# Cree P4 3200K-3500K (7A/WW Tint)



## LukeA (Mar 6, 2008)

I got one from Cutter today. It's impressive. If you didn't know it was an LED, you would think it was incandescent. 

Here it is next to a Cutter Q5 WC. Guess which is which. Same current; they're in series @ 350mA from the pictured Microdriver4. As you can see, the P4 is not as bright, but look at that color. 







Here's the P4 7A, a DX Q5 and a Cutter Q5 WC. The Cutter Q5 is the one with the silver inside. Look at the color of the P4 7A's phosphor compared to the DX Q5's phosphor. I think it's interesting. 






Based on the first pic, I say LEDs are here for interior fixed lighting.


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## holeymoley (Mar 7, 2008)

Luke, think you can give us a shot next to a Rebel emitter? Looks pretty nice, I might have to pick up a few.


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## jtr1962 (Mar 7, 2008)

I tested one of these last October. Results here.

Yes, I noticed the same thing about the different color phosphor. And it does do a pretty good imitation of an incandescent lamp. Definitely quite a bit more deep red there than even the warmer-tinted cool whites.


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## LukeA (Mar 7, 2008)

holeymoley said:


> Luke, think you can give us a shot next to a Rebel emitter? Looks pretty nice, I might have to pick up a few.



Yes, and I'll probably get to it tonight.


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## VanIsleDSM (Mar 7, 2008)

I have some of these LEDs aswell, I'm working on a home lighting project where I'll be running 3 of them on mr16 style heatsinks that I'm going to be turning on a lathe.. for proof of concept I arranged 3 of them on a standard heatsink and compared output to 1 of the 50w halogen bulbs they will be replacing.. the LEDs are brighter.. and only 9w each 'bulb' factoring in driver losses.

Pics and more info here:

https://www.candlepowerforums.com/threads/183477



However.. I think I might drop down to the P3 flux 2900-3100k LEDs for the final product.

I also have one of the 2720k to 3050K N2 flux LEDs.. it's ridiculously warm, but not very bright at all.


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## LukeA (Mar 7, 2008)

VanIsleDSM said:


> I have some of these LEDs aswell, I'm working on a home lighting project where I'll be running 3 of them on mr16 style heatsinks that I'm going to be turning on a lathe.. for proof of concept I arranged 3 of them on a standard heatsink and compared output to 1 of the 50w halogen bulbs they will be replacing.. the LEDs are brighter.. and only 9w each 'bulb' factoring in driver losses.
> 
> Pics and more info here:
> 
> ...



I was actually thinking that the next bin cooler would be about perfect for lighting, but that's for replacing CFLs and edison screw-base incans, and halogens are typically warmer. In any case, I think we're going to see more LED fixed lighting.


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## LukeA (Mar 12, 2008)

LukeA said:


> Yes, and I'll probably get to it tonight.



I really mean to do it. Saturday I will get this shot for you.


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## holeymoley (Mar 13, 2008)

haha...OK. I'm waiting because I was about to buy some Rebel stars for a night-light project I'm working on. I have wood floors and I think these Crees might look better than the relatively cooler tint on the Rebel emitters. I will probably have to undervolt them anyway, and I am following VanIsle's thread and this thread with interest.


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## LukeA (Mar 16, 2008)

holeymoley said:


> haha...OK. I'm waiting because I was about to buy some Rebel stars for a night-light project I'm working on. I have wood floors and I think these Crees might look better than the relatively cooler tint on the Rebel emitters. I will probably have to undervolt them anyway, and I am following VanIsle's thread and this thread with interest.



ARG! I was busy all day yesterday and today. Soon, I promise!


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## kavvika (Mar 17, 2008)

That is an absolutely beautful tint! Do you think you could link me or show me where they're listed on cutters site? Their website layout isn't all that easy to search.


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## LukeA (Mar 17, 2008)

kavvika said:


> That is an absolutely beautful tint! Do you think you could link me or show me where they're listed on cutters site? Their website layout isn't all that easy to search.



