• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.3
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• pp.495-502
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• 2020

In this paper, a power management circuit was designed to drive the emergency lighting LED in the underground facility for public utilities using magnetic energy harvest. The magnetic energy harvest consists of a harvest elements and power management circuits. The proposed circuit was made of a rectifier, a battery charging circuit, and an LED driving circuit. In normal times, the battery is charged with the harvested power, and in the event of an emergency, the energy stored in the battery is used to drive the LED. As a result of the measurement, it took two minutes to charge the 47 mF capacitor. This is the amount of power that can drive an LED for emergency lighting for about three and a half minutes. Through this, it was confirmed that the power management circuit for magnetic energy harvest proposed in this paper can be used as an emergency lighting LED-driven power device in an underground facility for public utilities where it is difficult to draw separate power.

• Journal of Power Electronics
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• v.12 no.6
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• pp.954-959
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• 2012

A hybrid switch that uses a microelectromechanical system (MEMS) switch as a gate driver of a MOSFET is applied to an energy harvesting system. The power management circuit adopting the hybrid switch provides ultralow leakage, self-referencing, and high current handling capability. Measurements show that solar energy harvester circuit utilizing the MEMS-MOSFET hybrid switch accumulates energy and charges a battery or drive a resistive load without any constant power supply and reference voltage. The leakage current during energy accumulation is less than 10 pA. The power management circuit adopting the proposed hybrid switch is believed to be an ideal solution to self-powered wireless sensor nodes in smart grid systems.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.1
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• pp.196-200
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• 2015

The switching noise in the power electronics of the power conversion equipment (Power Conditioning System) for large energy storage devices are generated. Since the burst-level transient noise from being generated in the power system at a higher power change process influences the control circuit of the low voltage driver circuit. Noise may cause the malfunction of the control device even if no dielectric breakdown leads to a control circuit. To overcome this, this paper proposes the installation of an additional nano-surge protection device on the power supply DC output circuit of the battery management unit.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.2
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• pp.357-362
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• 2020

The TMFT, a sub-system of TINC, provides voice calls, data transmission and reception, and multimedia services to individual users. At the time of development in 2011, the power circuit of the TMFT was designed to electrical power supply to each device via a charger IC. However, the newly improved power supply circuit allows power to be supplied to each device through the PMIC without configuring the charger IC separately. In this paper, the power circuit design structure of TMFT applied in the development stage and the improved power circuit design structure were compared. And we verified through experiments whether the improved power circuit can be applied to TMFT. The experimental method was verified by directly comparing the current consumption test, charge time comparison test, and rising temperature test during charging each of before and after improvement terminals.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.1
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• pp.41-46
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• 2012

In this paper, An efficient circuit design algorithm considering constraint is proposed. The proposed algorithm sets up in time constraint and area constraint, power consumption constraint for a circuit implementation. First, scheduling process for time constraint. Select the FU(Function Unit) which is satisfied with time constraint among the high level synthesis results. Analyze area and power consumption of selected FUs. Constraint set for area and power constraint. Device selection to see to setting condition. Optimization circuit implementation in selected device. The proposed algorithm compared with [7] and [8] algorithm. Therefore the proposed algorithm is proved an efficient algorithm for optimization circuit implementation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.419-422
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• 2011

In this paper a dual-input self-powered power management system is proposed for low-power applications. The system is powered by merging the energy from a PZT vibration element and a solar cell. The proposed system consists of a charge pump for increasing the output voltage of a solar cell, a rectifier for DC conversion of the PZT output and a power management circuit for merging and managing the harvested energy. The performance of the design circuit has been verified through extensive simulation using a 0.18um CMOS technology. The chip area is $295um{\times}275um$.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.4
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• pp.631-640
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• 2016

A dual-mode power management for a hybrid-electric UAV with a cruise power of 200W is proposed and empirically verified. The subject vehicle is a low-speed long-endurance UAV powered by a solar cell, a fuel cell, and a battery pack, which operate in the same voltage bounds. These power sources of different operational characteristics can be managed in two different methods: passive management and active management. This study proposes a new power management system named PMS2, which employs a bypass circuit to control the individual power sources. The PMS2 normally operates in active mode, and the bypass circuit converts the system into passive mode when necessary. The output characteristics of the hybrid system with the PMS2 are investigated under simulated failures in the power sources and the conversion of the power management methods. The investigation also provides quantitative comparisons of efficiencies of the system under the two distinct power management modes. In the case of the solar cell, the efficiency difference between the active and the passive management is shown to be 0.34% when the SOC of the battery is between 25-65%. However, if the SOC is out of this given range, i.e. when the SOC is at 90%, using active management displays an improved efficiency of 6.9%. In the case of the fuel cell, the efficiency of 55% is shown for both active and passive managements, indicating negligible differences.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.10
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• pp.1839-1844
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• 2010

A power management controller circuit with switched capacitor mode down regulator and battery charger block for semi-active RFID tags was proposed and fabricated. The main purposes of the proposed switched capacitor mode down regulator and battery charger block are to reduce standby current and to provide a self-controlled thin film battery charger by detecting the received RF power, respectively. Fabricated chip area is $360,000{\mu}m^2$ and measured standby current was about $1.3{\mu}A$. To further reduction of standby current, a wake-up circuit has to be included in the power management controller.

• The Journal of Korean Institute of Information Technology
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• v.16 no.12
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• pp.101-107
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• 2018

In wireless sensor network technology, which has been applied to various fields, the power supply and the power management of sensors are the most important issues. For this reason, a new concept of power supply and power management device is required. In this paper, we developed an autonomous independent power supply system that supplies the stable power to a sensor node without an additional external input by applying the energy harvesting technology using the electromagnetic induction principle by utilizing the current flowing in the transmission line. The proposed autonomous independent power supply system consists of a power supply using Power CT and a power management system including a charging circuit. The power management device uses a voltage limiter circuit and a monitoring circuit of charging voltage and current to ensure the safety of charging of the battery. In order to verify the performance of the proposed system, we applied it to the SVL diagnostic system and confirmed that it operates stably.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.561-564
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• 2014

In this paper a photovoltaic energy harvesting charger with battery management circuit is proposed. The proposed circuit harvests maximum power from a solar cell by employing MPPT(Maximum Power Point Tracking) control and charges an external capacitor battery with the harvested energy. The charging state of the battery is controlled according to the signals from the battery management circuit. The proposed circuit is designed in a 0.35um CMOS process technology and its functionality has been verified through extensive simulations. The maximum efficiency of the designed entire system is 84.8%, and the chip area including pads is $1350um{\times}1200um$.