• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.4
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• pp.231-237
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• 2006

This paper proposes an effective drive of high intensity discharge (HID) lamp ballast for cars. All control functions of the proposed ballast are implemented using a low-cost single chip microcontroller, PIC16C73 to optimize the total system size and to minimize cost through minimization of total component number. The proposed ballast generates high open-circuit voltage to ignite the lamp and is controlled to supply effectively the power required to shorten warm-up period after the breakdown. The DC-DC converter of the DC-AC converter part of the ballast utilizes the flyback converter topology that can minimize component number. Also, because to more minimize the ballast size, the transformer size must be minimized, for this, PWM (Pulse Width Modulation) pulses are generated with high frequency using the PWM module of the microcontroller. An analysis for this is explained, briefly. As if the operation of the lamp and ballast arrives at steady-state, then the ballast must AC-control the lamp, for this, the microcontroller utilizes the other PWM module. And the part related to the igniter is explained, briefly. It is shown through experimental results that the controller of the proposed ballast has good performance for the HID lamp for cars.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.7
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• pp.100-106
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• 2005

Generally, high frequency switching DC-DC converter that DC power supply for discharge lamp drive to generate ultraviolet rays(UV) is acted by hard switching mode is used. Therefore in this paper, wish to mix first existent first-side status phase shift PWM DC-DC converter and posing secondary-side status phase shift PWM DC-DC converter by high frequency link DC-DC converter that use soft switching circuit technology and develop DC power supply for discharge lamp drive. DC power supply driving Discharge lamp proposed describe validity through simulation and an experiment.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.2
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• pp.235-240
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• 2010

In order to substitute incandescent lamps, a power supply device for 7W class LED lamps which are environmentally friendly and energy saving is designed LED lamps consist of a multitude of chip LED connected in parallel and series. 11ms it is necessary to supply LED lamps with DC voltage and current. However, when LED lamps are in use, they are connected directly to AC 220V. This is why we need to have AC/DC, DC/DC power converters including a control system of voltage and current. For this, a transformerless and simple LED lamp driver is designed 조ich can control the current and output voltage for LED string of LED lamp.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.53 no.4
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• pp.166-170
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• 2004

In this paper, it has been proposed the simultaneous control of PFC (power factor corrector) and electronic ballast for fluorescent lamp by one chip micro-controller. Boost DC-DC converter is adopted for PFC, and half bridge inverter for electronic ballast. It controls, simultaneously and independently, the boost DC-DC converter and the half bridge inverter. As PFC and electronic ballast are controlled by one chip micro-controller, it is possible to achieve the simpler and the cheaper controller for fluorescent lamp. Experimental results have shown the feasibility of the proposed simultaneous control of PFC and electronic ballast by one chip micro-controller.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.635-638
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• 1999

Manufacturing TGV-Korea, international standards and TGV-standards should be strictly applied in order to insure the normal operation and the safety of passengers in a train service. This paper presents a development of 800W DC-DC converter for the reading lamp of TGV-korea. The converter is designed for satisfying the regulations of international standards and TGV-standards regarding the burning-in test, the vibration test, the electro-magnetic emissions test, etc. As an experimental result, the maximum efficiency is obtained as 92.3[%] at normal input voltage and output power.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.3
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• pp.357-361
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• 2009

This study performed analysis on the thermal pattern and current characteristics of an LED ((Light Emitting Diode) street lamp. It did this using a TVS (Thermal Video System) to analyze the LED street lamp's thermal pattern, and measured its characteristics using an oscilloscope. The ambient temperature and humidity during the experiment were maintained at $24{\pm}2[^{\circ}C]$ and 50~60[%]. The capacity of the LED street lamp was 120[W] and nine sets of modules were arranged at uniform intervals. On one module, 24 LED lamps were arranged in a radial pattern. The analysis of the thermal diffusion pattern at the front of the LED lamp showed that the maximum surface temperature was approximately $34[^{\circ}C]$. In addition, there was almost no change in the temperature of the upper cover, and the temperature at the side showed a uniform thermal diffusion pattern. The surface temperature of the converter converting AC to DC increased to approximately $46[^{\circ}C]$. The analysis results of the thermal characteristics of one LED indicated uniform thermal characteristics for an initial eight minutes. However, the temperature at the center of the LED increased to approximately $82[^{\circ}C]$ after 12 minutes had elapsed. It can be seen from this that the temperature at the center of the LED was higher than the allowable temperature, $70[^{\circ}C]$ of the insulating material for general electrical devices. Therefore, it is necessary to design a lamp in such a way that the plastic insulating material does not come into contact with or get close to the LED lamp. The voltage of the LED lamp converted by the AC/DC converter was measured at DC 27[V] and the current was DC 13[A]. Consequently, it can be seen that in order to secure an adequate light source, it is important to supply a stable current that was greater than the current of other light sources. Therefore, appropriate radiation of heat is required to secure the stability and reliability of the system.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.11a
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• pp.131-133
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• 2007

In a design of DC ballast for fluorescent lamp, pre-stage of DC-DC converter is required to keep the constant output lumen performance regardless of variable DC input voltage. In this paper, flyback topology is used for optimum performance of 32W lamp, and various important design points for successful operation over the whole operating range are described.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.6
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• pp.27-34
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• 2010

This study is for the improvement in the equipment environment of the emergency and recovery lamps in electric substations. To solve problem about the weak illuminance of existing emergency lamps, the AC/DC combination lamps and switches are reviewed. And the improved illuminance standards that are divided each room's purpose are suggested. It is based on a nuclear power plant's Illuminance Standards and a safety lamp's Illuminance Standards of Illuminance Standards Korean Industrial Standards - KS A 3011 -, not just 5~10[%] in according with normal lamp's illuminance. Lastly, The experiments are conducted to prove the suggested contents on this study. Consequently, a battery capacity is not increased, but illuminance of emergency and recovery lamps can be increased.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.595-598
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• 1999

A new of the automotive High Intensity Discharge(HID) lamp ballast systems is proposed. Proposed scheme is consisted of the high frequency DC-DC converter and low frequency DC-AC inverter as same as conventional HID ballast system. But this system separates ignition voltage from dc link voltage, which results to used the lower voltage rating power devices for HID lamp ballast system compared with conventional system. As a result, proposed system has a lower cost and higher efficiency.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.253-256
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• 2002

This paper proposes the application of coreless PCB transformer to Half-Bridge (HB), Zero-voltage-Switched (ZVS) DC/DC converter for FPL lamp with electronic ballast in vehicle. The designed 5 coreless PCB transformers for ballast driving voltage are parallel-connected in primary windings and series-connected in secondary windings. Coreless PCB transformer is designed to have spiral winding in order to transfer higher energy. The computer simulations of the proposed power circuit show coreless PCB transformer to have good performance.