Darn "UV", aka Violet LEDs browning out. New silicone lenses better?

[BlueThumb]

I know this has already been discussed in the past but I'm a bit late to the race. So my first generation of SemiLEDs "True Violet" (from StevesLeds) were a total fail. They started off impressive but quickly browned out (discolored) into uselessness. StevesLeds now offers a "2.0" version with soft silicone lenses. Anyone have experience with these? Alternatively, the CREES still available, e.g. the ones that don't brown out, e.g. the real deal, not some Chinese fandangled version sold in group buys?

 

By the way, I've asked StevesLeds to talk me off the ledge. I hope they work a deal out with me to get me into the 2.0 as I only ran the True Violets at 350mA at a max of 100F...well within posted specifications. I like StevesLeds, they've always stood behind their products and I hope they do so now.

[Milad LEDGroupBuy.com]

If you dont want brown lenses then the way to go is with the XTE footprint version:

http://www.ledgroupbuy.com/exotic-hyper-violet-led-430nm/

 

and for your info they blow the semiled out of the water

http://www.nano-reef.com/topic/318320-tv-uv-hv-violet-showdown-ledgroupbuy-vs-semiled/

[jedimasterben]

Yep, the silicone lens is the way to go, combined with the superior thermal efficiency of the XT-E footprint/connection. I threw away around $100 worth of hyper violets (the old style) because they browned out after a few months. I've had the new style running for several months now (in a test fixture and now on my new LED array on my tank) and haven't had any issues. Will be interesting to see what happens to the Carclo secondary lenses do, though.

[farkwar]

If you dont want brown lenses then the way to go is with the XTE footprint version:

http://www.ledgroupbuy.com/exotic-hyper-violet-led-430nm/'>http://www.ledgroupbuy.com/exotic-hyper-violet-led-430nm/

 

and for your info they blow the semiled out of the water

http://www.nano-reef.com/topic/318320-tv-uv-hv-violet-showdown-ledgroupbuy-vs-semiled/'>http://www.nano-reef.com/topic/318320-tv-uv-hv-violet-showdown-ledgroupbuy-vs-semiled/

 

Any chance you'll have these available in 3 ups or 4 ups anytime soon?

[Milad LEDGroupBuy.com]

Any chance you'll have these available in 3 ups or 4 ups anytime soon?

 

if there is enough interest

Why so keen on 3ups/4ups? Jedi has been petitioning for them also.

[jedimasterben]

Because they're awesome, duh!

 

Mostly just saves space on heatsinks, easier to solder two points than six, etc.

[farkwar]

if there is enough interest

Why so keen on 3ups/4ups? Jedi has been petitioning for them also.

 

What Ben wrote.

 

I know its not much, but if you make up some 4 ups, Ill take 8. I would prefer half 405 and half 430.

 

If you make up 3 ups, that's fine too, it just mess up the math and layout. One would need 5 to fill a channel, makes for odd layout patterns.

[MeepNand]

I have been using steve's leds violets for a long time, the 700ma version. Even running them at around 600ma round the clock, I never ran into problems. In fact, when I left my leds unshielded and they succumbed to salt creep, the only things that survived were the violets and 3 royal blues.

Your problems might be bigger than the brand of violets.

[BlueThumb]

LOL - I definity have bigger problems than LED issues. For now, I have given up on Violet LEDs for a couple of reasons...the "risk" of browning out being a big one of them. I'm going back to T5 actinics until Violet LEDs are more efficient and reliable. I'm betting on Soraa's GaN on GaN Technology to get there. I'm willing to wait...being my current gen of LEDS will supposedly last me 5 years. The LEDS will, not sure sure about my made-in-China power supplies.

[MeepNand]

Perhaps you should check your drivers. You might be overpowering them.

[jedimasterben]

Not really - the extra current will only hurt if the LED can't dissipate the extra heat. On a copper PCB, the Cree XM-l, which is max spec of 3A, can be run at 6A without overheating. At this point, I would say blame lies solely on the quality of the primary lens.

[BlueThumb]

Update: Since the Violet LEDS seemed nearly useless, I decided to play with them. In short, I sanded the the encapsulant/dome down to see how far the browning went. Well, it's NOT on the surface but definitely within the composition of the encapsulant itself (about half-way), which indicates to me there were contaminates during manufacturing. Or is porous? Probably not.

 

This said - both LEDS are working OK now. I don't know how much the beam angle has been affected by grinding the dome flat but given I use them as accent lighting just above the water's surface, they seem to be doing the job for now.

 

Thus, if any of you have browned out encapsulant, pull out the dremel, grind down the dome until the brown is gone, and then polish. I'm guessing that if also using a lense, grinding down has very little effect final beam angle.