• The Journal of the Korea institute of electronic communication sciences
• /
• v.10 no.4
• /
• pp.491-497
• /
• 2015

In this paper a method of design and Implementation of RFID based control system for reducing standby power consumption at the power outlet is described. The system is composed of a RF controlled power outlet having relay and an active RFID tag communicating with the RF reader module controlling the relay. When the tag carried by human approaches to the RF reader the reader recognizes the tag and switch off the relay based on the RSSI level measurement. A low power packet prediction algorithm has been used to decrease the DC power consumption at both the tag and the RF reader. The result of experiment shows that successful operation of the relay control has been obtained while low power operation of the tag and the reader is achieved using above algorithm. Also setting the distance between the reader and the tag by controlling transmission power of the tag and adjusting the duty cycle of the packet waiting time when the reader is in idle state allows us to reduce DC power consumption at both the reader and the tag.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2015.08a
• /
• pp.104-104
• /
• 2015

Due to the demand of the cold neutron flux in the neutron science and beam utilization technology, the cold neutron source (CNS) has been constructed and operating in the nuclear research reactor all over the world. The majority of the heat load removal scheme in the CNS is two-phase thermosiphon using the liquid hydrogen as a moderator. The CNS moderates thermal neutrons through a cryogenic moderator, liquid hydrogen, into cold neutrons with the generation of the nuclear heat load. The liquid hydrogen in a moderator cell is evaporated for the removal of the generated heat load from the neutron moderation and flows upward into a heat exchanger, where the hydrogen gas is liquefied by the cryogenic helium gas supplied from a helium refrigeration system. The liquefied hydrogen flows down to the moderator cell. To keep the required liquid hydrogen stable in the moderator cell, the CNS consists of an in-pool assembly (IPA) connected with the hydrogen system to handle the required hydrogen gas, the vacuum system to create the thermal insulation, and the helium refrigeration system to provide the cooling capacity. If one of systems is running out of order, the operating research reactor shall be tripped because the integrity of the CNS-IPA is not secured under the full power operation of the reactor. To prevent unscheduled reactor shutdown during a long time because the research reactor has been operating with the multi-purposes, the introduction of the standby cooling system (STS) can be a solution. In this presentation, the design considerations are considered how to design the STS satisfied with the following objectives: (a) to keep the moderator cell less than 350 K during the full power operation of the reactor under loss of the vacuum, loss of the cooling power, loss of common electrical power, or loss of instrument air cases; (b) to circulate smoothly helium gas in the STS circulation loop; (c) to re-start-up the reactor within 1 hour after its trip to avoid the Xenon build-up because more than certain concentration of Xenon makes that the reactor cannot start-up again; (d) to minimize the possibility of the hydrogen-oxygen reaction in the hydrogen boundary.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.16 no.6
• /
• pp.745-753
• /
• 2016

This paper presents a fully synthesizable low power interconnect bus for millimeter-scale wireless sensor nodes. A segmented ring bus topology minimizes the required chip real estate with low input/output pad count for ultra-small form factors. By avoiding the conventional open drain-based solution, the bus can be fully synthesizable. Low power is achieved by obviating a need for local oscillators in member nodes. Also, aggressive power gating allows low-power standby mode with only 53 gates powered on. An integrated wakeup scheme is compatible with a power management unit that has nW standby mode. A 3-module system including the bus is fabricated in a 180 nm process. The entire system consumes 8 nW in standby mode, and the bus achieves 17.5 pJ/bit/chip.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.5
• /
• pp.67-73
• /
• 2016

Recently, wireless power transmission has attracted much interest and is the subject of much research in industry and academia. As its name implies, it is a technology which involves transferring power without wires. This paper presents the design of an ICT-based wireless power transmission system. The proposed system consists of a wireless transceiver unit and high-efficiency coil unit, which can increase both the transmission efficiency and the effective power distance. In particular, the wireless transceiver unit was designed to work with the ICT technique to enable real-time remote monitoring. Also, studies were done relating to the effect of reducing the standby power. The optimal frequency of IGBT devices used in industrial wireless power systems of 20[KHz] was utilized. The values of $23.9[{\mu}H]$ and $2.64[{\mu}F]$ were selected for L and C, respectively, through many field experiments designed to optimize the system design. In addition, an output current controlling algorithm was developed for the purpose of reducing the standby power. The results presented in this paper represent a 75[%] to 85[%] higher power transmission efficiency with a 10[%] increase in the effective power transmission distance compared with the existing systems. As a result, the proposed system exhibits a lower standby power and maintenance costs. Also, the designed wireless transceiver unit facilitates fault detection by means of user acquired data with the development of the ICT applied program.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.15 no.4
• /
• pp.445-453
• /
• 2015

