• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.319-322
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• 2002

In this Paper, we suggested the Half-Bridge inverter for the automotive HID electronic ballast. electronic ballast for automotive HID lamp should be supplied by low-frequency square wave avoiding the acoustic resonance(11kHz ∼ 825kHz). When the HID lamp is hot state, the electronic ballast should supply the sufficient current for a few milli-second to the lamp at the re-strike ignition state. that is called take-over current. We have introduced the new take-over current control method that could have reduced the peak current and supplied the sufficient take-over current.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.527-530
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• 2001

In this paper, the basic characteristics of flat fluorescent lamp using ultraviolet generate from gas discharge and powder type electrolyminescent display(P-ELD) using a phenomenon of the light emission eaused by the electrical field applied to phosphor are studied. The lamp is a simple structure with insulator layer, phosphor layer, and gas gap. Current(displacement current + discharge current) in flat fluorescent lamp using.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1792-1794
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• 2001

In this paper, the basic characteristics of flat fluorescent lamp using ultraviolet generated from gas discharge and powder type electro luminescent display using a phenomenon of the light emission caused by the electrical field applied to phosphor are studied. The lamp is a simple structure with insulator layer, phosphor layer, and gas gap. Current(displacement current + discharge current) in flat fluorescent lamp using.

• 전기의세계
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• v.31 no.3
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• pp.197-203
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• 1982

The effects on the characteristics of 20-W fluorescent lamp were studied when applying magnetic field to its positive column. First, when the direction of the magnetic field is axial, i.e., along the lamp, if the magnitude of the field is stronger than the critical field, lamp voltage is increased, lamp current decreased, luminous flux increased, starting voltage decreased, as increasing the applied magnetic field. At the magnetic flux density is 130 gauss, luminous flux is increased to about 6 percents and starting voltage is increased to about 45 percents. Second, when the direction of the magnetic field is transverse to the lamp axis, as increasing the applied magnetic field, lamp voltage is increased, lamp current decreased, luminous flux increased and starting voltage is nearly constant, but the rates of increase or decrease of this case is different from those of the first. At the magnetic flux density is 300 gauss, luminous flux is increased about 45 percents. In both cases, electric power dissipated by lamps is the same as that of the lamp which magnetic field is not applied to.

• Proceedings of the KAIS Fall Conference
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• 2008.11a
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• pp.160-163
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• 2008

This study developed selecting equipment for damage of street lamp circuit used by current transform and diode. To develop this system, current check used current transform and indication system used LED device. As faulted, current of street lamp circuit change with fault decivce. This chage of current detected and indicated by selecting equipment

• 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.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.4
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• pp.262-267
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• 2014

This study describes that light flicker of LED lamp is improved by placing an AC-powered LED block in each phase of three-phase AC power. Rectified current is considered as an instantaneous luminous flux because the current flowing through the LED block is proportional to the amount of light emitted by the LED block. Percent flicker is calculated simply by modeling the rectified current flowing through the LED block to a triangular wave current. Percent flicker is 100% in single-phase AC powered LED lamp. Percent flicker of the same level as that in an incandescent lamp (6%~14%) is however, achieved if light emission starts before $40^{\circ}$ in each voltage phase of three-phase AC power.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.3
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• pp.140-146
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• 2003

In this paper, we suggested electronic ballast with the half bridge inverter for the automotive HID lamp. The electronic ballast for the automotive HID lamp should be supplied by the low-frequency square wave avoiding the acoustic resonance. When the HID lamp is hot state, the electronic ballast should supply the sufficient current to the take over to the lamp at the re-strike ignition state for a few milli-second. We have introduced the new take-over current control method that could have control operating frequency and minimize circuits to the take over current circuits.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.8
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• pp.45-51
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• 2008

HID(High Intensity Discharge) search lamp for shipment requires a high open circuit and output current compare than vehicle. This paper presents a soft-start open circuit voltage and constant current sequence control method for 2.5[kW] HID search lamp. The proposed method controls the opal circuit voltage and discharge current of HID lamp according to ignition signal with a simple 8-bit micro-processor and PWM device. For the stable control of lamp, micro-processor checks the output voltage and current. And the checked signals are compared with ignition signal and changes the control mode for stable operation. An ignition signal and micro-processor change the control mode from open circuit voltage contort to constant current control. The proposed control scheme is verified from experimental tests of 2.5[kW] HID search lamp for shipment.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1199-1201
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• 2000

This paper proposes a harmonics reducing circuit for fluorescent lamp inverters using hybrid type smoothing circuit with pumping and smoothing capacitors. A waveform of full-wave rectification used as a direct current power supply at fluorescent lamp inverters contains a lot of harmonic wave from inrush current which is generated near the maximum of input voltage with purse shape when voltage smoothing capacitor is charged. Therefore, in order to suppress inrush current which will result in harmonic wave. this paper proposes a method to control abrupt charging current by use of charging voltage at pumping capacitor. The suppression of harmonics generation at lamp current is confirmed through simulations.