cree gen ltg training

General Lighting

Cree Proprietary - CONFIDENTIALCopyright © 2008, Cree, Inc. pg. 2

What is light ?Spectrum of Electromagnetic Radiation H

Cosmic Gamma X-rays UV Infrared Radar FM AMrays rays radio radio

Visible Spectrum

380 (nm) 780 (nm)

10-16 10-12 10-8 10-4 0 104 108 (m)


What is a lamp ?

A LAMP (light source) is an emitter of electromagnetic radiation in

the visible part of the energy spectrum.


Radiometry & Photometry H

• Radiometric light is specified according to its radiant energy and power without regard for the visual effects of radiation.

• Photometric light is specified as radiation in terms of human visible response according to the CIE standard observer response curve (photopic luminous efficiency function)


Terms of the industry H

Luminous Flux

Eye sensitivity

Illuminance

Luminous Intensity

Luminance

Color


Luminous Flux H

The amount of light radiated

by a light source.

Unit: lumen (lm -photometric)

Watts (W - radiometric)


wavelength (nm)

rela

tive

eye

se

nsitiv

ity

4000

500 600 700 800

V( )

555 nm

0,2

0,4

0,6

0,8

1,0

1 W555nm = 683 lm

Eye Sensitivity H


The amount of light falling

on a unit of surface.

Unit: lux (lx=lm/m2)W/m2

E

IlluminanceDefinition of illuminance


100 lux 2500 lux 5000 lux 10000 lux 100000 lux

Illuminance

Typical illuminance levels in and outdoors (noon on a sunny day).


Luminous Intensity

Definition of Luminous Intensity (unit: candela (lm/sr,cd), W/sr)

The amount of light radiated

by a light source in a given direction.

1 candela = 1 lumen per steradian


Luminance: The amount of light radiated by a unit of apparent surface in a given direction.

At same luminous flux: same luminous intensity but different luminance (brightness)

Luminance (Brightness)Definition of Luminance (unit: candela per m2 (cd/m2))


Color Impression of the Light H

The color impression of light

is characterised by:

•Color temperature (Tc)

•Color rendition (Ri)


Tc = 5500K

Color of the LightColor Temperature

Tc = 2200K


(Correlated) Color Temperature

• Incandescent (temperature of the filament)

• Gas discharge (correlated color temperature)


Luminous Flux and Color of the Light CIE Chromaticity Diagram: Black Body Line

x

y

0.2

0.3

0.4

0.5

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

770

580

600

20 000K

10 000K

7000K

5000K

3000K

2000K

A

D65


Color Rendition

• Object spectral reflectance

• Light source color distribution

• Adaptation of the eye


Color Rendition

Sunlight Has a CRI of 100. When

objects are illuminated with sunlight, all

the colors look good.

Low Pressure Sodium has a CRI less

than 0. Objects illuminated by it all

look brown.


Color Rendition

Test Colors Illuminated by a source with

a CRI of 100, i.e. an incandescent lamp.

Test Colors Illuminated by a red LED

1 2 3 4

5 6 7 8

9 10 11

12 13 14

1 2 3 4

5 6 7 8

9 10 11

12 13 14


Color Rendering Index (Ra)

• Ra = 90 - 100Excellent color rendering properties

• Ra = 80 - 90Good color rendering properties

• Ra = 60 - 80Moderate color rendering properties

• Ra < 60Poor color rendering properties


White LEDs

• RGB Mixing

By mixing Red, Green and Blue sources any color light, including White, can be made.


How a Phosphor LED Works

If the phosphor is thin, some blue photons get

through without being absorbed.

The phosphor emits a yellow photon. This

process is called fluorescence.

Different phosphors emit different colors: blue, green, yellow, orange, red. The color

of the fluorescence photon is always at a longer wavelength than the incident photon.


White LEDs

• Phosphor Conversion Approach

Blue emission is converted to yellow by the phosphor coating over the chip and reflector cup. The mixture of blue and yellow light appears white.

Blue LED chip

Yellow phosphor

coating

on chip and

reflector cup

Blue + yellow appears white.


