• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.76-77
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• 2009

This paper is concerned with the development of the piezoelectric energy harvesting(PEH) device using Wind. In this study, the piezoelectric energy harvesting system consisting of a cantilever with a pinwheel and piezoelectric wafer was investigated in detail both theoretically and experimentally. The power output characteristics of the PEH was then calculated and discussed. Theoretical and experimental results showed that the PEH was able to charge a battery with ambient vibrations but still needed an effective mechanism which can convert mechanical energy to electrical energy and an optimal electric circuit which dissipates small energy.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.270-273
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• 1996

This paper describes a type of piezoelectric transformer with improved design principles. It consists of a thin rectangular piezoelectric ceramic plate having two input electrodes and one output electrode. The length of each input and output electrode is nearly one third of that of piezoelectric transformer itself. In the driving section, the ceramic plate is poled in the thickness direction reversely with each other, and has electrodes on both main faces. The electric input near its fundamental resonance frequency is applied to the driving section in parallel and the output voltage from the generating section is connected to the resistor load. Its equivalent circuit is derived from the Mason\`s model. The frequency characteristics near the resonance frequency under no load have been investigated. Moreover, using this piezoelectric transformer we measured the LCD backlight characteristics.

• 전기의세계
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• v.27 no.3
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• pp.43-46
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• 1978

The prezoelectric ceramic specimen compoxed of PbO, ZrO$_{2}$, TiO$_{2}$ were prepared in this Lab, and showed properties of dielectric constant .epsilon.$^{33}$ /.epsilon.$_{0}$ 487 at 1kHz, electromechanical coefficient Kr 0.524. As the characteristics of piezoelectric HF filter used these piezoelectric specimen were the resonant point 6.7 MHz, effective bandwidth 690KHz, it was exellant. Since a LC resonant filter can be replaced bt this piezoelectric HG filter, it will greatly contribute to compose a compact circuit. If the resont point can be controlled, this piezoelectric HF filter practically.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.9
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• pp.736-743
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• 2001

Contour vibration mode piezoelectric transformers were designed and fabricated to the square plate with size of 27.5x27.5x2.6㎟ using PNW-PMN-PZT ceramics. Electrical characteristics of the piezoelectric transformer were investigated for fluorescent lap ballast application. The electrical properties and characteristic temperature rise were measured by oscilloscope and infrared temperature sensor. A 28W fluorescent lamp was successfully driven by the fabricated transformers. The electronic ballast using piezoelectric transformer showed an excellent output power of 28.85[W], efficiency of 86.3% and characteristic temperature rise of 15[$\^{C}$].

• Electrical & Electronic Materials
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• v.9 no.1
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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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.299-299
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• 2007

This paper presents an omni-directional piezoelectric actuator which utilizes only one actuator. The actuator has a simple structure of cone type consists of two piezoelectric ceramics of ring type and electrodes divided four segments and a stainless steel body. To find the optimal operating condition of the actuator, the frequency characteristics of the actuator are analyzed by ATILA, FEM and measured by Impedance Analyzer. We have also developed a stage using the omni-directional actuator and an actuator driver circuit to create four sinusoidal waves with a variable frequency and phase difference.

• Proceedings of the KIEE Conference
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• 2008.05a
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• pp.179-180
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• 2008

In this paper, the variable tendency piezoelectric constant and resonance characteristics piezoelectric ceramics due to the electric field is studied. The practical application of piezoelectric ceramics is not only applied in field of small signal. For example, in case of an ultrasonic motor, $120{\sim}130Vrms$ of driving voltage is needed and that of an piezoelectric pump, $200{\sim}220Vrms$ of voltage is required. Therefore, to examine the characteristics of piezoelectric ceramics in large signal contributes to reducing the susceptibility to the multifarious application and securing the ease of the production of control circuit. These contributions may be connected to the expansion of industrial application. We fabricated disk-type piezoelectric ceramic samples by using conventional method and measured the resonance characteristics of these samples under from low to high voltage driving conditions. According to increasing the value of the input voltage, we measured the resonance frequency of the piezoelectric ceramic, and inquired into the cause of these phenomena.

• Journal of Power System Engineering
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• v.13 no.3
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• pp.65-71
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• 2009

This paper presents the energy harvesting technique which is carried out by vibration system with a piezoelectric element. In this study, low frequency characteristics of the piezoelectric element bonded to the aluminum cantilever were experimentally investigated. The piezoelectric element of size of $45L{\times}11W{\times}0.6H$ and piezoelectric constant($d_{31}$ ) of $-180{\times}10^{-12}C/N$ was used. The material of cantilever is an aluminum and two kinds of cantilever of which dimensions are (150, 190)$[mm]{\times}13[mm]{\times}1.5[mm]$ were experimented, respectively. The cantilever was fixed on the magnetic type vibrator and the vibrator was operated by power input with a sine wave. The characteristics of requency and mass variation of cantilever end part such as 0, 2.22, 4.34, 5.87, 8.66, 11.01 [g] were investigated. Finally, this paper suggests a method of generating electrical energy with a piezoelectric element using wind, an energy source that is easily applied and from which we can obtain "clean" energy.

• Proceedings of the KIEE Conference
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• 1984.07a
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• pp.188-190
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• 1984

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.215-219
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• 2001

The resonators made of piezoelectric crystals such as a quartz crystal are widely used. Their frequency-temperature characteristics are of primary importance for their applications to the frequency control devices. The characteristics estimation is useful for determining their design parameters. In the present paper, several types of resonators are numerically analyzed. The numerical solutions are made using 3-D Finite Element Modeling, and the results are compared with the theoretical values whenever they are available. To demonstrate the validity of the present numerical approach, the application is made to the analysis of the plates with some well-established cutting angles. For the resonator stable with temperature change, the cutting angle is important in which the temperature coefficient of the first order is chosen to be zero. The rotated Y-cut plates in thickness-shear mode are considered. The equivalent circuit representation is often used fur describing the characteristics at the electrical terminals which enables the circuit analysis including the effect of temperature change by using the circuit simulators. The equivalent circuit parameters are obtained by fitting the admittance-frequency curve from the finite element analysis.