• Proceedings of the KIEE Conference
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• 2000.07e
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• pp.157-161
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• 2000

The electronic ballasts for low pressure discharge lamps are produced and commercialized. However, the electronic ballasts for high pressure lamps are now in progress because of poor reliability and high cost. The major case of troubles with electronic ballasts are thermal destruction of semiconductor output switches due to non ideal i-v characteristics of switch. The loss converts to heat and rises the temperature of switch and it increases proportionally to switching frequency and value of current and voltage. This study shows the variable frequency ballasts which can suppress the heating of switches efficiently. It is used for the limitation the switch current and the rising temperature of switch by impedance variation of lamp inductor. As a result, initial warm-up time of the proposed ballasts was faster than that of magnetic ballasts about 90 msec. Power factor of tested ballasts follow as ; input and output average of magnetic ballasts are 93 [%] and 86 [%], respectively, And proposed ballasts are 97 [%] and 99 [%], respectively.

• Journal of Power Electronics
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• v.15 no.2
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• pp.567-575
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• 2015

An improvement in the current fed parallel resonant half bridge (CFPRHB) circuits used in fluorescent lamp electronic ballasts is provided in this paper. The CFPRHB belongs to the self-oscillating family which includes the current fed push-pull and series resonant inverters, most of which are used in instant-start applications. However, many failure modes are related to the bypass capacitor according to an analysis of failed samples. In this paper, the operating functions of the existing topology in the steady state are analyzed and the main root cause of failure modes has been found. Comparisons between the two topologies are conducted in terms of the voltage stress of the bypass capacitor as well as the thermal and performance of the ballasts to verify the advantages of the proposed topology. It is found that the improved topology is capable of enhancing the reliability and reducing the cost of products without having a negative influence on the system performance.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.1
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• pp.42-48
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• 2016

Light-emitting diode (LED) drivers are recently replacing fluorescent lamps; these drivers can operate adaptively with various ballasts without modifying and removing such ballasts. To satisfy these trends, a LED driver that is compatible with both electronic and magnetic ballasts is proposed in this study. Unlike conventional LED drivers, the proposed driver has a ballast recognition circuit and a mode selection circuit to operate ballasts at optimal conditions. Therefore, it features low voltage stress, high efficiency, and good compatibility with both electronic and magnetic ballasts. Moreover, it can be compatible with a wide selection of ballasts from various manufacturers. To confirm the validity of the proposed LED driver, results of the theoretical analysis and experimental verification performed on a 15 W-rated prototype are presented.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.62 no.2
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• pp.79-83
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• 2013

An electronic ballast and magnetic ballast are two major types of ballasts used in HID(High Intensity Discharge) lamp. Compared with magnetic ballasts which can last for over 30 years and are recyclable at the end of their long lifetime, electronic ballasts have very short lifetimes due to the use of the electronic devices. In this paper, we developed a magnetic ballast for dual lamps and analyzed electrical characteristics and efficiency. As the experimental results, we confirm that the magnetic ballast for dual lamps makes it possible to effectively reduce current, active and reactive powers than conventional ballast.

• Journal of Korean Society for Quality Management
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• v.35 no.2
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• pp.27-36
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• 2007

A study to build a reliability model of electronic ballasts for the fluorescent lamp has been performed in this study. We selected the widely being used specification, MIL-HDBK-217 for the study. We briefly reviewed the basic concepts of the electronic ballast with the selected reliability specification. We then developed a reliability model for the ballast using MIL-HDBK-217 and predicted the reliability. We further provided some guides which should be considered in future model development.

• Proceedings of the Korean Society for Quality Management Conference
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• 2006.11a
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• pp.327-332
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• 2006

A study to build a reliability model of electronic ballasts for the fluorescent lamp has been performed in this paper. We selected the widely being used specification, MIL-HDBK-217 for the study. We briefly reviewed the basic concepts of the electronic ballast with the selected reliability specification. We then developed a reliability model for the ballast using MIL-HDBK-217 and predicted the reliability.

• Proceedings of the Korean Society for Quality Management Conference
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• 2006.11a
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• pp.333-338
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• 2006

A simple but practical approach to evaluate the reliability of electronic ballasts for the low wattage fluorescent lamp has been presented in this study. We briefly reviewed the basic concepts of the electronic ballast. We then proposed a simple model and evaluated the reliability of the ballast using computer simulation.

• Proceedings of the Korean Society for Quality Management Conference
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• 2006.04a
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• pp.69-75
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• 2006

As the level of technology and the standard of living improve, product reliability plays an Increasingly significant role. This study has been performed to build a reliability model of electronic ballasts for the low wattage fluorescent lamp. Telcordia SR-332, one of the most widely used reliability specifications, was selected for the model development. We briefly reviewed the basic concepts of the electronic ballast. We then developed a reliability model for the ballast using SR-332 concepts and the reliability has been examined.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2072-2074
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• 1997

A new low-cost high power factor correction circuit for electronic ballasts is proposed. The proposed circuit provides good power factor correction, low current harmonic distortion and cost-effectiveness. The prototype meets the IEC555-2 requirements satisfactorily with nearly unity power factor.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.51-53
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• 2007

Ballasts for HID lamp need a igniter to start the lamp with very high voltage over several kV. Electronic ballasts use various internal igniter in electronic circuits. The paper describe the simulation method for designing the igniter, which helps selecting the component properly by estimating operation voltage and current in circuits.