LED lighting

[ervinelin]

eddy: Yep, forgot to mention it, I am using Arctic Silver Thermal Compound for it =)



ervine: Yep, I bought some optics for it from www.ledsupply.com, supposedly able to diffuse the light to 47degrees, but I have yet to try it yet. And my Crees from DealExtreme just arrived! I waited a month for them though.. but it is half-priced! Btw my tank is 1.5ft so I think 6 Crees should flood it thoroughly regardless =)

Oh, and the thermal epoxy... I admit I cheated! I just ordered from www.ledsupply.com since I saw that they were selling it too. $13USD if I'm not wrong.

AND YES, my hands are SUPER itchy haha.. meanwhile I have been thinking how I can use my Arduino/Atmega chip to control the sun simulation. Which microcontroller are you using? Atmega or PIC?

I must say ervine's DIY automation post has been the worst poison of all for me =P

Oooo... cool they sell thermal epoxy, that will save you a lot of trouble.

The sun simulation is done via a custom pic program i wrote, it fires the LEDs via PWM (pulse wave modulation). No Arduino as it's a bit too expensive leh, I built the circuit myself (which is probably why it's so buggy!!). I had to incorporate the clock into the software, the clock itself took up half the space on the chip!

[edwardchuajh]

I see!

Well I doubt I will finish the thermal epoxy so if you ever need some I can provide!

I was considering PIC too, but realised I have to plunk money down for the programmer also. Bought two Arduino's a while back, so now I can just buy the Atmega chip (~$7) and program it, to incorporate in my self-built circuit. So cheaper =)

I'll check with you again once my LED light is up!

[ervinelin]

I see!

Well I doubt I will finish the thermal epoxy so if you ever need some I can provide!

I was considering PIC too, but realised I have to plunk money down for the programmer also. Bought two Arduino's a while back, so now I can just buy the Atmega chip (~$7) and program it, to incorporate in my self-built circuit. So cheaper =)

I'll check with you again once my LED light is up!

Happy DIY-ing!

[felix_fx2]

Oooo... cool they sell thermal epoxy, that will save you a lot of trouble.

The sun simulation is done via a custom pic program i wrote, it fires the LEDs via PWM (pulse wave modulation). No Arduino as it's a bit too expensive leh, I built the circuit myself (which is probably why it's so buggy!!). I had to incorporate the clock into the software, the clock itself took up half the space on the chip!

ervine, you mean your wrote the program yourself? GOOD
I am getting even more impressed by you

[edwardchuajh]

felix:

see! ervine is DIY automation poison lol..

[ervinelin]

ervine, you mean your wrote the program yourself? GOOD
I am getting even more impressed by you

Ah yes.. haha.. went to get a book and learnt how to do it. Quite simple actually, just logic. Of course I used PicBasic and not assembly language to program the chip...

[felix_fx2]

wha, solid i never expected chip programing was so friendly.
But soldering is way hard for me. Due to the nature of my illness, i can't hold the soldering iron in place long enough.

But i still wish to learn more tricks .

[edwardchuajh]

Felix: nowadays there're two pretty easy platforms to get into microcontrollers quickly. Can google more on Arduino or PICAXE.

[bezz]

Hi Guys, where in SG can get an Arduino + the shields?
And roughly how much?

Thanks

[bezz]

Oooo... cool they sell thermal epoxy, that will save you a lot of trouble.

The sun simulation is done via a custom pic program i wrote, it fires the LEDs via PWM (pulse wave modulation). No Arduino as it's a bit too expensive leh, I built the circuit myself (which is probably why it's so buggy!!). I had to incorporate the clock into the software, the clock itself took up half the space on the chip!

Actually why you use thermal epoxy?
Its a permanent bond, if the LED fails, it'll be very difficult to get it out to change.

Why not use thermal pads?
3M thermal pads can be bought from Sim Lim Sq cheaply at $1 for 4-6 pads. These are the same pads used for attaching heatsink to computer chips. Can peel the LED off if the need arises in future.

[BFG]

Bezz, got a picture of how this thing looks like?

[edwardchuajh]

Hi Guys, where in SG can get an Arduino + the shields?
And roughly how much?

Thanks

You can try www.sgbotic.com but its quite expensive I think.

I got mine from www.solarbotics.com in US, the Freeduino, which is one with more upgrades.

I am using thermal epoxy to attach the heatsinks to aluminium bar, then using screws and thermal paste to stick LEDs to aluminium.

Best part of epoxy is its VERY quick and fast to you. Plus if you dont think you are going to take out the LEDs, its a good option.

Personally I don't think thermal pads will be a good option, because it might not be as adhesive as epoxy, and we are using it above a tank with high evaporation. Thermal pads might corrode/melt over time and lose stickiness. LED falling into tank = very bad =)

So I think screws + thermal paste is a good compromise. Though you have to screw the holes. But star PCBs allows quick mounting with screws.

Lastly, GOOD NEWS!! my entire package came, now to collect my 24V DC wall adaptor and I can start work

[bezz]

BFG,

Heres the link to a discussion on thermal pads vs screws vs thermal epoxy:
http://www.nano-reef.com/forums/inde...hl=thermal+pad

Advice from Evilc66 is worth taking note of as he is the LED Guru who started designing LED lights for aquarium use a few years ago.

I got the thermal pads from SL Sq and will use it on my 24 LED build. I have all the parts, just need time to sit down and put things together.

[edwardchuajh]

bezz:

Interesting thread! hmm maybe we can each attempt thermal pads and screws + thermal compounds, and run it for a period of time and then share our findings with the forum =)

Do post your setup when it's done!