• Journal of Magnetics
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• v.17 no.1
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• pp.61-67
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• 2012

The miniaturization of an electrostatic precipitator has become a key element in successfully constructing an efficient electrostatic precipitator because of the limited space allowed for installation in a subway tunnel. Therefore, the miniaturization of the rapping system of the electrostatic precipitator has also become important. This research proposes a resonant-type electromagnetic vibration exciter as a vibrating rapper for an electrostatic precipitator. The compact vibrating rapper removes collected dust from the collecting plates without direct impact on those collecting plates. To characterize the dynamic performance of the electromagnetic vibration exciter, finite element analysis was performed using a commercial electromagnetic analysis program, MAXEWLL. Moreover, we analyzed the resonant frequency of an electrostatic precipitator, to which the electromagnetic vibration exciter was applied, by ANSYS. Also, to measure the acceleration generated by the electromagnetic vibration exciter, we manufactured a prototype of the ESP and electromagnetic vibration exciter and measured its acceleration at the resonant frequency.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.4
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• pp.176-180
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• 2004

This paper presents the fabrication and test of a micro cell exciter actuated by an electromagnetic force for the study on the chondrogenic differentiation of rabbit mesenchymal stem cells (MSCs). The micro cell exciter is designed to apply compressive loading to the alginate gel mixed with the MSCs. The magnetic cell exciter consists of an actuator component and a cartridge-type chamber component. An actuator is composed of a permanent magnet, a core and a coil. The chamber has seven PMMA wells and a cell culture Petri dish. Two types of alginate gels were stimulated by the cell exciters for 10 minutes every 12 hours for 7 days. In order to determine the expression of these matrix components during differentiation, RT-PCR analysis was performed. Collagen type II was expressed in the MSCs subjected to the compressive stimulation.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.329-329
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• 2000

In this paper, a spindle system using an electromagnetic exciter is proposed to compensate a spindle disturbance such as unbalance and machining force etc A spindle compliance can be readily varied with a disturbance which is generated by the interact ion between the spindle / workpiece structure and the cutting process dynamics. The varied compliance is one of the major constraints that deteriorates the surface quality of workpiece. This paper suggests a compliance compensation by using the EME in the proposed spindle system. To compensate the varied compliance, firstly a spindle system modeling was conducted by using the bond graph. Then the model is simulated by numerical analysis method and an optimal EME position is determined to compensate a disturbance effectively through simulation, which makes the bearing load to be minimized

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4136-4141
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• 2013

One of the most significant requisite that should be considered for effective rapping of the electrostatic precipitator using electromagnetic vibration exciter is vibration acceleration and resonance frequency of collecting plates. This vibration acceleration shows its peak points when natural frequencies of the system are corresponded with excitation frequency from the power source, and effective rapping performance can be expected. In this research, extend view of single electrostatic precipitator using one electromagnetic vibration exciter, the system was remodeled by arrangement of the exciters in view of multiple modules of the electrostatic precipitator in fields. And vibration acceleration measurement experiment is performed and measured values are compared with these remodeled systems. By this experimental comparison in series and parallel arrangement, effectiveness of arrangement methods for the electromagnetic vibration exciter, expected rapping performance, and power consumption are verified.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.505-509
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• 2001

When the spindle is rotated for machining the workpiece, the vibration is generated due to the spindle unbalance. This vibration affects surface finish, dimensional accuracy, tool life, and spindle bearings. To compensate this effect of the spindle unbalance, the spindle system using an EME(electro magnetic exciter)is proposed in this paper. In the proposed spindle system, the vibration due to the spindle unbalance is monitored using vibration sensors and is compensated by electromagnetic attractive forces generated in the EME which are excited by anti-direction forces corresponded with the measured unbalance. Firstly, the spindle system using an EME and control system are constructed to compensate the effect of spindle unbalance in this paper. And then the system is modeled by bond graph to analyze the system. Finally, a controller for vibration compensation due to spindle unbalance is designed and is implemented in real experimental system. As a result, experimental results show this proposed spindle system is very effective to compensate the spindle unbalance.

• Journal of the Korean Magnetics Society
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• v.24 no.6
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• pp.171-178
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• 2014

Remote Field Eddy Current Testing (RFECT), one of the ways which is a nondestructive testing using electromagnetic fields, can make up for Magnetic Flux Leakage (MFL) weaknesses and general Eddy Current Testing (ECT) weaknesses which is an occurrence of a huge friction force or disadvantage of detecting defects on the outer wall. So many of institutes and laboratories have studied on RFECT for the past 50 years. But There is a lack of discussion about a study on eddy current and magnetic field distributions in a pipe wall and designing of RFECT exciter coil. In this paper, eddy current and magnetic field distributions in a pipe wall and influence of altering variables are analyzed. Also, the optimal design algorithm about the RFECT Exciter coil are proposed, and influence on defect signals caused by alteration of its shape is analyzed.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.2
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• pp.147-152
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• 1999

Semiconductor piezoresistive type vibration sensor was fabricated by using semiconductor process and micromachining technology. To measure the micro electromagnetic force between coil and magnet, fabricated vibration sensor was used. Toapply micro electromagnetic force produced from the micro exciter, small-sized NdFeB permanent magnet was attached on the mass of the fabricated vibration sensor. The measured electromagnetic force are about 5~180dyne when the applied sinusoidal current of 1KHz in the range of 1.5~8mA. The measurement of micro electromagnetic forcewas performed by changing the distance between coil and magnet. Output characteristics of micro electromagnetic force according to the applied coil current were linear. Furthermore, output results were used to get the transfer constant that is important to decide the efficiency and the performance of the coil and magnet.

• Proceedings of the Korean Magnestics Society Conference
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• 1998.10a
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• pp.122-123
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• 1998

• Journal of Welding and Joining
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• v.23 no.4
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• pp.66-72
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• 2005

An electromagnetic inductive sensor consisted of one exciter and three separated (triple) detectors has been developed for both tracking the weld seam of a workpiece and controlling the sensor-to-workpiece distance (height) simultaneously. The left and right detectors are used to track the seam, while the fore and the other two detectors allow the sensor to determine the height and the gap width by being coupled their outputs together. A series of experiments with the proposed sensor located above a mild steel plate containing a weld seam of gap are carried out to examine the feasibility of the sensor. The results revealed that the proposed sensor could fairly well track the desired seam and also well control the height to be constant even when the gap width of the seam varied. The gap width can be also determined during the seam tracking by using the sensor outputs. As a consequence, these can provide the developed sensor with substantial improvement for industrial uses with respect to the previous electromagnetic sensors being used for the weld seam tracking.

• Journal of the Korean Magnetics Society
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• v.21 no.2
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• pp.61-66
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• 2011

The miniaturization of electrostatic precipitator is becoming a key element to the success of the efficient electrostatic precipitator due to the limited space allowed to install electrostatic precipitator in subway tunnel. Nowadays, a research on electrostatic precipitator in urban railroad equipment technology is under an active study. Finite element method has been used one of the most popular techniques, but it consumes a lot of time especially in computation iterations. Accordingly, the lumped parameter analysis can be an alternative tool to FEM because of its computation iteration capability with fair accuracy. In this paper, lumped parameter model and the simulation results are presented. In addition, the result of lumped parameter analysis is compared with those obtained from finite element analysis for verification.