Lamp Performance Terms

• Efficacy

• Lamp Life and Lumen Depreciation


1940 1950 1960 1970 1980 1990 20000

50

100

150

200

Low-pressure Sodium

High-pressure Sodium

Fluorescent

Metal Halide

Compact Fluorescent

High-pressure Mercury

Halogen

Incandescent

lm/W

Lamp EfficacyImprovement

Luminous flux (lm)Efficacy (lm/W) =————————

Power Input (W)


Lamp Life and Lumen Depreciation

operating hours 20 00010 000 15 00050000

%

100

90

80

70

60

50

Lumen depreciation of /Colour 80 series lamps

operating hours 20 00010 000 15 00050000

surv

ivals

in %

100

90

80

70

60

50

Rated average lamp life (‘TL’D on HF gear)


Lamp Life and Lumen Depreciation

Average Rated Life

• ‘The time after which 50% of a large sample batch have failed when operated under test conditions.’

Service Life

• ‘Takes into account lumen maintenance curves and lamp survival curves’


Dimensions of Lamps and Light Emitting Area

Accent lighting

Narrow beam

accents

Medium beam

accents

“Compact”

Downlighting

Linear systems

& tiles

General lightingLocalised lighting

Compactsource

Pointsource

Linearsource

“Small” Spots “Power” Spots “Floods”

DiffuseWide beam / Directional

size

Smaller lamp gives luminaire size reduction or improved optical performance


Control Gear

Discharge lamps must be used with control gear to:

1. limit lamp current2. create ignition peak3. power-factor correction

Gear may be electronic or conventional

Cree Proprietary - CONFIDENTIAL

Dfc, Damage Factor, is a relative ranking of light sources related to their potential for causing a fading of illuminated objects. The factor is calculated using equal conditions of illumination and exposure time, and the sensitivity characteristics

of paper.

Effect of UVPermitted Exposure Time

PET* is the Permitted Exposure Time a human being can spend beneath a given source at 1000 lux illumination without experiencing eye or skin irritation/damage.

Lamp type PET*

(hr x klux)

TL /840 65

CDM-T /830 24

SDW-T 34

Damage Factor

Lamp type Dfc

TL /840 .21

CDM-T /830 .20

SDW-T .10


Improved Ecological Balance

1. Efficacy improved

2. Miniaturization: less material in products and packaging reduced

3. Less hazardous materials


Performance:Image & Comfort

FluxSize

Color Quality

Costs:Cost of Ownership

EfficacyLife

Maintenance

Lamps - Performance/Cost Balance


Light Generation

Metal Halide Lamps

Incandescence

MercurySodium

Gas Discharge

Tungsten Tungsten

Halogen

Low Pressure Sodium

‘SOX’

High Pressure Sodium

‘SON’

Low Pressure Mercury

‘Fluorescent’

High Pressure Mercury

‘HPL’

LED


Luminous flux 120 - 18 800 lm

Luminous efficacy < 19 lm/W

Color temperature 2700 K

Color rendering Ra 100

Lamp power 15 - 1000 W

Rated average lifetime 1000 hrs

Incandescent Lamps Lamp Characteristics

Issues

• Dimming is possible

• Voltage fluctuations do influence luminous flux, power consumption and rated average lifetime

• Lumen depreciation during lamp lifetime because of evaporating tungsten (lamp blackening)

• Instant start and restart

• Cheap


Halogen Cycle

W + 2 Br WBr2

WBr2

bulb wall 2Br

dissociation

tungsten halide

molecules

>250°C

1000°C

formation

W

Tungsten Halogen Lamps Working Principle




Color temperature 2900 / 3200 K



Rated average lifetime 2000 - 5000 hrs

Tungsten Halogen Lamps Lamp Characteristics

Issues

• Dimming is possible

• No lamp blackening during lamp life

• Voltage fluctuations do influence luminous flux, power consumption and rated average lifetime

• Low voltage halogen lamps require a transformer

• Halogen lamps without double envelope should not be touched with bare fingers


bend insulation cap

discharge tube

outer bulb

dimple filled with sodium

electrode

getter

lamp cap

Low-Pressure Sodium LampsLamp Construction

___

+++

+_

anodecathode

electrons

positive ions




Color temperature 1700 K

Light color monochromatic yellow

Color rendering Ra not applicable


Rated average lifetime 18 000 hrs

Low-Pressure Sodium Lamps Lamp Characteristics

Issues

• Control gear required

• Run-up time of 12 minutes approx

• Re-ignition time of 1-10 minutes

• Most efficient light source, but with worst light quality


support wire

getterdischarge tube

of sintered aluminalamp cap

electrode PIAPhilips Integrated Antenna

„Hg free‟indication

outer bulb

High-Pressure Sodium LampsLamp Construction




Color temperature 2000, 2200, 2500 K

Light color orange, warm white

Color rendering Ra 25 - 80


Rated average lifetime 10 000 - 24 000 hrs

High-Pressure Sodium Lamps Lamp Characteristics


• Run-up time of 3 - 6 minutes

• Re-ignition within 30 seconds - 4 min.

