H.I.D Headlight system

[byron]

headlamp lens cleaning systems and automatic beam levelling control

there's your project for this week then
see you sometime soon

[mark]

Hmmmm I wonder. ..….…

[GP Kevo]

It looks like you may need to come up with lens and reflector optics to match the H.I.D. light source as well. You do realise that if you blind oncoming traffic there's a greater chance of a collision, not a lesser one.

From http://www.danielsternlighting.com/tech ... te]Halogen headlamps and HID headlamps require very different optics to produce a safe and effective—not to mention legal—beam pattern. How come? Because of the very different characteristics of the two kinds of light source.

A halogen bulb has a cylindrical light source: the glowing filament. The space immediately surrounding the cylinder of light is completely dark, and so the sharpest contrast between bright and dark is along the edges of the cylinder of light. The ends of the filament cylinder fade from bright to dark. An HID bulb, on the other hand, has a crescent-shaped light source -- the arc. It's crescent-shaped because as it passes through the space between the two electrodes, its heat causes it to try to rise. The space immediately surrounding the crescent of light glows in layers...the closer to the crescent of light, the brighter the glow. The ends of the arc crescent are the brightest points, and immediately beyond these points is completely dark, so the sharpest contrast between bright and dark is at the ends of the crescent of light.

When designing the optics (lens and/or reflector) for a lamp, the characteristics of the light source are the driving factor around which everything else must be engineered. If you go and change the light source, you've done the equivalent of putting on somebody else's eyeglasses: You can probably make them fit on your face OK, but you won't see properly.
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There's much more info on the site with diagrams and links to .pdf downloads of research and I encourage you to read it. And there's a You Tube video that they posted as well.

He concludes by saying

What about the law, what does it have to say on the matter? In virtually every first-world country, HID "retrofits" into halogen headlamps are illegal. They're illegal clear across Europe and in all of the many countries that use European ECE headlight regulations. They're illegal in the US and Canada. Some people dismiss this because North American regulations, in particular, are written in such a manner as to reject a great many genuinely good headlamps. Nevertheless, on the particular count of HID "retrofits" into halogen headlamps, the world's regulators and engineers all say DON'T!

The only safe and legitimate HID retrofit is one that replaces the entire headlamp—that is lens, reflector, bulb...the whole system—with optics designed for HID usage. In the aftermarket, it is possible to get clever with the growing number of available products, such as Hella's modular projectors available in HID or halogen, and fabricate your own brackets and bezels, or to modify an original-equipment halogen headlamp housing to contain optical "guts" designed for HID usage (though it should be noted that "cooking" the lens off a composite headlamp, installing HID optics and re-sealing the lens creates major problems of its own, and does not result in a legal headlamp).

[mark]

Thought I had already said I was looking for a lens and reflector.

[GP Kevo]

It's an interesting topic so please post your progress. I've not yet been blinded by a Lambretta, but I have been many times by oncoming cars running this type of headlamp and at those times when I was on my Lambretta I wished I could blind them back. It just seems to me that we're in a competition to dazzle each other when what we all really need to remember is that we share the road and I wish car drivers especially woud remember that.

I just ran across this from the UK Department of Transport: http://www.dft.gov.uk/pgr/roadsafety/drs/hidheadlamps

In the Department's view it is not legal to sell or use after market HID lighting kits, for converting conventional Halogen headlamps to HID Xenon. If a customer wants to convert his vehicle to Xenon HID he must purchase completely new Xenon HID headlamps. The reason for this is that the existing lens and reflector are designed around a Halogen filament bulb, working to very precise tolerances. If one places a HID "burner" (bulb) in the headlamp, the beam pattern will not be correct, there will be glare in some places and not enough light in other places within the beam pattern.

The following is the legal rationale:

The Road Vehicle Lighting Regulations 1989 regulate the situation in the UK.
Under these Regulations, HID/Gas Discharge/Xenon headlamps are not mentioned and therefore they are not permitted according to the strict letter of the law.

However new vehicles have HID headlamps. This is because they comply to European type approval Regulations. The UK cannot refuse to register a vehicle with a European type approval. These are to ECE Regulation 98 (for the HID headlamps which are tested on a rig in a laboratory) and ECE Regulation 48 (Lighting Installation on the vehicle).

For the after market, a used vehicle cannot obtain type approval because it is only applicable for new vehicles. However we feel that saying "HID is banned in the after market" would not be reasonable. Instead we should make analogies with new vehicles. It would be reasonable to require HID in the after market to meet the same safety standards as on new vehicles. The same level of safety should apply.

Therefore a HID headlamp unit sold in the after market should:

1. be type approved to ECE Regulation 98 as a component.

2. when fitted to the vehicle should enable ECE Regulation 48 to be complied with (although no government inspection will take place).

3. Comply with RVLR as far as "use" is concerned.

In practice this means:

1. The headlamp unit (outer lens, reflector, bulb) shall be type approved to ECE 98 and be "e-marked" to demonstrate this. That can only be done by the headlamp supplier - Hella, Valeo etc. who must test the headlamp in an independent laboratory.

2. Once fitted to the vehicle it must have headlamp cleaning and self-levelling (which can be for the headlamp or can be in the vehicle suspension - some expensive estate cars have "self-levelling suspension" and that is adequate). Also the dipped beam must stay on with the main beam.

3. The headlamp must be maintained in good working order, kept clean, and aligned/adjusted correctly like any other headlamp.

Under the Road Traffic Act 1988 it is an offence to supply, fit or use vehicle parts which are not legal.

In summary it is not permitted to convert an existing halogen headlamp unit for use with HID bulbs. The entire headlamp unit must be replaced with one designed and approved for use with HID bulbs and it must be installed in accordance with the rules stated above.

If you require any further information regarding the regulations covered by this fact sheet, please contact the DfT at the address below:

Transport Technology and Standards 6
Department for Transport
Zone 2/04
Great Minster House
76 Marsham Street
London
SW1P 4DR

Telephone: 020 7944 2078
Fax: 020 7944 2196
Email: [email protected]