Auto Lights.

[Hockaday]

Ello! I have been searching ( this forum included ) for some kind of reference of LEDs to headlights for automobiles.

I want to build custom headlights and have come to the realization that leds would be the best solution assuming I could get some that were bright enough.

Here is some info on my basis of design.

It will be in a rectangular housing. It probably will not have much of a reflector so the light needs to be controlled mostly by the leds themselves. there will be a good amount of them.

Something like this but three on each side. Click

Thank you for any advice in advance. :help:

 

[DM51]

Welcome to CPF, Hockaday.

We have a separate section for Automobile lights, so I'll move your thread there.

 

[Hockaday]

ok thank you very much, i did not see the sub cat.:thinking:

 

[Hockaday]

maybe this is a better question...if i take ( just for arguement sakes ) 10 100 lumen ( i realise there are some differences between lumen and candlepower...keeping it simple so my head doesn't blow up ) leds and put them in one houseing, will that light set put out aprox 1000 lumen? or would each led need to put out 1000 lumen each in order to produce that much.

I am trying to make 6 headlights for my pontiac fiero. i am basing it on this.

Ooo ahhh

 

[tay]

erm the design process and requirements in getting a DOT or ECE beam pattern is a bit complicated.

Just get HID projectors or something like that and call it a day.

don't take offense to this, but if you're asking whether 10x 100 lumen LEDs is 1,000 lumens (which it is, BTW), then you do not have the design or lighting experience to be able to pull this off. This ain't just grab a few COTS Cree LEDs and point them forwards. You need thermal management and a LED array that provides for a standard low-beam cutoff and light distribution.

The way to go is quality, not quantity. The OEMs use a Lambertian LED pointing upwards with a parabolic-ish reflector above it to give a "half circle" type of output that goes through a plano-convex lens and gives a standard DOT lowbeam pattern.

I'd say 2-3 SSC P7 LEDs on each side, but off-the-shelf optics will not give you the correct pattern. It will need to be custom, and that means $$$, and time, and a background in optical engineering.

 

[Hockaday]

yeah i figured it would most likely be a mute point but I figured i'd try and get some info. hid's won't work due to the need of a reflector i beleive, and i'm not sure if you can cut material out of a reflector inorder to make it thinner.

 

[Hockaday]

oh and i'm not concerned with dot approval due to anything that is not stock to the car is not dot approved.

 

[John_Galt]

+1 for an HID projector refit...

We've had several people try (and fail) to create a legal beam pattern LED headlight for cars. Noone has succeeded.

The picture of an LED light you linked to is an off road light, meant to light up the outdoors, and everything around you. In no way is that comparable to a safe, legal LED headlight.

The optics for legal beam patterns just aren't available to your average person, and even if they were, would be prohibitively expensive. Believe it or not, it takes a lot of engineering time (expensive) to create a proper optic or reflector to distribute the light from a LED in a safe, effective, conscientious manner.

The problem with LED lights, as compared to halogen or HID, is the lot of little things that have to be done extremely well, in order to be safe and long lasting.

There are:
Thermal issues
Beam pattern issues
Electrical issues
weatherproofing issues
mounting issues

A big problem with an LED headlamp is going to be the many small (but very bright) points of light. Even with the proper beam pattern and cut-off, anyone who sees these bright points traveling down the road at them is going to be subjected to lots of glare (yes, even with the proper, legal cut-off pattern).

This is just a taste of what goes into the design.

 

[tay]

oh and i'm not concerned with dot approval due to anything that is not stock to the car is not dot approved.

Not talking about DOT approved (obviously you're not gonna put any custom lighting through comprehensive and expensive testing to ensure FMVSS 108 compliance).

I'm talking about a DOT beam pattern. Center blob of light, decent width, a well-defined cutoff, and slightly lower on the left side than the right side. What I mean is that they produce a decent beam pattern that you can see with but which also minimizes glare to other drivers. Not just a spotlight or something which will not have a good beam pattern. It's not a legal issue, it's a safety issue.

We're not a bunch of bible-thumpers (I mean FMVSS108-thumpers), but with any custom lighting solution, safety plays a huge role.

It's fine and dandy to say that your modifications might not be DOT approved, but if you get into a head on collision, they aren't gonna say "Oh, you hollowed out your pre-cat, which caused the accident" but they may say "Your illegal and unsafe lighting equipment blinded the other driver, which caused the accident"

yeah i figured it would most likely be a mute point but I figured i'd try and get some info. hid's won't work due to the need of a reflector i beleive, and i'm not sure if you can cut material out of a reflector inorder to make it thinner.

What? You're gonna need reflectors (whether it be a parabolic for lens optics, a freeform for reflector optics, a bowl for projector optics, or a collimator for LED optics) for ANY headlight light source (whether it be halogen or HID or LED or even a beeswax candle). Any LED headlight will require reflectors, and there's a good chance that you will need to custom design them in CAD. And why would you cut reflectors to make them thinner? They're precision optical instruments. Would you saw one of your struts in half for a more aggressive stance?

 

[Hockaday]

because i need very specific dimensions in order to complete the design 2 inches or less preferably in height.

 

[tay]

because i need very specific dimensions in order to complete the design 2 inches or less preferably in height.

Your car has 7x6 pop-up headlights. You can retrofit them with NSX headlights if you want to get rid of the pop-ups and don't mind doing some custom hacking. Or, retrofit HIDs in the 7x6, or go with reputable Cibie replacement housings and good H4 bulbs.