• Journal of IKEEE
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• v.22 no.3
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• pp.767-773
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• 2018

This paper proposes the simple structure LED-driving power converter with high power factor. As the proposed power converter combines the PFC boost converter and the conventional flyback converter into only one power conversion circuit, it simplifies the structure of LED-driving power converter. Thus the proposed converter is controlled using only one PWM controller IC, and it achieves high power factor, constant output voltage/current and cost-effectiveness. Therefore the proposed converter is suitable for the industry production and utilization of LED-light-system. In this paper, the operation analysis and design example of the proposed converter are explained, briefly. Also experimental results of the prototype that is implemented based on the designed circuit parameters are shown to validate operation characteristics of the proposed converter.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.3
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• pp.555-561
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• 2010

In this paper, the constant current controller is designed to regulate the driving current of a power LED. The controller design model of the power LED including its driving circuit is proposed to design the constant current controller. A buck converter is also introduced to drive the power LED. The PI-based digital controller is implemented to validate the proposed strategy for the power LED driving.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.2
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• pp.174-179
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• 2017

We designed the CMOS analog integrate and fire (I&F) neuron circuit for driving memristor based on resistive-switching random access memory (RRAM). And we fabricated the RRAM device that have $HfO_2$ switching layer using atomic layer deposition (ALD). The RRAM device has gradual set and reset characteristics. By spice modeling of the synaptic device, we performed circuit simulation of synaptic device and CMOS neuron circuit. The neuron circuit consists of a current mirror for spatial integration, a capacitor for temporal integration, two inverters for pulse generation, a refractory part, and finally a feedback part for learning of the RRAM. We emulated the spike-timing-dependent-plasticity (STDP) characteristic that is performed automatically by pre-synaptic pulse and feedback signal of the neuron circuit. By STDP characteristics, the synaptic weight, conductance of the RRAM, is changed without additional control circuit.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.3
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• pp.495-502
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• 2020

In this paper, a power management circuit was designed to drive the emergency lighting LED in the underground facility for public utilities using magnetic energy harvest. The magnetic energy harvest consists of a harvest elements and power management circuits. The proposed circuit was made of a rectifier, a battery charging circuit, and an LED driving circuit. In normal times, the battery is charged with the harvested power, and in the event of an emergency, the energy stored in the battery is used to drive the LED. As a result of the measurement, it took two minutes to charge the 47 mF capacitor. This is the amount of power that can drive an LED for emergency lighting for about three and a half minutes. Through this, it was confirmed that the power management circuit for magnetic energy harvest proposed in this paper can be used as an emergency lighting LED-driven power device in an underground facility for public utilities where it is difficult to draw separate power.

• Journal of Satellite, Information and Communications
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• v.8 no.4
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• pp.17-20
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• 2013

In this study, we introduce an LED Driving circuit in order that the information state can indicate audio signal gain and radiate pattern of ultrasonic speaker system for a sign board. Ultrasonic speaker system decreases energy loss and transmits the sound farther. Ultrasonic speaker having such characteristics is useful in that it can be widely used in daily life. Additionally, Proposed LED circuit indicates the information state as linear LED brightness taken from interface of ultrasonic speaker system. Designed circuit is confirmed through $0.35{\mu}m$ CMOS process by Dong-bu.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.5
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• pp.378-385
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• 2007

AC PDP has disadvantages that power consumption and sustain voltage are high. An energy recovery circuit for AC PDPs with reduced sustain voltage was proposed to solve these disadvantages. However, the circuit has disadvantage that the switching elements are performed hard switching at the start point of discharge and sustaining region. The reason is that the panel voltage is lower than sustain voltage at that point. In this paper, we propose the improved driving method that switching devices are operated with ZVS by using CIM(Current Infection Method) also at that point. CIM region is designed by theoretical circuit analysis. Finally, the validity of the proposed driving method is verified by the simulations and experimentation.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.2
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• pp.244-250
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• 1994

This paper presents the design of a new turn-off gate drive circuit for GTO which can accomplish faster turn-off switching. The major disadvantage of the conventional turn-off gate drive technique is that it has a difficulty in realizing high negative diS1GQT/dt because of VS1RGM(maximum reverse gate voltage) and stray inductances of turn-off gate drive circuit[1~2]. The new trun-off gate drive technique can overcome this problem by adding another turn-off gate drive circuit to the conventional turn-off gate drive circuit. Simulation and experimental results of the new turn-off gate drive circuit in conjunction with chopper circuit verify a faster turn-off switching performance.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.242-245
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• 2007

To improve the efficiency of PDP TV, it should minimize the power losses transpired during AC-to-DC power conversion and PDP driving process. Generally the input power supply for PDP driving employes a two-stage power factor corrected converter, and it independently consists of sustain driver, which has high power consumption. However, such a circuit configuration has a difficulty for the PDP market requires low cost. To alleviate this problem, a new circuit composition is presented. It integrates input power supply with sustain driver in a single power stack. The input power supply of the proposed circuit has a single-stage structure to minimize power conversion loss, and it directly supplies power to the sustain driver so as to reduce the system size and cost.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.8
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• pp.13-18
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• 2005

The variation of discharge characteristics of an ac PDP was observed with the charge of scan electrode driving circuit. Conventional scan electrode driving circuit provides two switches per one scan line, and the suggested one can be constituted by one switch per one scan line with the consideration of capacitive load characteristic of an ac PDP. To verify the workability of the suggested scheme, the performances of the ac PDP was investigated. The dynamic voltage margin was slightly decreased with the adoption of the suggested scheme, which is estimated to result from the misfiring of unselected discharge cells due to the deformation of voltage level of the neighboring scan electrode. In the observation of the delay characteristics of addressing discharge, the performances of the conventional circuit and the suggested one are assumed to be equivalent.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.9
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• pp.78-84
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• 2022

An air circuit breaker (ACB) is an electrical protection device that interrupts abnormal fault currents that result from overloads or short circuits in a low-voltage power distribution line. The ACB consists of a main circuit part for current flow, mechanism part for the opening and closing operation of movable conductors, and arc-extinguishing part for arc extinction during the breaking operation. The driving mechanism of the ACB is a spring energy charging type. The faster the contact opening speed of the movable conductors during the opening process, the better the breaking performance. However, there is a disadvantage that the durability of mechanism decreases in inverse proportion to the use of a spring capable of accumulating high energy to configure the breaking speed faster. Therefore, to simultaneously satisfy the breaking performance and mechanical endurance of the ACB, its driving mechanism must be optimized. In this study, a dynamic model of the ACB was developed using the MDO(Mechanism Dynamics Option) module of CREO, which is widely used in multibody dynamics analysis. To improve the opening velocity, the Taguchi design method was applied to optimize the design parameters of an ACB with many linkages. In addition, to evaluate the improvement in the operating characteristics, the simulation and experimental results were compared with the MDO model and improved prototype sample, respectively.