A nano/experimental LED build

[kcress]

Hi zur!

Those would be just great, as smaller than 24 takes more handling care anyway. That's the stuff I'd use.

Back to the strain issue if you use that solid core you would NOT want straight short pieces between LED pads. If they either have an arc or are more than about 6" you will be fine. You could also put a little U in the wire somewhere midpoint on a short otherwise straight run.

Anyway that's the ticket.

 

[Neogenocide]

der_wille_zur_macht,

If I may, have you tried using a higher quality wire? I used this stuff, and yes I'm a R\C nut as well, it's very easy to work with, withstands high heat, and the price isn't too bad for the extra piece of mind. The kicker to me is with solid core wire, it's stiff and much harder to work with. What's in the links I listed below hsd a silicone jacket and is very pliable. It's often referred to as noodle wire.

Just a thought.

http://www.hobbycity.com/hobbycity/...Turnigy_Pure-Silicone_Wire_20AWG_(1mtr)_Black

http://www.hobbycity.com/hobbycity/...e=Turnigy_Pure-Silicone_Wire_20AWG_(1mtr)_RED

Scott

 

[SpacedCowboy]

zur; Nice!
Comment: zur, I wish you would stop using the wrong size wire. You should not be using anything over 20AWG on those LEDs. You are going to have future issues. Copper has a large expansion coefficient. Every on/off cycle you are working those pads and solder joints. Smaller wire is more flexible and produces less thermal strain. We're only running about an amp. That means you could use 30 or 28AWG not 18 or 16!! You want bigger than 30 or 28AWG? Okay use 24 or 22. But don't use anything under 20.

Agreed on the general principle, and in Nate's case he's only running 0.5A per string, so 30AWG would work well, but if you're running 1A, or close to it to get those LEDs shining brightly, I think 30AWG is too thin. See here for a table of wire-sizes and current-carrying capacities. The accepted guideline for 30AWG is ~0.86 amps in chassis-wiring. Similarly, if you're designing your own PCBs for drivers, you can look here to determine how wide you need to make those traces to safely carry the amperage.

There's a bit of safety margin built into both of the above, but with (salt!) water and electricity, safety margins are my friend

Example: I have a PCB which provides 3 drivers for 6 LEDs each, and 3A requires traces on the PCB that are 108 mils wide (!!), for 0.5oz copper. Since the circuit is essentially 3 instances of the same module, I added a terminal block to provide power individually to each module, and the traces went down to a far-more-reasonable ~23mil.

Simon

 

[SpacedCowboy]

der_wille_zur_macht,

If I may, have you tried using a higher quality wire? I used this stuff, and yes I'm a R\C nut as well, it's very easy to work with, withstands high heat, and the price isn't too bad for the extra piece of mind. The kicker to me is with solid core wire, it's stiff and much harder to work with. What's in the links I listed below hsd a silicone jacket and is very pliable. It's often referred to as noodle wire.
Scott

[gulp]. That's $79 for 100m. I generally pay circa $18 for 100m of 20 AWG wire (at extended intervals, because it takes me a while to use 100m )

Simon

 

[Neogenocide]

Edit:

nvm....I'm stupid and misread your post.


But in response, it is high quality wire that is very very easy to work with. It's what I used to build my experimental LED rig.

Scott

 

[Izzone001]

What kind of PAR are these working with? I am not too familiar with the 3 star LEDs and how they compare with a CREE. I would imagine less par? Also is there a reason that you are not using optics?

 

[der_wille_zur_macht]

What kind of PAR are these working with?

Don't have a meter to test that, but plenty of people have tested other LED fixtures, and given the consistency of the technology (no reflectors, different ballasts, etc - a given LED at a given drive current will always put out the same amount of light!) - you should be able to extrapolate.

I am not too familiar with the 3 star LEDs and how they compare with a CREE. I would imagine less par? Also is there a reason that you are not using optics?

It's literally just three Rebels soldered to a single star. The Luxeon Rebel is very close to the XR-E if you compare equivalent bins - they're both doing around 90 - 100 lumens/watt at their most efficient. The main difference is that the Rebel has a wider field of view, so the light is a little more spread out.

No optics in these photos because I didn't use them on these particular builds. I do have optics for XR-E and the three-up Rebels and I've used them on other builds. On a small, shallow tank (like the 14g these ended up on) IMHO optics are a bit overkill - focus the light TOO much at such a close distance and you're just going to evaporate all your corals.

 

[Izzone001]

Thanks for the info, this is a great build. I am very interested in recreating this for a smaller 20 gallon all in one frag tank build. How much in total did one of these units cost to build? I would imagine that with the current plans of the tank being roughly 13 usable gallons that 2 or maybe 3 of these units would suffice.

 

[jonnybravo22]

looks great der!

if you're looking for smaller wires (and tons of other stuff) you could also check out Mcmaster Carr.

i got some stuff from digikey but wont go back cuz the next day i had a fraud alert on my cc.

 

[kcress]

Neogenocide; That's nice wire. That would be the Cadillac route. Silicone wire is a high temperature, floppy pleasure. It can be pricey. It didn't appear to be pre-tinned which I'd typically prefer in a moist application.

SpacedCowboy; Yes you're correct. That's a chart I turn to often. Most DIY LED builders run under the 0.86A but certainly you can use bigger wire. The 24 we're talking about is very nice. It's mechanically good. It's basically the Momma Porridge. Not too small, not too large.. Just right.


jonnybravo22: I've made probably 300 Digikey purchases. I have that happen the first time on any new card. It happens the first time for a lot of people. It's because Digikey is not a normal consumer spot so it flags the credit card AIs as a suspicious deviation in purchasing. After you call your CC company and say it's a valid purchase the AIs take it off the list. You won't have another problem with that card there.

 

[der_wille_zur_macht]

Neogenocide; That's nice wire. That would be the Cadillac route. Silicone wire is a high temperature, floppy pleasure. It can be pricey. It didn't appear to be pre-tinned which I'd typically prefer in a moist application.

I probably still have a spool of that silicone stuff laying around from my R/C days. One of my sailplanes pulled 80 or 90 amps at 12v. It used THICK wire.

jonnybravo22: I've made probably 300 Digikey purchases. I have that happen the first time on any new card. It happens the first time for a lot of people. It's because Digikey is not a normal consumer spot so it flags the credit card AIs as a suspicious deviation in purchasing. After you call your CC company and say it's a valid purchase the AIs take it off the list. You won't have another problem with that card there.

Not quite up to 300 yet but prototyping this LED driver alone probably had me over a dozen. Funny I never got flagged. Probably depends on the bank holding your card and what their fraud algorithm is.