DIY LEDs - The write-up

[chrisfowler99]

chris ,
Two 9 amps power supplies would eat your circuit up. However, they are probably drawing closer to 2 amps. 9 amps at 24 volts is 216 watts. 216 watts at 120 volts is 1.8 amps. Add in some inefficiencies (80%) and you are at 2.25 amps. Just because it supplies 9 amps at 24 volts does not mean it draw 9 amps from the wall. It could, but would only be about 20% efficient.

Aha! I knew it was a stupid question!

That knowledge was in there somewhere...it's just 20 years old or so and having to be pulled back out.

Thanks!

 

[ti-christ]

Paralleling LED Strings "“ Make Sure You Understand the Risks

TheFishMan65, Thanks for your summary!

For people that want to run LED in parallel, there is a good article here : http://www.ledsmagazine.com/features/6/2/2

They are teaching how to use mirror current safely using transistor. It's a little complicated for people which does not have electronic knowledge but the circuit can be experimented using few LED.

Good luck

 

[Neogenocide]

Hey guys, I've been successful running 34 LED's over my 46g bow for around 9 months now, but am a little stumped on a design for my 180g Oceanic with a glass center brace. Take a look at the pic and let me know what you think. The current design is for 4 array's with 30 LED's each. My other thought is 5 array's with with 24 LED's each.

Thoughts?

 

[Taqpol]

I use 5x24 LEDs on my 220 (72"x30" footprint, so similar) and think it works perfect, but with that glass center brace, and if you don't want to keep corals in the center of the tank, I think 4x24 or 4x30 would work perfectly.

 

[Neogenocide]

I think you hit on something there. I'm thinking 5 array's with 24 each is the way to go. I'll start with 4, leaving the very middle without a array to start with, but since I have to custom make my hood, I'll have it ready to accept a 5 array if I decide to add it.

Thanks,

Scott

 

[czinn]

I am looking at doing leds for the 125g tank 72x18x22. I am looking at making 3 fixtures 18x8.5x1 with 12 Cool White Cree Q5 XR-E LEDs, 12 Royal Blue Cree XR-E LEDs, 6 Blue Cree® XR-E Star, 3 Mean Well LPC-35-700W, and 30 Cree XR-E Lenses 80 degree. I will be wiring in a variable resistor in to all the drivers. I want to be able to keep sps in the top half on the tank. Does this look about right.

if i set the power supply to gradual increase output over a 2 hour period would it mess the divers up or would that be ok.

thank you for any responses

 

[TheFishMan65]

czinn the LPC is not dimmable. Are you talking about putting a potentiometer in line with the resistors. Not sure this is a good idea it could dmp an awful lot of energy. I have no idea if it is designed to handle. IMHO it is a bad idea. However, they loayout looks good for the color you have chosen.

 

[Swim]

I've been enjoying these DIY LED threads very much and the learning curve really seems to be producing results for many reef nuts that might not have attempted such a project otherwise. I just thought I would barge in here for a minute and ask how many people realize they are building a Solaris I5 version light? Yes the driver parts and LEDs are newer better versions but other than experimenting with color there really isn't much difference technically. Of course there is the reward of DIY and cost savings but how many realize without the Solaris these threads probably wouldn't exist?

 

[widmer]

But no one really is trying to emulate the Solaris. After all, it had an extremely poor reputation as far as its cost and reliability was concerned. In both of these ways, the DIY fixtures people are building are a night-and-day difference as compared to the Solaris. And this is only a small effect of how there are many technical differences. So I would argue that if anything, it is the noted differences between the DIY rigs and the Solaris that has allowed the DIY LEDs to gain such popularity.

That's my IMO though, and it's a very interesting subject to me - I was following all the updates on the litigation that put Solaris under. Anyone else get nostalgic about Solaris?

 

[widmer]

I know it's unconventional and a LITTLE overkill, but I like the custom lighting options with the dimmers and the ability to use it over a larger tank if desired.

Hey, it's a great way to save money on the heatsink - with the 24 LEDs over 3g you could be running them dim enough to have the stars mounted on cardboard and not worry about heat issues.

