Best LEDs today? Share info!
- Thread starter JMD
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PSUAGRO.
Well-Known Member
Are you buying one?Now that I read more carefully, Hans stated that he expects over 15% improvement over the earlier model in light output. I think that could be counted just for better thermal performance of XB-D chips vs. older XP-E. For oslons, if they were 3T bin overall improvement would be larger. So my guess is that they are 2T, or even Hans doesn't know and estimates conservatively. Added white I see as a good thing maybe for slightly better plant morphology and health, performance wise, maybe not. Blues should be also a little more inefficient vs. XT-E depending on bin of blues in older model panel.
Same thoughts with PSU on the cooling thing, but that would most likely affect the price. I think he would have to change the design radically for that, or at least the pcb would become a lot more expensive to manufacture. But overall, nice boost to output, even if it was slightly less than I anticipated. Now lets see what this upgraded version can do!
Would love to hear what guod has to say about this upgrade too!
.......Can't even get an upgraded 120mm fan? Ha, oh well....... I guess the cooling is sufficient, wanted a larger bump in the lm/per watt. Do you know how the junction temps on these emitters are vers the older panel.? Granted the remote driver takes the brunt of the heat away, but my version still gets"warm"on the panel itselfHope you understand as my phone's keyboard is useless
Oh yes, 120mm fan should produce a little less noise if chosen right. The gap between the plastic(?) casing and pcb must be quite small, so I don't know if a bigger fan is better for cooling though. Someone should try it, if it can be done easily?Are you buying one?
Hope you understand as my phone's keyboard is useless
I was very tempted to buy one earlier, but I think I will save few hundred more and try to build a "better" panel myself. Passive, or at least a design that doesn't need much airflow for cooling would be my main goal. I ordered some parts already for a smaller test panel, but got stuck to calculating efficiencies and learning more about spectrums etc. Seems like an endless journey, hunting for the best price/performance ratio for diy panel. It would be easy with deep pockets, just buy the best parts regardless of price, lots of leds and underdrive the shit out of them for efficiency.
edit: Sorry, missed the junction temperature part.
I don't know how to estimate junction temperatures yet, but assuming Hans hasn't changed the pcb - the improvement comes mainly from better leds. Oslons should have better thermal resistance than older XP-E, as should XB-D chips too. Difference if I remember correctly, is 5C/W for XB-D and 10C/W for old XP-E.
Improved thermal properties I think is the main reason for general improvement in output of Cree red leds, as especially older chips output "droops" a lot with higher current -> higher junction temperatures. Getting heat away from the chip faster will help when driving them harder, like in Hans panel.
JMD
Well-Known Member
Yep, it's really great! Better than I hoped the response would be!
I have a few 500x120x20mm heatsinks comming in from China - they only cost $7.35 each! With a single 120mm fan you can easily dump 150W into it.Oh yes, 120mm fan should produce a little less noise if chosen right. The gap between the plastic(?) casing and pcb must be quite small, so I don't know if a bigger fan is better for cooling though. Someone should try it, if it can be done easily?
I was very tempted to buy one earlier, but I think I will save few hundred more and try to build a "better" panel myself. Passive, or at least a design that doesn't need much airflow for cooling would be my main goal. I ordered some parts already for a smaller test panel, but got stuck to calculating efficiencies and learning more about spectrums etc. Seems like an endless journey, hunting for the best price/performance ratio for diy panel. It would be easy with deep pockets, just buy the best parts regardless of price, lots of leds and underdrive the shit out of them for efficiency.
Along that, I also bought two CC LED drivers (650 mA, 45-65V out) for just $5.88 each!
So heatsink and drivers for running about 80W is merely $19. That's quite cheap.
captainmorgan
Well-Known Member
I'm planning a 660 nm supplemental LED light and only have a space 9" x 9" to fit it in so I came up with this plan. Steves LED's has 1 1/4" square tube for heat sink and a pressurizing fan to fit it. With the fan at the center and the tube spiraling out from there I would have 7-3 watt 660 nm Luxeon ES LED's running at 700 ma spaced out. I would have about 24" of tube if measured on the inside of the spiral. I also thought of adding 730 nm which would run for 10 minutes when the 660 nm turns off. Could I get some input from the LED guys here,do you think this fan will handle the cooling with 24" of tube and 4 90 degree turns in it?
Attachments
JMD
Well-Known Member
Of course!
Heatsink: http://item.taobao.com/item.htm?id=14388534522
Driver: http://item.taobao.com/item.htm?id=19437932900
I will do a test of drivers when I get them, to see ripple etc. I can post results if anyone is interested.
Get a regular heatsink. The reason why he uses the square tube, is because a regular heatsink wouldn't work because it's mounted underneath the lid.
It seems like warm white is what to get, complimented by some 660nm and some 700+ nm.
captainmorgan
Well-Known Member
I have 150 watts 2700k and 38 watts of 5000k LED that I want to supplement with about 10% 660 nm,the design worked out with 21 watts of it.A regular heatsink and fan on the back won't work for my setup and the tube and fan works well. The 730 nm only goes for 10 minutes after all lights are out for a flower initiator.
captainmorgan
Well-Known Member
If you average out the kelvin numbers for my Cree cabinet I end up with 188 watts of 3160k,not sure how accurate that is but I'm sure it's in the ballpark.I forgot where I read it but adding about 10% 660 nm was suggested,most whites fall off after 630 nm. I'm sure a little 700+ nm would be fine but I'm just using 730 nm to switch the Phytochrome Pfr/Pr state.
JMD
Well-Known Member
Why won't a regular heatsink work for you?
captainmorgan
Well-Known Member
Thanks! How much did you pay for delivery? Those are quite heavy, so I expect high delivery charges at least when buying several pieces.
Please do test those drivers! I would like to know if it's possible for these drivers to fail in a way, that would destroy the leds? I would hate to burn 100's of euros worth of leds just because trying to save in wrong place.
captainmorgan
Well-Known Member
I just use it at lights out for 10 minutes to switch the plants over to flower building,if you don't it takes them about two hours to do it on their own with indoor lighting. I do 12/12 with the 730 nm for the first week then you can go up to 14/10 for the bulk of time then back to 12/12 for the last two weeks.
captainmorgan
Well-Known Member
Almost forgot,my UV bulb should arrive tomorrow.
JMD
Well-Known Member
I think it was around 40 RMB for 2 heatsinks, 2 large drivers and a smaller driver - but that was to China. Got someone to bring it to meThanks! How much did you pay for delivery? Those are quite heavy, so I expect high delivery charges at least when buying several pieces.
Please do test those drivers! I would like to know if it's possible for these drivers to fail in a way, that would destroy the leds? I would hate to burn 100's of euros worth of leds just because trying to save in wrong place.
I will run a test of the drivers when I get them (should be at the end of the month). It's possible for everything to fail in a way that not only destroys your LEDs, but also burns your house down. But is it likely to happen? Luckily no!
All electrical can fail in a very destructive way, but it is highly unlikely that it ever will.
Your LEDs are quite safe, no worries.
Look at http://en.wikipedia.org/wiki/Emerson_effect
I would run them for just as long as your other lights are on.
captainmorgan
Well-Known Member
If money wasn't so tight I would just buy one of these and I would like some 680 to 690 LEDs to mix with the 660 but couldn't find any.
http://growlightsource.com/products/red-boosters-boost-flower-and-fruit-production/