• Title/Summary/Keyword: Power Devices

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Software Engineering Principles for the Development of Power-Efficient Mobile IoT Devices (파워 효율이 높은 모바일 IoT 단말 개발을 위한 소프트웨어 공학 원칙)

  • Lee, Hyesun;Lee, Kang Bok;Bang, Hyo-Chan
    • KIISE Transactions on Computing Practices
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    • v.21 no.12
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    • pp.762-767
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    • 2015
  • An Internet of Things (IoT) is a system where various "things" are connected to each other via a wired/wireless network, and where information is gathered, processed, and interchanged/shared. One of the important actors in IoT is a mobile IoT device (such as a smartphone or tablet). These devices tend to consume a large amount of power in order to provide various high performance application services; however, as the devices cannot be supplied with power all the time, efficient power management is necessary. Power management of mobile IoT devices involves complex relationships between various entities such as application processors (APs), HW modules inside/outside AP, operating systems, mobile IoT platforms, and applications. In order to develop power-efficient mobile IoT devices, a method is needed to systematically analyze these relationships and manage power based on a clear understanding of them. To address this problem, software engineering principles for the development of power-efficient mobile IoT devices are presented in this paper. The feasibility of the proposed principles have been validated in the domain of smartphone camera power management.

A Method for Enhancing Data Transmission Performance in the Power-Line Communication Channel with Low-Voltage Surge Protective Devices (저압용 SPD가 설치된 전력선통신에서 데이터전송 성능 향상)

  • Choi, Jong-Min;Jeon, Tae-Hyun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.2
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    • pp.78-85
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    • 2012
  • Low-Voltage power lines should equip surge protection devices which protect electronic equipments and human lives against lightning and abnormal voltages. Data transmission capacity of the power line is determined by frequency characteristics of the surge protective devices. To analyze the effects of surge protective devices on the data transmission performance, various combinations of installation methods are tested which include ZnO varistor elements that is compatible with class I, class II and class III. The result claims that ZnO varistor for class III is found to be one of the main factors that deteriorates the transmission performance. To overcome this problem a serial connection methed between Gap type SPD and ZnO varistor is proposed. With the proposed scheme, laboratory experimental results show that the data transmission performance can be improved up to 91.9[%] with proper SPD combination.

A Study on the 0.5μm Dual Gate High Voltage CMOS Process for Si Liquid Display System (실리콘 액정표시 장치 시스템을 위한 00.5μm 이중 게이트 고전압 CMOS 공정 연구)

  • 송한정
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.12
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    • pp.1021-1026
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    • 2002
  • As the development of semiconductor process technology continue to advance, ICs continue their trend toward higher performance low power system-on-chip (SOC). These circuits require on board multi power supply. In this paper, a 0.5 ㎛ dual date oxide CMOS Process technology for multi-power application is demonstrated. 5 V and 20 V devices fabricated by proposed process is measured. From 5 V devices using dual gate precess, we got almost the same characteristics as are obtained from standard 5 V devices. And the characteristics of the 20 V device demonstrates that 3 ㎛ devices with minimum gate length are available without reliability degradation. Electrical parameters in minimum 3 ㎛ devices are 520 ㎂/㎛ current density, 120 ㎷ DIBL, 24 V BV for NMOS and ,350 ㎂/㎛ current density, 180 ㎷ DIBL, 26 V BV for PMOS, respectively.

Fabrication and characterization of fault current limiting devices made of stabilizer-free coated conductors (Stabilizer-free 초전도 선재를 이용한 한류 소자 제작 및 특성 시험)

  • Yim, Seong-Woo;Park, Chung-Ryul;Yu, Seong-Duck;Kim, Hye-Rim;Hyun, Ok-Bae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.371-371
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    • 2009
  • For the application of superconducting wires to fault current limiting devices, it is required that they have a high rated voltage when a fault occurs. Stabilizer-free coated conductors, particularly, shows a good performance for the high rated voltage, which is beyond 0.6 V/cm. In this study, using the stabilizer-free coated conductors, we made fault current limiting devices and examined their characteristics. Fault current limiting devices were fabricated with a shape of the cylinder of a mono-filar coil winding. Stabilizer-free coated conductors were wound along the mono-filar coil line and the terminal parts between the wire and metal were soldered using In solder. Two kinds of devices were fabricated by a different method in the terminal joint, one was made by a soldering and the other was made by a soldering-free joint. Critical currents and resistance at the joint parts were measured. In addition, long-time current flowing tests were also carried out for the characterization of the fault current limiting devices.

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Power-Efficient Wireless Neural Stimulating System Design for Implantable Medical Devices

  • Lee, Hyung-Min;Ghovanloo, Maysam
    • IEIE Transactions on Smart Processing and Computing
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    • v.4 no.3
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    • pp.133-140
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    • 2015
  • Neural stimulating implantable medical devices (IMDs) have been widely used to treat neurological diseases or interface with sensory feedback for amputees or patients suffering from severe paralysis. More recent IMDs, such as retinal implants or brain-computer interfaces, demand higher performance to enable sophisticated therapies, while consuming power at higher orders of magnitude to handle more functions on a larger scale at higher rates, which limits the ability to supply the IMDs with primary batteries. Inductive power transmission across the skin is a viable solution to power up an IMD, while it demands high power efficiencies at every power delivery stage for safe and effective stimulation without increasing the surrounding tissue's temperature. This paper reviews various wireless neural stimulating systems and their power management techniques to maximize IMD power efficiency. We also explore both wireless electrical and optical stimulation mechanisms and their power requirements in implantable neural interface applications.

