Reef Central Online Community

Go Back   Reef Central Online Community > General Interest Forums > Lighting, Filtration & Other Equipment
Blogs FAQ Calendar

Notices

User Tag List

Reply
Thread Tools
Unread 04/19/2011, 07:27 PM   #1
redfishsc
Registered Member
 
redfishsc's Avatar
 
Join Date: Sep 2008
Location: Wake Forest, NC
Posts: 3,696
LED spectral analysis about to begin. Need your input.

We are about to begin doing some spectral analysis of our most commonly used LEDs for DIY arrays. We will also do some PAR testing to compare (roughly) the PAR output of various similar-sized LEDs.


We have available spectral graphs for most of our LEDs already, but we don't have much data that tells us what the resultant spectrum is for the combinations we use over our tanks. I'm sure some folks with ninja math skills could give a solid educated guess on the resultant spectrum if they had the data for the intensity of each LED at each wavelength, etc...

But we want to get some real data. We'll be using a radiometer at a University, and we will drive the LEDs using a benchtop power supply (constant current capable). I'll have a 700mA Buckpuck and a Meanwell ELN60-48 handy just in case.

I have all the LEDs mounted to temporary heatsinks and soldered with quick disconnect fittings.

Here is a list of the LEDs I will be testing. Note that I do not have exact data regarding the tint bin of each of these LEDs but I do have the flux bin, which gets us in the right ball park.

Cree XPG:
---cool white
---neutral white
---warm white

Cree XML
---Cool white

Cree XPE
---Blue
---Royal blue
---Red
---Neutral white

Cree XRE
---Cool white
---Royal blue

Bridgelux
---402 cool white (10 watt capable).

Luxeon
---Rebel neutral white
---Rebel royal blue
---Rebel Cyan

Satistronics
---3 watt "pure white"
---3 watt "red"
---10 watt "pure white"
---10 watt blue 455nm
---20 watt 15,000K cold white


HERE IS WHAT I WOULD LIKE YOUR INPUT ON:



1. What combinations, from the list above, do you think would be the most helpful? (for reef or planted aquaria, we will study them for both applications).

2. Do you have any LED you would like us to analyze that is NOT on the list? If so, PM me and I can arrange to study it for you but you MUST hurry. It must be here before April 28th).

3. What drive current for the 3-watt class do you think is most useful? Most of these are capable of 1,000mA but we will be using 700mA as the standard.

4. We may do some testing with optics, but given our time constraints, we may not be able to use optics at this point. Optics will only serve to show PAR data and footprint changes, but not likely effect spectral analysis, which is our main priority.

5. Any other suggestions are appreciated.



__________________
"The measure of a life is not its duration but its donation." Corrie Ten Boom

“The tyrant dies and his rule is over, the martyr dies and his rule begins” -- Søren Kierkegaard

Current Tank Info: ghetto grad school reef.....11g rimless tank, 36X9X9, lit by Cree and Rebels scobbled together. Stocked mostly with free stuff I got from panhandling my fellow reefers.
redfishsc is offline   Reply With Quote
Unread 04/19/2011, 07:30 PM   #2
redfishsc
Registered Member
 
redfishsc's Avatar
 
Join Date: Sep 2008
Location: Wake Forest, NC
Posts: 3,696
By the way, I am keenly interested in testing some of the larger LEDs that are out there, but since I am funding most of the LED expenditures out of my own pocket, I simply could not justify buying anything larger than the Bridgelux 402 and the Satistronic 10w and 20w that I have.

If anyone would like some data on the bigger Bridgelux, the new larger Cree multichips, or import LEDs that go up to insane wattages, PM me. If you can get it to me in time, I should be able to test it.


Also note that I would love to test things like the PAR30 and PAR38 bulbs out there. I have contacted some of the resellers that carry them, and only one expressed interest, but hasn't sent me anything.


__________________
"The measure of a life is not its duration but its donation." Corrie Ten Boom

“The tyrant dies and his rule is over, the martyr dies and his rule begins” -- Søren Kierkegaard

Current Tank Info: ghetto grad school reef.....11g rimless tank, 36X9X9, lit by Cree and Rebels scobbled together. Stocked mostly with free stuff I got from panhandling my fellow reefers.
redfishsc is offline   Reply With Quote
Unread 04/19/2011, 08:32 PM   #3
b_s_c1
Registered Member
 
Join Date: Apr 2009
Location: Victoria, Texas
Posts: 466
I know you say given time constraints in your post but what I would really like to know if there is a shift in the spectrum during the life of the LED's.

