• Journal of Korean Port Research
• /
• v.11 no.2
• /
• pp.273-280
• /
• 1997

Recently the importance of the cargo handling equipments in a port has been increasing to get strong competition from other ports. Many ports are making efforts to modernize their cargo handling equipments. The kernel technology of such equipments is the speed control of DC motor which is used as an essential part of them. In this paper, we discuss the speed control of a DC motor as a basic work for building cargo handling equipments in a port. DC Motors are still widely used in industrial fields, as driving power motor for electrical fields. DC drives, being easy to control, are widely used in many variable-speed and position control drive system. Traditional analog control circuits used in such applications have many disadvantages. Complex control schemes are difficult to implement with analog components. All these factor and invention of the microprocessor has made it possible to use digital control circuits, using microprocessing system. These digital circuits have been found to be reliable, flexible, and also immune to noise. In this paper it presents the speed control of a SCR DC motor driver which using dual converter by 80c196kc microprocessor. We developed a thyristor power amplifier which does not cause damage thyristor because it is designed to prevent triggering the two SCRs in the same arm simultaneously. And it was analyzed voltage and currents wave at reactive load.

• Transactions of the KSME C: Technology and Education
• /
• v.4 no.1
• /
• pp.63-71
• /
• 2016

Although mechatronics education in a mechanical engineering curriculum is recently recognized as important, its experimental education has been done generally in the laboratory equipped with all the apparatus and could not be done at home by students. This paper introduces experimental educations on mechatronics, e.g., digital logic circuits, 7-segment LED drive, square wave generation, microcontroller programming using assembly and C languages, timer interrupt, and step motor drive using a small 5 V power supply, a breadboard, various electronic and electric components, a microcontroller and its programmer, a step motor, and a student's PC. In the developed mechatronics course, experimental educations are scheduled in parallel with content's lectures together, and cheap and economic experimental environment is prepared for students in which students can easily practice experimental works in advance or later at home by themselves.

• Proceedings of the KSME Conference
• /
• 2001.06d
• /
• pp.903-908
• /
• 2001

A web-based client/server program, MOVIDIK(Motor-Operated-Valve Integrated Database Information of KEPCO) has been developed to perform a design basis safety evaluation for a motor-operated-valve(MOV) in the nuclear power plant. The MOVIDIK consists of seven analysis modules and one administrative module. The analysis module calculates a differential pressure on the valve disk, thrust/torque acting at a valve stem, maximum allowable stress, thermal-overload-relay selection, voltage degradation, actuator output and margin. In addition, the administrative module manages user information, approval system and code information. MOVIDIK controls a huge amount of evaluation data and piles up the safety information of safety-related MOV. The MOVIDIK will improve the efficiency of safety evaluation work and standardize the analysis process for the MOV.

• Journal of computational fluids engineering
• /
• v.22 no.1
• /
• pp.103-109
• /
• 2017

The aerodynamic noise reduction of railway traction motor is required to satisfy new enhanced Korean noise regulations for a train. This paper is the study result on a noise reduction of a railway traction motor using Lattice Boltzmann Method(LBM). To verify the reliability of numerical analysis, the noise performance of the base model evaluated using LBM, and calculated result was compared with the experimental data. In addition, main noise sources were selected to design parameters through analyzing the flow field of the base model. Based on the noise sources analysis result, a design improvement model of traction motor for this study was derived to reduce the noise. The performance of a design improvement model was evaluated by applying a validated numerical scheme. As a result, it was confirmed that the noise was reduced due to the suppression of the internal turbulent flow components.

• 제어로봇시스템학회:학술대회논문집
• /
• 1990.10a
• /
• pp.281-285
• /
• 1990

Our N.C. sewing machine is a device that acts sewing automatically in reference to N.C. data made by data input device. Our N.C. sewing mechine is composed of induction motor that has electric clutch and brake, step motor that drives x-y table. Sewing area of our machine is 170 mm * 100 mm, maximum sewing speed is about 2000 spm, maximum stitch length 6.2 mm. In actual sewing, synchronization between motion of needle up-down and motion of x-y table is a critical factor. In this paper, technology about synchronization will be profoundly discussed.

• Proceedings of the KOSOMBE Conference
• /
• v.1997 no.11
• /
• pp.71-74
• /
• 1997

MR acoustic sound or noise due to gradient pulsings has been one of the problems in MRI, both in patient scanning as well as in many areas of psychiatric and neuroscience research, such as brain fMRI. Especially in brain fMRI, sound noise is one of the serious noise sources which obscures the small signals obtainable from the subtle changes occurring in oxygenation status in the cortex and blood capillaries. Therefore, we have studied the effects of acoustic or sound noise arising in fMR imaging of the auditory, motor and visual cortices. The results show that the acoustical noise effects on motor and visual responses are opposite. That is, for the motor activity, it shows an increased total motor activation while for the visual stimulation, corresponding (visual) cortical activity has diminished substantially when the subject is exposed to a loud acoustic sound. Although the current observations are preliminary and require more experimental confirmation, it appears that the observed acoustic-noise effects on brain unctions, such as in the motor and visual cortices, are new observations and could have significant consequences in data observation and interpretation in future fMRI studies.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.55 no.4
• /
• pp.203-208
• /
• 2006

This paper presents characteristics of SynRM(Synchronous Reluctance Motor) that is compared with a high speed induction motor. SynRM is much suitable for high speed electric machines because of structural robustness. There are many kinds of SynRM according to the shape of rotors. Particularly, axially laminated anisotropic (ALA) rotor is suitable for high speed instruments. Characteristics of SynRM with ALA rotor is obtained from a governing voltage and torque equation mainly composed of d-axis and q-axis inductance that will be identified with finite element method.

• Proceedings of the KIEE Conference
• /
• 1993.11a
• /
• pp.53-55
• /
• 1993

This paper describes the development of a software that has the man expert knowledge, experience and inference. This software is helpful for selecting the motors and driving systems which are best fit for the applications. Developed software can automatically select the most reasonable motor driving systems, only if a semi-skilled engineer inputs the performance criteria for the applications and mechanical data. Expert system inference engine and knowledge-base are implemented by C programming language. Data-base was implemented from manufacturer's catalogues for DC motors and brushless DC motors. Efficiencies of the various motor driving systems are compared reference on the average efficiency depends on the operating profiles. Developed expert system was tested in various of applications to verify the reliability, quick and easy selecting of the motor driving systems.

• Proceedings of the KIEE Conference
• /
• 1992.07a
• /
• pp.239-241
• /
• 1992

In this paper, back-propagation neural network is used for the identification and trajectory control of a DC motor. The neural network is trained to identify the unknown nonlinear dynamics of the motor and load and the trained neural network is used for speed control of the DC motor to have good performance. Simulation results show the good performance of the control system based on the neural network under arbitrarily chosen speed trajectories.

• 한국신재생에너지학회:학술대회논문집
• /
• 2008.10a
• /
• pp.47-50
• /
• 2008

The sub-zero cold is a major environmental consideration for the operational readiness of FCEVs because fuel cells produce water and utilize wet air with varying water content to generate electricity. Typical fuel cells thus have a fatal flaw in freezing conditions at startup. This drawback becomes more serious with the outsourced fuel cell that is entirely water-based for its internal humidification. In this background, the HMC's self-designed fuel cell was developed as an alternative and was employed in the Tucson-based FCEV in 2006 demonstrating its good cold-startup characteristics. The cold-startup capacity of the vehicle was validated through tests in the cold chamber and on the road, resulting in 50% stack power achieved in 250 seconds at $-15^{\circ}C$.