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RAKC
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Discussion Starter · #1 ·
IN DIY sub as well (by mistake)

Well the light geek in me got the better of me. At first just built the sphere, not good enough. 80mm thick foam sphere (lots of research digging on how to do it). But set up to do bike lights and flashlights. The upside of having action cameras and doing a couple reviews of them, plenty of extra gopro style mounting parts.




Wanted to be able to run bike lights for extended periods with proper air flow. So added a "cooling tube". The upside of 80mm thick walls, can do all kinds of stuff without affecting the integrity of the inner sphere. press in t nuts and some foam safe CA can do amazing things. YES THE TUBE IS EASILY REMOVABLE. And you can see it, but I made adapters plates to close up the whole around the lights, quickly changeable with tube off. Tube is just held on by 4x M4 short screws into the t-nuts.



You can see at the interface to the sphere there is inlets on all 4 sides, all tapered to "scoop" air in towards the lights heads then back over them. Fan is set on "suck" through the tube. Preliminary testing has been great so far.

For convenience I moved my Voltage/Amp display onto the sphere base. Both fan and display are on DC connectors, then I made a "y" for each to plug in separately. Then own wire coming off with standard DC connector again to plug into my normal PSU or a wallwort so sphere can be totally stand alone and easier to move upstairs or to the garage.




And totally finished:




Then, in honor or Andy dubbing my contraption to generate air flow for testing thermal management of light heads the "Wind Tunnel", I found a BIG 120mm 12V fan at radio shack on clearance for $9, hehe. New Anemometer should be here tomorrow (didnt want to bug my friend to borrow his again). Fan set to "suck" through the tub as it gives the most evenly balanced air flow through the tube.

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NOW HERE'S THE REASON THIS BELONGS HERE

Work in progress, but now youll be able to see full comparisons of every light I have, I review, I build, whatever. If its a bike light or flashlight I end up with, it will end up on these sheets. Plan to do run time graphs of output and everything. Taking alot of time to build the sheets, relearn how to do graphs and all that, but its coming along. Then have to run the tests on everything (that I feel is worth testing).

Lumen Outputs of my lights

I do have a stock Yinding I need to put back together, but that's the only "unmodded" light I have that's not listed but can be functional.
 

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Very cool tigris! Funny but was just contemplating the purchase of a 12V fan myself. Hope my local RS has the same kind of deal going on.

BTW, could you devise a means of measuring color temperature as well?

Thanks for all your work on this!!!
 

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RAKC
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Discussion Starter · #3 · (Edited)
The only way to do color temp is the same way I have been doing it. The tool needed to be able to do that is $1000+, so my eyes comparing against other tints is the best I can do.

Well I am planning on getting a full selection of emitter tints and making a piece of board that's smooth, flat white to make a way to compare tints/color temps.
 

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Hummm...either you're the ultimate "Light Geek Par Excellence" or someone trying to build a "Thermonuclear device" and then trying to pull the wool over everyone's eyes....;)...hopefully the former ( and not the latter ). :smilewinkgrin:
 

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RAKC
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Discussion Starter · #5 ·
Well I got my son a mini quad copter for Xmas, good delivery system :p

Its a cross between being a light geek (though can't afford to be like Artur or those other guys with the fancy equipment and knowledge) for doing reviews/having fun when i cant ride and having a "project" I'm slowly working on.
 

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Well I am planning on getting a full selection of emitter tints and making a piece of board that's smooth, flat white to make a way to compare tints/color temps.
Think if you print out the LED color graph, then what ever tint square matches the illuminating emitter will disappear into a white background, if that makes any sense. Couldn't find the one I was looking for real quick, but something like this:

image.jpg
 

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RAKC
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Discussion Starter · #7 ·
That's a good idea, ill try to find something too, thanks.

Well outta propane for garage heat :( so ill be doing final testing of the set up tonight to make sure everything is good to go.
 

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RAKC
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Discussion Starter · #8 ·
OK testing going good. Airflow on the cooling tube is about 6.5mph, little over 9 on the new wind tunnel. have some tests to do on how well its cools, first light head attempt was Xeccon Z10 (Z11 is being "worked on" atm) and its responding same as it did on the old wind tunnel. Guess 6.5mph isnt going to cut it any way I try it for current "stock" form of those heads. Well see how the 3A yinding does.