As far as combination I think a 25-75%, 50-50%, and 75-25% would be a good base line. I think this will cover most questions and a person would be to take an educated guess on something out of this combination.


b_s_c1 is offline   Reply With Quote
Unread 04/19/2011, 10:43 PM   #4
marc111
Registered Member
 
Join Date: Aug 2009
Posts: 198
Based on what people have been trying I would suggest
1:1 and 2:1 mixes of EPE:XPG and RE:XPG The most relevant will be the newer series as that is what most are buying at the moment.
RB:NW
RB:CW
RB: with both CW and NW
the same with an single blue added to the mix
Also a violet from nanotuners 420 nm led could be added to the mix.
Please pay attention to the beam overlaps as this will significantly affect the measured intensities which is key as both output power and frequency are in the PAR equation.
Note that optics will not affect the spectrum but will have major overlap and PAR effects.

Mark


marc111 is offline   Reply With Quote
Unread 04/20/2011, 04:50 AM   #5
redfishsc
Registered Member
 
redfishsc's Avatar
 
Join Date: Sep 2008
Location: Wake Forest, NC
Posts: 3,696
Quote:
Originally Posted by b_s_c1 View Post
I know you say given time constraints in your post but what I would really like to know if there is a shift in the spectrum during the life of the LED's.
I may be able to test some 1.5 year old cool white XPG against a brand new one, but if they vary much in their tint bin (which is hard to get constant, even from the same supplier) then this will skew the test.

The only way I know to do it is to test a couple LEDs, burn them for a couple years, and re-test them.


Quote:
As far as combination I think a 25-75%, 50-50%, and 75-25% would be a good base line. I think this will cover most questions and a person would be to take an educated guess on something out of this combination.

Which colors are you talking about? Cool or neutral whites, and blue/royal blue (or combinations thereof)?


__________________
"The measure of a life is not its duration but its donation." Corrie Ten Boom

“The tyrant dies and his rule is over, the martyr dies and his rule begins” -- Søren Kierkegaard

Current Tank Info: ghetto grad school reef.....11g rimless tank, 36X9X9, lit by Cree and Rebels scobbled together. Stocked mostly with free stuff I got from panhandling my fellow reefers.
redfishsc is offline   Reply With Quote
Unread 04/20/2011, 04:52 AM   #6
redfishsc
Registered Member
 
redfishsc's Avatar
 
Join Date: Sep 2008
Location: Wake Forest, NC
Posts: 3,696
Quote:
Originally Posted by marc111 View Post
Based on what people have been trying I would suggest
1:1 and 2:1 mixes of EPE:XPG and RE:XPG The most relevant will be the newer series as that is what most are buying at the moment.
RB:NW
RB:CW
RB: with both CW and NW
the same with an single blue added to the mix
Also a violet from nanotuners 420 nm led could be added to the mix.
Please pay attention to the beam overlaps as this will significantly affect the measured intensities which is key as both output power and frequency are in the PAR equation.
Note that optics will not affect the spectrum but will have major overlap and PAR effects.

Mark

That's mostly where we'll start. I can't get the 420's from Nanotuners, they don't sell them anymore. If anyone has one they want tested, they can send it to me and I can mail it back when we are done.


__________________
"The measure of a life is not its duration but its donation." Corrie Ten Boom

“The tyrant dies and his rule is over, the martyr dies and his rule begins” -- Søren Kierkegaard

Current Tank Info: ghetto grad school reef.....11g rimless tank, 36X9X9, lit by Cree and Rebels scobbled together. Stocked mostly with free stuff I got from panhandling my fellow reefers.
redfishsc is offline   Reply With Quote
Unread 04/20/2011, 06:40 AM   #7
wfournier
Registered Member
 
Join Date: May 2009
Posts: 379
I might be able to supply a couple bigger Bridgelux LEDs if interested.


wfournier is offline   Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Spectral Analysis of 70 watt MH Lamps & ballasts??? ALIFER Lighting, Filtration & Other Equipment 3 01/01/2007 09:46 PM
Question rgds spectral analysis chindapol Sanjay Joshi, Ph.D. 2 03/24/2006 12:40 AM
Dr. SJ's Spectral Analysis... TheVillageIdiot Lighting, Filtration & Other Equipment 4 02/16/2006 11:32 PM


All times are GMT -6. The time now is 02:55 AM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2025 Axivo Inc.
Use of this web site is subject to the terms and conditions described in the user agreement.
Reef CentralTM Reef Central, LLC. Copyright ©1999-2022
User Alert System provided by Advanced User Tagging v3.3.0 (Pro) - vBulletin Mods & Addons Copyright © 2025 DragonByte Technologies Ltd.