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8X Diode Murder fund

daguin

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I wish to some day build things like you, Igor.
I have already accepted that, for me, I will NEVER build things like IgorT does. That's actually OK. We have IgorT. Who needs two? ;)

Peace,
dave
 



Tech_Junkie

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Sorry to jump off topic, but how are the lenses progressing? There still is a pile of us waiting for the final product. Or did I miss something?
 

bryce007

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Sorry to jump off topic, but how are the lenses progressing? There still is a pile of us waiting for the final product. Or did I miss something?
Last I heard, there is a GB coming soon. I'm anxious to get my hands on one of these also. The dot is very clean on his lenses (huge selling point for me).
 

daguin

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Sorry to jump off topic, but how are the lenses progressing? There still is a pile of us waiting for the final product. Or did I miss something?
Jayrob sent his prototype lens nut to IgorT. I don't think he has it yet. Then he needs to get someone to CNC them.

Peace,
dave
 
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bryce007

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Jayrob sent his prototype lens nut to IgorT. I don't thin he has it yet. Then he needs to get someone to CNC them.

Peace,
dave
He does have the one that Jayrob sent him. I've seen some dot comparisons, and it looks very nice. Hopefully there will be a GB coming soon.
 

daguin

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He does have the one that Jayrob sent him. I've seen some dot comparisons, and it looks very nice. Hopefully there will be a GB coming soon.
How time flies when you are busy

It has been almost a month since Jayrob finished the prototype :yabbem:

Peace,
dave
 

Krutz

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looks really nice, Igor!
how about putting a microscopic slide (or any other glass) in the beampath, so the reflection (8%) could be measured for a rough quick test if anything changed? good enough for relative comparisons and rough trends maybe, so you know when its worth to replot?

manuel
 

IgorT

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Seems like there is less consensus on where to test the second 8x diode, than there is on the 12x... And it's the 12x, that's the total mystery...


I've seen all kinds of different current suggestions, and i feel as if i'm expected to make the final decision.

But you have to understand what a huge responsibility this is for me. If i am too careful (and i often am), we get "too many" hours, and those of you wanting max-power won't be happy, knowing that we should have tested higher. If i go too far, i waste a diode for no good reason. And it's not my diode to waste.

That's why i wanted to hear other people's recommendations for this one. My own initial wish was to test 330mA. It's not too far from the first diode, so the results could still be correlated a little. And it felt like the max i would be willing to set these to normally..

But i don't want to force my own wishes on this experiment. Many of you contributed to make it possible at all, and i would like to do it in a way that everyone is happy in the end.


Fact is, many are setting their 8x diodes to 360mA or even higher. And as far as i know, there are no reports of rapid degradation.
So i was almost at a point, where i wanted to set the second 8x to 360mA.


But there is one tiny thing that is worrying me.

A short time ago, i decided to put my personal 8x together. It was a good diode, it came out to 440mW after my medium custom lens at 320mA! I was impressed!
Since then i have used it very little, but i measure it often, and i fear something scary is happening! Every time i measure, i measure less! :undecided:


Now, i have seen degradation in personal (usually exerimental) lasers more times than i can count. And it's always the same.

I always see it happening, but don't want to believe it. First i blame it on the temperature being higher. Then i blame it on the lens. In the end i even start fearing there is something wrong with the driver...
But then i check one thing after another, and everything checks out fine, and yet the power keeps measuring lower and lower...


Shortly after assembling it, i measured it at 436-437mW, just now imeasured my 8x at 433mW. If correct, that would be a 7mW drop after only minutes of use, which does not make much sense, unless i lucked out and got the weakest diode of the bunch.

But then again, it was a VERY cold night, when i made it, i recall measuring the laser at 17°C. Right now it's 22°C or so, so i'm still in the denial phase. :whistle:


Still, this is the thing that made me pause. I was wondering before, if higher efficiency diodes would live longer at same currents, due to being "healthier", or shorter, due to the higher optical flux they produce at the die. Of course efficiency is not the only factor in diode toughness, but it used to be a good indicator of it with GGWs...

I need to re-check my personal laser at the original temperature as well as keep track of it's powers at all the different temperatures, but it's gonna take a while before i can be sure of anything.
I might just be paranoid, and the difference i'm seeing could still be from the temperature alone. We shall see.



Anyway, this is the reason i started doubting if it's a good idea to go with the very high currents.
On the other hand, if we test the second diode at say 340-350mA and it does not degrade too rapidly, it might also dispel my fears about my personal 8x a little... :angel:


It would also answer everyone's questions about whether or not these are capable of going close to (or above - depending on efficiency) 500mW with a long enough life...



So, how about we go with 345mA for the second 8x?
It seems like a good "middle ground"...


I need a final decision, so i can set the drivers and start the "Double Murder Experiment". I really want to start both diodes at once, as it would allow me to do the re-plotting of both simultaneously, and the experiment to progress faster.
 

jayrob

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345mA's sounds good Igor!
 
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LarryDFW

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Igor;

345 ma would be 15% higher current than the 1st 8X.

That is a significant boost, and should answer many hi-power durability questions.

Nichia's graph of various efficiency 12X diodes,
shows fairly stable powers out to 1000 hours at peak power (50% duty cycle).

I posted the graph previously on post #768 :

Nichia 12X 1000 Hour Testing

LarryDFW
 
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HIMNL9

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Lol !

Any updates on the testing.
:wtf:

Not in the end-of-the-year vacation, i guess ..... after all, also IgorT need to eat, breath, sleep, and do all the other normal things that all us do ..... at least once in a year :whistle: ..... :san: :san: :san: :san: :san:
 

CHP

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Re: Lol !

:wtf:

Not in the end-of-the-year vacation, i guess ..... after all, also IgorT need to eat, breath, sleep, and do all the other normal things that all us do ..... at least once in a year :whistle: ..... :san: :san: :san: :san: :san:
Wow, I wasn't trying to offend anyone or imply that Igor should dedicate 100% of his time toward this testing. I was just curious if the 1st 8X diode was still living.
 




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