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Using the same brand emitter


MeCasa

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I'm not talking about using different brand emitters on the same channel. I'm asking about whether or not using different brand emitters on clusters has any effect on color blending?

 

Originally I was going to use Luxeon Rebels but I found a deal to buy Cree XPE emitters from China for $2.50 with free shipping but I already purchased some Rebels, I can use them in conjunction with the Cree's or I can save them for another project and buy Cree's in this color to keep all clusters the same brand and same series.

 

They will not be on the same channel

 

Thanks

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1. It may be fake, but may be not fake, because the LEDs with low-efficacy bins Cree sell very cheaply.

2. Also please keep in mind - XPE is very old LED, price for it is very low in anyway.

3. Cheapest delivery from China is really very cheap. But requires very long time for delivery - at least 30 day to USA or even more.

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I truthfully don't believe they are fake. Chinese companies are no different than any others there are good and bad.

 

Here's the link, decide for yourself

 

http://www.satisled.com/

 

Hello DNK, I don't need cutting edge, the XPE was a proven product with a good reputation and an excellent product for the price. As for the shipping time, they get better all the time and I will wait if it means more bang for my dollar. As for the binning, I am only running the same color emitters on specific channels, this should minimise binning problems.

 

Do you have any idea if I will have any negatives blending a Rebel with a XP-E in the same cluster?

 

Or is the question foolish?

 

Thanks

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jedimasterben

When it comes down to it, why would you purchase an XP-E for $2.50 that you're unsure of versus a Rebel or Rebel ES from Steve's for $3?

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I won't say that money doesn't affect every decision I make but I've read so many articles touting the brightness of Cree emitters that it did indeed influence my decision.

 

I truthfully thought I was upgrading for less money.

 

Am I not?

 

I need roughly 80 emitters

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jedimasterben

The XP-E white and royal are no match for Rebel ES, and even the colored XP-E are less efficient than the Rebels.

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I started out with Steve's and my project is currently on hold because Steve's has promised the introduction of DMX boards this month.

 

To date I have recieved good service from Steve's and a gentleman named Jeff has answered every email promptly. Like many people I was name brand buying on assumptions.

 

Thanks

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jedimasterben

Yes, while Cree does make good diodes, there does seem to be an almost 'cult' among this hobby and a few others of people that exclusively use Cree because they're 'better' - when asked how they are better, they have no answer, just that they are better :)

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I am not sure Cree has any better advertising than Philips do. Rebel ES in best bin royal Blue is no better than XTE in best bin and certainly in whites Cree are not matched in XPG2 or XPL. You have a bias as do I, but I think to be objective requires a sticky with a lot more data based on all leds not those that only a few people have tried. Luxeon Z is a terrible led re efficacy but everyone is on it, and there is very little objective review of its performance relative to other similar leds in that platform. All leds are the best led on their day, but that changes with blistering speed, so better to open to all possible offerings out there, Cree, LL or other

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welight, you right. Theoretically. But we can't buy anyway best efficacy bin of Cree, however, best bin of LL LEDs is hardly, but commercially available.

 

About advertizing of Cree. In day of introducing of MK-R Cree said "200LPW is commercially available now". Since then, year and a half has passed. Until now, is impossible to buy this LED. But many people believe about Cree has a champion efficacy. It is fake.

 

Moreover, even in the graphs shown by Cree in newest datasheet on MK-R (I'd like to remind - year and a half has passed! Where "changes with blistering speed"?) we can't see this LED! I mean - for 85C, i.e. for test conditions for this LED. Of course, you can find dot on graphs for 200LPW for 25C :) But it will be only for very low current (again, much lower than test condition!) and I have a question for Cree - why 25C? Why not -25C? It is a fake again. Cree - not best LED manufacturer, Cree first of all is advertizing company, that is producing also usual LED, but more often fake press releases.

 

Cree misleading consumers in pursuit of profit. In Russia, it is a crime. What about USA?

 

PS May be "Cree is producing usual LED" seems an exaggeration for you? Please be reminded - best commercially available white and royal blue LED from Semileds has a similar efficacy to the best commercially available (sic!) Cree.

