LED lamp

Teacher:Ru-Li LinStudents:Yuan-Yu Liu Kai-Meng Zeng

Department of Mechanical EngineeringSouthern Taiwan University of Science and

Technology

Outline

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 solid-state 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 light to other colors.

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 current supply.

Series connection

Parallel connection

A mixture of series and parallel

The Advantages and Disadvantages of each connection

Series connection Advntages ： Equal currents, LED brightness is consistent. Disadvantages ： An LED broken all LEDs do not work.

Parallel connection Advntages ： An LED broken does not affect other LED work. Disadvantages ： LED driver needs a larger current to the output.

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 selection of consumer LED bulbs 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 comparisonHID > LED > Incandescent light bulbs > Krypton bulb

Power consumptionHID > 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

Incandescent

Halogen

CFLLED (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 3,5008,000

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/article030610.htm

http://udn.com/NEWS/LIFE/LIF1/6284415.shtml

http://en.wikipedia.org/wiki/Wiki

http://www.everlightlighting.com/