• 제목/요약/키워드: Effective Driving Width

검색결과 14건 처리시간 0.025초

두 개의 셔터 구멍이 적용된 원심식 비료 살포기의 살포패턴 분석 (Spray Pattern Analysis for a Centrifugal Fertilizer Distributor with Two Shutter Holes)

  • 황석준;박정현;이주연;김기덕;신범수;남주석
    • 한국기계가공학회지
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    • 제18권10호
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    • pp.8-19
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    • 2019
  • In this study, the spray pattern of a centrifugal fertilizer distributor with two shutter holes was analyzed and an effective driving width that satisfies proper spray uniformity was derived. The centrifugal fertilizer distributor was mounted on a tractor with a rated power of 23.7 kW and static and dynamic spray pattern tests were performed according to the standard procedure proposed by the American Society of Agricultural and Biological Engineers Standard ASAE S341.5. The height of the fertilizer distributor was 80 cm from the ground and the PTO (power take-off) shaft speed of the tractor was fixed at 540 rpm. The fertilizer scattered in space was collected using 275 evenly spaced collectors at shutter opening ratios of 25%, 50%, 75%, and 100%. The spray pattern was analyzed via the amount of sprayed fertilizer at each collector location and the coefficient of variation was used as an indicator of spray uniformity. Using the analyzed spray pattern, the effective driving width that satisfied less than 15% of the coefficient of variation was derived for different tractor driving patterns (race track mode, back and forth mode). From the results, spray uniformity increased as the shutter opening ratio decreased. The largest effective driving width was 8 m at a shutter opening ratio of 25% for both driving patterns.

전극 홈 형상에 따른 스캐닝 미러의 구동 특성 (Driving Characteristics of the Scanning Mirrors to the Different width and Number of the Grooves on the Electrodes)

  • 박근우;김용권
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제50권11호
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    • pp.575-580
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    • 2001
  • In this paper, using $500\mum-thickness\; (100)\; silicon\; wafer,\; flat\; 65\mum-thickness$ silicon mirror plates were fabricated through dry etching and wet etching, and $45\mum-depth$ grooved driving electrodes were fabricated through UV-LIGA process. Four shapes of the driving electrode were fabricated: twenty four grooves of the $50\mum-width$, twelve grooves of the $100\mum-width$, six grooves of the $200\mum-width$, and no grooves on the driving electrode. Fabricated mirror plate size and spring size are $2400\times2400\times65\mum3\; and \;500\times10\times65\mum3,$ respectively. Mirror plate parts and driving electrodes were assembled into the scanning mirrors. Measured natural resonance frequencies were about 600Hz which have error within $\pm 2%$ to calculated value. Due to the squeeze effect in the narrow gap between the mirror plate and the driving electrode, measured resonance frequencies were reduced as raising the amplitude of the mirror plate. In a case of driving electrode without grooves, the resonance frequency was reduced largely, compared with a case of driving electrode with grooves. According to the experimental results, squeeze effect was smaller in the driving electrode with smaller-width and many grooves. Therefore, the driving electrode with smaller-width and many grooves was effective in low voltage and high speed operation.

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연속주조기의 몰드 폭 변경 패턴 개발 (Development of High-Speed Width-Changing Pattern in Continuous Caster)

  • 강기판;신건;강충길
    • 대한기계학회논문집A
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    • 제34권7호
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    • pp.919-928
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    • 2010
  • 연속주조 시에 폭변경 속도를 향상시키기 위해 폭조정의 4 가지 패턴에 대해 연구하였다. 주요 사항은 폭변경 장치의 구동력을 최소화하고, 몰드 내의 응고막의 변형해석 모델을 개발하고, 폭변경 속도 상승을 제한하는 주요인자를 도출하는 것이다. 폭변경 실험을 근간으로 4 개 패턴의 주요 특징을 도출하였고, 각 패턴에 대한 힘을 비교하였다. 실험은 각 패턴의 구동력 비교를 위해 동일한 주조속도에서 수행하였다. 응고막변형 해석모델의 변수를 조정하기 위해 실험결과를 모델에 적용하였다. 폭변경 속도를 상승시키고, 구동력을 저감시키기 위해 패턴의 변수를 제어하였다. 가장 효율적인 패턴은 고속패턴이었으며, 구동력을 저감하기 위한 주요인자는 구동장치가 이동할 때의 기울기였다.

