• Journal of electromagnetic engineering and science
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• v.8 no.4
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• pp.153-157
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• 2008

Most of malfunctions in electronic equipment or systems controlled by processors is occurred by the differential- and common-mode noises, and the electrical fast transient (EFT). The International Electrotechnical Commission (IEC) has prepared the dummy signal to test the immunity level of the equipment. For the countermeasure against the differential- and common-mode noises, and the EFT, we designed, fabricated, and tested a new electromagnetic compatibility (EMC) filter, which is composed of feed-through capacitors and ferrite beads with high permeability. As a result, the filter showed excellent differential- and common-mode noises filtering, and immunity improving characteristics over the frequency band from 30 MHz to 1.5 GHz and 1.8 GHz, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.5
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• pp.437-443
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• 2003

A interference of outside electric source and electric fast transient(EFT) are origins of destroy and malfunction in the precise electrical and electronic equipments. It makes a serious obstacle as the form of conducted noise. Therefore, it is strongly needed to protect precision electrical and electronic equipments from the interference and EFT. In this research, a EMC filter composed of feed-through capacitors and ferrite beads of high permeability is designed and it＇s properties are investigated for PDP. The filter produced in this research have wide band frequency characteristics and more than 40 dB reflection loss in the frequence of 10 MHz∼1.5 GHz which satisfy the standard of CISPR Pub. 22 and the level 4 of IEC 61000-4-4.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.3
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• pp.1-6
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• 2011

Low-power logic gates, i.e. inverter, NAND, and NOR, are proposed employing only n-channel oxide thin film transistors (TFTs). The proposed circuits were designed to prevent the pull-up and pull-down switches from being turned on simultaneously by using asymmetric feed-through and bootstrapping, thereby exhibited same output voltage swing as the input signal and no static current. The inverter is composed of 5 TFTs and 2 capacitors. The NAND and the NOR gates consist of 10 TFTs and 4 capacitors respectively. The operations of the logic gates were confirmed successfully by SPICE simulation using oxide TFT model.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.11-15
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• 2004

This paper deals with EMC filter for a personal computer( PC). A PC contains many sources of noise inside and out, with many connected cables. High noise levels are also emitted from the PC became of high-speed signals. So radiated noise from the computer body may sometimes cause problems. Therefore, we design and fabricate an electromagnetic compatibility (EMC) filter for PC, which is composed of feed-through capacitors and ferrite beads with high permeability. Through extensive test, the proposed EMC filter is shown to have excellent differential-mode and common-mode noises filtering characteristics above 30 dB in the frequency band from 10 MHz to 1.5 GHz. The immunity characteristics are improved more than 10 to 30 dB over the frequency band from DC to 1.8 GHz

• Journal of Navigation and Port Research
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• v.28 no.8
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• pp.715-719
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• 2004

This paper deals with EMC filter for a personal computer(PC). A PC contains many sources of noise inside and out, with many connected cables. High noise levels are also emitted from the PC because of high-speed signals. So radiated noise from the computer body may sometimes cause problems. Therefore, we design and fabricate an electromagnetic compatibility (EMC) filter for PC, which is composed of feed-through capacitors and ferrite beads with high permeability. Through extensive test, the proposed EMC filter is shown to have excellent differential-mode and common-mode noises filtering characteristics above 30 dB in the frequency band from 10 MHz to 1.5 GHz. The immunity characteristics are improved more than 10 to 30 dB over the frequency band from DC to 1.8 GHz.

• Journal of Navigation and Port Research
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• v.26 no.5
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• pp.525-528
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• 2002

The proposed EMC filter composed with feed-through capacitors and ferrite beads of high permeability was prepared which satisfy the EMC standard for a wide-band noise signal in the frequence of 10 MHz to 1.5 GHz in power supply line. The optimum structure of ferrite bead was found by calculating the load effect of ferrite beads. As a result, the filter showed excellent differential- and common-mode noises filtering characteristics above 30dB in the frequency band from 10 MHz to 1.5 GHz. The immunity characteristics are improved more than 10 to 30 dB over the frequency band from DC to 1.8GHz.