• Most efficient light source with acceptable light quality for most functional outdoor lighting applications

Issues


ultraviolet

radiationlight

fluorescent

powder

mercury

atomelectrons electrode

capglass tube

Fluorescent LampsLamp Construction


Luminous flux 200 - 5200 lm


Color temperature 2700 - 6500 K

Color rendering Ra >80, >90, 60(depending on composition offluorescent powders)

Lamp power 4 - 58 W

Rated average lifetime 14 000 hrs (conv.)

20 000 hrs (electr.)

15 000 hrs (PLE-T)

Fluorescent Lamps Lamp Characteristics

• 80/ Series recycling

• Trend to lower mercury doses

• Fully dimmable (4 pin)

• Not instant start without special circuitry - usually 2.5s min “off”

• Starting, warm-up, flux and even CCT are temperature dependent, usually 1-5 min for 80% flux.

Issues


Fluorescent Lamps Issues

3 different groups of fluorescent powders

• Standard fluorescent lamps

– moderate luminous efficacy

– moderate color rendering (Ra: 50 - 75)

– moderate lumen depreciation

• 3-line fluorescent lamps

– very good colour rendering (Ra > 80)

– very low lumen depreciation

• de-Luxe fluorescent lamps

– moderate luminous efficacy

– excellent color rendering (Ra > 90)

– low lumen depreciation

IncreasingPrice


operating hours 20 00010 000 15 00050000

lum

en in %

100

90

80

70

60

50

Super /80

/90 de Luxe

Standard

Fluorescent Lamps Issues

Lumen Maintenance


T12

TLD

TL5

PL-L

PL-S / PL-C / PL-T

PLE-C / PLE-T

The Range of Fluorescent Lamps


QL Fluorescent Lamps


Auxiliary amalgam

Main amalgam

Glass bulb

Heat conducting rod

Mounting flange

Fluorescent powder

Lamp cap

Coil

Antenna

Coaxial cable

Mercury

Induction Fluorescent LampsLamp Construction





Light color (inc.) warm & neutral white


Lamp power 55, 85, 165 W

Lifetime* 60 000 hrs* 10% lamp failure, 30 % lumen depreciation

Induction Fluorescent Lamps Lamp Characteristics

• Run on electronic gear only

• Luminous flux is independent of fluctuating supply voltage

• Fast run-up and instant re-ignition

• Not dimmable

• Limited distance between lamp and HF-generator

Issues


fluorescent powder

discharge tube support

discharge tube (quartz)

outer bulb

main electrode

auxiliary electrode

resistor

stem

lamp cap

High-Pressure Mercury LampsLamp Construction




Color temperature 3400, 4000 K

Light color neutral white

Color rendering Ra 40, 55



High-Pressure Mercury Lamps Lamp Characteristics

• Control gear required (ballast only)


• Re-ignition within 5-10 minutes

• Useful lifetime is reached when lamp color shifts to green

Issues


getter

discharge tube support

discharge tube (quartz)

electrode

outer bulb

stem

lamp cap

Metal Halide LampsLamp Construction





Color rendering Ra 65 - 92


Rated average lifetime 4000 - 20 000 hrs

Metal Halide Lamps Lamp Characteristics

• Control gear required.

• Quartz metal halide technology cannot totally avoid visible light color differences between individual lamps.

• Useful lifetime: light color shifts to greenish/blueish color appearance.

• Run-up time of 3 - 5 minutes

• Re-ignition time of 15 - 20 minutes

• Pay attention to limited burning positions!

