# Custom LED Fogs and Spot lights



## werearemyleds

Hi,
I saw these LED Fog/Driving lights (6 leds/ 2600 lumens per light/ 12 leds 5200 lumens per pair).

http://www.rigidindustries.com/D2-p/d2.htm

I then saw this thread about the SST-90's in that awesome flashlight:

http://www.candlepowerforums.com/vb...s-Led-Flashlight-18-000-lumens-more-beamshots.

I think the parts I need are:



SST-90's : 6 or 8
Heat Sink large enough for the lighthead
6 or 8 reflectors, 10 degree or 20 degree or combination of both.
Low voltage protector
high voltage protector
Voltage regulator
Lexan glass plate for front of the case
the case for the light.
Wire to wire it up
Fuse % fuse holder
On/Off switch
Dimmer module and control

What I want to know, is how hard would it be for me to make a pair of Fog/Driving lights for off road use like the Rigid ones, but with 6 or 8 SST-90's?

It would need to be compatible with 9v-14v DC. I was also thinking that a Dimmer with a digital readout 0%-100% in the truck would be nice so I can control how bright they are.

With 8 SST-90's @ 100% that would give me 18,000 lumens. 50% would be 9,000 lumens, per light head.

I know it can be done, but what all do I need and where to get the parts?


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## AnAppleSnail

SST90 would make a crap fog/driving light. It's the gospel truth. You want a careful beam pattern for fog lights. I guess if you wanted mega flooders they might work.

It would be very hard. You need to address durability, waterproofing, optical design, electrical systems, high-power (100W+) drive electronics, thermal design, and aiming. Don't forget to cover these while on roads.


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## werearemyleds

AnAppleSnail said:


> SST90 would make a crap fog/driving light. It's the gospel truth. You want a careful beam pattern for fog lights. I guess if you wanted mega flooders they might work.
> 
> It would be very hard. You need to address durability, waterproofing, optical design, electrical systems, high-power (100W+) drive electronics, thermal design, and aiming. Don't forget to cover these while on roads.



I am sure the electrical system in the truck would be fine. I am running 2x Yellow tops with a 300amp alternator.

How would the SST-90's affect beam pattern? it would make more sense that the reflectors and the pattern of the lens in front of the reflector would affect the beam pattern?.

As you can see from the first link, 2600 lumens is possible. I just don't think I can buy a set of those from rigid and replace the LED's with the SST-90's. That would make it too easy.

Even if I bought the rigid ones, and put 6 SST-90's in it instead of what they are using that would be almost 12,000 lumens per light x 2 for a pair of lights x 6 for a full light bar on my roof.

My "big 3" (alternator to battery, battery to chasis ground, battery to engine ground) are all 5200 strand 1/0g cable. and any cable I am running to these lights will be between 6 and 4ga.


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## alpg88

the beam pattern of fog light is very specific, no led optic today, (that includes oval lenses), is sutable as true fog light. even that led light that is sold in first link, is not real fog light. in event of fog, you will create huge ball of light right in front of you, that you can't see past, and with 12000lm you will blind yourself. not to mention cold spectrum of led isn't the best to poke thru fog. you need warm light. there is a reason why fogs used to be yellow.

in auto lighting beam shape isn't all that matters, light disribution inside the beam is very important, something that isn't an issue with flashlights, street lamps, home lighting..


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## AnAppleSnail

You know how if your headlights aren't aimed right, they put a bunch of glare on the ground nearby so that you can't see very far? That's because the beam pattern is wrong. The technical reason you can't see well with mis-aligned headlights is that you have lux in the wrong places. Lux is the scientific unit for 'How intense is the light?' It's 1 lumen per square meter. Full noon is about 100000 lux, while inside an office it's about 500 lux. The reason you want to be careful with driving beams (On or off-road) is that if you have too many lux nearby, you need WAY more far away to be able to see things at a distance.

In general, a larger LED requires larger optics to get a certain amount of light down where you need it. If I get a flashlight made for a small LED, then put in a larger one, I'll get a wider beam pattern. But even if I get more lumen, the lux (intensity) of the center of the beam will not rise much, and may even decrease. The nearby spill of light can keep me from seeing as far as with the smaller LED.

The same is true of any vehicle light. An on-road headlight is a marvel of optics. It puts light where you need it, and if properly adjusted wont' blind oncoming drivers. Shine them at a flat wall to see how crafted the output is; most in the US create a T-shaped beam. Now, off-road lights can sometimes be big bucket blasters and give you enough light to see twenty yards, but if the ground nearby is flooded with light, even fifty thousand lumen won't be enough.

In other words, lumens aren't how you see. Lux is - because it takes into account how the light spreads out. For reference, a car headlamp running correctly is about 500 lumen. Off-road lights will have a wider beam pattern, but if you want to see very far ahead it cannot be "too" wide and still be useful.

Most optics you can get easily are for flashlights. They're pretty simple, being mostly-conical reflectors or optics. There are some lens-based ones that might do better, but a cone isn't a good driving beam. It'll shine up into the sky or down into the ground if you drive over a speed bump, much less real terrain. The lack of optics is a challenge to any DIYer, although blending beam widths can help.

Large LEDs are more difficult because of the optics size I mentioned. For something like an SST-90, you'd need several large-ish reflectors (ten-cm to see about thirty yards) for your light. These get pricey, and must be housed to protect them. Big durable cases are pricey too. LEDs want heatsinks, which means big machined metal, and the driver may want heatsinks as well.

I don't know a lot about automotive drivers for LEDs. 0-100% dimming isn't as useful as you'd think; you'll really manage most needs with three to five output levels. Fortunately a driver suited for automotive stuff will control the power. LEDs reallyw ant regulated current, not voltage.

