• Title/Summary/Keyword: Soft-starting

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The Starting System Implementation of SPIM with Detecting Main Winding Current (주권선 전류검출에 의한 단상유도전동기의 구동시스템 구현)

  • 최낙일;박수강;오금곤;백형래;임양수;오기진
    • Proceedings of the KIPE Conference
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    • 1997.07a
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    • pp.166-170
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    • 1997
  • A Single phase induction motor is the predominant fractional horsepower power rated, extensively used in domestic and industrial application. For example, these motors provide the motive power to washing machines, fans, refrigerators, etc. In this paper, single phase induction motor input current was detected by a small current transformer and determined TRIAC gate signal by using op-amp analog circuit. The soft-start strategy is based on limited auxiliary current angle during starting period in the closed-loop control. The Simulation and experimental result show the motor's starting characteristics of the proposal starting system and are compared with centrifugal switch starting motor.

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The Metaverse and Video Games: Merging Media to Improve Soft Skills Training

  • Shin, Edward;Kim, Jang Hyun
    • Journal of Internet Computing and Services
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    • v.23 no.1
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    • pp.69-76
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    • 2022
  • Education systems have made efforts to prepare students by providing technical and nontechnical courses. With video games, however, there is the potential to develop dedicated metaverses that can help teach soft skills even during casual pastimes. The research conducted will propose a set of design practices for metaverse and game development to promote soft skills. While there are many soft skills people can acquire, this paper will focus on certain aspects based on specific games and studies. There will be some information collected from the information to support the design model and arguments. This paper will provide developers with a starting point for imaginative game creation and impart users with soft skills to assist in their professions and social life.

Soft Start-up Algorithm of Single-Phase Induction Motor Based on Full-bridge Inverter (풀 브리지 인버터 기반 단상 유도전동기의 소프트 기동 기법)

  • Kim, Tae-Seong;Kang, Hyung-Do;Hwang, Seon-Hwan
    • Journal of IKEEE
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    • v.22 no.2
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    • pp.258-265
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    • 2018
  • This paper proposes an algorithm for reducing the starting current when the single-phase induction motor starts and analyzes its operation. Generally, the single-phase induction motors require several starters to generate the starting torque due to their structural characteristics. In this paper, a capacitor-start / capacitor-run method of the single-phase induction motor is basically adopted. This conventional method is efficient and has a large starting torque, but it generates about 5 ~ 6 times of inrush current at startup. As a result, the freezer starting device and peripheral devices are damaged and life time may be reduced. To reduce the inrush current, the current control algorithm based on the virtual dq model is presented to control the starting current. In addition, it validates the proposed algorithm through experiments to smooth transit from start-up operation to the rated operating region.

Design of a Electronic Ballast using Microprocessor (마이크로 프로세서를 이용한 전자식 안정기 설계)

  • Lee, Chang-Hoon
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.5
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    • pp.44-52
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    • 2007
  • In this study, design and control method using low cost Micro-controller(MCU) for inverter driving circuit in fluorescence lamp is presented. Soft starting technique is adopted to reduce switching loss and moment deterioration which are induced by high speed switching frequency in inverter ballast. Performance of the ballast stabilizer and the lighting characteristic of the fluorescence lamp have been improved by stabilizing switching pulses through the Pulse Width Modulation control.

Design and Control of SRM For LSEV Drive

  • Lee, Hee-Chang;Lee, Man-Hyung;Ahn, Jin-Woo
    • Journal of Power Electronics
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    • v.4 no.2
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    • pp.96-101
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    • 2004
  • This paper presents an application of SRM drive for LSEV(Low Speed Electric Vehicle). In this paper, a 5〔㎾〕 SRM for a traction of a LSEV is to design and investigate the characteristics of the drive system. The main design parameters and control strategy are given. In the control method, a current control, for the soft-starting technique at a starting operation, is adopted. In the high speed range, an angle control technique is implemented, for a high efficiency drive of SRM. Some experimental tests are executed to find the drive performances.

