• Proceedings of the KIEE Conference
• /
• 1995.11a
• /
• pp.169-171
• /
• 1995

Automatic control equipment in hydro power plant, such as turbine governor or automatic voltage regulator have to act promptly against for variation of power system, so it is necessary to check and test continuously. During last five years, the performance test of automatic control equipment was performed about 20 units of hydro turbine generator. In this process, because it has complex connection and before calibration, signal conditioner was developed as an auxiliary equipment for performance test. It includes function of signal amplifier, transducer, and meters. As a result of use this equipment for electric governor test at soyang-gang hydro power plant, it was possible to find output data equal to old one.

• Journal of Internet of Things and Convergence
• /
• v.7 no.4
• /
• pp.1-7
• /
• 2021

Recently, technological differentiation(sensor, AI) of products using IoT technology to satisfy consumer needs in the mature market for smart home appliances has received a lot of positive responses. However, air conditioner products are in the early stages of convergence technology. Therefore, air conditioner products are fields that require ICT technologies for information production, collection, processing, storage, and service development beyond IoT. In this paper, we collect and store contactless bio-signal using IR-UWB radar technology. The blowing direction of the air conditioning is controlled according to bio-signal and user's sleep is monitored to provide an optimal sleep environment. In addition, we propose a service algorithm that can provide comfort with changes in the optimal conditions of air conditioning and emotional lighting depending on the discomfort index environment. Through this study, we developed an intelligent smart air conditioning service platform with ICT technology of bio-signal, discomfort index, and emotional lighting.

• Proceedings of the Korean Nuclear Society Conference
• /
• 2005.10a
• /
• pp.1071-1072
• /
• 2005

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.6
• /
• pp.1061-1068
• /
• 2017

A RVDT is a sensor that measures angular displacement and the output signal of RVDT is a DSBSC-AM signal. For this reason, a DSBSC-AM demodulation processor is required to determine the angular displacement from the output signal. In this paper, DADC(Digital Angle to DC) which extracts the angular displacement from the output signal of a RVDT is implemented based-on modified Costas Loop usually used in the demodulation of DSBSC-AM signal by using FPGA. DADC can used with both 4-wire and 5-wire RVDTs and can exactly compensate the phase difference between the input excitation and output signals of a RVDT unlike the conventional analog RVDT signal conditioners which require external components. Since digital signal processing technique that can enhance the linearity is exploited, DADC shows 0.035% linearity error, which is smaller than 0.005% that of a conventional analog signal conditioner. The DADC are tested in an integrated experimental environment which includes a commercial RVDT sensor, ADC and an analog output block.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.5B no.4
• /
• pp.374-381
• /
• 2005

The ability to provide quality power has become a significant issue in power systems. The main causes of poor power quality are harmonic currents, poor power factor, supply-voltage variations, etc. A technique of achieving both active current distortion compensation, power factor correction and also mitigating the supply-voltage variation (sag or swell) at the load side is presented in this paper. The operation and rating issues of the proposed Single-phase Unified Power Quality Conditioner are also highlighted. To reduce the total cost while simultaneously increasing the performance, the system is fully digitally controlled using the fixed-point TMS320F240 digital signal processor. The performances of the UPQC, which is composed by shunt and series PWM controlled-converters, have been verified on a laboratory prototype.

• Journal of the Korea Convergence Society
• /
• v.12 no.9
• /
• pp.31-37
• /
• 2021

Recently, in the market of home appliances, the technical differentiation of products using convergence technology has been receiving a lot of response to satisfy consumer demand. However, air-conditioner products are an area that requires research and development in the early stages of convergence technology. In this paper, it is developed that a non-contact bio-signal(respiration, movement) collection technology using IR-UWB(Impulse-Radio Ultra Wideband) technology, which controls the air-conditioner direction according to the user's location and also monitors sleep to provide an optimal sleep environment. In addition, emotional lighting and ASMR are developed to provide a comfortable and emotional place of life. Finally, based on the developed convergence technology, we develop intelligent smart air-conditioning services for the convenience of daily life and a comfortable resting space.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.32 no.9
• /
• pp.305-314
• /
• 1983

This paper presents a general purpose data acquisition system based on the microprocessor system with M 6800. instrument and lograrithmic amplifiers and A/D converters are used to implement a signal conditioner for a various kinds of signals. The proposed system has a function such that the processor may select the one of the input signals as will and also it is proved that the system may control the control signal and digital converted signal through I/O port of PIA. Practical measurement by the proposed system shows in good results.

• Journal of Biosystems Engineering
• /
• v.14 no.4
• /
• pp.221-228
• /
• 1989

A data acquisition system was designed to measure the forces on a rolling coulter in three coordinated directions, angular velocity of the coulter and travel speed of a soil bin. The data acquisition system consisted of a dynamometer, speed transducers, a signal conditioner, an inter-face board, an Aim-65 microcomputer and a digital data recorder. Strain gages were attached on the surface of the dynamometer and connected to form three Wheatstone bridges, which measure the draft force, the vertical force and the side force on the coulter. An interaction among three dimensional forces was found during the calibration. A matrix procedure was used to correct the forces for this interaction. Rotary shaft encoders were mounted on the coulter and on the soil bin drive to measure the angular velocity of the coulter and the travel speed of the soil bin. The angular velocity and the travel speed were computed by counting the number of pulse signals from the rotary shaft encoders every 0.2 second. The digital signals from the rotary shaft encoders were connected to counters and the analog signals from the dynamometer, after passing through the signal conditioner, were connected to the A/D converter. The microcomputer programs, written in assembly language, were developed to read signals from the transducers, convert them to actual unit, display them upon request and record them on a sigital tape every 0.2 second.

• Journal of Power System Engineering
• /
• v.18 no.1
• /
• pp.32-37
• /
• 2014

In this study, the optimum design process of an indoor package air-conditioner (PAC) was implemented by Taguchi method. The goal of this study is to obtain the best set condition of each control factor composing of an indoor PAC. The number of revolution of a double inlet sirocco fan installed in an indoor PAC was measured by the orthogonal array of $L_{18}(2^3{\times}3^4)$ and analysed by using the-smaller- the-better characteristic among the static characteristic analyses. As a result, the optimum condition of an indoor PAC was found as a set of when the cost of production, assembling and working conditions were considered. Moreover, the number of revolution of a double-inlet sirocco fan used for an optimum condition was reduced about 8.5% more than that of a standard condition for the target flowrate of $18.5m^3/min$.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.20 no.12
• /
• pp.808-813
• /
• 2008

The study was to evaluate the air-conditioning of sleep algorithm. The algorithm was developed through the analysis of brain waves and MST, the experiments using air conditioner was performed in a apartment bedroom. Five female subjects were participated for the experiment. Eight hours of data collection a day was performed under different algorithm, case A, case B and case C. Physiological signals, EEG, ECG, EOG, and EMG, were obtained using polygraph and converted into digital signal. Then, subjects were asked to answer the questionnaire about their thermal sensation after experiment in bedroom. Sleep stages were classified, then TST, Sleep latency and Sleep efficiency were calculated for the three different air conditioner algorithm. As results, TST, Sleep efficiency, questionnaire showed the higher values for Case B algorism than that for other algorism. On the other hand, SWS latency was lower than for other conditions. Therefore, it was concluded that Case B of the algorithm was the best for comfortable and deep sleep.