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DNK, you have my interest, which Semileds white and Royal Blue is equal to Cree?

 

Q bin XTE has been available readily for some time, Im not sure why you cant buy it, but we have stocked it for at least 2 years.

 

Surely you not telling me when a Led company promotes a product, it is unreasonable to not promote that product in its best possible light, if so Cree is hardly alone. There is nothing in the Cree datasheets that dont support what they promote, yes MKR is 200LPW at low current, it is not misleading and will take anyone 5 mins to work out reading the datasheet. The choice is then to consider it relative to other products to decide if you wish to use such a product. I can spend a $100,000 on a Mercedes only to find it has poorer turning circle compared to $20,000 Toyota but I wont see that in the Mercedes advertising, all customers make descisions based on alot more than a big headline ad.

 

As I said all these companies we are discussing make excellent products but I think we need to offer balanced facts rather than rhectoric without the full details

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1. Please check latest datasheet for Semileds C35.

 

2. It is mistake. Please check - Q bin (as I understand you talked about royal blue, because best bin of white is R5) of Cree XT-E can output 600mWt at current 350mA and approx. 1050mWt at 1000mA. Voltage drop will be 3.2V, so we have efficacy 1.050/(0.7*3.2)*100=47%. However, Luxeon T on this current will have output up to 1200mWt, and voltage drop 2.8V, so we have efficacy 1200/(0.7*2.8)*100=61%. But is not all benefits of a Philips Lumileds technology. I would like to show one more example. XT-E is designated as 1500mA LED. Let's look how much does it have radiation on current 1500mA. It will be approx. 600*3.25=1950mWt and efficacy 1950/(1.5*3.35)*100=39% and for Luxeon T on current 1200mA approx 1200*1.45=1740mWt and efficacy 1740/(1.2*2.9)*100=50%.

In other words, 10pcs of Luxeon T will give 1740*10=17400mWt of radiation and consume 10*1.2*2.9=34.8Wt and 8pcs of Cree will consume the same amount of power 8*(1.5*3.35)=35.18Wt, but give only 8*1950=15600mWt. It is mean - to achieving the same radiation quantity as from 10pcs of Luxeon we should add one more Cree XT-E, but all power, that will consumed by this LED, will eat your money!

You do not think it is rout for Cree? OK, one more example. 10pcs of Luxeon T will require 2.9*10=29V from the LED driver, and 9pcs Cree XT-E 3.35*9=30.15V! Cree contrives losing and here.

 

3. Cree indicated test current for MK-R as 700mA. Can you please indicate exact bin of MK-R, that can reach 200LPW at test current? I sure, NO. Please be informed - Luxeon TX on current 50mA and 25C will have output approximately 205LPW. Can you please show me press-release with this fact? I sure - NO again. It is a fair play, but Cree, I'll forced to repeat - is misleading consumers in pursuit of profit. Indeed in USA it is not crime?

 

All examples above is simple and I sure you know crystal clear about it. But you is distributor of Cree, not Philips. It is simple - LED from Cree is easier to sell due to an advertising power (in other word - effrontery in advertizing) of Cree and LED from Cree has a cheaper partners price. I'm sorry for inconvenience, it is your business and I would not want to disturb it. But I ask you not to argue with me on this issue. Because I have more devastating examples for Cree.

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jedimasterben

DNK, you have my interest, which Semileds white and Royal Blue is equal to Cree?

They don't have any. The C35L and C35L-XX-A both have less flux and a higher forward voltage than even the XT-E, and the XP-G2 widens the gap by a bit.

 

What I don't know is why Cree still produces the XT-E white and the XP-G2 whites since they are so similar in flux, you'd think they'd package the XP-G2 diodes as a higher bin of the XT-E.

 

Q bin XTE has been available readily for some time, Im not sure why you cant buy it, but we have stocked it for at least 2 years.