:lolspin:

 

[Swim]

But no one really is trying to emulate the Solaris. After all, it had an extremely poor reputation as far as its cost and reliability was concerned. In both of these ways, the DIY fixtures people are building are a night-and-day difference as compared to the Solaris. And this is only a small effect of how there are many technical differences. So I would argue that if anything, it is the noted differences between the DIY rigs and the Solaris that has allowed the DIY LEDs to gain such popularity.

That's my IMO though, and it's a very interesting subject to me - I was following all the updates on the litigation that put Solaris under. Anyone else get nostalgic about Solaris?

Welp, they may not be trying to emulate the Solaris but the design of the I5 is exacty what everyone is building. The early versions used darlingtons and then mosfets to drive the LEDs but the I5 used the STCS2 driver chip. The Zilog micro controller of the I5 is a faily powerfull device and PWM has been the control method. The infamous power supply for the "G", "H" and "I4" were replaced with the 24v meanwell that many here have used in their projects. Don't take me wrong, all I'm saying is the differences of these DYI designs are only subtle differences.

 

[rpp]

Hi,

I'm trying to build my own LED lamp and I've got some questions.

Tank will be ca. 110g (420 liters).
I want to use 42 RB XP-E and 30 CW XP-G leds.

Question - does it matter which exactly bin I'll use? Especially in CW I've got 2 options:
- XP-G R4 bin 0D from Cutter
- XP-G R5 bin 1B or 1C from my local supplier
in both cases price will be similar (for me easier to buy are those 1B/1C bin but if it's better to buy 0D I can do it).

And for RB XP-E - I can buy either D4 bin without major problems or D3 bin with some combination (they are not on star PCB so I have to find sb to solder it).

Regards,
rpp

 

[TheFishMan65]

DWZM could probably tell you for sure, but IMHO most people have just order XP-G R5 and royal blue LEDs. The R4 and R% are lumens/watt so R% is better. THe 1A, 1B etc are the exact color. Color is sort of personal preference and can be somewhat controlled by dimming. Go back to page 200 near the bottom and I copied the color chart DWZM has posted that may help.

Short answer IMO is pick (from what you listed) is easiest to get and work with.

 

[TheFishMan65]

kcress or whoever,
I want to hang my LEDs as a pendant type. I don't really want a lot of extra wires. What kind of wire do I need (I assume they make it) that is structural enough to hold the weight and carry the current. I am assuming normal wire won't do it. I am thinking power, ground, PWM a, and PWM B to each corner.

Thanks

 

[DustinB]

If you want to use a single cord we sell pendant cable where I work for use with pushbutton controls on cranes(*not a commercial ad, we don't sell to the public*). This place sells it: http://www.hoistsdirect.com/round_pendant_control_cable.htm They list 3 conductor at the bottom with internal strain relief. Should give you the 4 wires you need, 3 conductors+gnd. This may not work for you in the way you are thinking by supporting the corners.

 

[TheFishMan65]

I think based on that info I am looking for one conductor with strain relief. At least now I know what to search for. Thanks

 

[kcress]

Man65; That is usually considered bad form to hang things from the wires. Four corner wires often looks amateur. It also complicates what's happening at the top(ceiling).

If you are talking about four corners use less wires by using one single chain and weave the wires down that. Hang your pendant from the single chain. If you are class-less and still need to use four corners, make that transition down close to the fixture so you still only have one top hanger.

As for suspending cables.. I'd never heard of them till DustinB described them. I have seen plain old SO cord used for hanging something a trivial as a quad receptacle box.

 

[TheFishMan65]

I have seen some nice pendants that hang from three thin cables. IMHO they look nicer than chain and the are easier to keep flat, but the ones I have seen still have an extra power cable. I was thinking of replacing the thin cables with thin wires.

This is sort of what I am thinking

 

[chrisfowler99]

I have seen some nice pendants that hang from three thin cables. IMHO they look nicer than chain and the are easier to keep flat, but the ones I have seen still have an extra power cable. I was thinking of replacing the thin cables with thin wires.

To pull that off, you have to get the balance exactly right.

 

[TheFishMan65]

That is why I want three. You have the same balance problem with a single chain.