RF Energy Harvesting and Charging Circuits for Low Power Mobile Devices

  • Ahn, Chang-Jun;Kamio, Takeshi;Fujisaka, Hisato;Haeiwa, Kazuhisa
    • IEIE Transactions on Smart Processing and Computing
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    • v.3 no.4
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    • pp.221-225
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    • 2014
  • Low power RF devices, such as RFID and Zigbee, are important for ubiquitous sensing. These devices, however, are powered by portable energy sources, such as batteries, which limits their use. To mitigate this problem, this study developed RF energy harvesting with W-CDMA for a low power RF device. Diodes are required with a low turn on voltage because the diode threshold is larger than the received peak voltage of the rectifying antenna (rectenna). Therefore, a Schottky diode HSMS-286 was used. A prototype of RF energy harvesting device showed the maximum gain of 5.8dBi for the W-CDMA signal. The 16 patch antennas were manufactured with a 10 dielectric constant PTFT board. In low power RF devices, the transmitter requires a step-up voltage of 2.5~5V with up to 35 mA. To meet this requirement, the Texas Instruments TPS61220 was used as a low input voltage step-up converter. From the evaluated result, the achievable incident power of the rectenna at 926mV to operate Zigbee can be obtained within a distance of 12m.

Z-Source Inverter with SiC Power Semiconductor Devices for Fuel Cell Vehicle Applications

  • Aghdam, M. Ghasem Hosseini
    • Journal of Power Electronics
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    • v.11 no.4
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    • pp.606-611
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    • 2011
  • Power electronics is a key technology for electric, hybrid, plug-in hybrid, and fuel cell vehicles. Typical power electronics converters used in electric drive vehicles include dc/dc converters, inverters, and battery chargers. New semiconductor materials such as silicon carbide (SiC) and novel topologies such as the Z-source inverter (ZSI) have a great deal of potential to improve the overall performance of these vehicles. In this paper, a Z-source inverter for fuel cell vehicle application is examined under three different scenarios. 1. a ZSI with Si IGBT modules, 2. a ZSI with hybrid modules, Si IGBTs/SiC Schottky diodes, and 3. a ZSI with SiC MOSFETs/SiC Schottky diodes. Then, a comparison of the three scenarios is conducted. Conduction loss, switching loss, reverse recovery loss, and efficiency are considered for comparison. A conclusion is drawn that the SiC devices can improve the inverter and inverter-motor efficiency, and reduce the system size and cost due to the low loss properties of SiC devices. A comparison between a ZSI and traditional PWM inverters with SiC devices is also presented in this paper. Based on this comparison, the Z-source inverter produces the highest efficiency.

Commercialization and Research Trends of Next Generation Power Devices SiC/GaN (차세대 파워디바이스 SiC/GaN의 산업화 및 학술연구동향)

  • Cho, Mann;Koo, Young-Duk
    • Journal of Energy Engineering
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    • v.22 no.1
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    • pp.58-81
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    • 2013
  • Recently, the technological progress in manufacturing power devices based on wide bandgap materials, for example, silicon carbide(SiC) or gallium nitride(GaN), has resulted in a significant improvement of the operating-voltage range and switching speed and/or specific on resistance compared with silicon power devices. This paper will give an overview of the status on The Next generation Power Devices such as SiC/GaN with a focus on commercialization and research.

Study on comparisons between PSS/E and Matlab Simulink/SimPower Result on network system data (PSS/E - Matlab Simulink/SimPower 간 순시치 시뮬레이션 비교에 관한 연구)

  • Yoo, Yeuntae;Kim, Kisuk;Lee, Changun;Jang, Gilsoo
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.249-250
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    • 2015
  • Technological advance of power elcetronic devices using semiconductor switches in last several decades, invoke the increase of switching devices' penetration in the system like STATCOM or HVDC and also, increase the difficulty to adjust switching characteristics in the virtual simulating configuration, which are not capable of reflect the detailed phenomena. To investigate harmful effect of switching devices into the grid, detailed modeling of power electronic devices are necessary, and the first step for entire grid modelling is simulate power system in time domain model. In this paper, simple two bus system with synchronous generator and infinite bus on the other side has been compromised in two simulation environment, using PSS/E and Matlab/Simulink. Comparing the result of two simulation result will give answers to the fundamental difference between two type of simulation environment.

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Design of 4.5kV/1.5kA IGCT (4.5kV/1.5kA급 IGCT 설계 및 특성분석)

  • Kim, Hyoung-Woo;Kim, Sang-Cheol;Seo, Kil-Su;Kim, Eun-Dong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07a
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    • pp.357-360
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    • 2003
  • In this paper, we designed 4.5kV/1.5kA IGCT devices. GCT thyristor has many superior characteristics compared with GTO thyristor, for examples; snubberless turn-off capability, short storage time, high turn-on capability, small turn-off gate charge and low total power loss of the application system containing device and peripheral parts such as anode reactor and snubber capacitance. In this paper we designed GCT thyristor devices, and analyzed static and dynamic characteristics of GCT thyristor depending on the minority carrier lifetime, n-base thickness and doping concentration of n-base region, respectively. Especially, turn-on and turn-off characteristics are very important characteristics for GCT thyristor devices. So, we considered above characteristic for design and analysis of GCT devices.

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