Yep, that bin is as old as dirt lol, it's been available for about as long as I've seen the XT-E be around, I'm surprised that Cree doesn't advertise better bins of it, as I'm sure the process has matured more, unless they're working on something in its place that they're not sharing.

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They don't have any. The C35L and C35L-XX-A both have less flux and a higher forward voltage than even the XT-E, and the XP-G2 widens the gap by a bit.

I think, this gap is not noticeable. Please be informed - royal blue C35 is also has 600mWt @350mA bin, and best white has a 148lm @350mA, exact 148LPW. Difference only in FW, but not very big - much lesser than between Luxeon and Cree ;)
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I'd really like to see all the datasheets you guys bandy about.

 

Apparently there's like three different sets the way these disagreements seem to go.

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1. Please check latest datasheet for Semileds C35.

 

2. It is mistake. Please check - Q bin (as I understand you talked about royal blue, because best bin of white is R5) of Cree XT-E can output 600mWt at current 350mA and approx. 1050mWt at 1000mA. Voltage drop will be 3.2V, so we have efficacy 1.050/(0.7*3.2)*100=47%. However, Luxeon T on this current will have output up to 1200mWt, and voltage drop 2.8V, so we have efficacy 1200/(0.7*2.8)*100=61%. But is not all benefits of a Philips Lumileds technology. I would like to show one more example. XT-E is designated as 1500mA LED. Let's look how much does it have radiation on current 1500mA. It will be approx. 600*3.25=1950mWt and efficacy 1950/(1.5*3.35)*100=39% and for Luxeon T on current 1200mA approx 1200*1.45=1740mWt and efficacy 1740/(1.2*2.9)*100=50%.

In other words, 10pcs of Luxeon T will give 1740*10=17400mWt of radiation and consume 10*1.2*2.9=34.8Wt and 8pcs of Cree will consume the same amount of power 8*(1.5*3.35)=35.18Wt, but give only 8*1950=15600mWt. It is mean - to achieving the same radiation quantity as from 10pcs of Luxeon we should add one more Cree XT-E, but all power, that will consumed by this LED, will eat your money!

You do not think it is rout for Cree? OK, one more example. 10pcs of Luxeon T will require 2.9*10=29V from the LED driver, and 9pcs Cree XT-E 3.35*9=30.15V! Cree contrives losing and here.

 

3. Cree indicated test current for MK-R as 700mA. Can you please indicate exact bin of MK-R, that can reach 200LPW at test current? I sure, NO. Please be informed - Luxeon TX on current 50mA and 25C will have output approximately 205LPW. Can you please show me press-release with this fact? I sure - NO again. It is a fair play, but Cree, I'll forced to repeat - is misleading consumers in pursuit of profit. Indeed in USA it is not crime?

 

All examples above is simple and I sure you know crystal clear about it. But you is distributor of Cree, not Philips. It is simple - LED from Cree is easier to sell due to an advertising power (in other word - effrontery in advertizing) of Cree and LED from Cree has a cheaper partners price. I'm sorry for inconvenience, it is your business and I would not want to disturb it. But I ask you not to argue with me on this issue. Because I have more devastating examples for Cree.

 

1. I did check and the data does not support what you say. It is pointless to quote data if the parts are not commercially available

 

2. I am interested in the way you respond. I note in other threads on this forum you complain about the bul**&* about binning data by some suppliers and here you refer to data on the LuxT E bin in Royal Blue, I dont know of anyone who has this bin so the comparison is valid on the datasheet but not in reality. I have spoken with Lumileds and most of their distributors and it is rare to ever find the best quoted bins. EVER. In XPG-2 best bin always available in Cool white is S2 rank. I do agree in most cases if you can purchase the right bins, Lumileds has better vf figures than Cree

 

3. The press release did not state the data of 200LPW was at 700ma that I can see, where did you see that?

 

I have no problem with much of what you say, except you use the same misrepresenation method you complain other people use, to make your point, so you diminish your arguement

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1. I asked Semileds about right datasheet for C35, please wait.

 

FYI I'd like to show to you part of our PI from December 2013:

post-84603-0-70843100-1403122395_thumb.jpg

As you can see, more than a half of a year this LEDs is available.