Cutter is a tough site to find things on. 

Search Cree XR-E
Go to page 2 (!)
Scroll down to Cree XR-E Power LEDs
Click the bubble for P4 7A

I got it on a star, so much easier to deal with.


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## WeLight (Mar 17, 2008)

I would be interested in ideas to make our web site more user friendly


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## LukeA (Mar 17, 2008)

WeLight said:


> I would be interested in ideas to make our web site more user friendly



One thing I would be interested in is moving the actual LEDs to the top of the search results for terms like 'Cree' and 'Cree XR-E'. And last time I looked, there were a few empty categories of switches. But I have really only looked at the site for LEDs...

Although I do have to thank you guys for labelling the bottom of the LEDs I ordered with the flux bin. :thumbsup:


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## holeymoley (Mar 26, 2008)

Or listing all the items in a category on one page with small thumbnails and hyperlinks we can click for the full info/price, etc. I agree with *kavvika* , the site could be easier to navigate.

Luke, ever get to those pics? Seriously, don't bother if its too much hassle, I'm curious to see them though.


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## KrisP (May 6, 2008)

LukeA said:


> ARG! I was busy all day yesterday and today. Soon, I promise!




Has anyone else played with these? I've got a few now and will be replacing all my home LED lighting with them. Has anyone used a slightly higher colour temp?


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## LukeA (May 7, 2008)

holeymoley said:


> Or listing all the items in a category on one page with small thumbnails and hyperlinks we can click for the full info/price, etc. I agree with *kavvika* , the site could be easier to navigate.
> 
> Luke, ever get to those pics? Seriously, don't bother if its too much hassle, I'm curious to see them though.



The emitter is mounted in the light it's going to go in, but that light needs to be installed. Might happen this weekend. Then the pics will follow.


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## LukeA (May 7, 2008)

KrisP said:


> Has anyone else played with these? I've got a few now and will be replacing all my home LED lighting with them. Has anyone used a slightly higher colour temp?



That's the highest warm tint that Cutter has, and Cutter is the only place I've seen Crees sold by tint.


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## KrisP (May 8, 2008)

I made a bedside lamp with a single one of these in a white dome diffuser and found it great for a night light but the colour wasn't right for a brighter light... So i've made a light with 2 of these warm white LEDs and a single P4 (unknown tint) which makes a much nicer colour overall. The P4 is a crappy tint so it's slightly blue, but i'm looking at getting a Q2 WH tint LED and using that with the 2 warm whites.
This light will also be a bed lamp but it has a variable resistor and transistor to vary the output from 5mA up to 1A


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## LukeA (May 9, 2008)

KrisP said:


> I made a bedside lamp with a single one of these in a white dome diffuser and found it great for a night light but the colour wasn't right for a brighter light... So i've made a light with 2 of these warm white LEDs and a single P4 (unknown tint) which makes a much nicer colour overall. The P4 is a crappy tint so it's slightly blue, but i'm looking at getting a Q2 WH tint LED and using that with the 2 warm whites.
> This light will also be a bed lamp but it has a variable resistor and transistor to vary the output from 5mA up to 1A



Sounds good, can you share more details about the dimming?

I was thinking about using 2 of theses warm emitters and a WC for a light I'm building, but I decided to use all 3 to see what happens. I've been waiting for Cutter to ship them.


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## WeLight (May 9, 2008)

I am going to stock True Neutral in Q2/Q3 flux, this would be around 4000k in the unbiquitous Q3 (160 lumens at 3 watt) if this is of interest


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## KrisP (May 9, 2008)

LukeA... The dimmer is just a basic circuit, see the link below. It's the top circuit but I have the light before the collector, not after the emitter. I had some spare components laying around, so I used a 2SD2396 transistor, 1K linear pot, and 120ohm resistor gave me the widest variation of output (5mA to 1A). I found a 1K resistor to give a variation of about 550mA to 1A which was not suitable.
http://www.cpemma.co.uk/ef.html

WeLight... I'd try a few of those. But for the moment, i'll be using the two 7A and one Q2 WH that I just ordered from you. 

