• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.9
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• pp.1733-1740
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• 2011

In this research, a MEMS vibratory gyroscope with dual-mass system in the sensing mode has been proposed to increase the stability of the device using wide bandwidth. A wide flat region between the two resonance peaks of the dual-mass system removes the need for a frequency matching typically required for single mass vibratory gyroscopes. Bandwidth, mass ratio, spring constant, and frequency response of the dual-mass system have been analyzed with MATLAB and ANSYS simulation. Designed first and second peaks of sensing mode are 5,917 and 8,210Hz, respectively. Driving mode resonance frequency of 7,180Hz was located in the flat region between the two resonance peaks of the sensing mode. The device is fabricated with anodically bonded silicon-on-glass substrate. The chip size is 6mm x 6mm and the thickness of the silicon device layer is $50{\mu}m$. Despite the driving mode resonance frequency decrease of 2.8kHz and frequency shift of 176Hz from the sensing mode due to fabrication imperfections, measured driving frequency was located within the bandwidth of sensing part, which validates the utilized dual-mass concept. Measured bandwidth was 768Hz. Sensitivity calculated with measured displacement of driving and sensing parts was 22.4aF/deg/sec. Measured slope of the sensing point was 0.008dB/Hz.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.8
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• pp.1095-1100
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• 2013

Piezo devices have large power density and simple structure compared with conventional electrical motors. Thus they can generate larger forces than the conventional actuators with small size. Their resopnses to commands are also very fast and thus the bandwidths are very wide. Thus the piezo devices are expected to be used widely in the future for actuating devices requiring fast response and large actuating force with small size. However, the piezo actuators need high voltage with high driving current due to their large capacitive property. In this paper, proposed is a simple method to drive piezo devices using voltage inversion circuit with coli inductance. The coil inductance carries the charges in the piezo device to the opposite side, inverting the polarity of the applied voltage, thus saving the power to drive the device with AC voltages. Experiments with real circuit demonstrates that the proposed scheme can improve the energy efficiency very much.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.511-514
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• 2011

Recently, devices such as smartphone and vehicle blackbox and EDR(Evern Data Recorder knowed automotive real-time control and driving data to use OBD-2(in-vehicle network). when devices receive vehicle driving data, communication way use each Wifi, Bluetooth. but if user and driver change device to use OBD-2 connect, the device differ communication network way. and driver buy and change OBD-2 connect. In this paper, to remedy one's shortcomings, there integrate Bluetooth and Wifi network module and design integrability hardware as any another device know vehicle real-time control and driving data with one integrability connect.

• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.29-31
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• 2008

Recent years have witnessed that the Korean government prompts the 'Power IT' enterprise to combine electric Power industry with information technology (IT). Especially, in a move to shore up the distribution automation system, the necessity for remote control of molded case circuit breaker (MCCB) is getting more and more important. In this paper, we aimed to propose a remote-controlled MCCB of which the driving device is substituted to electrical equipment for mechanical parts. Driving device of MCCB was designed with the Electromagnetic Force driving Actuator (EMFA). Electromagnetic force and dynamic characteristics of the designed EMFA are analyzed using 2-D finite element method (FEM).

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.4
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• pp.24-29
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• 2020

Measuring the torque of the wheel loader of a driving device is a preemptive task to ensure its performance. In this study, wireless torque measurements were successfully conducted. Moreover, based on the experimental results and the adopted design method, the key factor of torque generation, which is the main load in driving devices, was analyzed. Other data not analyzed in this paper will be the basis for the logical design of wheel loader-based driving devices.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.12
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• pp.1843-1847
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• 2012

Piezo devices have large power density and simple structure. They can generate larger force than the conventional actuators. It has also wide bandwidth with fast response in a compact size. Thus the piezo devices are expected to be used widely in the future for small actuators with fast response time and large actuating force. However, the piezo actuators need high voltage with high driving current due to their large capacitive property. In this paper, we propose a simple method to drive piezo devices using voltage inversion circuit with coil inductance. Experiments with real circuit demonstrates that the proposed scheme can improve the energy efficiency very much.

• Journal of Power System Engineering
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• v.10 no.4
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• pp.11-16
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• 2006

This research is to verify the cooling effect of the acting surface on the rotary motor using heat pipe and conventional cooling fan. In order to show the cooling performance of the rotary motor and heat pipe with the fin-typed heat sink, the surface temperature of the motor and condenser was measured in real time. The experiments were also conducted as for not only cooling device installed with heat pipe only, but with heat pipe and conventional cooling fan simultaneously. The present experiment reveals that the cooling combination of the heat pipe and cooling fan is far superior to the conventional cooling device for the driving motor such as the fin-typed heat sink. When the driving voltage of 20V and 14V were supplied to the driving motor, the cooling performance of the rotary motor with heat pipe was 170% and 500%, respectively better than that without heat pipe on steady state condition.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.1
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• pp.48-52
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• 2012

The charged particle type display device is a kind of the reflectivity type display and shows an image by absorption and reflection of external light source. The charged particle is important factor for driving of the display and quantity of charge per mass of the charged particle determines the driving voltage, contrast ratio, response time, etc. But it is easy for the charged particles to be damaged in the putting process of the display and the damages cause lumping phenomenon of the charged particles. Because the lumping phenomenon makes high driving voltage, low quality of optical properties, short life time, etc, so the charged particles must be filled by stable putting methods. In this paper, we filled the charged particles into the panels by electric fields to improve the electrical and optical characteristics of the display. Also, we analyzed the driving characteristics of the charged particles according to the applied putting voltages.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.258-260
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• 2017

Smart mobility is rapidly emerging as a next-generation eco-friendly transportation system, and the market is booming every year. However, due to the characteristics of the devices that use electricity as the power source, the motor and the battery are different from the performance and actual performance indicated by the manufacturer depending on the user's weight and driving environment. Therefore, The frequency of the overload is increased and the failure and damage of the device are increasing. In this paper, we propose an application that provides personalized recommended driving guidance and overloaded driving situation notification at the actual driving separately from the recommended driving provided by the manufacturer after measuring the driving environment of the user, so as to prevent malfunction and damage of the smart mobility device, To ensure safety.

• Proceedings of the KIEE Conference
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• 2007.11a
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• pp.154-155
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• 2007

This paper describes frequency response of two-mass system for gyroscope applications. The two-mass system of the proposed device is adapted to the sensing part of the gyroscope in this research. Two-mass system has two resonant peaks and wide flat region between two resonant peaks. The resonant frequency of driving part is in this flat region. Therefore, frequency tuning is not necessary for mode matching. In the proposed device, resonant frequency is designed as 7183 Hz in driving part. Mass ratio of two masses in sensing part is 0.1 and device size is 6 mm $\times$ 6 mm. The device is fabricated by SiOG process. The fabricated spring width is increased from $4{\mu}m$ to $4.5{\sim}4.7{\mu}m$, and the measured resonant frequency is 8392 Hz in driving mode. We operated the sensing part using parallel plate of proof mass to verify the sensing part. It is confirmed the device has a wide fiat region in frequency response curve and the resonant frequency of the driving part is in the wide flat region of sensing mode.