need some advice before my DIY LED project...

[Skeeter7424]

So we are beginning the buildup of our 4 gallon pico. I have decided I want to build an LED enclosure for it. It is going to be 4 RB and 4 CW. I would like the blues on a buckpuck with a pot so we can dim these and color the tank as she sees fit. So what I am looking for is a confirmation that what I am looking at is right, and that I don't need anything else.
- 30 watt power supply w/12vdc out
- 4 cree xr-e CW
- 4 cree xr-e rb
- custom heatsink
- 80x15mm fan (old computer part)
- 1 dimmable 1000mA buckpuck with pots (for the blues to control color temp)
- 1 constant current 1000 mA buckpuck

I think that is my build list. I have all the wiring and solder in my workshop now. My other question was, I was planning on wiring the fan in series with the blues. Is this going to work? I know it will run at the amperage that the blues are running, thus controlling the fans speed as well, but if it ends up running to slow, I will wire it seperately or in the whites. Just making sure this will work. So pumped to build this for the pico, we wanna pack it with corals...

Thanks for any and all help as usual!

Cheers
...Skeeter...

 

[PasstheTorch]

My hint is that you should put the whites on the dimmer because the whites wash out the blues sooooo much. I have 3 cw and 4 rb and it's too white. Deff put the whites on the dimmer IMO. You will be much happier I think.

 

[Cheetos]

For the difference of $5 I would use two dimmable pucks so you can set the color temp to whatever you want! You can't run that fan in series with the leds. It has to run on 12 volts. Everything else looks good. What are you using for a custom heatsink?

 

[Skeeter7424]

ok, so I'll run the fan pre-buckpuck on its own switch. The heatsink is a pair of AMD processor heatsinks that I "tied" together. Don't worry, you'll see. And the 1000 mA buckpucks are the ones I should be running correct? Not the lower amperage? Thanks again.

...Skeeter...

 

[jarrodsanborn]

i am for building and diy stuff, but have you considered using a par38 style light? might be cheaper/better for your build.

also, if you do diy, i think the 1000 mA may be overkill. you wont need to run the leds to the max, and may not want to.

ps, i think the buckpucks can only run 6 at a time. just wondering, are you sure you want to put 24w of led power over a 4 gal tank?

im not trying to discourage you, i cant wait to see the build.

 

[Cheetos]

The 1000 mA pucks are fine. That's max for the XREs. You could run the royal blues at 700 mA. You won't notice much more brightness after the 700. Those 8 LEDs are fine for that tank. I built an 8 LED array for a 2.5 gallon I had and now use it on my 7 gallon. Those are running on 1000 mA pucks. Just remember you can't run a 12 volt fan on a 30 volt power supply. The fan would need it's own power supply. Also that power supply is overkill for the number of LEDs you will be running.

 

[DoctaQ]

you also cannot run 4 leds on a 12v power supply, you are going to need a 17v power supply at least, save the 12v for the fans if you are going to use a laptop power brick as the PS

 

[Cheetos]

I so missed that! I thought he said 30 volt power supply! I agree an 18 volt would be more likely to find.

 

[Skeeter7424]

Jarrod: I ahve considered the par38, I just dont like it. I have seen a couple tanks running these bulbs, and I wasn't a fan of the color they were getting. This gives me all the flexibility I could ever want. And I may go down an amperage on the buckpucks, But i also figured why go lover when I can just turn them down? Again, if I'm wrong please correct me.

Cheetos: Got it on the power supplies now. I didn't wuite think over what I was putting on the list, again, thats the reason I post things Anyways I will supply the fan and the lights seperately. A 24V PS for the lights should be enough correct?

Doctaq: Thank you for your input. I will be running the fan seperate, with its own smaller PS

Thanks to all for the help, any more in still appreciated. Didn't get any of it ordered yet because I am working on the stand/canopy combo for this same tank, that thread will come later...

Cheers
...Skeeter...

 

[DoctaQ]

go for the 1000ma because yes you can turn them down, a 24v PS is plenty, you could actually up it to 6 leds in series with a 24v

 

[Skeeter7424]

OK so after all of this discussion (among others) , and kicking prices around, I have decided to ditch the "piece my own kit together" idea and just spring for one of the retrofit rapidled.com kits. Maybe I'll piece my next build together for the 34 gal... I am looking at either the dimmable or the non-dimmable 12 LED kits. I like the idea of it being dimmable so I can turn it down initially and slowly acclimate my corals to the light source. However when I read the directions on the two drivers, my head begins to spin again. On the ELN-60-48D driver (if I understand correctly) I also need to purchase the 10k ohm pot, and a 10V power source. On the ELN-60-48P driver, its dimming circuit is controlled by a PWM (pulse width modulation) circuit, which you can only control with a controller, not by a simulated DIY dimmer (correct?). Is there another way to dim the 48D driver? And is there a way other than a controller to dim the 48P driver? As soon as I figure this out I am pulling the trigger on one of the kits. I am pondering also not running all 12 of the lights on either kit as I think that may be just a little too much light (even turned down) on our 4 gallon. Thanks for the input all.

...Skeeter...

 

[DoctaQ]

buckpucks is all you need, the meanwells are better for builds of 24 or more leds.
however as a reference, the D model needs a 10v voltage, then depending on how much voltage is being fed the current will increase proportionally
the P model can be run off of any pwm controller but you can also build your own with a 555 timer and other parts