LED lamp
Teacher:Ru-Li Lin
Students:Yuan-Yu Liu
Kai-Meng Zeng
Department of Mechanical Engineering
Southern Taiwan University of Science and
Technology
Outline
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LED lamp introduce
LED lamp Technology overview
LED lamp drive circuit
LED lamp Application
Household LED lamps
Comparison of the lamp
LED Specs
Taiwan bulb market
Reference
LED lamp introduce
An LED lamp (or LED light bulb) is a solidstate lamp that uses light-emitting
diodes(LEDs) as the source of light
LED lamp Technology overview
General-purpose lighting needs white
light. LEDs emit light in a very small
band of wavelengths, emitting light of a
color characteristic of the energy band
gap of thesemicon ductormaterial used
to make the LED. To emit white light
from LEDs requires either mixing light
from red, green, and blue LEDs, or
using a phosphor to convert some of the
l i g h t t o o t h e r c o l o r s .
LED lamp drive circuit
LED is a low-voltage semiconductor
products, high voltage can cause
damage, not directly from a standard
AC drive, the need for additional
circuitry to control the voltage and
c u r r e n t
s u p p l y .
Series connection
Parallel connection
A mixture of series and parallel
The Advantages and Disadvantages of each connection
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Series connection
Advntages：Equal currents, LED brightness is consistent.
D i s a d va n t a g e s ： A n L E D b r o k e n a l l L E D s d o n o t w o r k .
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Parallel connection
Advntages：An LED broken does not affect other LED work.
Disadvantages：LED driver needs a larger current to the output.
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A mixture of series and parallel
Advntages：Combines the advantages of the series and parallel
Disadvantages：The design is very complex
LED lamp Application
Household LED lamps
A s el ecti o n o f co nsumer L ED b ul bs
available as drop-in replacements for
incandescent bulbs in screw-type sockets
Comparison of the lamp
Incandescent light bulbs
Krypton bulb
Comparison of the lamp
HID bulb
LED bulb
Brightness comparison and Power consumption
Brightness comparison
HID > LED > Incandescent light bulbs > Krypton bulb
Power consumption
HID > Incandescent light bulb> Krypton bulb > LED
LED Specs
 Lumen：luminous flux, a measure of the total
"amount" of visible lightemitted by a source.
 Watt(W)：defined as one joule per second,
measures the rate of energy conversion or
transfer.
 Luminous efficacy：Is a parameter of the light
source. The ratio of the luminous flux and power
High-wattage≠high-brightness
High luminous efficiency, the higher the number
of lumens per watt of electricity is higher c / p value.
Cost Comparison
Incandesce
nt
Haloge
CFL
n
LED
(Generic)
LED
(Philips)
Purchase price
$0.41
$4
$4
$10
$16
Watt
60 W
42 W
13 W 13.5 W
12.5 W
Lumens
860
570
825
850
805
Lumens/Watt
14.3
13.6
63.5
63
64.4
Color
Temperature Kelvin
2700
3000
2700 3000
2700
CRI
100
100
82
>75
85
Lifespan (hours)
2,000
3,500
8,00
0
25,000
25,000
Comparison based on 6 hours use per day (21,900 hours over 10 yrs)
Taiwan bulb market
 Taiwan bulb market currently saving light bulbs
mainstream, the most power-hungry incandescent
bulbs each less than one percent market share and most
energy efficient LED bulbs, LED bulbs and more local
lighting and create an atmosphere.
 Same brightness, for example six hundred to eight
hundred lumens.60-watt incandescent bulb power
consumption, energy saving bulbs significantly
reduced to 12 watts power consumption, LED only
nine watts
Reference
 http://homelight.iproducts.com.tw/ledlamps.html
 http://home.educities.edu.tw/jmhwang/newsfile/art
icle030610.htm
 http://udn.com/NEWS/LIFE/LIF1/6284415.shtml
 http://en.wikipedia.org/wiki/Wiki
 http://www.everlightlighting.com/