• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.3
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• pp.14-21
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• 2010

For the ubiquitous healthcare environment, real-time measurement of biomedical signals and accuracy of the measured biomedical information are very important. In addition, it is important to develop a healthcare device with low power In this paper, the synchronized pulse in a heartbeat was detected from the radial artery using the piezo film sensor, in order to eliminate inconvenience to wear a pulse detection finger probe. We can get a best output after applying the adaptive noise canceller using two piezo film sensor signals, pulse signal having motion artifacts and motion artifacts reference signal. To detect heartbeat, we use maximum point detection method from pulse removed motion artifacts.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.118-122
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• 2000

Recently, High accuracy and precision are required in various industrial field especially, semiconductor manufacturing apparatus, Ultra precision positioning apparatus, Information field and so on. Positioning technology is a very important one among them. For composition of this technology, the development of system with high speed and high resolution is needed. At start point and end position vibration must be repressed on this system for composition of position control. This vibration is arisen nose, is increased setting time, is reduced accuracy. Especially, repressed for the lead with high speed. The small actuator with high speed and high resolution is need to repression against this residual vibration. This actuator is, for example, piezo actuator, piezoelectric material that converting from electronic signal to mechanical force is adequate material, beacause of control of control to position and force. In this study, piezo electric material is used to actuator, ultra precision positioning apparatus with stage of hinge structure is designed, simulation is performed, control performance is tested by producing apparatus. For easy usage and stability in industrial field, we perform to simulation and to position control test by digital PID controller.

• Journal of the Korean Society of Safety
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• v.24 no.6
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• pp.50-54
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• 2009

Ionizer is used for improving manufacturing process and reducing inferior goods in the clean room. As a general rule, neutralization of the electrostatic charge is most important to make TFT-LCD, PDP and OLED. Pulse AC-static eliminator with output voltage of about 10.5kV has been used these days as neutralization device. But this device has a problem with lower performance which was caused by particles-adhesion on the electrode when it has been used for a long time. So we studied to solve the problem with lower performance using high Frequency(72kHz) static eliminator which was produced by Piezo transformer device, and compared Pulse-AC type with Piezo-electronic device such as decay time and ion balance for 10 weeks periods. As a result of this study, we found that Piezo transformer device has been maintained normal condition for 10 weeks. Also, we made the rule by this study, normally Piezo transformer device has to clean the electrode during every 11th weeks.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.65-69
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• 2000

The crimping connection is a permanent connection that maintains mechanical and electrical property for a long time by crimping two conductors. In this paper, we have done a basic study to make a decision the normal or abnormal condition depending on crimping. By using PZT piezo-sensor, we have compared and analyzed crimping waveforms of abnormal conditions(core ommiting, cover biting) at the normal crimping height. And hence the normal or abnormal condition of crimping connections in real time could be determined by comparison of crimping waveforms in the cases of normal crimping, core omitting and cover biting.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.279-279
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• 2009

$LiFePO_4$는 낮은 전기전도도로 인하여 전이금속의 도핑과 카본코팅으로 전기화학적 특성을 향상시키려는 연구가 많이 되어 왔다. 또한 다양한 합성법으로 $LiFePO_4$의 입자사이즈를 최적화 하기 위해 많은 연구가 진행중이다. 특히 고상 합성법은 결정의 미세화가 가능하고, 상온에서 쉽고 용이하게 원소간의 합금화 및 화학반응을 유도하는 등의 장점으로 인해 가장 널리 사용하고 있는 합성법중 하나이다. 이번 연구에서도 고상합성법을 사용하여 $LiFePO_4$를 합성했으며, 카본소스로서 카르복시산등의 유기산을 사용하여 코팅을 시도해 보았다. 이렇게 합성된 $LiFePO_4$의 물리적 측정을 통하여 입사의 형상 및 크기를 관찰하였고, 하프셀을 구성하여 전기화학적 특성을 확인하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.401-401
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• 2009

