• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.580-582
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• 2001

In moving coil LOA, the variation of mover position and the consequent changes of coil flux path affect the coil inductance because of unbalanced magnetic circuit. Furthermore, the armature field shifts and distorts the airgap flux density distribution due to the magnet alone by a certain amount, which cause the unbalanced reciprocating force. In this paper, we propose the reduction method of armature reaction and coil inductance. The proposed LOA has the shorted ring the saturated core, the double coil, and Halbach array.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.2
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• pp.105-110
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• 2012

This paper designs the high-efficiency and the low-cost drive system of the smallsize electric vehicles (EVs). The power circuit for driving the dc motor is designed by considering both the cost and efficiency. In order to reduce the conduction loss of MOTFET and diode for controlling an armature voltage, some MOSFETs and diodes at the armature are in parallel connection. An operating sequence for both the field current and the armature voltage according to the accelerator pedal angle is suggested for changing smoothly the rotating direction of dc motor. Through the simulation studies, the performances of the proposed methods are verified.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.5
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• pp.245-249
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• 2006

This study tries to test and analyze the static friction torque generated by an electromagnetic clutch. Then the torque is improved by optimizing the shape of armature. For the purpose of design change and optimization of the electromagnetic clutch, the static friction torque prediction is very important. We construct an axi symmetric FEM model for analyzing the static friction torque and used a torque tester for evaluating the real torque. For a test, predicted static friction torque is compared with the experimental one to discuss the rationality of torque analysis process. The analytical result agrees well with experimental data, explaining the validity of the mathematical process and FEM model. After confirming the torque analysis process, the optimization process is investigated. The optimization result shows that the static torque is improved by changing the armature shape.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.56-58
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• 1993

This report describes the high speed DC motor (8,000 rpm) that we have designed, manufactured and tested. DC motor is the best drive system in electric-mechanical energy conversion. The design concept for high speed and high energy density to DC motor is to maximize Ampere-conductor in armature and to maximize flux density in armature teeth, armature core, pole, yoke using flux path.

• Journal of Korean Elementary Science Education
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• v.17 no.1
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• pp.105-112
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• 1998

It is well known that making electric motors is very difficult in chapter 2, "Electric Current and Magnetic Field", natural science textbook 6-1 in primary school. In the present paper, we propose a new and successful method for making them. The most important point is that iron cores are not used in making electromagnets. This resolves the problem that both poles of electromagnet can be attracted by any pole of permanent magnet because of iron core in the electromagnet. The thick enamel wire is used as arms of armature so that they can support the electromagnet stably and we can reliably strip off the skin of the enamel wires, completely for one end and half for the other end of the enamel wires coming from the electromagnet. In addition, we suggest the ring-type support made of aluminum foil and the M-shaped support made of thick enamel wire that can substitute for the M-shaped copper wire support for armature. armature.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.3
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• pp.380-383
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• 2012

Small permanent magnet generator can be used not only as an emergency power source but also an exciting power source of generator for small generating systems because it does not need the external exciting power source. Especially the air-gap flux density of the buried PM synchronous generator can be increased more than that of the permanent magnet. In this study, the analysis of the small buried type PM synchronous generator is performed. From the phasor diagram considering armature resistance for exact analysis, analytic equations are induced and the efficiency, developed voltage, load current are calculated. The experimental results are compared with the calculated results for the appropriateness.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.4
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• pp.441-447
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• 2007

The speed and torque control performance of the DC motor used in the industrial field is affected by the change of parameters. In particular the change of armature resistance can be greatly originated from various load conditions. Accordingly a large number of studies to estimate those problems in the servo motor control field have already been under way. In this paper, the armature resistance on the DC motor under several load and speed conditions is estimated by the Artificial Neural Network(ANN), and the validity is proven by the speed estimation of sensorless speed control system.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.113-115
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• 1995

The calculations of the temperature rise in the armature have long been considered among some of the most important problems in the design of the rotating machine. Despite the many methods of calculation propose, very few have been used in the actual design. In most cases, These methods are inadequate for measuring a wide range of temperature distribution because of the complicated structure of the machine. In this paper, the armature is divided into seven portions, and the thermal equivalent circuit is introduced as a simulation of the armature. The test machine is 1000Kw salient-pole synchronous generator.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.1056-1061
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• 2004

The vibration of rotor systems is caused by various factors, such as misalignment, unbalance, gear meshing, error of assembly, etc. Modal test and TDA/ODS analysis were done. The dynamic analysis of the armature was done with SAMCEF which is a commercial software for finite element and kinematic analysis. The transient response of the armature is calculated by the SAMCEF with the consideration of magnetic force and bearing stiffness, which are the essential elements for the design of high speed cutter. Main frequency of the vibration is due to the unbalance of the armature. The FEM analysis model considering unbalance and the high speed cutter have same vibration properties. The vibration sources of the high speed cutter is proved to be unbalance.

• Journal of Species Research
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• v.10 no.3
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• pp.287-300
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• 2021

Three new species of Myzomolgus are described as associates of sipunculans from a tidal flat in Phuket, Thailand. As diagnostic features, Myzomolgus leptocercosus n. sp. has elongate caudal rami which are 10.7 times longer than wide, 5 setae and a conical process on the first antennular segment, an armature formula 1, 0, 1+sucker, and 6 of antenna, and an inner coxal seta on all swimming legs. Myzomolgus spatulatus n. sp. lacks a rostrum, but bears 4 setae and a spatulate process on the first antennular segment, an armature formula 0, 0, 2+sucker, and 6 of the antenna, the inner coxal seta on legs 1-3, and 5 armture elements on the third endopodal segment of legs 1-3. Myzomolgus cucullatus n. sp. has short caudal rami which are 1.60 times longer than wide, a broad, hood-like tergite of fouth pedigerous somite, 4 setae only on the first antennular segment, the armature formula 0. 0. 2+sucker, and 6 of the antenna, and no iiner coxal seta on the swimming legs.