DIY LEDs - The write-up

[jjrreef]

Sorry I've lost track - how high up is your fixture? What's your LED count?

12" higth. 12 whtite and 12 blue 3 w leds

 

[jjrreef]

Sorry I've lost track - how high up is your fixture? What's your LED count?

12 " high 12 white leds and 12 royal blues




That strikes me as poor code structure. Ideally, I'd assume you'd have a single function that did the PWM mapping. Then you could have lots of code elsewhere to determine what "value" the pin should be set at, but let that single function actually map your range of values to the 0-255 range the Arduino can produce. Maybe it's just personal preference though.



You'd need a 10v source, not just a different transistor. FWIW, check the thread I posted above. I designed a shield that has a 10v source and transistors to convert the Arduino's PWM to a 10v signal. Waiting to get prototypes back from the board house, at which point I'll donate them to volunteers for testing since I don't have any mean wells to test with. I appreciate the all-in-one design (putting the drive circuits and LCD into a single package) in that circuit but it locks you in to those choices. Meanwhile if you break out the drive circuits onto a shield, you can just add it to any Arduino controller project - I like that approach because the circuitry required will vary depending on which LED driver you're using. Meanwhile, other reef-controller circuitry won't likely vary from tank to tank, so that stuff can be integrated without loss of flexibility.

Different approaches with different goals, though.

 

[Skeptic_07]

jjreef I hope that is for a fish only tank. With such a small amount of LEDs on such a big area I would say no optics.

 

[jjrreef]

jjreef I hope that is for a fish only tank. With such a small amount of LEDs on such a big area I would say no optics.

this is a suplementary light that will just use insted of t5 in whit Metal high lighs

 

[der_wille_zur_macht]

I agree, no optics.

 

[widmer]

Can anyone link me to a source for some dirt cheap little CPU heatsinks or something similar, where I could do one per LED and not use a fan? I have 6 LEDs that I am going to want to put lenses on and play around with for my macro, and am surprised that I haven't found anything good or cheap enough on ebay..

 

[der_wille_zur_macht]

Check mpja or even mouser, digikey, or jameco. I pondered that approach on my nano builds and remember finding some that were around $1 at one of those places, but I don't remember which.

 

[stugray]

This is a single CRE XRE on the other side:

I found those at a local Electronics surplus store for about 50 cents each.
I just drilled & tapped for 8-32 nylon screws.

Here's the other side:

Stu

 

[g8gxp]

Sometimes if you go to those pc repair shops they've got spare parts lying around you could get cheaply

 

[jjrreef]

I agree, no optics.

so if i want to go leds only how many will i need?

 

[der_wille_zur_macht]

On a 90g, depending on what you want to keep, what type of LEDs you use, drive current, etc. you might end up around 60 - 80 LEDs.

 

[jjrreef]

On a 90g, depending on what you want to keep, what type of LEDs you use, drive current, etc. you might end up around 60 - 80 LEDs.

White Cree Q5 XR-E Star D-E-1000PmA Wired BuckPuck
Royal Blue Cree® XR-E Star. D-E-700PmA BuckPuck

 

[kgk]

I am doing a ton of reading right now and am catching up, but I'm trying to figure out if this is worth doing or not. I want to build an LED fixture for a 3' cube that is 18" deep. How many LEDs in what configuration would you recommend? Mostly LPS tank.

edit: I have figured 48 LEDs without optics would be enough - but it won't be. That won't cover enough of the tank.

 

[der_wille_zur_macht]

White Cree Q5 XR-E Star D-E-1000PmA Wired BuckPuck
Royal Blue Cree® XR-E Star. D-E-700PmA BuckPuck

Pick a number in the range above depending on intensity you want. I'd bias slightly towards blue in terms of count, since you've chosen to run the whites at a higher current - unless you want a really white color.

I am doing a ton of reading right now and am catching up, but I'm trying to figure out if this is worth doing or not. I want to build an LED fixture for a 3' cube that is 18" deep. How many LEDs in what configuration would you recommend? Mostly LPS tank.

You've got ~1200 square inches of surface. Most people are in the range of 10 - 20 inches per LED. That puts you at a count of ~60-80 (lower end of the range, based on your livestock goal.) If you want to use optics to get the penetration, you'll want to be a little higher to maintain good coverage.

In a cube tank you have a good opportunity to match lighting to the aquascape. Just something to think about - it can dramatically reduce your LED count.

 

[ReefEnabler]

Had a question regarding Soundwave's initial setup running the 12v fans from the buckpucks. Quote from first post of the thread:

So, now you’re looking at this and thinking that the fans are 12V and the power supplies are 24V. How does this work? I had the same problem and the fix is simple. Wire them in series. The positive from one fan goes to the positive of the 24V power to the buckpucks. The negative of that fan goes to the positive of the other. That last negative goes back to the negative of the same buckpuck circuit.

I get the series wiring.... but why use a buckpuck to wire the fans??? Why not simply run them straight off the 24vdc power supply????

If buckpucks are constant current 700ma drivers, how would that work if you had fans that only need ~100ma or so? Also, did Soundwave run the fans from a buckpuck that already had LEDs on it, or a buckpuck that was all by itself??

Since we have so much extra juice on thes MPJA power supplies, wouldn't it work to just run them in series straight off the 24VDC supply, with no buckpucks??? Thanks to anybody who can clarify this.

Ryan

 

[der_wille_zur_macht]

Why not simply run them straight off the 24vdc power supply????

99.99% sure that's what he did, just a poor choice of words describing it. He meant wire it to the input side of the buckpucks, not the output side - in other words, put your two (series) fans across the 24v from the supply. I've done this on several builds and it works fine. Running common computer fans on the output side of a buckpuck would surely end in disaster.

 

[ReefEnabler]

Thanks!

Also was wondering if you wouldn't mind explaining how to do this (posted by Kecked and you agreed way back when):

From what I see, you can easily use one buckpucks voltage supply to feed all of the other buckpucks pots. The current is sooo low on these that it should not matter even in parallel. What I mean by power supply is not the output or the input but the supplied voltage reference used to dim the puck.

If you don't want to do that than get a 5 volt supply and use that as the refrence and use one single pot to feed the pucks dimmer input. Don't forget to common the ground of the reference to the supply.

Firstly, is he talking about using a single external pot to drive multiple buckpucks?

Any help understanding how to wire this up, using this as a starting point?

 

[der_wille_zur_macht]

Look at figure 10, right next to the image you grabbed. The REF pin is essentially a +5v source with a really low current limit, so it can serve as the "external 5v source" in figure 10, or use a regulated 5v wall wart. Connect either 5v source to a pot and connect the "output" to the CTRL pin(s) on the buckpucks you want to control.

 

[shackscs]

Has a working prototype board been made available yet?

I have been reading along but can't seem to recall a working board yet.

If there is, will it be made available to download in Eagle or one of the other CAD formats to be sent off and a PCB made?

I ask because my last original PS for my Solaris has died. I will make a new DIY cable and use an off the shelve PS as I have done in the past, but I want to start working away from the Solaris LED Boards and this setup.

Thanks,

 

[der_wille_zur_macht]

Sorry, a working prototype board for what? A driver? Or some other component?