Potential Parts for BIG DIY LED Lighting

[tawauboy]

frankly, the leds from cree, osram, seoul semi, philips lighting (luxeon) are similar. don't forget that they compete for market share.

as Edward as mentioned, you wil not go wrong with cree. personally, i would not hesitate to use seoul semi or osram.

cree uses a hard lens (primary optics). the hard lens seems to have an advantage of clarity so there is less light transmission loss; looks brighter compared to the others. however, the disadvantage (still to be proven) is that the adhesive holding the lens may come off after a period of time. this is due to expansion and contraction of both lens and led housing.

both osram and seoul semi uses silicone based lens. these are soft and flexible so is unaffected by expansion and contraction. however, the clarity is lower resulting in higher light transmission loss.

what is you measure of performance?
if you are going for 'green', drive the led at 350ma only; no more.
if you want the best-bang-for-the-buck, drive them at 1000ma (for 3w led). do not scrimp on heatsink and add fans as an additional measure.

[edwardchuajh]

Thanks thomas, never knew about the lens part.

But from what you know, what is the estimated time frame in which such a failure is known to occur in the Crees?

[tawauboy]

i do not have any figure.

let's assume a lowly figure of 10000 cycles before failure and 2 on/offs daily (4 cycles). this gives a working life of more than 6 years.

don't worry too much as it is still unproven. just a potential issue. given the rate of innovation/improvement in led technology, you may want to change your leds 3~5 years down the road. especially when you can gain a 50% increase (potential) in light output.

[edwardchuajh]

I see.. Yep you're right, I believe the LEDs will most probably be changed in around 3-5 years :P

[Goondoo]

I was at Ubi yesterday servicing my bike, saw a shop selling all sorts of aluminium plates and tubings etc.
Lau Brothers Aluminium Works
Blk 3005 Ubi Ave 3, #01-56, Singapore 408861
Tel: 6747 5771, 6747 5772
Fax: 6747 5772

[limsteel]

I have been reading about lights used by plants... Seems like the Red and Blue lights is all they need.

I have a DIY a 48 LED 0.5W blue as original intended as a phase in/out light (Blue LED On 1hrs before main T5 light and OFF 1 hrs after T5 light out). I am thinking of replacing my original light with 100 blue and 100 Red LEDs (maybe 200 later). I have spare computer PSU, couple with LM317to drive them LCDs...

Having just 1 T5 or T8 just for the daylight effect.

0.5W 140° 100mA 70 to 90 Kmcd (Blue) 90 to 110 Kmcd (Red)



Should I buy these 1W 120° 350mA 40 - 50lm brightness

[edwardchuajh]

Hi limsteel,

I'm not too sure about the performance of these LEDs as plant lights, but I think the 3W versions are much more efficient and you will not need as many of the 1W LEDs.. so I would suggest going directly to the 3W versions.

[neverwalkalone]

Keeping this thread alive, contemplating making a complementary LED strip for the 2xT5HOs for the 3'... Edward et al, perhaps we can do a "joint" project - cheaper to buy in bulk!

Found this thread on US (ReefCentral - 48 LED for 4' Tank). Caution - it's 80 pages long! (spread over just a few months - the guys got going alot on that I guess!)

Also noticed CREE's latest product XM series (Apr 2010 press release); 160lumens @350mA!! wicked!