Check out this guys' product: 6 XML Light Bar if you can stand to buy instead of building.


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## werearemyleds

alpg88 said:


> the beam pattern of fog light is very specific, no led optic today, (that includes oval lenses), is sutable as true fog light. even that led light that is sold in first link, is not real fog light. in event of fog, you will create huge ball of light right in front of you, that you can't see past, and with 12000lm you will blind yourself. not to mention cold spectrum of led isn't the best to poke thru fog. you need warm light. there is a reason why fogs used to be yellow.
> 
> 
> 
> in auto lighting beam shape isn't all that matters, light disribution inside the beam is very important, something that isn't an issue with flashlights, street lamps, home lighting..



I could get around that with an amber/yellow polycarbonate lens cover?


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## werearemyleds

So would I be better off just getting 5 pairs of 55w 6000k HID's for the roof of the truck? (Since apparently LED's can't get me a good light pattern).

I would prefer to go LED over HID, but I guess that is where technology is now, the LED's have the light output though.


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## alpg88

are we talking about fogs?? if so you can't put them on the roof, i mean if you want them to be useful in fog, that is.
fogs should be placed as low as possible. and have thin flat beam.
if you looking for just simple spotlight, that imo, yes, at this time you better off with hid, for far reaching focused beam.


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## werearemyleds

alpg88 said:


> are we talking about fogs?? if so you can't put them on the roof, i mean if you want them to be useful in fog, that is.
> fogs should be placed as low as possible. and have thin flat beam.
> if you looking for just simple spotlight, that imo, yes, at this time you better off with hid, for far reaching focused beam.



Looking at making fogs and spot lights. I guess as far as the driving and wide lights that rigid make in that first link, they must not be that good. Even if the pattern is not "ideal" the LED's are are lighting up the road ahead pretty well.

I guess what is the difference between being 100% perfect and being useful if only 60% effective?


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## AnAppleSnail

I think you are asking for off-road lights, not fog lights. Fog lights make a fan of light to use at low speed with minimum glare, and it doesn't sound like what you are describing. Off-road lights have some range of megablasting output, along with some spot. Some people describe off-road lights as pencil beams or floods, but useful fog lights are always a low-mounted horizontal fan of light.

Why have you decided on several thousand lumen of light? 5x 55w HIDs would be over ten thousand lumen, and the beam pattern would depend on the reflector. HID is a high-power small source (Pea-sized or smaller) and it can be quite focused with even a four-inch reflector. That doesn't mean that a four-inch reflector gives a useful pattern.


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## werearemyleds

I think some manufacturers use the term fog light loosely. I live 60 miles out in the country and have 300 acres, so these lights would only be used on my land in the middle of know where.


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## Hilldweller

Sounds like you'd like these:
http://www.rallylights.com/detail.aspx?ID=4970


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## electromage

Deleted


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## TEEJ

werearemyleds said:


> I think some manufacturers use the term fog light loosely. I live 60 miles out in the country and have 300 acres, so these lights would only be used on my land in the middle of know where.



Some manufacturers use the term "light" loosely.



Essentially, a fog pattern is for fog...its a type of light meant to be mounted low,and shine in a pattern that illuminates the centerline and fogline along the shoulder of the road...so you can slowly creep through fog w/o accidentally going off of the road/hitting a stopped rig infront of you, etc.

Its supposed to be mounted low, because a fog is pretty much just a low cloud...and, if the beam can be shined under it,, rather than through it, you'd have less glare, and, what you want to see will be lit up under the fog.

If the beam is too high, it shines ON the fog, which makes the fog glow...and, all that glowing fog is hard to see through.

This is also why, in drivers education, etc, they teach the kids to use low beams, not high beams, in fog....because the high beams are aimed higher and will glare more.


So there is such a thing as a fog light, and, its meant to be used in fog.





As for driving light, that's a far less specific description, but, generally, its used to supplement the high beams by illuminating things beyond the range of the headlight high beams.

If there's too much of its light within what the headlights are already illuminating, again, it makes your pupils stop down and your night vision degrade back to day vision, so you can't see distant things as well (But WILL see close up stuff great).


This pattern of light too close is what makes the ricers/newbs, etc, think that their light bars, etc, are so bright...there IS a giant pool of proximal light, and it LOOKS HELLA BRIGHT! 

They typically can't imagine that they see less than before...because their eyes are lying to them.


So, anyway - It doesn't sound as though you want to drive in fog, so lets for get about the fog patterns and so forth....it SOUNDS like you just want to be able to patrol your 300 acres and see as much as possible of what's out there at a time.

For that, roof lights will be better if they don't glare out your windshield and hood, etc....and bumper mounted versions are preferred if the hood glare, etc, is a problem.


If making your own lights (its been done, but, rarely well), you'd mostly be trying to figure out how to get the added light, to be added where it will be useful, and, avoid putting any of it where its detrimental. The less expensive/less well engineered systems tend to have a lot of proximal light, as that's what impresses customers and is easiest to get as a result. Their DESCRIPTIONS of that light are typically either outright lies, or, fanciful versions of reality, etc. Chinese lumens for example for the ebay specials are mostly fabricated, and occasionally based upon the theoretical maximum outputs of the LED itself, multiplied by the number of LED...w/o taking into account that ~ 1/10 to 1/14 of that output actually leaves the light and shines on something useful....and, as there's no rules for that, a 5k lumen light might be 4x as bright as a 20k lumen light, as far as advertising goes...you can't compare specs as they are mostly just made up.




Do you have a maximum line of sight, as in, how far CAN you see at a time out where you'll be, before a rolling terrain/trees, etc, block your view? What are some examples of what you'd want to be able to resolve at that range?

In some places, a guy might need to see if there's coyotes as far away as 500 meters, or find his cows, or whatever....what are some examples of your applications?


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