DIY Cree Rocklights

[slosurfer]

Those oznium ones say that the housing gets to be 120-130*F with regular use. I didn't realize that LED's put out that much heat.


Mike, do you epoxy over the whole thing or just up to the lens?

[CJM]

Really, I didnt read that part! ^

[slosurfer]

Yeah, it was on the tech sheet.
http://www.oznium.com/marine-led-light/tech
Surprised the hell out of me that they got that hot.

[Robinhood4x4]

The wattage is W=VA, so 3.3Vx0.5A = 1.65 watts, but wattage is not a good indicator of how much light a LED is outputting.

Chris, you're used to normal 5mm leds, like the ones for indicator lights. These high power LEDs put out a lot of heat and it's an important consideration in the construction. You can easily burn them out if they get too hot, thus the reason for the copper cups.

[4x4mike]

Really, I didnt read that part! ^

Yeah, hot. If they don't dissipate the heat they will dim and their life is decrease.

how many watts are those cree's? i just got a flashlight with a cree led so im really intrigued with how much light you must be getting from these things

The newer Q5 fenix lights put out around 160 lumens but I'm not sure what the current is.

The wattage is W=VA, so 3.3Vx0.5A = 1.65 watts, but wattage is not a good indicator of how much light a LED is outputting.

Chris, you're used to normal 5mm leds, like the ones for indicator lights. These high power LEDs put out a lot of heat and it's an important consideration in the construction. You can easily burn them out if they get too hot, thus the reason for the copper cups.

Each led consumes about 3.3 v and the regulator, 2v. Minimum lumens out of the Q5, AT 350ma is 104 lumens. Mine are set to run at 500ma.

[Robinhood4x4]

If it follows the same curve as the XR-E data sheet, then at 500ma you're about 35% brighter.

That works out to about 140 lumens. It's probably a little less because the curve is for a junction temperature of 25C and I'm sure it's hotter than that.

[slomatt]

Recently I picked up some similar switches for $2 each, they're still in transit but I'll put up better pictures when they arrive.

http://www.surpluscenter.com/item.as...tname=electric

The newest Cree XR-E Q5 bin puts out 228LM at 1A and can be bought for $6.50. This is great for high powered flashlights, but probably overkill for rock lights and require a lot of heat sinking if you run them at 1A. The older Q2 bin XR-Es are $3.60 each if you buy 10 of them, these are what I've used for my lights.

- Matt

[4x4mike]

Cutter has R2 cree xr-e's. I didn't need to go there but it's good to know where to get good ones.

[4x4mike]

I had time to finish my project because it's was a beautiful day and wanted to be outside. Anyways. Today was mounting the fixtures and wiring them all up. The wiring is not hard but you have to know what you are doing. If not you'll finish and they won't work or you'll short it out and pop the leds.

Lots of wire and loom later (and waiting until dark).
The back 2 were already there. This project was the front 4.










I might adjust them a bit to find the best spill but I'm pretty happy.

[slosurfer]

Nice! Those are some bright suckers.