A fully integrated cost-effective and low-power single chip Lithium-Ion (Li-Ion) battery protection IC (BPIC) for portable devices is presented. The control unit of the battery protection system and the MOSFET switches are integrated in a single package to protect the battery from over-charge, over-discharge, and over-current. The proposed BPIC enters into low-power standby mode when the battery becomes over-discharged. A new auto release function (ARF) is adopted to release the BPIC from standby mode and safely return it to normal operation mode. A new delay shorten mode (DSM) is also proposed to reduce the test time without increasing pin counts. The BPIC implemented in a $0.18-{\mu}m$ CMOS process occupies an area of $750{\mu}m{\times}610{\mu}m$. With DSM enabled, the measured test time is dramatically reduced from 56.82 s to 0.15 s. The BPIC chip consumes $3{\mu}A$ under normal operating conditions and $0.45{\mu}A$ under standby mode.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.10
• /
• pp.2171-2176
• /
• 2012

PCs and its peripherals uses more power in standby mode even if they are not actually being used. In particular, PCs and its peripherals used in school and office, plugged in at all times during working hours, but not used much time, even if turned off consume a portion of the power. In this paper, we developed Networked Smart Plug for Power Management of PC & Peripherals which is consist of EMS, Smart Plug, PC Agent and Smart Phone App. for power saving of PC and a variety of peripheral devices in office or home, and evaluated the performance of the system.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.1755_1756
• /
• 2009

본 논문에서는 전기전자 기기가 외부전원에 연결된 상태에서 그 주 기능을 수행하지 않거나 내부 혹은 외부로 부터 주 기능 수행을 위한 명령을 기다리고 있는 상태에서 소모하는 대기전력(Standby Power)을 저감할 수 있는 장치를 개발하고자 하였다. 기존의 멀티탭 형대기전력 차단장치는 그 장치 자체의 소비전력이 커서 사용 의미를 퇴색시키는 문제점을 안고 있다. 본 논문에서는 기존 제품의 이러한 문제점을 보완시키고 대기전력을 획기적으로 감시킬 수 있는 멀티탭 형식의 외장형 대기전력 차단장치와 가전기기 내장형 차단장치의 회로를 설계 및 구현하고 비교 실험을 통하여 그 우수성을 확인하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.05a
• /
• pp.978-980
• /
• 2013

In this paper, we have presented a basic idea of a power shut-off client based on NFC (near field communication). For the first step of the system design, we have shown the conceptual diagrams of the hardware configuration and the software logic flow. This system can be applied to the integrated power control in home, office, school, factory, and apartment. The standby power shut-off system will bring saving in electrical energy and cost.

• Proceedings of the KIPE Conference
• /
• 1999.07a
• /
• pp.448-451
• /
• 1999

This paper describes controller development for a dynamic voltage compensator using a shunt diode converter and series inverter. The control system was designed using 1/4 period integrator and vector relationship between the supply voltage and load voltage. A simulation model and scaled hardware model were developed for analyzing performance of the controller and the whole system. Both results confirm that the dynamic compensator can restore the load voltage under the fault of the distribution system.

• Proceedings of the KIPE Conference
• /
• 2019.07a
• /
• pp.136-138
• /
• 2019

무선급전 시스템에서 대기 모드 시에도 전력을 소모하는 비중이 큰 수신부 통신 모듈을 OFF 시켜서 대기전력을 낮출 수 있다. 이때 대기모드 시 PFC 동작을 OFF 시키게 되면 추가로 대기전력을 더 낮출 수 있지만 PFC가 OFF된 상태에서는 AC 입력전압 크기에 따라 인버터 입력 전압 범위가 크게 변동하게 된다. 하지만 수신 통신 모듈 OFF시에는 무선통신을 통한 출력전압제어를 할 수 없기 때문에 안정적인 전력전달이 힘들다. 따라서 본 논문에서는 대기모드 시 출력전압을 일정 수준으로 제어하기 위해, 입력전압 크기에 따른 Feed-forward 구조를 통하여 동작 주파수를 가변 하는 무선전력전송 시스템을 구현하고자 한다.