Macroscopic Coulomb Blockade Effect in a Constant Current Driven Light Emitting Diode

1996 ◽  
pp. 411-412
Author(s):  
Jungsang Kim ◽  
Hirofumi Kan ◽  
Yoshihisa Yamamoto
Keyword(s):  
Coulomb Blockade ◽  
Light Emitting Diode ◽  
Constant Current ◽  
Light Emitting

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

Observation of the collective Coulomb blockade effect in a constant-current-driven high-speed light-emitting diode

1997 ◽  
Vol 14 (6) ◽  
pp. 1295 ◽  
Author(s):  
Jun’ichi Abe ◽  
Gen Shinozaki ◽  
Takuya Hirano ◽  
Takahiro Kuga ◽  
Masamichi Yamanishi
Keyword(s):  
Coulomb Blockade ◽  
High Speed ◽  
Light Emitting Diode ◽  
Constant Current ◽  
Light Emitting

Analysis and design of a multi‐channel constant current light‐emitting diode driver based on high‐frequency AC bus

2013 ◽  
Vol 6 (9) ◽  
pp. 1803-1811 ◽  
Author(s):  
Quanming Luo ◽  
Shubo Zhi ◽  
Can Zou ◽  
Bo Zhao ◽  
Luowei Zhou
Keyword(s):  
High Frequency ◽  
Light Emitting Diode ◽  
Constant Current ◽  
Light Emitting ◽  
Analysis And Design ◽  
High Frequency Ac

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.

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.

Wide-band suppression of photon-number fluctuations in a high-speed light-emitting diode driven by a constant-current source

1998 ◽  
Vol 72 (3) ◽  
pp. 284-286 ◽  
Author(s):  
M. Kobayashi ◽  
M. Kohno ◽  
Y. Kadoya ◽  
M. Yamanishi ◽  
J. Abe ◽  
...  
Keyword(s):  
High Speed ◽  
Light Emitting Diode ◽  
Photon Number ◽  
Current Source ◽  
Wide Band ◽  
Constant Current ◽  
Constant Current Source ◽  
Light Emitting

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.

Optical Modeling of Organic Light-Emitting Diode Multilayer Device Structures

2000 ◽  
Vol 660 ◽  
Author(s):  
K. B. Kahen
Keyword(s):  
Power Distribution ◽  
Light Emitting Diode ◽  
Constant Current ◽  
Device Layer ◽  
Emission Layer ◽  
Radiant Intensity ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Dipole Emission

ABSTRACTWe present an exact classical solution to the problem of dipole emission in a planar multilayer organic light-emitting diode (OLED) device. The inputs to the model are the photoluminescence and quantum yield of the emitter material, and the device layer thicknesses and indices of refraction. The results of the model are applied to predicting the radiant intensity of OLEDs as a function of varying device layer thickness. It is shown that the calculated radiances are in excellent agreement with the data; this suggests that at constant current the variation in electroluminescence caused by modifications of the layer thicknesses can be completely accounted for by optical effects. Finally, we present results (for positions both internal and external to the diodes) for the Poynting power distribution from a randomly aligned dipole in the emission layer.

The Design of High Power LED Headlamp

2013 ◽  
Vol 423-426 ◽  
pp. 2098-2103
Author(s):  
Wen Lin Chen ◽  
Zhen An ◽  
Chao Qun Xiang ◽  
Chen Yang Liu ◽  
Li Na Hao
Keyword(s):  
High Power ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Current Drive ◽  
Constant Current ◽  
Light Emitting ◽  
High Power Led ◽  
Drive Circuit ◽  
Led Headlamp ◽  
The Stability

With the continuous development of LED(Light-Emitting Diode) manufacturing technology, the high power white LED is gradually applied in the field of all kinds of lighting .But with working time increasing of LED chips, their junctions temperature continue increasing, which lead to decrease light-emitting efficiency and reliability of LED chip, and even be failure. According to the serious heating of LED chip, this paper has been designed a fin-type aluminum radiator panels using Pro/E software. A LED constant current drive circuit is designed by using LTC3783 chip. With the ANSYS software, thermal analysis was carried out on the fin-type aluminum radiator panels, and eventually the mode of high power LED headlamps is determined. The stability of the LED constant current drive circuit is verified through experiments. The LED headlamps of 90W worked for ten hours, and the results of the experiments showed that the LED chip junctions temperature measured are less than 75°Cso we can solve heat dissipation of high power LED headlamps effectively.

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