Options for red

[Oznog]

Really, what are the "power" options for reds right now?
I need a wide, spread emitter. I was delighted with Lamina's BL2000 red, 270 lumens, which has since been discontinued.

I'm aware of the Luxeon Rebel reds (85 lumens @ 700mA) and the Cree XR-color (40 lumens @ 350mA, only 64 lumens @ 700mA), and the Lamina Atlas (120 lumens).

Can't beat or even match the BL2000 here, not without a lot of Rebels, and the Rebels present so many mounting issues that's not all that likely. And mechanically the BL2000 was the best design possible for what I needed- huge thermal backing, very flat, no lens to get knocked off, which was important because I got away with just leaving them exposed & uncovered for simplicity, size, and thermal reasons.

Are there any reds I'm missing?

 

[frenzee]

Yeah I agree about the BL2000s - not extremely efficient, but very robust both mechanically and electrically . I think I have one of those still left in my stockpile and I'm keeping it for my LED museum when I retire from this hobby :laughing:.

BTW, the red rebel 40 is not longer available (see this thread). I believe the red K2 with 51.7 Lumen at 350mA is, at the moment, the most efficient pure red power led in production. If you can live with the tint, the red/orange rebel might be an otion with 50 @ 350, but just like you said the rebels are not easy to live with (mechanically speaking). Electrically, they are pretty robust, but that polycarbonate substrate is terribly brittle, unless you can find or fashion your own MCPCB and have it mounted. And then there is the silicone dome which is very fragile unless you can coat it with an optically clear epoxy like the 3M or epotech stuff. All in all, a PITA to work with, but once you get it together, I think it is still a good product.

 

[evan9162]

Red Luxeon III.

 

[Lightingguy321]

+1 on the Red Luxeon III. I just did a real quick run through of lumileds Red LEDs. The Luxeon III is on top lumen output wise. However, it doesn't look to be the most efficient creature in this fight. I would have to go with the Red K2, which at the moment is the most efficient. If you are going to run the Luxeon III at 1400 milliamps (that is how you get the amazing 140 lumen output) you will need a really good heatsink.

 

[Oznog]

It's just killing me. Why did we have a great product several years ago, with loads of applications, just disappear from a high demand market with no equivalent much less superior replacement in sight??

Yeah I have one I based a project on, and I have one spare. I have enough of a market to need a good hundred or so, but even still, it's not really safe to base a product on a a part with no reliable supply.

 

[SemiMan]

My nod to the Lux-III RED. It has a big die and better thermals than the K2. It is also more expensive.

However, don't kid yourself you are going to get anywhere near 140 lumens out of a LuxIII red. You are likely to get a lot less after it heats up. I think that was an issue with the BL2000 as well. Great on its own, but without a huge heat sink, you quickly loss light output.

In many ways, you may do just as well with lots of Cree, K2, Osram, LuxIII, etc. to spread the heat out if it works mechanically for you.

Semiman

 

[frenzee]

I agree with SemiMan here. The red Lux III is a gem, but the 140 Lumens is at 25C Tj, which in the real world means 15-20C heat sink temp which is pretty unrealistic and by the time it reaches 60-80C opetating temp, you have to derate that output by about 50% (much worse than your typical white LED).

BTW, have you given the tri-rebel stars any thought? It won't be quite as bright and the Lamina, but it might get you close. If someone could come up with a 6- or 8-rebel metal core star, I think that would leave the Lamina in the dust even if you used the rebel 30s. I am working on a 16-rebel star as I write this, but it's just a prototype right now.

 

[SteveDavis]

OSRAM makes a red OStar projection in 617 and 625nm, which will hit about 170lm. Unfortunately Arrow doesn't have it in stock right now, but someone else might. Part number is LE R A2A-HAKA-1 for the 625, LE A A2A-HBKB-1 for the 617.

Another option is a 9 chip array from Optek, OVTL09LG3R is the part number. Search for it on http://www.arrownac.com
datasheet here: http://www.optekinc.com/pdf/OVTL09LG3x_Series.pdf

 

[Lightingguy321]

I have found that optek high output chips have one problem: there is no heat sink interface inbetween the chip and the surrounding air and therefore you must run these LEDs at spec and not too much further unless you want to get burned or burn out the LED. Opteks are also very sensitive to ESD (worst that I have ran into).

 

[Oznog]

Hey, check out this one!!

http://www.ledengin.com/products/15wLZ/LZ4-00R115.pdf

It's expensive, like $30 at Mouser, BUT it's a stock not special order product, and the fairly large thermal pad on back is electrically isolated!

445 lumens @ 1 A Vf=12V!

 

[Oznog]

I have found that optek high output chips have one problem: there is no heat sink interface inbetween the chip and the surrounding air and therefore you must run these LEDs at spec and not too much further unless you want to get burned or burn out the LED. Opteks are also very sensitive to ESD (worst that I have ran into).

I don't understand. All the high power LEDs rely on a thermal pad interfacing with a sink, not dissipating between the chip and the surrounding air.

The Optek has this nonisolated thermal pad, at least it's the cathode whereas Luxeon emitters and others have a pad that can't be tied to the anode OR cathode.

I don't get it. They have wires for each emitter. Since they're on the same substrate, do they share temp well enough that they can simply be put in parallel? Or does each need a series resistor?

And hmmm same question- can be parallel these emitters on the same part without individual series resistors?

 

[Oznog]

Actually that LEDEngin stuff, the 10W emitter puts out the same lumens @700ma (same Vf) as the 15W emitter at 1000mA, so the 10W actually has better specs all the way around here!

http://www.ledengin.com/products/10wLZ/LZ4-00R110.pdf

The 10W has a complicated bottom though- I don't think I'd try to use it on anything other than their supplied Star. Bonus- their Star board has teeny tiny zeners for each emitter for ESD protection!

I'm having some trouble reading the 10W spec:
Thermal contact, Pad 9, is electrically connected to Pad 3. Do not connect any pad to the thermal contact, Pad 9. When mounting the LZ4-00R110 onto a MCPCB, by default its dielectric layer provides for the necessary electrical insulation in between all contact pads. LedEngin offers a LZ4-20R110 MCPCB option which provides for electrical insulation between all contact pads.

Does the MCPCB provide isolation between the thermal pad and the contact pads? So the PCB backing can be grounded?

 

[Bikecop]

Actually, the red orange lux III is the brightest. I made a flashing tail light with 3 red orange lux III's with 180^ optics powered by a b-flex, and it kicks butt!

 

[Lightingguy321]

I don't understand. All the high power LEDs rely on a thermal pad interfacing with a sink, not dissipating between the chip and the surrounding air.

The Optek has this nonisolated thermal pad, at least it's the cathode whereas Luxeon emitters and others have a pad that can't be tied to the anode OR cathode.

I don't get it. They have wires for each emitter. Since they're on the same substrate, do they share temp well enough that they can simply be put in parallel? Or does each need a series resistor?

And hmmm same question- can be parallel these emitters on the same part without individual series resistors?

Some of their emitters (lie their 1 watt white) don't have a single thermal interface pad except for their leads. Other than that some of their LEDs are acceptable.