 

2. I'm agree - best bins of Luxeon is very rare. But if you really want to catch it, you may catch it, really.

 

By the way, not only best bin of Luxeon will outperform Cree, as we can seen in datasheet, isn't it?

 

3. As I understand "commercially available" is meant not in laboratory, isn't it? So, why Cree allows himself to write about 200LPW if commercially available MK-R has not this efficacy? Measuring LPW on unreal for commercial using small current - it is not fair play, I'd like to emphasize again and again. Best bin of MK-R in real has efficacy on test condition (sic! It is conditions that declared by Cree itself!) only 110LPW! It is rare joke, isn't it?

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1. I asked Semileds about right datasheet for C35, please wait.

 

FYI I'd like to show to you part of our PI from December 2013:

attachicon.gif11.jpg

As you can see, more than a half of a year this LEDs is available.

 

2. I'm agree - best bins of Luxeon is very rare. But if you really want to catch it, you may catch it, really.

 

By the way, not only best bin of Luxeon will outperform Cree, as we can seen in datasheet, isn't it?

 

3. As I understand "commercially available" is meant not in laboratory, isn't it? So, why Cree allows himself to write about 200LPW if commercially available MK-R has not this efficacy? Measuring LPW on unreal for commercial using small current - it is not fair play, I'd like to emphasize again and again. Best bin of MK-R in real has efficacy on test condition (sic! It is conditions that declared by Cree itself!) only 110LPW! It is rare joke, isn't it?

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1. Semiled bins are up there, but we stock and sell mostly S2 bin in Cool which is a bin better and Cree has had these same bins out for 2-4 years. Cree XPL in the same footpint is now well ahead of this. Your Royal blue data is 520mw-600mw. Cree is min 600mw at 350ma. Sorry but this is not equivalent

 

2. I have chased Lumileds for top bins many times and it is very difficult to get regular or any supply so if you cannot buy all day/everyday then you can not use that as base comparison data. In general LL not brighter but more efficient on vf yes.

 

3. Let me get more data on this and I will come back to you

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1. Excuse me, but you are unattentive to what I write. I wrote earlier about difference between top bin of Semileds and top bin of Cree is less than between top bin of Cree and top bin of Luxeon. It's true.

 

By the way. Efficacy of white and, of course, RB LEDs is very important for all LED manufacturers. Because of this, almost all of them (exclude sleaze Chinese LED) has today near to similar efficacy for this LEDs.

 

2. Agreed. As I wrote before, best bins of LL is very rare. It is uncomfortably for business, agree again. But in any way this LEDs exists, and you can buy it, but similar Cree you can't buy :) We discussing in this topic about technology power, not commercial availability, isn't it?

 

3. What do you mean? You can not make sure about 110LPW for best bin MK-R at test current?

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1. Excuse me, but you are unattentive to what I write. I wrote earlier about difference between top bin of Semileds and top bin of Cree is less than between top bin of Cree and top bin of Luxeon. It's true.

 

By the way. Efficacy of white and, of course, RB LEDs is very important for all LED manufacturers. Because of this, almost all of them (exclude sleaze Chinese LED) has today near to similar efficacy for this LEDs.

 

2. Agreed. As I wrote before, best bins of LL is very rare. It is uncomfortably for business, agree again. But in any way this LEDs exists, and you can buy it, but similar Cree you can't buy :) We discussing in this topic about technology power, not commercial availability, isn't it?

 

3. What do you mean? You can not make sure about 110LPW for best bin MK-R at test current?

I accept in Royal Blue LL has a slightly lower vf, but not absolute better brightness , I dont accept Semileds does, anymore than I accept Rebel ES in other colours are better than Cree colours but I do wish Cree made some more exotic colours

:huh:

 

I think you misunderstand me. I dont know of E bin Lux T RB anywhere, ever. They is no point to discuss technology if not commercially available, if so I can make up any story about any product without delivering a product for anyone to test my story. If it was available I would be happy to buy some

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