• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.595-598
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• 2004

We have explained Process and electrical characteristics of a step-down Rosen type piezoelectric transformer for AC-adapter. When the electric voltage is applied to the driving piezoelectric vibrator notarized in the thickness direction, then output voltage is generated at the generating piezoelectric vibrator polarized in the thickness direction due to the piezoelectric effects. Output voltage and current from a single-layered piezoelectric transformer were measured under the various condition of loads and frequencies It was shown from experiments that output voltage has increased and resonance frequency has changed according to various resistor loads. Output current has decreased inversely proportional to the loads

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 반도체 재료 센서 박막재료 전자세라믹스
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• pp.161-164
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• 2004

In this study, to develop the composition ceramics for the Ultrasonic vibrator, $Pb(Mn_{1/3}Nb_{2/3})O_3Pb(Zr.Ti)O_3$ system ceramics were manufactured as a function of PCN substitution. Its dielectric and piezoelectric characteristics were investigated. With increasing the amount of PCN substitution, electromechanical coupling factor(kp) were increased until 3mol% PCN and that after decreased. mechanical quality factor(Qm) showed the maxinum value at 2mol% PCN. Eletromechanical coupling factor, mechanical quality factor and dielectric constant were showed optimum value at PCN 2mol% as 0.58, 1630 and 1407, respectively for ultrasonic vibrator applications.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.204-207
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• 2000

An ultrasonic linear motor was composed of a slider and a stator vibrator including piezoelectric material and elastic material. The ultrasonic linear motors mainly consist of an ultrasonic vibrator which generates elliptical oscillations. L$_1$-B$_4$ ultrasonic linear motor use longitudinal and bending multi-vibration. In order to low driving voltage and improve the life time of the ultrasonic oscillator, we used stacked piezoceramics. Stacked piezoceramics are adhered to aluminum elastic material. The finite element method was used to optimize dimension of ultrasonic vibrator and direction of vibratory displacement. As a result of estimating the characteristics of the ultrasonic linear motor, no-load velocity was 2.04[m/s] when applied voltage was 70[V$\sub$rms/] in resonance frequency.

• E2M - 전기 전자와 첨단 소재
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• 제9권1호
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• pp.24-29
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• 1996

A composite piezoelectric ceramic transducer is fabricated with three piezoelectric ceramic disk vibrators and two sheets of thin insulator. Its equivalent circuit is derived from the Mason's model of a thickness-driven piezoelectric vibrator. When the electric input near its fundamental resonance frequency is applied to the center vibrator and the output voltages across the left and the right vibrators are connected in series to the resistor loads, the load characteristics at resonance frequencies under the various resistor loads and the frequency characteristics near the resonance frequency without load are investigated. Furthermore, symbolic expressions for input impedances, voltage ratios, resonance frequencies, and bandwidths are derived. The data calculated from those symbolic expressions are agreed well with the measurement data.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.254-256
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• 2007

In this study, in order to develop low temperature sintering ceramic ultrasonic nozzle, single-layer and multilayer ring-type piezoelectric vibrators were manufactured using PMN-PNN-PZT ceramics, And then the electrical properties were investigated. The piezoelectric vibrator were sintered at low temperature of $940^{\circ}C$. The resonant resistance decreased with the increases of the number of layer. And also, the capacitance increased with the increases of the number of layer. The mechanical quality factor (Qm) decreased with the increases of the number of layer.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1998년도 학술발표대회 논문집 제17권 2호
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• pp.129-132
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• 1998

A bond graph modeling approach which is equivalent to a finite element method is formulated in the case of the piezoelectric thickness vibrator. This formulation suggests a new definition of the generalized displacements for a continuous system as well as the piezoelectric thickness vibrator. The newly defined coordinates are illustrated to be easily interpreted physically and easily used in analysis of the system performance. The bond graph model offers the primary advantage of physical realizability and has a greater physical accuracy because of the use of multiport energic elements. While results are presented is general in scope and can be applied to arbitrary physical systems.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.316-320
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• 2000

An ultrasonic linear motor was composed of a slider and a stator vibrator including piezoelectric material and elastic material. The ultrasonic linear motors mainly consist of an ultrasonic oscillator which generates elliptical oscillations. Elliptical oscillations are generated by synthesizing two degenerated modes. The design of a stator for an Ultrasonic linear motor was optimized with respect to vibration mode and direction of vibratory displacement by employing the finite element method. The motors were designed by varying the width of stator vibrator and the thickness, the length and the position of piezoceramics.

• 대한전기학회논문지
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• 제39권10호
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• pp.1044-1049
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• 1990

This paper is concerned with a ceramic filter laminated in the order of piezoelectric vibrator/that insulator/piezoelectric vibrator, and introduces general expressions near the resonant frequency, related with electrical inputs and outputs, gain and phase difference between input and output voltages, resonant frequency, and bandwidth, when the electrodes of the output element are divided by n equi-sections. This paper also shows that those expressions describe well the related experimental phenomena when n=1.

• 전기학회논문지P
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• 제51권4호
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• pp.193-197
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• 2002

In this paper, the ultrasonic sensor for gas flowmeter was simulated, fabricated and measured according to the assembly step and the piezoelectric vibrator layers. The simulated resonant frequency and the measured resonant frequency were similar except two layer sensor. The simulated resonant frequency of three layer sensor was 48 kHz and the measured resonant frequency of three layer sensor was 45.2 kHz. From the results, the ultrasonic sensor for gas flowmeter could be designed and expected without fabrication.

• 지구물리
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• 제2권2호
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• pp.100-110
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• 1999

조간대 지역의 고해상 반사법 탐사에 적합한 탄성파 파원을 밝히기 위하여, 이동식 진동기, 1.2 kg 스패너, 4.7 kg 해머, 30 kg과 100 kg 중력추 등 모두 5 종류의 파원을 워커웨이 방식으로 시험하여 파원의 특성을 구명하였다. 원시자료 및 고주파 통과필터 적용 후의 자료를 이용하여 파원에 따른 탄성파 이벤트들의 수직분해능을 분석하였으며, 고해상 탄성파 탐사에 적합한 파원을 결정하기 위하여 파원별로 발생에너지 및 주파수 성분의 변화를 비교하였다. 분석결과에 의하면 20-30 m 정도의 천부 지층을 상세하게 구명하기 위해서는 주파수 대역이 가장 넓고 고주파 성분을 많이 발생시키는 이동식 진동기가 가장 적합한 것으로 나타난다. 반면 대상심도가 100 m 까지 증가하는 경우, 해머가 효과적인 파원으로 사용될 수 있을 것으로 분석된다.