• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.7
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• pp.1055-1061
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• 2002

This paper deals with a design and fabrication of an electronic ballast for 70[W] ceramic discharge metal halide lamps. The proposed ballast is composed of a rectifier, an active power factor correction circuit (PFC), a half-bridge inverter, a LC resonant circuit and a microprocessor. The developed ballast also includes a specially designed time circuit which provides reignition signal of lamps. Running frequency of the ballast is .jet at 40[kHz] to avoid acoustic-resonance and flickering. From the experimental results, input power factor and efficiency of the ballast are estimated 99.8[%] and 93.1[%], respectively.

• Journal of Magnetics
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• v.17 no.1
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• pp.27-32
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• 2012

Transcranial magnetic stimulation requires an electric field composed of dozens of V/m to achieve stimulation. The stimulation system is composed of a stimulation coil to form the electric field by charging and discharging a capacitor in order to save energy, thus requiring high-pressure kV. In particular, it is charged and discharged in capacitor to discharge through stimulation coil within a short period of time (hundreds of seconds) to generate current of numerous kA. A pulse-type magnetic field is formed, and eddy currents within the human body are triggered to achieve stimulation. Numerous pulse forms must be generated to initiate eddy currents for stimulating nerves. This study achieved high internal pressure, a high number of repetitions, and rapid switching of elements, and it implemented numerous control techniques via introduction of the half-bridge parallel load method. In addition it applied a quick, accurate, high-efficiency charge/discharge method for transcranial magnetic stimulation to substitute an inexpensive, readily available, commercial frequency condenser for a previously used, expensive, high-frequency condenser. Furthermore, the pulse repetition rate was altered to control energy density, and grafts compact, one-chip processor with simulation to stably control circuit motion and conduct research on motion and output characteristics.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.4
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• pp.108-112
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• 2017

High-intensity-discharge lamps are widely utilized in outdoor and indoor lighting circumstances that need high luminance. In lighting applications for MHD lamps, the size of the lamp ballast circuit is an important factor and should be as small as possible. The electronic ballast for MHD lamps is superior to the electromagnetic(EM) ballast in that it saves energy, and has smaller volume and lighter weight. In this paper, highly efficient cost-effective and small sized electronic ballast for Metal Halide Lamp with high power factor using Digital Signal Processor are proposed. The proposed electronic ballast for MHD lamps combines a boost PFC converter with a half-bridge inverter, the algorithms of the power factor correction and ballast control were implemented using the TI's TMS320LF2406 CPU. Experimental results validate the ballast is also useful and reasonably suggested.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.12
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• pp.58-65
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• 2009

In this paper, we designed high voltage gate drive IC including dead time circuit in which capacitors controlled rising time and falling time, and schimitt-triggers controlled switching voltage. Designed High voltage gate drive IC improves an efficiency of half-bridge converter by decreasing dead time variation against temperature and has variable dead time by the capacitor value. and its power dissipation, which is generated on high side part level shifter, has decreased 52 percent by short pulse generation circuit, and UVLO circuit is designed to prevent false-operation. We simulated by using Spectre of Cadence to verify the proposed circuit and fabricated in a 1.0um process.

• Journal of Advanced Navigation Technology
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• v.24 no.6
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• pp.566-572
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• 2020

In a wireless power transmitter, the characteristics and effects of wireless power transmission between two induction coils are investigated, and a power converter circuit and a battery charger/discharger circuit using wireless power transmission technology are proposed. The advantage of wireless power transmitters and wireless chargers is that, instead of the existing plug-in-mounted wired charger (OBC; on-board charger), the user can wirelessly charge the battery without connecting the power source when charging power to the battery. There is. In addition, the advantage of wireless charging can bring about an energy efficiency improvement effect by using the secondary side rectifier circuit and the receiving coil, but the large-capacity long-distance wireless charging method has a limitation on the transmission distance, so many studies are currently being conducted. The purpose of the study is to study the transmitter circuit and receiver circuit of a wireless power transmission device using a primary coil, a secondary coil, and a half bridge series resonance converter, which can transmit power of a non-contact type power transmitter. As a result, a new topology was applied to improve the power transmission distance of the wireless charging system, and through an experiment according to each distance, the maximum efficiency (95.8%) was confirmed at an output of 3 kW at an 8 cm transmission distance.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2091-2094
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• 1997

A half-bridge ZVS-PWM converter with complementary switch is described in this paper. Zero Voltage Switching is analyzed taking into account the effect of the leakage inductor of transformer. The main advantages of this converter, that are high efficiency for low output voltage, soft-switching for primary and very small pulsation for DC motor, are shown in a simulation.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.114-118
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• 1999

This paper shows a structure for an electronic ballast of HID lamps. An electronic ballast for HID lamps usually employs a high-frequency resonant inverter and voltage-to-frequency converter to control the output. A half-bridge and series resonant circuit are chosen for the ballast. The inverter with V/F converter is modeled with a transfer function and a self-feedback controller is proposed. This structure is analyzed and the feedback gain is determined by using the inverter model. Experimental system is built with a commercial 250W high pressure sodium lamp and the results show a validity of the proposed ballast.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.713-718
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• 1998

Due to high power ratings and low conduction loss, the IGBT has become more attractive in high power applications. However, its slower characteristics than those of MOSFET cause severe switching losses and switching frequency limitation. This paper proposes the IGBT's soft switching concept with the help of MOSFET, where each of the IGBT and MOSFET plays its role during on-periods and switching instants. Also, the switching losses are analyzed by using the linearized modeling and the modeling and the operations of a converter are investigated to confirm the soft switching of IGBT's.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.395-398
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• 2002

This paper presents generalized small-signal models for complementary driven double-ended isolated converters. The proposed small-signal models include the effect of the parasitic resistances, which have dominant influence on the damping of the secondary Power stage double-pole. To confirm the validity of the new models, an asymmetrical half-bridge converter with confer-taped rectifier and a forward-flyback converter with current doubler rectifier were built, and their performance were compared with the theoretical prediction.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.133-134
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• 2010

전자전기 제품의 수요가 증가하면서 다양한 전원회로들이 개발되고 있다. 특히 높은 전력밀도와 제작 단가 절감을 위해서 다 출력 컨버터의 개발 연구가 진행되고 있다. 본 논문은 3.3V와 5V 두 가지 출력을 가지는 비대칭 하프브리지 플라이백 컨버터를 제안한다. 제어기 하나를 통해 추가적인 제이기술 없이 간단한 방법으로 출력 전압을 제어하였으며, 다 출력 컨버터에서 문제가 되는 cross regulation 성능을 향상 시켰다. 제안된 다 출력 컨버터는 3.3V/16A, 5V/12A 출력 용량의 시제품 제작을 통해 성능을 검증하였다.