Influence of isolation transformer leakage inductance on constant current output of Class D series–parallel LCC‐type resonant converter for light‐emitting diode lighting application

2014 ◽  
Vol 7 (6) ◽  
pp. 1362-1373 ◽  
Author(s):  
Keng Chen ◽  
Nitin Kumar
Keyword(s):  
Light Emitting Diode ◽  
Constant Current ◽  
Resonant Converter ◽  
Current Output ◽  
Light Emitting ◽  
Leakage Inductance ◽  
Class D ◽  
Isolation Transformer ◽  
Lighting Application

scholarly journals Failure Analysis of Some Commercial Spotlights Based on Light Emitting Diodes

Electronics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 48
Author(s):  
Wei Zhong ◽  
Thomas Walther
Keyword(s):  
Integrated Circuit ◽  
Light Emitting Diode ◽  
Light Output ◽  
Open Circuit ◽  
Constant Current ◽  
Current Output ◽  
Light Emitting ◽  
Catastrophic Failures ◽  
Drive Circuit

The failure mechanism of two commercial light-emitting diode (LED)-based spotlights with GU10 form factor is analyzed. Through component testing and comparison to nominal values as well as to simulations, it is found that the cause of both device failures is related to damaged components within the drive circuits rather than the LEDs themselves. Both LED heads work as normal when connected to an external direct current (DC) source. The results show that the lack of light output of one spotlight is related to the open circuit caused by damaged resistors and inductors in its drive circuit, while the flickering of the other is related to the malfunction of the integrated circuit providing constant current output. Therefore, improving the quality of the LED drive circuits is considered the most effective way for manufacturers to reduce catastrophic failures of LED spotlights.

Soft switched full‐bridge light emitting diode driver configuration for street lighting application

2018 ◽  
Vol 11 (1) ◽  
pp. 149-159 ◽  
Author(s):  
Ch Kasi Ramakrishnareddy ◽  
Porpandiselvi Shunmugam ◽  
Neti Vishwanathan
Keyword(s):  
Light Emitting Diode ◽  
Street Lighting ◽  
Light Emitting ◽  
Lighting Application

Bridgeless electrolytic capacitor‐less valley‐fill AC/DC converter for offline Twin‐Bus light‐emitting diode lighting application

2013 ◽  
Vol 6 (6) ◽  
pp. 1132-1141 ◽  
Author(s):  
Hongbo Ma ◽  
Cong Zheng ◽  
Wensong Yu ◽  
Bin Gu ◽  
Jih‐Sheng (Jason) Lai ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Electrolytic Capacitor ◽  
Light Emitting ◽  
Valley Fill ◽  
Lighting Application

LIGHT EMITTING DIODE DRIVERS AND CONTROL

2011 ◽  
Vol 20 (02) ◽  
pp. 267-286
Author(s):  
STEVE WINDER
Keyword(s):  
Light Emitting Diode ◽  
Current Source ◽  
Constant Current ◽  
Constant Current Source ◽  
Basic Principles ◽  
Light Emitting ◽  
Control Techniques ◽  
Switching Regulator ◽  
Step Down ◽  
And Control

This paper outlines the various driving and control techniques for Light Emitting Diodes (LEDs). LEDs should be driven from a constant current source. High power LEDs are usually driven from a switching regulator, for reasons of efficiency. The types of drivers described include Buck (step-down), Boost (step-up) and Buck-Boost (step-up or step-down). Isolated drivers and Power Factor Correction (PFC) circuits are also described. This brief paper can only describe the basic outline of these circuits, but this should be sufficient to allow the basic principles to be understood.

Macroscopic Coulomb-blockade effect in a constant-current-driven light-emitting diode

1995 ◽  
Vol 52 (3) ◽  
pp. 2008-2012 ◽  
Author(s):  
Jungsang Kim ◽  
Hirofumi Kan ◽  
Yoshihisa Yamamoto
Keyword(s):  
Coulomb Blockade ◽  
Light Emitting Diode ◽  
Constant Current ◽  
Light Emitting

scholarly journals Thermal Performance of LED Filament in Flip-Chip Packaging Manufactured for Different Correlated Color Temperature

2021 ◽  
Vol 11 (19) ◽  
pp. 8844
Author(s):  
He Jiang ◽  
Jiming Sa ◽  
Cong Fan ◽  
Yiwen Zhou ◽  
Hanwen Gu ◽  
...  
Keyword(s):  
Thermal Performance ◽  
Flip Chip ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Color Difference ◽  
Junction Temperature ◽  
Color Temperature ◽  
Constant Current ◽  
Light Emitting ◽  
Flip Chip Packaging

The effect of correlated color temperature (CCT) on the thermal performance of light emitting diode (LED) filament in flip-chip packaging was investigated in detail. Two filaments with different lengths were selected as the research object, and the thermal resistance of filaments under three CCT (2200 K, 2400 K, 2700 K) were studied. The optical properties and thermal parameters of the two groups of filaments were measured, and the results were analyzed combined with the color coordinate. The experimental results show that thermal properties of LED filaments is closely related to CCT. Under constant current condition, junction temperature decreases with the increase of color difference. With the change of phosphor glue and phosphorus powder ratio, the color temperature of LED filament also changes. In the filaments with the same chip structure and packaging mechanism, the higher the proportion of red phosphorescent powder, the worse the heat dissipation performance of the filament. These results show that in the design and manufacture of LED filament, it is helpful to control the CCT of LED filament under the premise of meeting the use requirements.

Determination of LED’s Efficacy for Lighting Application

2014 ◽  
Vol 971-973 ◽  
pp. 946-949
Author(s):  
Yu Yan Man ◽  
Chi Zhang ◽  
Xiao Guang Xi ◽  
Ming Lei Wu ◽  
Yan Wei Dong ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Thermal Characteristics ◽  
Light Emitting ◽  
Dependency Relationship ◽  
Definition Of ◽  
Lighting Application

The efficacy and its degradation of light emitting diode (LED) are related to its PN junction’s temperature (Tj). Currently efficacy in certain Tjand thermo-resistant are defined for the thermal characteristics. In the paper samples from different manufacturers were tested for their efficacies and dependency relationship on Tj, results were investigated and show that current definitions on thermal characteristics are quite inconvenient or unreasonable for general lighting application. Then a new definition of LED’s efficacy was suggested for general lighting application.

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