• Title/Summary/Keyword: piezoelectric transducer

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Measurement of Axisymmetric-Wave Speed in a Pipe by Using Piezoelectric Cylindrical Transducers (원통형 압전 변환기에 의한 관 내 축대칭 파동 속도 측정)

  • Hwang, Kyo-Kwang;Kim, Jin-Oh
    • The Journal of the Acoustical Society of Korea
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    • v.23 no.1E
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    • pp.19-23
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    • 2004
  • This paper presents an experimental technique to generate and detect axisymmetric longitudinal waves in a pipe by using piezoelectric cylindrical transducers. Radial pulses transmitted by one transducer have propagated in two opposite directions along the pipe, and other two transducers have received the propagating waves. The difference of the transit times measured for the waves in two paths of known distance difference has yielded the phase speed of the wave propagation. Wave speed has been measured in an empty pipe and in a water-filled pipe.

Optimal Design of Deep-water 30kHz Omnidirectional Sonar Transducer Using a Coupled FE-BEM

  • Jarng, Soon-Suck
    • The Journal of the Acoustical Society of Korea
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    • v.18 no.4E
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    • pp.3-9
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    • 1999
  • Deep-water sonar transducers of FFR (Free Flooded Ring) type have been designed using a coupled FE-BEM. The proposed sonar transducers are composed of piezoelectric ceramic tubes and structural steel materials for simple fabrication. In order to have an omnidirectional beam pattern around 30kHz, a conic steel is placed below a piezoelectric tube or a steel disc is placed between two piezoelectric tubes. The dynamics of the sonar transducer is modelled in three dimensions and is analyzed with external electrical excitation conditions. Various results are available such as directivity patterns and transmitting voltage responses. The most optimal structure and dimensions of the steel material were calculated, so that the beam patterns of the sonar transducers had +/- 3dB omnidirectivity at 30kHz.

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Vibration Characteristics of Piezoelectric Stack Transducers (적층 압전 변환기의 진동 특성)

  • Kim, Dae Jong;Kim, Jin Oh
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.10a
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    • pp.66-68
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    • 2014
  • The paper deals with the vibration characteristics of the stack transducers made of piezoelectric discs with different radius. Natural frequencies of the stack transducers were evaluated by finite-element analysis. The natural frequencies of the analysis results were compared with those of each piezoelectric disc, and their relations were investigated.

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Broad-Band Underwater Acoustic Transducer for Doppler Velocity Log (도플러 속도계(DVL)를 위한 광대역 수중 음향 트랜스듀서)

  • Yun, Cheol-Ho;Lee, Yeoung-Pil;Ko, Nak Yong;Moon, Yong-Seon
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.9
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    • pp.755-759
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    • 2013
  • A broad-band underwater acoustic transducer that uses thickness vibration mode, derived from a disk type piezoelectric ceramic, has been proposed and designed for DVL (Doppler Velocity Log). Three different types of acoustic transducer were evaluated with respect to the transmitting voltage response, receiving voltage sensitivity and bandwidth of the transducer. The effect of the acoustic impedance matching layer and backing layer is discussed. The results demonstrated that three matching layer with lossy backing layer is the best configuration for underwater transducer. The trial underwater acoustic transducer with three matching layer has a frequency bandwidth of 55%, maximum transmitting voltage response of 200 dB and a maximum receiving voltage sensitivity of -187.3 dB.

A Study on the Aluminum Wire Bondingby Using Ultrasonic Vibrator (초음파 진동자를 이용한 알루미늄 와이어 용접에 관한 연구)

  • 김희수;이건복
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1994.10a
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    • pp.571-576
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    • 1994
  • In recent years, ultrasonic has been widely applied in measurement and industrial fields and its application range has been expanded as a result of continuous research and development. Wire Bonding Machine, an instrument fabricating semi-conductor, makes use of ultrasonic bonding method. In order to improve the currently used wire bonding machine using ultrasonic energy, technical accumulation is needed steadily through development of exciting device of ultrasonic composed of piezoelectic vibrator and horn. This study investigates the design conditions affecting the dynamic characteristics through the theoretical and experimental analysis of piezoelectric vibrator and horn, The study conducts separately the system identification of piezoelectric vibrator in time domain and the modal analysis of horn in frequency domain. In theoretical model, the integrated modeling is conducted via a combination of dynamic identification of piezoelectric vibrator and theoretical analysis of horn. Hence comparison is made for theoretical and experimental results of the dynamic characteristics of the ultrasonic transducer composed of piezoelectric vibrator and horn. Form the results of this study we develop the design technique of ultrasonic transducer using dynamic characteristic analysis and propose the possibility of ultrasonic welding considering the optimal condition of the natural frequency and vibration mode of horn.

