Thinking of DIY LED build and need advice

[ming]

Good to know! I'll place the order after I finish setting up the new tank. Thanks!

 

[smoq]

i dont know how far along you are but here are some tips anyway...

i've tested many 9v wall warts and none were nine volts or less. they all put out varying voltages depending on load, if you try to regulate the wall wart using a pot your current will also vary when you adjust them...it would be very convenient for you to get yourself a volt regulator off ebay for $7. look for this on ebay...there is a guy that ships from the US but his price is off by about $80 right now, i think it was a typo... look for one with an input voltage between 5-24v and output from 2-12 (they come with a pot to adjust down to ten.
LM317 Adjustable Voltage Regulator Prototype Module USA




I wouldn't tap, i would use thermal epoxy. it's very easy, nowhere near as time consuming as drilling and tapping and it is very easy to remove burnt LEDs.

check out the prices for LEDs at etgtech.com and check the prices for meanwells at CDI.com (i think)

Actually, I'm as far with this project as it's almost finished Too bad you didn't write earlier, I would get that voltage regulator. I'm using this wall wart http://www.sparkfun.com/commerce/product_info.php?products_id=298 and it's giving me constant 9.2V even under load so I think I'm good so far.
The best thing is that my project works! I can dim it to about half the brightness with 10K pot and then it turns off, but it's enough for the needs of the tank. When I turned the SRV2 screw inside the meanwell all the way I could get max 850mA, do you think the pot doesn't allow for more flow of electrons? Anyway, I drive them at 750mA. There are two things I need to figure out before I can hang this thing above my tank:
1. When I run the leds on full power the 0.125mm aluminum plate gets to hot to touch after some time despite two 60mm fans blowing at it. I ordered this thing instead as recommended by someone http://www.newegg.com/Product/Product.aspx?Item=N82E16835119093

2. The LEDs are so freaking bright! To the point where they hurt my eyes. Do you think I will get used to it? I've put 80 degress optics on the blue to minimize this effect but there are none optics for the xp-g's as far as I know. What would you suggest? Can I lower the light (currently I was planning to hang it 6" above the waterline)?

 

[qy7400]

Glad to hear the projects coming along, any pics yet? I picked up a 12 LED setup from RapidLED along with the Arduino chip to play with controlling it, figured start small and see how it works. I got the heat sink and it gets hot without a fan cooling it, I had some 120V 4” fans sitting around that do a great job, with the fan running the heat sink is warm at best but curious to see how the plate idea works out for you. On the fan you ordered from NewEgg what are you planning to use to power it? The pic looks like a standard 5V PC connections. I went the same route with the XP-G and they do not have reflectors available, they spec sheet from cree lists them at 125 degree and I decided to not use them on the blues just to see. 6” above is good, I have a pair of fixtures (Alibaba) from the LIRA group buy that site around that height over a 120 and the light spread seems OK. On this DIY I was going to mount a small acrylic sheet as a splash guard, Lowes has them for 2 or 3 buck.

 

[smoq]

Glad to hear the projects coming along, any pics yet? I picked up a 12 LED setup from RapidLED along with the Arduino chip to play with controlling it, figured start small and see how it works. I got the heat sink and it gets hot without a fan cooling it, I had some 120V 4? fans sitting around that do a great job, with the fan running the heat sink is warm at best but curious to see how the plate idea works out for you. On the fan you ordered from NewEgg what are you planning to use to power it? The pic looks like a standard 5V PC connections. I went the same route with the XP-G and they do not have reflectors available, they spec sheet from cree lists them at 125 degree and I decided to not use them on the blues just to see. 6? above is good, I have a pair of fixtures (Alibaba) from the LIRA group buy that site around that height over a 120 and the light spread seems OK. On this DIY I was going to mount a small acrylic sheet as a splash guard, Lowes has them for 2 or 3 buck.

Pics are gonna come soon, I'm planning to start a separate build thread when I'll have more time (overtimes are killing me now). Controlling the leds with arduino is a great idea but I have no knowledge about it myself. Can you guide me to a site with basics of programming in arduino?
Yeah, the leds are getting very hot without a fan. I let you know how it'll work with the newegg fan. The fan is supposed to be powered by 12V power source so I'm just gonna desolder the 60mm fans' connections and replace them with my new buy. My friend gave me today an used pentium processor fan so maybe I use them both. Anyway, the aluminum plate works very good and it's much cheaper than heatsink. The only thing to remember is to set fans to blow on the plate.
I also plan to use an acrylic sheet as a splashguard and Lowe's has the best prices on acrylic, much better than HD.

Good luck with your build, I'm still waiting till the fan arrives so I can finally hang this thing above the tank. The question is, should I dim it all the way and let corals accilmate (I'm switching from 4x24W t5's)? Then what?- adjust the lighting everyday till I get the full power of my leds? How much time do corals need to adjust to a new lighting?