LED tech for 4x4's

[Craig]

Yes you need some fabbin skills here, soldering is still molten metal there are two categories when talking led's those under 1watt and those over 1watt or high power led's. I going to try and cover more about the high power led's and the designs needed to make them run for max light. I added links to key words if you what to look at more details.
With that said the brightest led out there is the ( edit... Wait somebody put 4 on the star board for 900 lumnes ouch) endor star ( hey I not taking some billion cluster crap, but stuff us 4x4 guys can use) here's a term you will needed to know. lumens
The 55 watt tractor light we all love and hate produces 1475 lumen's with a life of 675 hours. Data taken from this site "I bought some horns from them too"
now what the h3 manufacture did not tell us is a lot of light can be lost in the design the fixture. That's why some nice big hella lights cost like a $100 and some harbor freight version are $10 bucks a pair and both use the h3 bulbs.

Specs on the endor star. From this site

End product for reference. Notice this has an led driver, heat sink and fan. Read more here

The biggest killer of an led is heat. Unlike the incandescent bulb which projects a lot of heat energy out, these led's don't produce any infrared light (heat) so all the heat is generated at the base of the led. But it a fraction of the heat created by the tractor light.

 

[Craig]

Leds can just have a current limiting resistor added and connected to 12volts. I have bought some of these and they are good for replacing interior lights and use appx 1/10 of the power. Here is a site For resistor calculation. Using the calc program you can see the endor star would need a whopper of the resister, couple ballast resisters would be needed.

So with high powered leds it best to use a current limiting device. You could build your own with an lm3403 chip and few other parts, but they have a driver already built and in a "potted" package. There are several models and types click here I bought the buckpuck 3021 And the harness with a dimmer pot. This driver also has a 5v ref for drivin other items like a and can accept input for a strobe feature too. An led driver gives you better efficiency over a resistor and better control. Basically if you running high power leds you really need a driver to control them. You can get a basic driver for 14.99. The driver with all the bells and whistles will cost you $17.99 plus $4.99 for the dimming wiring harness.

For you first project you might not what to use those endor stars as they are not cheap at $17.49 each Plus a driver your looking at $40 bucks for one light.

Do you really need all that much light? I think the 55 watt lights are a bit overkill when you running 2 on the front bumper, 2 behind the front tires, 2 in front of the rear tires and 2 on the rear bumper.
Since this is my first build of high power led devices. I opted for some smaller cheaper leds. These are less than $5 each. And put out 3 times the light of the roundeyes Leds. But since I will use a driver, vs a resistor I sure these will be closer to 5x the light. (no I ain't got a lumen meter ) just my eyes I might get a few of these as there are twice as bright and still under $8 bucks each.

here a pic of a rigs with the cheaper p4 led,s and these are low on the lumen's scale when compared to the endor star. Which means even lower amp draw. I will be build these in this rightup and 3 of these lights will pull 1 amp of current!!

 

[Craig]

While I'm waiting on my high power parts to arrive ( be patient as it can take a couple weeks) I'm working out the details for heat sinks as you need to keep leds cool. I'm still looking for ideas to mount them too. It would be nice if the mount could be some what adjustable as there never seems to be the "right" spot. Here is a design copy from the pirate, it looks good, but the heatsink imho is too small. Take 2 leds with the same power, but one with and one without a good heat sink and you will get about 40% less light out of the led. Now if they mount this led tight to some sheet metal it will work better longer.

 

[Craig]

Basic physics. Copper has a thermal transfer rate two times greater than aluminum, supporting data. With that said, I'm looking into designs that can use common copper plumbing parts.
I have some very expensive design software that allows me to model many shapes and led's configureations. (the gave me a 1 week trail license, its only a $10,000 per year license ) but like all things, it will come down to build it and test it.

 

[Craig]

Ok this thread is read more likea saga then a how to.
I found some cheap led drivers fixed at 755ma and order it to test it out. At $3.44 if these work out this will be the way to go

I sold some junk and my pal-pay has some money in there so I order a couple of these too. 228 lumens this is like 6 1 watt led flashlights.

 

[Craig]

Just keeping track of all the details, looks like the chip manufacture susgests adding a couple componets if over 12 volts is used.

 

[Craig]

Hey it's only been days and my driver arrived. Wow its small.

 

[Craig]

Ohh ahh, more parts arrive.
Using my spare laptop power supply I connected up the led driver and touched the leds to the led star.

 

[Craig]

I've never tried these, but here are some pre built 1 watt leds $12.22 to your door. For the lazy
dealextreme: $12.22 waterproof water tight high powered 1w led module (12v/white)

I'll hit blue collar supply this weekend for some aluminum bar to use as led heat sinks and post some pic's soon of what they look like on the Scout.

Edit.. I hate driveway shots, but had to see what they look like.

These things are are bright as a stick welder

heres another shot from the other side. I have 3 leds under my rockers in this photo. I found I could turn them down ( I have a pot attached) and it's more then bright enough at 1/2 power. Compare to 55watt light comming soon.

 

[Craig]

I know major slacker, went wheelin instead of buying some aluminmun to mount the lights, this weekend is not looking much better either

 

[Craig]

Ok stop off at blue coller supplly for some surplus aluminum $3 a pound. Came home with 2 pieces of 3/8 x 2.5 x 12" long

using the the table saw, I made a base and cover to protect the light. Calling this one proto type 1. I ran it for two hours at full power and it was getting warm but not hot, so the heat sink is big enough. You can see where I sanded and then polished the surface before silver epoxy to the surface for better heat transfer.

Also my other drivers came in, I will hook one up and run it for a few hours to see how it works. This are dirt cheap compared the the other drivers. Any smaller and I won't be able to solder the wires on. My red leds came into, so I need hook one of them up to see how bright they are.

 

[Craig]

Quick update. The cheap drivers listed in post 5 will not work. They look to be made for cheap flash lights, the first 2 blown up on me and the third was very dimm. These things are junk!!!

I'm going to order some of the first driver I got

 

[BigTallKen]

Hey Craig,

just throwing this out there, but would some thermal grease such as arctic silver used for mating cpus to their heat sinks help with thermal efficiency?

 

[Craig]

The grease would work fine, but better for inside applications where water would not mess with with it. You would need to add screws or something to hold the led in place too. Thats the reason I did the glue. I need to order more of those good drivers and add more lights. I need a couple under the hood for night work, plus a few more to use as courteous lights when getting in and out.