디지털날염용 고속 구동형 잉크젯 프린팅 헤드의 특성해석 (Characteristic Analysis of High Speed Inkjet Printing Head for Digital Textile Printing)

  • 이덕규;허신
    • 센서학회지
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    • 제27권6호
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    • pp.421-426
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    • 2018
  • To develop a piezoelectric inkjet printhead for high-resolution and high-speed printing, we studied the characteristics of an inkjet printhead by analyzing the major design parameters. An analytical model for the inkjet printhead was established, and numerical analysis of the coupled first-order differential equation for the defined state variables was performed using state equations. To design the dimension of the inkjet printhead with a driving frequency of 100 kHz, the characteristics of the flow rate and discharge pressure of the nozzle were analyzed with respect to design variables of the flow chamber, effective sound wave velocity, driving voltage, and voltage waveform. It was predicted that the change in the height of the flow chamber does not significantly affect the Helmholtz resonance frequency and discharge speed of the nozzle. From the analysis of change in flow chamber width, it is observed that as the width of the flow chamber increases, the ejection speed greatly increases and the Helmholtz resonance frequency decreases considerably, thereby substantially affecting the performance of the inkjet printhead.

TFT-LCD 패널의 구동 파형을 위한 파라미터 최적화 설계에 관한 연구 (A Study on Optimizing Parameter for Driving Waveform of TFT-LCD Panel)

  • 하종호;김광태
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 V
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    • pp.2851-2854
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    • 2003
  • The purpose of this paper was to find out the stabilized and effective value of RC-parameter by using PSpice simulation, considering that gate signal voltage can be distorted by RC-delay of signal line. the results of this study were as follows: TFT-LCD with high quality resolution increased the number of gate signal line and this made TFT on-time shorter over-width of signal line to improve the performance of TFT made the electrostatic capacity increase and the time constant higher, making problems and errors. and owing to the decrease of the aperture ratio, an electro optic character of LCD, we must consider the capacity and the condition of production process in deciding the width and the thickness of the gate signal line.

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Position Measurement Using Enclosed Signal Field with Pulse-Width-Modulated function

  • Ohyama, Shinji;Iizuka, Junya;Kobayashi, Akira
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.455-455
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    • 2000
  • A novel pulse-width-modulated (PWM) function is introduced for precise position measurement in an enclosed signal field. An amplitude modulation was used to light the LEDs for the conventional study. However, the transform properties from the driving signal to the lighting intensities of the LEDs are non-linear, and accurate control of the lighting power was necessary. Therefore, a lighting function independent of these properties is desired. Well-known PWM functions are used to construct the enclosed signal field by simulation, and the precision of the phase detecting system is analyzed. A novel "axial symmetry PWM" function is found to be effective for orthogonal pahse detection.

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IGBT PWM 인버터 구동 유도전동기의 절연성능 향상기술 연구 (A Study on the Insulation Performance Improvement of Induction Motors Fed by IGBT PWM Inverter)

  • 황돈하;박도영;김용주;이영훈;김동희;이인우
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2001년도 전력전자학술대회 논문집
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    • pp.335-339
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    • 2001
  • The recent advancements in power electronic switching devices have enabled high frequency switching operation and have improved the performance of pulse-width modulated (PWM) inverters for driving induction motors. But, the insulation failures of stator winding have attracted much concern due to high dv/dt of IGBT PWM inverter. In this paper, the test results for evaluation on the stator winding insulation of low-voltage induction motors for IGBT PWM inverter applications are presented. The insulation characteristics are analyzed with partial discharge and dissipation factor tests. Also, insulation breakdown tests by switching pulse voltage are performed. An effective insulation technique to enhance the insulation strength is suggested from the test results.

