LED DIY with photos

[DiverDude]

I dunno, that wire seems awfully thin for the kind of current that array is going to draw....

Where'd you get the Hakko 936 ? Those have been discontinued for a while now (I have 2 of 'em)

[mike31154]

Originally Posted by DiverDude

I dunno, that wire seems awfully thin for the kind of current that array is going to draw....

Where'd you get the Hakko 936 ? Those have been discontinued for a while now (I have 2 of 'em)

Ya, 28AWG is small stuff. I think it's still within the ampacity limits for the current he's running, but might be worthwhile upsizing that several iterations to pad the safety factor. Thinner wire also presents more resistance & therefore voltage drop. This could be a factor depending on how many are hooked up in series with that tiny wire. Look up ampacity & you'll find plenty of charts. Here's one example:

http://www.powerstream.com/Wire_Size.htm

According to the chart, max current for 28AWG in a chassis wiring application is 1.4 amps or 1400 milliamps. That stuff could be tricky to solder as well. A little too much heat & the insulation will shrink back a ways or even start cooking.

[eli@fijireefrock.com]

I will post few more pictures and info later on tonight as the array was finished yesterday.
The wire I am using is of no hassle and is of correct amperage resistant to what its used for and its a little tricky not to strip it whyle soldering.
Unfortunately I need to upgrade to a bigger heat sink as the U Chanel aluminum gets too hot if run the array at full blast witch what I intend to do.So I have to wait a couple days to receive a 1.8" X 36" heatsink from Martin.

[reefermadness]

I run that type of U channel no problem with 3w leds run 2" apart. They are barely warm to the touch, no fans. I mount them so the fins are facing up though I think that would make a difference. I also paint them with a high high flat black paint. My research indicated that a painted heat sink has better heat dissipating properties (emissivity).

I definitely would have went with a larger awg wire.....for the small cost it's a nice piece of mind.

[eli@fijireefrock.com]

I think the reason for over heating my array is because I placed 22 LED running at 700ma in a U shaped aluminum of 34" length.witch gives me a gap of aprox 1.4" between each LED.
I just placed another U shaped aluminum on the back side (with heat transfer grease) and turn the array on so far 15 minutes passed and its running warm that maybe the answer as more surface area for heat dissipation

[eli@fijireefrock.com]

Originally Posted by DiverDude

Where'd you get the Hakko 936 ? Those have been discontinued for a while now (I have 2 of 'em)

I think I got it from B&E by your recommendation about a year ago and I must say that I love it

[eli@fijireefrock.com]

While waiting for a couple fans and a heat sink here are couple photos of the 80% finished array

Here is what I am placing as lens on each LED as I had some laying around from a prior DIY with some phylips LED and must say these lens fit perfect.


All lens are on tight,last night I cut and bent an acrilic sheet for a cover I must say it turned out a perfect shield




and now its wired and ready



Plug is going into the wall and voila





Man its bright too bad the camera doesn't do it any justice.

[Stones]

Nice LED build. I imagine you were seeing spots after testing out the fixture.

[reefme]

Nice! One question, how do you get air evenly into here?

[eli@fijireefrock.com]

Originally Posted by reefme

Nice! One question, how do you get air evenly into here?

Because its a small array and not running at full blast,room temperature keep it cool with no added fans.
Although because I have 22 led and max at 700 ma it I was to run it at full shouldn' t br a problem in my case as it sits near 2 other arrays with high power fans to keep it cool.