• Journal of Industrial Technology
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• v.35
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• pp.41-45
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• 2015

This paper presents a development of the ELB (Electronic Leakage Breaker) based on a reduction of standby power dissipation as with maintaining conventional performance. In order to minimize the standby power consumption of the conventional circuit, we analyze the cause of 0.3W dissipation of the circuit. By employing the TR-triggered circuit to secure the standby power of 0.10W after testing and evaluation while CRD inserted circuit showed the performance of 0.17W levels. Implementing SMPS IC and TNR device circuit was designed and showed of its power to less than 0.06W. Developed ELB is expected much standby power savings in large power distributor or heavy users.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.15-16
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• 2007

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.2
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• pp.181-188
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• 2005

In this paper, a DC smoothing filterless soft switching pulse modulated high frequency AC power conversion circuit connected to utility. frequency AC power source is proposed for consumer induction heating hot water producer, steamer and super heated steamer. The operating principle of DC link filterless utility frequency AC-high frequency AC (HF AC) power conversion circuit defined as high frequency cycloinverter is described, which can operate under a principle of ZVS/AVT and power regulation based on alternate asymmetrical PWM in synchronization with the utility frequency single phase AC positive or negative half wave voltage. The dual mode modulation control scheme based on high frequency PWM and commercial frequency AC voltage PDM for the proposed high frequency cycloinverter are discussed to enlarge its soft switching commutation operating range for wide HF AC power regulation. This high frequency cycloinverter is developed for high frequency IH Dual Packs Heater (DPH) type boiler used in consumer and industrial fluid pipeline systems. Based on the experiment and simulation results, this high frequency cycloinverter is proved to be suitable for the consumer use IH-DPH boiler and hot water producers. The cycloinverter power regulation and power conversion efficiency characteristics are evaluated and discussed.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.134-139
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• 2005

This paper presents a cost effective quasi-resonant soft-switching PWM high frequency inverter with minimum circuit components. This inverter can achieve wider soft commutation, simpler power circuit configuration, smaller volumetric size, lower cost and wider power regulation range, higher-efficiency as compared with single ended quasi-resonant ZVS-PFM inverter and active voltage clamped quasi-resonant ZVS-PWM inverter. The operation principle of the proposed inverter is described on the basis of the simulation and experimental results, together with its operating performances in steady state. The operating performances of this unique proposed high frequency inverter based on ZVS and ZCS arms-related soft commutation principle is evaluated and discussed as compared with the active voltage-clamped ZVS-PWM inverter and a conventional single-ended ZVS-PFM inverter. The practical effectiveness of a novel type quasi-resonant soft-switching PWM high frequency inverter using IGBT is actually proved for consumer induction heated appliances as rice cooker, hot water producer, steamer and super heated steamer. The extended bidirectional circuit topology of quasi-resonant PWM high frequency inverter with minimum circuit components is demonstrated, which operate as the direct frequency changer.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1364-1367
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• 2005

In this paper, a novel prototype topology of soft switching PWM controlled high frequency AC power conversion circuit without DC voltage smoothing chemical capacitor filter link from the voltage grid of utility frequency AC power supply source with 60Hz-100V or 60Hz-200V is proposed and introduced for innovative consumer induction heating(IH) boiler applications as hot water producer, steamer and super heated vapor steamer.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.5
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• pp.605-614
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• 2016

We develop a novel SAD circuit for power-efficient H.264 encoding, namely a-SAD. Here, some highest-order MSB's are approximated to single MSB. Our theoretical estimations show that our proposed design simultaneously improves performance and power of SAD circuit, achieving good power efficiency. We decide that the optimal number of approximated MSB's is four under 8-bit YUV-420 format, the largest number not to affect video quality and compression-rate in our video experiments. In logic simulations, our a-SAD circuit shows at least 9.3% smaller critical-path delay compared to existing SAD circuits. We compare power dissipation under iso-throughput scenario, where our a-SAD circuit obtains at least 11.6% power saving compared to other designs. We perform same simulations under two- and three-stage pipelined architecture. Here, our a-SAD circuit delivers significant performance (by 13%) and power (by 17% and 15.8% for two and three stages respectively) improvements.

• Journal of the Korean Society of Safety
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• v.28 no.3
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• pp.51-55
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• 2013

The purpose of this study is to find the causes of malfunctions and defective operation of printed circuit boards(PCBs) built into home refrigerators to perform power saving functions. This study performed an electrostatic test of a PCB built-in using an Auto Triggering system; lightning and impulse tests using an LSS-15AX; and an impulse test using an INS-400AX. From the analysis of a secondarily developed product, it was found that electrostatic discharge(ESD) caused more malfunctions and defective operations than electric overstress(EOS) due to overvoltage. As a result of increasing the condenser capacity of the PCB circuit, withstanding voltage was increased to 7.4 kV. In addition, this study changed the power saving mode and connected a varistor to the #2 pin of an IC chip. As a result, the system consisting of all specimens of a finally developed product was operated stably with an applied voltage of less than 10 kV. This study found it necessary to perform quality control at the manufacturing stage in order to reduce the occurrence of electrostatic accidents to IC chips built into a PCB.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.387-390
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• 2006

This paper presents a novel soft-switching PWM utility frequency AC to high frequency AC power conversion circuit Incorporating boost-half-bridge inverter topology, which is more suitable and acceptable for cost effective consumer induction heating applications. The operating principle and the operation modes are presented using the switching mode and the operating voltage and current waveforms. The performances of this high-frequency inverter using the latest IGBTs are illustrated, which includes high frequency power regulation and actual efficiency characteristics based on zero voltage soft switching (ZVS) operation ranges and the power dissipation as compared with those of the previously developed high-frequency inverter. In addition, a dual mode control scheme of this high frequency inverter based on asymmetrical pulse width modulation (PWM) and pulse density modulation (PDM) control scheme is discussed in this paper in order to extend the soft switching operation ranges and to improve the power conversion efficiency at the low power settings. The power converter practical effectiveness is substantially proved based on experimental results from practical design example.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.838-841
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• 2012

To avoid the damage to circuit and performance degradation by temperature changes, temperature sensing circuit applicable to the IC is proposed in this paper. Temperature sensing is executed by PTAT circuit and power saving mode is activated by internal switch if internal temperature is in high. Also, characteristics of current matching are increased by using current mirror and cascode circuits. From the simulation results, this circuit is operating in action mode if input signal is in low. But it immediately goes into power saving mode if output signal is in high. It shows the output voltage of 1V at $75^{\circ}C$ and 1.75V at $125^{\circ}C$ in action mode and near 0 V(0V~ 7uV) in power saving mode.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.61 no.1
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• pp.18-22
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• 2012

In this paper, we propose a sensor-based LED lighting system that can significantly reduce standby powers. The proposed LED lighting system has the more advanced power circuit and control mechanism compared to existing one. The whole power circuit consists of two subcircuits. One is designed to apply electric powers to controller, PIR(Pyroelectric Infrared Ray) sensor and CdS, and the other one is designed to apply electric powers to LED module. Such a power circuit configuration makes the standby powers reduction of LED lighting system possible. From the experimental results, we confirmed that the standby powers saving performance of the developed power circuit is superior to that of the conventional one.