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Optimal Friction Materials of Tiny Piezoelectric Ultrasonic Linear Motor

  • Lee, Kyong-Jae;Nahm, Sahn;Kang, Jin-Kyu;Ko, Hyun-Phill;Kang, Chong-Yun;Kim, Hyun-Jae;Yoon, Seok-Jin
    • Transactions on Electrical and Electronic Materials
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    • v.6 no.6
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    • pp.249-255
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    • 2005
  • In recent years, a novel tiny piezoelectric linear motor converting a radial mode vibration to a longitudinal mode vibration driven by the impact force has been developed for a camera optical module. The tiny piezoelectric motor is consisted of a shaft, mobile element, and piezoelectric transducer. In this work, the frictional coefficient and static friction force of the interface between the shaft and the mobile element have been investigated according to their respective materials. It was found that two combinations, namely Pyrex glass or stainless steel for the shaft and stainless steel (SUS) for the mobile element, exhibited good dynamic behaviors in the tiny ultrasonic linear motor, which was newly developed based on operating concepts based on Newton's law.

Development of a High-power Ultrasonic System for Sonochemistry Reaction (음향화학 반응용 강력초음파 개발)

  • Lee, Yang-Lae;Kim, Hyun-Se;Baek, Min-Hyuck
    • Journal of Power System Engineering
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    • v.17 no.6
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    • pp.142-148
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    • 2013
  • High-power ultrasonic promotes a chemical reaction by its own energy, thus it has been used for sonochemistry applications. For example, it has been mostly used for mixing, reaction catalyst, dispersion and disintegration. High-power ultrasonic transducer is made with structure based on a Bolt-clamped Langevin type Transducer (BLT), But it has difficulty in the development because degradation of piezoelectric ceramic by the heat generation of BLT. In this study, for a development of the transducer of 25 kHz and 1000 W used in sonochemistry and industrial cleaning, BLT with a hole in its center and tubular type waveguide of the transducer were designed based on finite element method (FEM). The transducer was fabricated based on the design parameter, and the impedance characteristics are measured experimentally and compared with the numerical results.

Optimal Design of Piezoelectric Cantilever Fan by Three-Dimensional Finite Element Analysis

  • Kim Byoung-Jai;Rho Jong-Seok;Jung Hyung-Kyo
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • v.5B no.1
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    • pp.90-94
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    • 2005
  • As the structure of the piezoelectric bimorph cantilever becomes increasingly more complicated, a more accurate and efficient analysis of piezoelectric media is needed. In this paper, the piezoelectric transducer is analyzed by using the three-dimensional finite element method. The validity of the three-dimensional finite element routine is confirmed by comparing the experimental result. The resonance characteristics, such as resonance frequency and anti-resonance frequency, of the piezoelectric cantilever are calculated by the experimentally verified three dimensional finite element method. Subsequently, the characteristics, such as mechanical displacement and impedance, are calculated at the resonance frequency. Besides, to design the piezoelectric bimorph cantilever shape that maximizes displacement at the tip, the ES (Evolution Strategy) algorithm is applied. Finally, optimal design for the fan of the piezoelectric cantilever is fulfilled to obtain maximum displacement at the tip. From these results, the application potentiality of the piezoelectric bimorph cantilever fan is identified.

Radial Vibration of Cylindrical Piezoelectric Transducers (원통형 압전 변환기의 반경방향 진동 특성)

  • 김진오;정형곤
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.11 no.7
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    • pp.247-252
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    • 2001
  • The paper deals with a theoretical study on the redial vibration of cylindrical piezoelectric transducers The differential equations of piezoelectric radial motion have been derived in terms of the radial displacement and electrical potential. Applying mechanical and electrical boundary conditions has yielded the characteristic equations of natural vibration. Numerical resutls of the fundamental natural frequency have been compared with experimental observations for the transducers of several sizes, and have shown a good agreement.

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