Now I just need to find a lamp suitable to mount it all in.


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## LukeA (May 17, 2008)

LukeA said:


> The emitter is mounted in the light it's going to go in, but that light needs to be installed. Might happen this weekend. Then the pics will follow.



I'm no liar. Sorry it took me so long. 

The scenario in the pics is the hardwired Cree running at 350mA with a 1AAA Rebel100 light running also at 350mA laying in the cavity, so discrepancies in brightness should probably be ignored.












The Rebel is slightly yellow of white, the Cree is very orange. I have high hopes for my 3 7A/WW mod in progress.


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## LukeA (Jun 19, 2008)

LukeA said:


> I have high hopes for my 3 7A/WW mod in progress.



I finished the mod a few weeks ago and it's great! Nice beam, great color, I should put up my construction pics and take some beamshots.


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## DM51 (Jun 20, 2008)

Thanks for the link in the dive-light thread pointing me here. Very interesting - it looks extremely nice. 

Is there someone who could do a spectrogram of it?


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## LukeA (Jun 21, 2008)

DM51 said:


> Thanks for the link in the dive-light thread pointing me here. Very interesting - it looks extremely nice.
> 
> Is there someone who could do a spectrogram of it?



The LED Museum has equipment to do this. If I had any spares, I'd send him one.


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## DM51 (Jun 21, 2008)

Yes, I posted in his thread asking him if he had done one, but he hasn't had the opportunity. 

I'm sure he'd like to do it, and it would be very interesting indeed to see the result. Anyone got a spare to send him?


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## LukeA (Jun 21, 2008)

DM51 said:


> Yes, I posted in his thread asking him if he had done one, but he hasn't had the opportunity.
> 
> I'm sure he'd like to do it, and it would be very interesting indeed to see the result. Anyone got a spare to send him?



I PM'ed Erasmus the other day to ask if he has any plans to break and sell a roll of WW Crees, but I haven't heard back yet. I don't have any projects going right now, so I don't have any upcoming orders from Cutter, and shipping is too expensive from Cutter to order just one.


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## Patriot (Jun 21, 2008)

DM51 said:


> Yes, I posted in his thread asking him if he had done one, but he hasn't had the opportunity.
> 
> I'm sure he'd like to do it, and it would be very interesting indeed to see the result. Anyone got a spare to send him?




Maybe someone would be willing to send one of these to Craig for a spectrogram test....?


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## VanIsleDSM (Jun 21, 2008)

I imagine he would like them ready to use? I have some spares that are just emitters, but I could fit them into some heatsinks and lend them out.. I have CREE N2 8B 2720-3050K, P3 8A 2900-3100K, and the P4 7A 3200-3500K. Have to see if I can't find the 8B though, I only have one and I haven't seen it in a while, but I'm sure it's around somewhere.


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## LukeA (Jun 22, 2008)

VanIsleDSM said:


> I imagine he would like them ready to use? I have some spares that are just emitters, but I could fit them into some heatsinks and lend them out.. I have CREE N2 8B 2720-3050K, P3 8A 2900-3100K, and the P4 7A 3200-3500K. Have to see if I can't find the 8B though, I only have one and I haven't seen it in a while, but I'm sure it's around somewhere.



It might stand to wait. The LED Museum is moving, and it seems quite complex and stressful enough already.


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## LukeA (Jun 22, 2008)

Page 6 of the XR-E datasheet has spectrographs of cool white, neutral white and warm white emitters. 615nm or so is the peak, but there's as much 660nm as 450nm.


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## Blindasabat (Jul 2, 2008)

Definitely!!! Just the thing for a Nitecore EX10, Surefire L1, or KX1/2 upgrade. Let us know when they are available.


WeLight said:


> I am going to stock True Neutral in Q2/Q3 flux, this would be around 4000k in the unbiquitous Q3 (160 lumens at 3 watt) if this is of interest


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