THE STARTING CHARACTERISTICS IMPROVEMENT OF SPIM WITH ONE-CHIP MICROCONTROLLER

  • Park, Su-Kang;Choi, Nak-Il;Cho, Geum-Bae;Oh, Keum-Gon;Baek, Hyung-Lae;Lim, Yang-Su
    • Proceedings of the KIPE Conference
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    • 1998.10a
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    • pp.321-324
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    • 1998
  • A single phase induction motor (SPIM) rated in fractional horsepower is widely used in home and industrial equipment: washing machines, fans, refrigerators, etc. In this paper, authors present the experimental results of the SPIM under controlling of currents of main and auxiliary windings by using a one-chip micro stator(OMS). This new starting method is developed to replace the conventional starting device consisted with a mechanical switch and a capacitor. In mentioned method, the soft-starting of SPIM is simply implemented and higher efficiency is obtained in comparison with conventional condenser type SPIM.

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Sensorless Fuzzy Logic Soft Start of Induction Motor With Load Detection

  • Arehpanahi, Mehdi;Monfared, Jafar Mili;Abbaszadeh, Karim
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2378-2381
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    • 2003
  • In recent years, fuzzy logic has received greater emphasis in the field of power electronics and motion control by virtue of its adaptive capability. A new fuzzy logic based soft-start scheme for induction motor drives close to load detection has been discussed here using microcontroller based thyristorised voltage controller. Rule based soft-start algorithm is fully realised through a software approach only. The soft-start strategy is based on the change of input impedance during starting period. The prototype has been tested under various loading conditions and found to be reliable.

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Investigating Ten-Finger Text Entry on Tablet PCs

  • Choi, Seungho;Park, Kyeongjin;Kim, Kyungdoh
    • Journal of the Ergonomics Society of Korea
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    • v.36 no.5
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    • pp.355-372
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    • 2017
  • Objective: The aim of this study is to investigate the performance and usability of ten-finger text entry on Tablet PCs. Background: Generally a soft keyboard is used on Tablet PCs. However, the soft keyboard's performance is usually worse than physical keyboard's performance. In this study, we proposed a modified keyboard for tablet PCs to improve the performance of ten-finger text entry and evaluated the performance and subjective ratings of the keyboard. Method: The modified soft keyboard that is suggested in this study was compared with current Google and Samsung soft keyboards on Tablet PCs. Results: The three keyboards were not significantly different in terms of typing speed, error rate, and mental workload and showed bad performance. Also, the subjective ratings were not shown positively. Conclusion: Based on our results, ten-finger text entry using soft keyboards on Tablet PCs seems to be very difficult. However, we need to research the possibility continuously since ten-finger text entry can improve typing speed. Application: Our study can be a starting point of research that explores ten-finger text entry on Tablet PCs. The new soft keyboard design can be one of the soft keyboard alternatives. However, the key factors to improve the performance and usability of the soft keyboard will not be 'key size' or 'convenience to typing special characters or numbers', but other factors (e.g., 'tactile feedback').

Interactive Technology: Soft Engineering

  • Yoon, Joong-Sun
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2682-2686
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    • 2003
  • Recent paradigm in technology shifts from object-based technology to environment-based technology. Issue here is interaction among human, machines, and environment. This requires new interpretations for the space among them. Holistic interactions based on “Mom (embodiment)” suggest a good starting point for this endeavor. The past, present, future of technology are presented in terms of technology’s fundamental virtue: “humanizing technology” or “technology serving human.” Interactive technology initiative (ITI) is an interdisciplinary research group to search for the proper technology and the proper way of implementing technology: “interactive technology” or “soft engineering.” Some experimental activities conducted by ITI are presented in this organized session, “Interactive Technology.” Metatechnology, soft engineering, “Mom (embodiment),” holistic interactions, tangible space, and ubiquitous computing are key concepts in interactive technology.

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Soft Start-up Characteristics Analysis of Squirrel Cage Induction Generator (농형 유도 발전기의 소프트 기동 특성 해석)

  • Kim, Jong-Gyeum;Park, Young-Jeen
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.1
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    • pp.103-107
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    • 2016
  • In general, the voltage stability of induction generator is lower than synchronous generator. Induction generator has a number of advantages over the synchronous generator on the side of price and maintenance. So Induction generator has been applied to the small hydroelectric power of low output. Induction generator usually generates a high current during grid connection. The high current that occurs during grid connection can cause a voltage drop in the system. In order to increase the supply of the induction generator, it is necessary to propose a method of reducing high current. This paper proposes some method of the soft start to reduce voltage drop caused by the large starting current. soft-start method has high voltage drop effect than direct start method, control of firing angle can be increased the voltage drop effect.