• Journal of Navigation and Port Research
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• v.34 no.1
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• pp.33-37
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• 2010

It is very important to prevent the electromagnetic interference and to prevent malfunction of electronic equipments mounted on ships. To solve these problems, in this paper, the EMC filter was designed, fabricated, and tested. The Ni-Zn ferrite beads with high permeability were used to make large inductance as the inductor and the feed-through capacitors without any resonance points. As a result, excellent attenuation characteristics of 25~70 dB were obtained from the 0 kHz~1.5 GHz band. In addition, when the Electric Fast Transient (EFT) of 4 kV in the level 4 of IEC 61000-4-4 was induced the EFT reduced to 600 V. Therefore, it was clearly shown that the developed EMC felter can be used for suppressing the electromagnetic interference on-board electronic devices and equipments.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.183-184
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• 2009

In this paper the internal or external of the ships mounted electronic devices due to the propagation of electromagnetic interference and to prevent malfunction EMC filter was designed and fabricated. It was designed and fabricated with Ni-Zn ferrite beads of high permeability to make large inductance as the inductor and Feed-through capacitors, which did not have any resonance point, to restraint resonance effectively, and the characteristics was evaluated. The results from the 0 kHz$\sim$1.5 GHz bandwidth of $25{\sim}70$ dB were able to obtain excellent attenuation characteristics. And, when the Electric Fast Transient (EFT) of 4 kV in the level 4 of IEC 61000-4-4 was induced, it was soon attenuated more than 1/6 to 600 V. Therefore, it was confirmed that the developed EMC filter can be used for suppressing ships mounted electromagnetic interference between electronic devices.

• Journal of Power Electronics
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• v.17 no.4
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• pp.1037-1047
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• 2017

The Differential Power Processing (DPP) converter is a promising multi-module photovoltaic inverter architecture recently proposed for photovoltaic systems. In this paper, a DPP converter architecture, in which each PV-panel has its own DPP converter in shunt, performs distributed maximum power point tracking (DMPPT) control. It maintains a high energy conversion efficiency, even under partial shading conditions. The system architecture only deals with the power differences among the PV panels, which reduces the power capacity of the converters. Therefore, the DPP systems can easily overcome the conventional disadvantages of PCS such as centralized, string, and module integrated converter (MIC) topologies. Among the various types of the DPP systems, the feed-forward method has been selected for both its voltage balancing and power transfer to a modified H-bridge inverter that needs charge balancing of the input capacitors. The modified H-bridge multi-level inverter had some advantages such as a low part count and cost competitiveness when compared to conventional multi-level inverters. Therefore, it is frequently used in photovoltaic (PV) power conditioning system (PCS). However, its simplified switching network draws input current asymmetrically. Therefore, input capacitors in series suffer from a problem due to a charge imbalance. This paper validates the operating principle and feasibility of the proposed topology through the simulation and experimental results. They show that the input-capacitor voltages maintain the voltage balance with the PV MPPT control operating with a 140-W hardware prototype.

• Journal of electromagnetic engineering and science
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• v.9 no.2
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• pp.53-60
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• 2009

Remarkable developments in the electric and electronic industry have given people's daily life much more convenience and abundance. However, in electrical communication, or electric and electronic fields, making electrical and electronic devices more functional, more integrated, and faster have put electromagnetic interference(EMI) into more complex forms, and lots of problems such as interruption, malfunction, or interference by noise between electrical communication systems occurs every day. In this research, the electromagnetic compatibility(EMC) filter in the high powered breaker was designed and fabricated as a counter measure. The filter attenuated noise more than 20${\sim}$50 dB in the range of 10 MHz${\sim}$1.5 GHz. And, when the electric fast transient(EFT) of 4 kV in the level 4 of IEC 61000-4-4 was induced, it was soon suppressed to 600 V.