Issues


quartz glass bulb

PCA* discharge tube

electrode

sealing glass

support wire

lamp cap

getter

* Poly Crystaline Alumina

Ceramic Discharge Metal Halide LampsLamp Construction


Ceramic Discharge Metal Halide Lamps Color Stability




Color temperature 3000, 4200 K

Light color warm, neutral white

Color rendering Ra > 80, 90

Lamp power 35, 70, 150 W


Ceramic Discharge Metal Halide Lamps Lamp Characteristics


• Stable color impression during lifetime

• Hardly any spread in color characteristics between individual lamps


• Re-ignition time of 15 minutes approx

• Luminaires for CDM-TP and -R do not need front cover, but all others do.

Issues


Relative Lamp Sizes

HPI Plus SON HPL-N QL CFL-I SDW-T CDM-R GLS Masterline LED

Plus

„TL‟D

„TL‟5

SOX

MHD


Lamp Survey

Incand. Tungsten Linear

fluoresc.

Non

retrofit

CFL

Retrofit

CFL

QL SOX SON SDW-T HPL HPI MHN/MHD

CDM ML

Power[W]

15 -1000

5 - 2000 4 - 58 5 - 55 5 - 23 55 - 165 18 - 180 50 - 1000 35 - 100 50 -1000

250 -2000

70 -2000

35 - 150 100 –500

Luminous flux[lm]

120 -18 800

60 -48 800

200 -5200

250 -4800

200 -1500

3500 -12 000

1800 -32 500

3500 –90 000

1300 -5000

1770 -58 500

19 000 -189 000

5300 -220 000

3300 -14 000

1100 -13 000

Luminousefficacy

[lm/W]< 19 < 27 < 104 < 87 < 65 < 70 < 203 < 150 < 52 < 61 < 94 < 110 < 95 < 26

Light colour warmwhite

warmwhite

warm,neutral,daylightwhite

warm,neutral,daylightwhite

warmwhite

warm,neutralwhite

yellowmonochromatic

orangeish warmwhite

neutralwhite

neutralwhite

warm,neutral,dalightwhite

warm,neutralwhite

neutralwhite

Colour temp.[K]

2800 3000,3200

2700 -6500

2700 -6500

2700 3000,4000

1700 2000, 2200 2500 3300 -4200

4300 3000 -5600

3000,4200

3300 -3700

Ra 100 100 > 80, >90, 60

> 80 > 80 > 80 n.a. 25, 65, > 80 45 , 55 69 75 - 90 > 80,> 90

48 - 72

Rat. aver.Lifetime [hrs]

1000 2000 -5000

13 000 -20 000

8 000 -16 000

6000 -12 000

100 000 18 000 10 000 16 000 <20 000 2000 -9000

6000 -12 000

10 000

Ballast no no yes yes no HFgenerator

Yes yes yes yes yes yes yes no

Ignitor no no yes yes no no yes yes yes no yes yes yes no

Run-up time[min]

zero zero zero zero < 1 zero 12 4 - 6 3 5 3 3-5 3 5 - 10

Re-ignitiontime [min]

zero zero zero zero zero zero 1 - 10 30 sec. - 4min.

30 sec 10 15 15 - 20 15 5


85-100

GLS

Point

400-1200lm

2700K

CRI

CCT

Lumens

Source size

Benchmark

TH QLGLSMHCDMSONCFLTL

Lighting for the Home



Accent lighting for Shops

85

CDM/TH

Point

1000-14000lm

3000K

CRI

CCT

Lumens

Source size

Benchmark



Lighting for Roads

20

SON

Point

30K-50K

2000K

CRI

CCT

Lumens

Source size

Benchmark



Lighting for Residential streets / City centres

20-60

SON/CDM

Point

3500-16k lm

2000-3000

CRI

CCT

Lumens

Source size

Benchmark



Lighting for Signs / Contours

80

Fluorescent

Linear

300-5000lm

6500K

CRI

CCT

Lumens

Source size

Benchmark



Lighting for Sports

80 Low end

90 High end

MH

Point

100k-200k lm

4000k Low end

5000k High end

CRI

CCT

Lumens

Source size

Benchmark



Lighting for Industry

65

TL

Linear

5k-40k

4000k

CRI

CCT

Lumens

Source size

Benchmark

cree gen ltg training

Documents

color light

light color temperature

color rendition1

lamp light source

light radiatedby

photometric light

color rendition sunlight

eye copyright