HV halogen lamps

Incoherent Light SourcesJörn Runge

Table of contents

● Introduction● Structure of a HV halogen lamp● Functionality of a HV halogen lamp

– Interference filters and mirrors● Comparison between HV- and NV halogen lamps● Fields of application

– Different types of HV halogen lamps– Ban on selling HV halogen lamps

Introduction

History● 1882: The first halogen lamp was invented by

E.A. Scribner.– Chlorine prevents lamps from clouding

● 1953: The first halogen tungsten lamp was developed by E. Fridrich

– Iodine was used – Discovery of tungsten-transport-reaction

● 1955: F.A. Mosby adapted the halogen tungsten lamp for the usage in regular lamp sockets

● 1959: Usage of bromide instead of iodine (Philips)– Bromide improves the efficiency

● later: Many companies and engineers made the halogen lamp more efficient and developed

different types

Img. 1: Scribner Lamp

Img. 2: E. Fridrich

Img. 3: F.A. Mosby

IntroductionComparison between halogen lamp and light bulb:halogen lamp:

● Higher filament-temperature leads to a better light efficacy

– Leads to radiation of UV-A- and UV-B-waves

● Lifetime about 2.000 - 5.000 h● The compact filament could be used in

projectors or floodlights ● Efficiency about 10%● No clouding● Extreme glaring for direct look into the

lamp.● Higher temperature leads to a larger fire

danger● The emitted light feels „colder“ as the

emitted light of a light bulb.

light bulb:● No radiation of UV-A- and UV-B-waves● Efficiency about 5%● Lifetime about 1.000 h● Clouding

Structure of a HV halogen lamp

Img. 4: build up of a HV halogen lamp

Img. 5: magnification of the coiled-coil filament

Structure of a HV halogen lamp

Calculation of the filament dimensions:

electr. Power: emitted Power:

With T = 3000 K; ρ = 0,75 Ωmm²/m; σ = 5,77∙10-8 W/m²K²; A: surface of the filament, you can calculate the length l and the diameter d of the filament:

Functionality of a HV halogen lamp

● Erosion of a tungsten filament / clouding within a light bulb:

Oxigen and water are residual gases within the bulb.● Cycle-transport-reaction of tungsten:

(reaction at the filament surface)

(reaction at the bulb surface)

If this hypothesis is correct, a HV halogen lamp has a infinite lifetime.

→ There musst be another way for the reaction.

Functionality of a HV halogen lamp

● If WO2I

2 could make the way back without changing, it could make the endothermal

back reaction at the hottest/thinnest point of the filament.

● But the generated parts of WO2I

2 (espacially the tungsten) can not make an

endothermal reaction at the filament surface.● The only way for the tungsten to get back at th filament surface is a condensation at

the thickest/coldest place of the filament.

Img. 6: Reaction-process of tungsten and the halogen

● WO2I

2 was build by a

exothermal reaction at the bulb surface.

● But it can not diffus back to the filament without changing.

● It decomposes on the way back to the filament.

Interference filters and mirrors● Interference filters can optimize the efficiency of HV halogen lamps

– The biggest part of the emitted radiation by an halogen lamp is IR-radiation.

– Only visible light can pass the interference filter.– The reflected energey can be used for the heating process of the filament.

● The UV-A- and UV-B-radiation can not pass a interference filter.● The efficiency with a inteference filter is about two times larger than without it.

Img. 7: Reflectivity of an interference filter for HV halogen lamps

Interference filters and mirrors

Interference filter:

Interference filters and mirrors

Cold light mirror:● IR- and UV-radiation can transmit.● Visible light is reflected.● This can reduce the heat about 66%.

Img. 9: Reflectivity of a cold light mirror for HV halogen lamps

Img. 8: Principle of a cold light mirror

Comparison between HV- and NV halogen lamps

With the equations on slide 5 you can calculate the different properties of NV- and HV halogen lamps:

HV halogen lamp:

NV halogen lamp:

electr. Power [W] : 20 20Voltage [V] : 230 12Temperature [K] : 3100 3100Length of the filament [cm] : 15,81 2,21Diameter of the filament [μm] : 7,56 54,1Lifetime [h] : 1.000 - 2.000 2.000 - 5.000Energy-saving in comparison to a light bulb:

up to 25 % up to 50 %

Fields of application

● Home usage● Architectural usage● Automobile lamps● Gastronomy● Stage lighting● Studio lighting● Floodlights● Projection lamps

Different types of HV halogen lamps

EcoClassic Reflector EcoHalo Twist GU10 Twistline Alu 3000h

(EEL: D) (EEL: D) (EEL: D)

HalogenA PAR16 HalogenA PAR20 HalogenA PAR30S (EEL: D) (EEL: D) (EEL: D)

Different types of HV halogen lamps

HalogenA PAR38 Master PAR20 E PAR56 – PAR64 (EEL: D) (EEL: B)

Halogen High Voltage DE Plusline ES kurz Plusline ES standard

(EEL: C) (EEL: C)

Different types of HV halogen lamps

Halogen High Voltage SE (Film-Studio) Halogen High Voltage SE (Theater)

Ban on selling HV halogen lamps

Sources

● Script: Incoherent Light Sources, Prof. Dr. T. Jüstel● http://home.frognet.net/~ejcov/newhalogen.html● http://www.edisontechcenter.org/halogen.html● http://www.deutsches-museum.de/fileadmin/Content/TRASH/Lichtblicke-

online.pdf● http://www.hochvolthalogenlampen.de/● http://daten.didaktikchemie.uni-bayreuth.de/umat/gluehlampen/

gluehlampen.htm#kap6● http://www.energiekosten-unternehmen.de/energiesparlampe-und-

gluehbirne/eu-verbot-von-gluehbirnen.php● http://www.paulmann.com/de/all/rund-ums-licht/halogen-lampen.html● http://www.ecat.lighting.philips.de/l/professionelle-

lampen/halogenlampen/hochvolt-halogenlampen/19251/cat//