• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.6
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• pp.78-89
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• 2015

Conventional EMI filters have tried to use an active EMI filter as a series by the series connection of two EMI filters for CM and DM noise. However, the proposed filter is formed into one circuit by using the active EMI filter which is able to filter CM and DM noise components together. As a result, the active EMI filter showed the outstanding quality in mass and volume under 50% and electric characteristics have been compared to the passive EMI filter in approximately 150kHz~10MHz. Furthermore, the proposed circuit has simple circuit components by comparing with the series EMI filters, and electrical characteristics are similar. The noise have been attenuated to maximum 20dBuV.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.4
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• pp.112-120
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• 2012

In this paper, we manufactured the wireless video stream system after we scanned EMI(Electro Magnetic Interference)noise in the system. and then, we analysed the noise frequency in the interface, circuit and PCB(Printed Circuit Board). we suggested EMI noise reduction technique. The applied reduction method is low pass filtering, the internal layer placement for high speed video data line and optimization of the system ground condition. the manufactured system improved about 2 ~ 20[dB] margin for EMI limit 40[dBuV/m] at 30 ~ 230[MHz] and 47[dBuV/m] at 230 ~ 1000[MHz].

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.2
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• pp.151-154
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• 2020

Radiation noise due to EMI noise generated by the driving circuits of LED lighting devices in a medical imaging room was reduced by decreasing the noise source in the driving circuits and changing the number of corrections in EMI filters. Noise attenuation and filter changes enabled driving circuits that reduced the electromagnetic waves. Such circuits were efficiently designed by using capacitors and inverters in a given space. Therefore, the malfunction of radiation devices can be minimized by using EMI-reduction filter circuits, and reliable operation of medical devices can be expected by blocking electromagnetic waves.

• Journal of Power Electronics
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• v.12 no.4
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• pp.632-642
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• 2012

This paper presents a filter analysis of conducted Electro-Magnetic Interference (EMI) in switching power converters (SPC) based on noise impedances. The EMI characteristics of SPC can be analytically deduced from a circuit theoretical viewpoint. The analytical noise model is investigated to get a full understanding of the EMI mechanism. It is shown that with suitable and justified model, filters pertinent to EMI noise is investigated. The EMI noise is identified by time domain measurements associated with an isolated half-bridge ac-dc converter. Practical filters like LC filter, ${\pi}$ filter and complete EMI filters are investigated. The proposed analysis and results can provide a guideline for improving the effectiveness of filtering schemes in SPC. Experimental results are also included to verify the validity of the proposed method. The results obtained satisfy the Federal Communications Commission (FCC) class A and class B regulations.

• Journal of IKEEE
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• v.21 no.3
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• pp.248-251
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• 2017

In this paper, The proposed board is developed by EMI compliant Dash Camera with $360^{\circ}$ omni angle. The proposed board is designed by designing DM and CM input noise reduction circuit and applying active EMI filter coupling circuit. The DM and CM input noise reduction circuit design uses a differential op amp circuit to obtain the DM noise coupled to the input signal via the parasitic capacitance(CP). In order to simplify the circuit by applying the active EMI filter coupling circuit, a noise separator is installed to compensate the noise of the EMI source to compensate the CM and DM active filter simultaneously. In order to evaluate the performance of the board for the proposed EMI response, an authorized accreditation body has confirmed that the electromagnetic certification standard for each frequency band is satisfied.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.12
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• pp.277-284
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• 2012

In this paper, we analyzed various noise in the video stream system that have largely influence on EMI noise. We presented the remedy for these various noises and then designed the wireless video streaming system for a vehicle. To minimize EMI noise, we derived the improvement of noise characteristic from impedance matching, new design of the inner layer of the PCB line design and new design of high-speed data Interfaces. As a result, the final system showed 40[dBuV/m] and 47[dBuV/m] dB in the each regulation band.

• Journal of Power Electronics
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• v.16 no.3
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• pp.1236-1243
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• 2016

This paper presents the analysis and design of an active electromagnetic interference (EMI) filter (AEF) for the common-mode (CM) noise reduction of switching power converters. The features of the several types of AEFs are discussed and compared in terms of implementation. The feed-forward AEF with a voltage-sensing and voltage-cancellation (VSVC) structure is implemented for an LLC resonant converter to replace a multiple-stage passive EMI filter and thereby reduce CM noise. The characteristics and performance of the VSVC-type AEF are investigated through theoretical and experimental works.

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.2
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• pp.141-148
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• 2001

There are several ways for reducing EMI(Electromagnetic Interference) in the switching power supply, which can be largely divided into suppression methods in the noise source, noise path solution, and attenuation techniques using the filter. In this paper, the method will be discussed to simplify the design process of the filter along with the noise path solution. In particular, some practical EMI suppression methods are suggested for SMPS, which is widely used recently, with or without a chassis, respectively and also verified through the experimental results of a 10W flyback converter.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.7
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• pp.374-379
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• 2006

The switch mode power supply is a source of EMI with other equipment as well as with its own proper operation because of rapid changes in voltages and currents within a switching converter. The EMI is transmitted in two forms: radiated and conducted. Conducted noise consists of two categories known as the differential mode and the common mode. Common mode noise current is a major source of EMI in the switch mode Power supply. Recently, a current balancing technique has been studied to reduce the common mode noise. This paper investigates the reduction of common mode noise according to a node expansion of the switch mode power supply which is based on a current balancing technique. In this paper, seven PCB patterns of the forward converter are manufactured and experimented.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.32-33
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• 2017

기존 EMI 필터 설계의 경우, 설계 가이드 없이 반복적인 측정을 통해 규제를 만족하도록 설계하기 때문에 많은 시간을 소모하게 된다. 또한 필터 내의 불필요한 소자 사용으로 인해 회로의 부피 및 가격 상승의 문제점이 있다. 따라서 본 논문은 대상 시스템에 대한 노이즈를 공통모드 노이즈(Common Mode Noise)와 차동모드 노이즈(Differential Mode Noise)로 분리하여 측정하였으며, 등가회로 모델링 및 제안 설계 가이드를 통해 최적 EMI 필터를 설계하였다. 또한 제안 EMI 필터 설계방법을 통해 설계 시간 단축, EMI 필터 단가 및 부피 저감이 가능하게 된다. 본 논문에서는 제안 방법을 이론으로 분석하고 모의실험을 통해 확인하였으며, 실제 측정을 통해 제안 방식의 우수성을 검증하였다.