Recently, demands for the development of compact, lightweight power supplies with higher power density and higher efficiency have been increased. Since Piezoelectric Transformer (PT) was emerged in device and material industry, it has been suggested as a viable alternative to the magnetic transformer in some applications. PT has some advantages such as low profile and mechanical energy transfer with little electromagnetic interface (EMI). Also, PT can provide high voltage stepping ratio with good isolation and requires no copper windings saving copper usage especially for large voltage conversion differences. Conventional control of PT converter has mainly two-way. One is the pulse frequency modulation (PFM) control method and the other is the pulse width modulation (PWM) control with frequency fixed method. It is known that the maximum PT efficiency can be obtained when it operates near the resonant frequency of the PT. And, also PT's resonant frequency moves according to the load condition. Therefore, selection of PT converter control method is very difficult. This paper analyzes general piezo-electric converter modeling and proposes a guide-line to selection of control method and stabilization control.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.671-674
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• 2004

This paper presents design and analysis of multi-layered ring-dot type piezoelectric transformer. These transformers are useful for step up and step down. The transformers consist of disk type multi-layered piezoelectric ceramic plates. The finite element method(FEM) was used for analysis transformer. Vibration mode, electric field and equivalent elastic strain of piezoelectric transformer were simulated by changing frequency. As results, the strain was distributed in isolation part entirely. We can get the operated in step up transformer when the inner side electrode using by input parts. Also we can get the step down transformers using by input Part as outer side electrode. The step up ratio and step down ratio was increased by decreasing inner side electrode. The resonance frequency was increased by increasing inner side electrode when the transformer was operated in step down transformer. But the step up one was decreased. From these results, we can expect to multi-layered ring-dot type piezo transformers as step up and step down transformers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.414-417
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• 2001

Recently, developments of device using characteristics of ceramics as a new technical material is in progress. While doing so, Ultrasonic motor which is a part of research & development of piezo-actuator by piezo-effects is being used in the various applications. So, we fabricated a flat-type $L_{1}-B_{8}$ mode Ultrasonic motor and measured the operation characteristics of its. The size of USM is 80*20*1.5[$mm^{3}$](length*width*thickness) and is constructed with stator by piezo-ceramics and stainless elastic body and rotator by bearings. As results of experiments, the fastest speed of revolution(v), the maximum torque(T) and the efficiency( $\eta$ ) were 37.5[cm/sec], 5.0[ $mN{\cdot}m$ ] and 1.17[%] respectively when 27.9[kHz], 150[gf], 50[V] were applied. So, we think this $flat-type_{1}-B_{8}$ mode Ultrasonic motor is able to be used for applications in forwarding device of a paper or electric card and so on.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.340-343
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• 2003

This paper presents characteristics of piezo transformer for AC-DC converter. This transformer uses transverse vibration mode and the origin of the structure was the ring dot type transformer. Because, the ring dot type transformers produce only step-up phenomenon, we made a multi-layered ring dot structure for a step-down output. The characteristics of the transformer were simulated by using the ANSYS. And frequency and voltage were measured by changing the load resistance and current. Frequencies that have the maximum output voltage and current were gradually increased, when the resistance were increased. Output voltage and current show a stable linearity according to the input voltage. The maximum output power was expected greater than 20 [W]. So, we expect that this type of multi-layered step-down ring dot transformer can be adopted for a small AC adapters.

• Nuclear Engineering and Technology
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• v.55 no.8
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• pp.3114-3120
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• 2023

A high-accuracy magnetic field measurement device based on a cyclotron is being developed for accelerator mass spectrometry (AMS). In this study, a magnetic field measurement device consisting of a Hall probe sensor, piezo-motor, and step motor was developed to measure the magnetic field of the AMS cyclotron magnet. The Hall probe sensor was calibrated to achieve positional accuracy by using polar coordinates. The measurement results between the ratchet gear and piezo-motor, which are the instruments used for driving the measurement device, were analyzed. The measurement result of the device with a piezo-motor exhibits a difference of 5 Gauss (0.04%) as compared with the simulation result.