DIY LEDs - The write-up

[terahz]

To add to the latest prices info from ETG.
Monday I got from them XPE Royal D316 (450-455nm) and XPG 1TR5 (6500K) both at $6 mounted on starts. At this point, cutter doesn't have any XPE royals in the D3 range, and their XPGs are more expensive even at the 50+ qty price break.

 

[Reef_Matrix29]

Anyone hooked up their XPG's and done PAR measurements just yet?

 

[TheFishMan65]

WHOA price must have just changed if you got yours one Monday. The number I quoted were 10+. Also XP-G went upto $6.50 for 10+. Lean time is 5 days to 2 weeks depending stock for those that want to know. WAMAS maybe doing a group buy which why I got pricing info.

 

[jesserettele]

tag

 

[KafudaFish]

Ok if a person wanted to learn and hopefully understand doing a DIY LED project what page would one begin looking at and reading?

Normally I would fail in my searching before asking but I would like some direction please.

 

[Hockeyman]

I now have a source of 10 and 20watt emitters a bit deeper in color than Cree RB's, and getting ready to build some big lights for a friend. By NOT using Cree and using these emitters we figure we can cut the price by 1/2, if not more for the DIY light. We can concentrate the emitters in the middle like a halide and also eliminate the need for optics reducing cost. There's a thread here showing a high end LED light using the same 'center coverage' concept.

Would you mind sharing this source of 10 and 20 watt emiters?

 

[Hockeyman]

Ok if a person wanted to learn and hopefully understand doing a DIY LED project what page would one begin looking at and reading?

Normally I would fail in my searching before asking but I would like some direction please.

Check out page 171 post 4260 by TheFishMan65... He's compiled the most recent info in a couple of posts for us newbies.

 

[KafudaFish]

Thank you.

So I needed one more click.....

 

[westmoorenerd]

Would you mind sharing this source of 10 and 20 watt emiters?

I've seen a few 10-50w LED emitters, basically an array of 4x5 1w emitters stuck on one star for a 10w. Only issue is I haven't seen any even come close to having 100lm/w efficiency, most are about 70lm/w, which is around of an XP-G.

 

[dwl]

I have a question or two.

I have a ~12 volt DC supply and have used a potentiometer to adjust the output to 10 volts. Next I wired another 10K potentiometer from that 10V output and found that it would operate between 0 and ~ 6 volts, so I adjusted the first pot until the second pot tanged between 0 and 10 volts.
First question, is doing this OK?

Next question: Can I wire 2 pots off of the first pot and adjust until they both (hopefully) range between 0 and 10 volts? Is this OK, or will there be problems with a common negative between these?

Thanks.

 

[Garage1217]

Been searching but cannot find any info on which optics you guy think are the best? I have never used optics with wider angles before so seeking guidance.

I see some that are...
- black and look like a telescope lens
- Taller and white with what looks like a honeycomb lens
- All clear body with what looks like another lens inside

I am looking for the most even beam output / 80 degree lens.

Any help would be appreciated!

 

[der_wille_zur_macht]

I've seen a few 10-50w LED emitters, basically an array of 4x5 1w emitters stuck on one star for a 10w. Only issue is I haven't seen any even come close to having 100lm/w efficiency, most are about 70lm/w, which is around of an XP-G.

To be clear, I think you meant to say "around half of an XP-G."

I have a question or two.

I have a ~12 volt DC supply and have used a potentiometer to adjust the output to 10 volts. Next I wired another 10K potentiometer from that 10V output and found that it would operate between 0 and ~ 6 volts, so I adjusted the first pot until the second pot tanged between 0 and 10 volts.
First question, is doing this OK?

Next question: Can I wire 2 pots off of the first pot and adjust until they both (hopefully) range between 0 and 10 volts? Is this OK, or will there be problems with a common negative between these?

Thanks.

The first thing you explained is more or less OK. The second starts to get tricky.

The problem with using a potentiometer to control voltage is that it's passive - it doesn't respond to changing conditions to regulate the voltage, it just presents a resistance which happens to drop the voltage a certain amount in certain conditions. When you start ganging up pots like that, depending on loads on each, resistance of each, etc - you may find that adjusting one of your "child" pots throws the other one off. This can be frustrating at best, and dangerous to your drivers at worst. IMHO this is a good reason why it's preferable to have the initial voltage regulation (12v down to10v) done by an actual voltage regulator. Then you can stick as many pots on that 10v source as you want and the reg will keep things constant.

Been searching but cannot find any info on which optics you guy think are the best? I have never used optics with wider angles before so seeking guidance.

I see some that are...
- black and look like a telescope lens
- Taller and white with what looks like a honeycomb lens
- All clear body with what looks like another lens inside

I am looking for the most even beam output / 80 degree lens.

Any help would be appreciated!

What model LEDs are you trying to fit optics to? In some cases there may be only one choice in a given beam width, so you HAVE to use that.

Basically, other than differences in beam width, the main differences are surface finish and efficiency. Available surface finishes include plain, ripple, frosted, etc. - generally, we want plain if available. Efficiency is self-explanatory - get the highest you can. Values in the 80 - 90% range are fine.

 

[westmoorenerd]

DWZM- thanks for catching that, I could have sworn I wrote half...

 

[Garage1217]

I will be fitting them to XR-E's

 

[dwl]

The first thing you explained is more or less OK. The second starts to get tricky.

The problem with using a potentiometer to control voltage is that it's passive - it doesn't respond to changing conditions to regulate the voltage, it just presents a resistance which happens to drop the voltage a certain amount in certain conditions. When you start ganging up pots like that, depending on loads on each, resistance of each, etc - you may find that adjusting one of your "child" pots throws the other one off. This can be frustrating at best, and dangerous to your drivers at worst. IMHO this is a good reason why it's preferable to have the initial voltage regulation (12v down to10v) done by an actual voltage regulator. Then you can stick as many pots on that 10v source as you want and the reg will keep things constant.

Thanks for the reply. I would really like to use a regulator, but am pretty ignorant of exactly how to do so.
I am more than willing to learn though LOL

So, I assume that an LM317 would be a good choice of regulator, is that right?
I am at a loss of exactly how to connect things up though. It appears that a pot is used to adjust the regulator output, but all of the schematics that I have found also have some caps, resistors, etc. and that is where I get lost.
So, is there any chance of someone being able to take this completely ignorant soul and show me how to build a regulator based supply?

Thanks.

 

[wld1783]

I will be fitting them to XR-E's

I really like the 80 degree optics. The 60 were a bit tight. Here is the PDF data sheet.

https://reefledlights.com/PDF/DIA.20-CREE-70,80(E)-1.pdf

Bill

 

[Garage1217]

Cool, those were the ones I was thinking of going with!

 

[jtma508]

Has anybody seen a datasheet on the upcoming Cree XM? Spectral plots especially?

 

[der_wille_zur_macht]

Hasn't been released yet, to my knowledge. I know Cree is currently providing samples, but likely only to accounts in the multi-million dollar range. The news I've heard is that it's going to be an expansion of the XP-G die, and I'd guess it'll be binned by the new ANSI standards - we may see only "outdoor white" instead of the current Neutral White and Cool White models.

 

[powdr_dayz]

Here's my recently finished DIY LED lighting fixture for my 72 Gallon Bowfront. I just want to add that the color is unbelievable and all corals and fish have responded in a positive way since I put it over the tank ~1 Month ago...

By using independant potentiometers for both the blues and whites, I can really dial in the color that I want...

Whites only:

Full Blue/Full White:

Blues only:

This thread was very beneficial in my design and build. Thanks Reef Central.