Update: Ran the yinding through on a 30 minute test. Got results I didnt expect and if I wasnt seeing it I wouldnt believe it. Blue yinding is set up on KD2 driver, modded to 3A, dual XP-L HI V2 3C emitters on DTP copper Noctigons. Vancbikers LowPro gopro mount adapter. For the first part of the test it did exactly what i expected. Slowly dropped lumen output as things heated up. Stabilized at 1892 lumens (from 1966 at 30 seconds). just hovered at or slightly above 1892 for a while. Then pack voltage dropped below 7.35V... current draw started to increase slowly, but so did output. 2032 lumens when I stopped checking to try another, more charged pack. Which light went right back to 1892. PUt the previous pack back on, and dropped to 1892 at first then started climbing back up as current draw from the pack increased.

TEst proved ONE THING, XP-L emitters are the future of bike lights. My yinding on XM-L2 couldnt handle the heat well at all at 3A unless air speed was at or above 10mph. now at 6.5 mph, its thermally stable, awesome output, never stepping down or loosing the output from getting good and hot.

Cant wait to get the graphing sorted out so I can start running comparisons. Nothing like "tested and true" proof to what some of us have been saying for a while now.
 

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Think if you print out the LED color graph, then what ever tint square matches the illuminating emitter will disappear into a white background, if that makes any sense. Couldn't find the one I was looking for real quick, but something like this:
One of method used to determine K of the light is using good picture camera with manual White Balance settings. You are adjusting WB to the K where the piece of paper looks completly white. This will tell you at least the range or the class to which the light belongs.

Anyway, very good job Tigris!!! Now you are becoming Led light scientist ;)

PS. You have also proved you need stable and adjustable power supply to get consistent results.
 

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RAKC
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Discussion Starter · #10 ·
Thanks ledoman, im trying!!!

My power supply is still battery pack for the lights :p. My adjustability was the pack voltage, wasnt fully charged. I actually do get consistent numbers as long as im consistent on pack voltage. Be ALOT easier with an adjustable power supply but those things arent cheap.
 

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RAKC
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Discussion Starter · #12 ·
Lmao, hell no, I just checked I to figuring that out, um NO. There's A LOT to that (really involved in sorting it all out) and this stuff costs me enough valuable riding time :p. There is a standardized color chart that's part of the process which can show if CRI is high or low, basically what I do shining lights in my kids toys outside.
 

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RAKC
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Discussion Starter · #13 ·
Ok I found a chart for cri, need to find one for color temp like it. Though I think the one you show if I have it printed on poster board would work.
 

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Great job Tigris99! Love it! One thing though - I'm using that same cheap Lux Meter and not getting accurate results. It's on my wishlist to buy the "good one". Yours seems to be working well though.

-Garry
 

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RAKC
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Discussion Starter · #15 ·
U have to calibrate to ur set up is a lot of it. We don't have the accurate spheres with the special coatings, so have to adjust the "surface area" in the equation till you start getting lumens you should. A good meter will be off too.
 

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I'm talking straight lux readings to generate kcd #'s (throw distance). My modded Courui flashlight should be up over 100kcd, but with my meter I'm only calculating around 50kcd.

-Garry
 

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RAKC
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Discussion Starter · #17 ·
That would be hard to do with the way the sensor is on these as if I understand correctly, its based off lux at a given distance but hard to hit the little sensor on this thing. But hey, its cheap and works good in the sphere (though I am curious as to what a better one will read). Still trying to sort out HOW to figure that out directly since it cant be done with a sphere to my understanding. That whole trying to do it at a distance thing is difficult at best with optics because of the beam spread.
 

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RAKC
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Discussion Starter · #18 ·
Ok here's my runtime output test. Used wiz20 as its the simplest to deal with (and easily consistent).

Wish my camera had longer time lapse gap than 60 seconds. But i am going to condense time increments cause almost 3hrs is a bit too much to type in each reading from every 60 second data sample picture.

 

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Ok, I'm looking into / pursuing the "round hollow foam sphere" idea. What size is your foam ball? I've had a really tough time finding even 12 inch diameter for a reasonable price and yours looks much larger than 12 inches. You say "80mm" in the O.P., but that ain't no 80mm diameter sphere! 80cm? 12 inches should work for my purposes, but if I can go larger without a huge jump in price I would. Care to share a link where you purchased?

For reference, here's the BLF thread I am following proving the concept: Integrating sphere #4 (the fast and cheap one) | BudgetLightForum.com

-Garry
 
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