center.

High Efficiency Bridgeless Power Factor Correction Converter With Improved Common Mode Noise Characteristics (우수한 공통 모드 노이즈 특성을 가진 브릿지 다이오드가 없는 고효율 PFC 컨버터)

  • Jang, Hyo-Seo;Lee, Ju-Young;Kim, Moon-Young;Kang, Jeong-Il;Han, Sang-Kyoo
    • The Transactions of the Korean Institute of Power Electronics
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    • v.27 no.2
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    • pp.85-91
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    • 2022
  • This study proposes a high efficiency bridgeless Power Factor Correction (PFC) converter with improved common mode noise characteristics. Conventional PFC has limitations due to low efficiency and enlarged heat sink from considerable conduction loss of bridge diode. By applying a Common Mode (CM) coupled inductor, the proposed bridgeless PFC converter generates less conduction loss as only a small magnetizing current of the CM coupled inductor flows through the input diode, thereby reducing or removing heat sink. The input diode is alternately conducted every half cycle of 60 Hz AC input voltage while a negative node of AC input voltage is always connected to the ground, thus improving common mode noise characteristics. With the aim to improve switching loss and reverse recovery of output diode, the proposed circuit employs Critical Conduction Mode (CrM) operation and it features a simple Zero Current Detection (ZCD) circuit for the CrM. In addition, the input current sensing is possible with the shunt resistor instead of the expensive current sensor. Experimental results through 480 W prototype are presented to verify the validity of the proposed circuit.

A new continuous-time current-mode integrator for realization of low-voltage current-mode CMOS filter (저전압 전류모드 CMOS 필터 구현을 위한 새로운 연속시간 전류모드 적분기)

  • 방준호;조성익;김동용
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.4
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    • pp.1068-1076
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    • 1996
  • In this paper, a new continuous-time current-mode integrator as basic building block of the low-voltage analyog current-mode active filters is proposed. Compared to the current-mode integrator which is proposed by Zele, the proposed current-mode integrator had higher unity gain frequency and output impedance in addition to lower power dissipation. And also, a current-mode third-order lowpass active filter is designed with the proposed current-mode integrator. The designed circuits are fabricated using the ORBIT's $1.2{\mu}{\textrm{m}}$ deouble-poly double-metal CMOS n-well process. The experimental results show that the filter has -3dB cutoff frequency at 44.5MHz and 3mW power dissipation with single 3.3V power supply and also $0.12mm^{2}$ chip area.

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A MPEG-4 Video Codec Chip with Low Power Scheme for Mobile Application

  • Park, Seongmo;Lee, Miyoung;Kwangki Ryoo;Hanjin Cho;Kim, Jongdae
    • Proceedings of the IEEK Conference
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    • 2002.07b
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    • pp.1288-1291
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    • 2002
  • In this paper, we present a design of mpeg-4 video codec chip to reduce the power consumption using frame level clock gating and motion estimation skip scheme. It performs 30 grames/s of codec (encoding and decoding) mode with quarter-common intermediate format(QCIF) at 27MHz. A novel low-power techniques were implemented in architectural level, which is 35% of the power dissipation for a conventional CMOS design. This chip performs MPEG-4 Simple Profile Level 2(Simple@L2) and H.263 base mode. Its contains 388,885 gates, 662k bits memory, and the chip size was 9.7 mm x 9.7 mm which was fabricated using 0.35 micron 3-layers metal CMOS technology.

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Simulation of the Structural Parameters of Anti-resonant Hollow-core Photonic Crystal Fibers

  • Li, Qing;Feng, Yujun;Sun, Yinhong;Chang, Zhe;Wang, Yanshan;Peng, Wanjing;Ma, Yi;Tang, Chun
    • Current Optics and Photonics
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    • v.6 no.2
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    • pp.143-150
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    • 2022
  • Anti-resonant hollow-core photonic crystal fiber (AR-HCF) has unique advantages, such as low nonlinearity and high damage threshold, which make it a promising candidate for high-power laser delivery at distances of tens of meters. However, due to the special structure, optical properties such as mode-field profile and bending loss of hollow-core fibers are different from those of solid-core fibers. These differences have limited the widespread use of AR-HCF in practice. In this paper we conduct numerical analysis of AR-HCFs with different structural parameters, to analyze their influences on an AR-HCF's optical properties. The simulation results show that with a 23-㎛ air-core diameter, the fundamental mode profile of an AR-HCF can well match that of the widely used Nufern's 20/400 fiber, for nearly-single-mode power delivery applications. Moreover, with the ratio of cladding capillary diameter to air-core diameter ranging from 0.6 to 0.7, the AR-HCF shows excellent optical characteristics, including low bending sensitivity while maintaining single-mode transmission at the same time. We believe these results lay the foundation for the application of AR-HCFs in the power delivery of high power fiber laser systems.