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PDP의 ADS 구동방식에서의 초기화 방전특성에 관한 연구 (A Study on the Characteristics of Reset Discharge in the ADS Driving Method for the PDPs)

  • 염정덕
    • 조명전기설비학회논문지
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    • 제17권2호
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    • pp.17-22
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    • 2003
  • 본 연구에서는 mP의 ADS 구동방식에서 초기화기간의 프라이밍 방전 특성에 대하여 실험적인 해석을 하였다. 방전에 의해 축적되는 벽전하의 총량과 벽전하가 축적되는 시간은 프라이밍 펄스의 폭과 무관하다. 또한 과잉 벽전하에 의한 자기소거 방전은 프라이밍 방전에 의한 벽전하량과 관계가 있으며 또한 프라이밍 방전에 의해 생성되는 공간전하와도 관계가 있다. 실험결과 프라이밍 펄스 폭은 8[$\mu\textrm{s}$], 전압은 163[V] 정도가 최적이다. 그리고 자기소거방전을 돕는 공간전하는 파라이밍 방전이 발생한 직후로부터 약 16[$\mu\textrm{s}$] 동안 존재한다. 그러므로 효과적인 초기화 과정을 위한 프라이밍 펄스의 폭은 16[$\mu\textrm{s}$] 이내가 적당하다.

HDIV를 위한 PDP의 표시방전특성에 관한 연구 (A Study on the Display Discharge Characteristics of PDP for the HDTV)

  • 염정덕
    • 조명전기설비학회논문지
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    • 제19권4호
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    • pp.39-46
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    • 2005
  • 본 연구는 3 전극 교류구동형 PDP의 ADS구동방식에 관한 것으로 휘도의 저감이 없는 안정적인 표시방전이 가능한 최소의 어드레스와 표시방전 유지펄스의 폭을 도출하는 것이다. 실험결과로부터 어드레스 펄스폭이 $1.5[{\mu}s]$이 상만 되면 효과적인 어드레스 방전이 가능하였고 35[V] 어드레스 동작마진을 얻을 수 있었다. 또한, 표시방전 유지펄스의 폭이 $2[{\mu}s]$이상 되면 25[V]의 동작마진을 가지고 안정적인 표시방전의 유지가 가능하였다. 이 조건들을 수평 주사선수 1080라인의 Full-HDTV급 PDP에 적용할 경우 8개의 서브필드와 총 1420개의 표시방전 유지펄스를 사용할 수 있다.

High-Current Trench Gate DMOSFET Incorporating Current Sensing FET for Motor Driver Applications

  • Kim, Sang-Gi;Won, Jong-Il;Koo, Jin-Gun;Yang, Yil-Suk;Park, Jong-Moon;Park, Hoon-Soo;Chai, Sang-Hoon
    • Transactions on Electrical and Electronic Materials
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    • 제17권5호
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    • pp.302-305
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    • 2016
  • In this paper, a low on-resistance and high current driving capability trench gate power metal-oxide-semiconductor field-effect transistor (MOSFET) incorporating a current sensing feature is proposed and evaluated. In order to realize higher cell density, higher current driving capability, cost-effective production, and higher reliability, self-aligned trench etching and hydrogen annealing techniques are developed. While maintaining low threshold voltage and simultaneously improving gate oxide integrity, the double-layer gate oxide technology was adapted. The trench gate power MOSFET was designed with a 0.6 μm trench width and 3.0 μm cell pitch. The evaluated on-resistance and breakdown voltage of the device were less than 24 mΩ and 105 V, respectively. The measured sensing ratio was approximately 70:1. Sensing ratio variations depending on the gate applied voltage of 4 V ~ 10 V were less than 5.6%.