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Current for the 12x murder experiment.

  • Thread starter Deleted member 8382
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What current would you want the 12x diode to be tortured at?


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    36
  • Poll closed .

IgorT

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[About reaching 600mW with the test diode]

I think that is the answer most people want.
Of course, and i realize that.

However i also know, that 500mW+ is almost (if not completelly) exclusivelly reached only with the higher efficiency 8x's. The lower ones peak at 460mW at 360mA.


Because of that, when we are testing if 8x's can survive 500mW+, i set the test diode to 350mA, not 500mW+, because it would require a ridiculous current for that, since it's a low efficiency diode.

Before that we set an 8x to 300mA, where high efficiency ones reach 400mW+, while the test diode reached 360mW or so.


Thus, going by the same logic, i initially set the test 12x to 550mW, since it's at a current, where the high efficiency ones would actually reach 600mW+.


Basically, the idea is (or was), to test a CURRENT, where good 12x's reach 600mW and less good ones 550mW (or anything in between).


In theory, it would show that if the "bad" 12x's can survive this current, so could the good ones...




In any case, right now the 12x's driver is set to 420mA, where it will produce approx 590mW, and i'm just waiting for confirmation, to flip the Torture Switch.
 



Dusty

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well 420mA is not what I would have chosen, but if thats what most people want...:whistle:
 

Slipstream

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Do it at 550mA
:sigh:

So by what your saying Igor , is that the test subject should actually be a normal efficiency diode then, thats what i gathered from what your saying.

I didn't chip in but this experiment would definitely change what i will set my 12x at.
 

mfo

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lol
seriously, it's not even funny.
I really don't understand why people voted no on the ban poll for him. He's still acting stupid as always which basically proves he don't care about this forum, not to mention he contributes nothing. Oh well, at least I tried.
 

ossumguywill

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I really don't understand why people voted no on the ban poll for him. He's still acting stupid as always which basically proves he don't care about this forum, not to mention he contributes nothing. Oh well, at least I tried.
Man... give it a week, do another one. This time you'll have more evidence I guess, I'm kinda tired of his sh*t.

will
 

mfo

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Man... give it a week, do another one. This time you'll have more evidence I guess, I'm kinda tired of his sh*t.

will
Screw it, as I've said I tried. I'm not going to keep begging people on the issue. I mean a lot of people even voted to keep Tyler here in his second ban poll (which ended up giving him the boot) so what does that say? Maybe you can start one next week idk.
 

Byrnz93

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I think we should keep it below 400mA. We don't know very much about this diode and what it can withstand so we should keep it low at first and then work up to higher currents.
Just because a lot of people want lots of power doesn't mean we should start off at such a high current.
IMO anyway.
 

IgorT

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I think we should keep it below 400mA. We don't know very much about this diode and what it can withstand so we should keep it low at first and then work up to higher currents.
Just because a lot of people want lots of power doesn't mean we should start off at such a high current.
IMO anyway.

After a good week, this will become a VERY important question again.
But as i mentioned before, not what current to test the second 12x at, but rather what power to test it at.


Now we have a big problem here. The first experiment ended badly after only 6 hours of 390mA + one power measurement at 420mA.

At the same time we know of 12x's surviving ridiculous powers, altho none of them has an hour on them yet most likelly, most of them probably less than half...


The problem is this:

After i saw the 12x "die" (or rather become undead) after only 6 hours of 390mA ON-Time, i thought we should test the next one lower.
But just because of that i also expected the 8x's wouldn't live very long, being close to the 12x's power.

But now the 8x's completelly baffled me with their toughness, we got nearly 200 hours at 453mW, and 360 hours (and still running) at 356mW starting power.

I expected much lower numbers from 8x's especially after seeing the 12x "die", and that 12x's would turn out to be reliable (as in 100h+) at 500mW, while the 8x's would not come close and would only be reliable at around 400mW.
But a rough lifetime approximation graph (won't be finished until the first 8x dies) i made for 8x's at different powers (from 125mW CW to 650mW CW) suggests that even an 8x should survive 500 - 550mW for a significant amount of time, perhaps as much as 100 hours! (altho the graph won't have the correct shape until the first diode dies it still already indicates the 8x's are incredibly tough)


Obviously we want more power from the 12x's than from 8x's, so i don't understand why the first 12x gave up so soon at only ~550mW.
Which makes the question of where to test the second one a really hard one to answer.... :undecided:



P.S. In terms of current as well as in terms of power we are making REALLY HUGE steps here.

With GGWs 200mA or 185-215mW (with acrylics on average) turned out to be "reliable" in pointer terms. And GGWs are 100 or 105mW CW diodes..
Then the 8x's come along, and someone decides to push them with 100-160mA more, even tho they are only 125mW CW diodes (altho this data was unknown at that time).

Well, as surprising as it is (at least to me), the 100-160mA more actually turned out to be more reliable for 8x's, than 200mA is for GGWs!


The 8x's definitely set a new standard for diode "toughness". But this behavior of theirs is completelly different from all the 405nm diodes before them - no other BR so far could survive being overdriven to these levels for nearly as long..


Question is, will 12x continue the same trend of toughness only at a higher power, or are they different somehow and not as "flexible" when it comes to extreeme overdriving?

One thing is almost certain - it won't be as huge a step as it was from 6x's to 8x's....
 

RA_pierce

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After i saw the 12x "die" (or rather become undead) after only 6 hours of 390mA ON-Time, i thought we should test the next one lower.
But just because of that i also expected the 8x's wouldn't live very long, being close to the 12x's power.

But now the 8x's completelly baffled me with their toughness, we got nearly 200 hours at 453mW, and 360 hours (and still running) at 356mW starting power.
I thought I read in the murder thread that one of the diodes was was emitting only spontaneous emissions (LED as we call it)?

Obviously we want more power from the 12x's than from 8x's, so i don't understand why the first 12x gave up so soon at only ~550mW.
Which makes the question of where to test the second one a really hard one to answer.... :undecided:
Based on the curve of the diodes graphed in the 12X diode thread, and as Hemlock Mike pointed out, there seems to be 2 distinct lines showing up which might indicate 2 different diodes at 2 different efficiencies.

The lower efficiency 12Xs seem to follow a similar curve to the 8Xs you tested.

I have not seen data sheets for either the 8X or 12X diodes (do we have them?) so I would think that it might be possible that some 12X drives are using the same diodes as the 8X drives. However, I do not think this is very likely.

P.S. In terms of current as well as in terms of power we are making REALLY HUGE steps here.

With GGWs 200mA or 185-215mW (with acrylics on average) turned out to be "reliable" in pointer terms. And GGWs are 100 or 105mW CW diodes..
Then the 8x's come along, and someone decides to push them with 100-160mA more, even tho they are only 125mW CW diodes (altho this data was unknown at that time).

Well, as surprising as it is (at least to me), the 100-160mA more actually turned out to be more reliable for 8x's, than 200mA is for GGWs!

The 8x's definitely set a new standard for diode "toughness". But this behavior of theirs is completelly different from all the 405nm diodes before them - no other BR so far could survive being overdriven to these levels for nearly as long..

Question is, will 12x continue the same trend of toughness only at a higher power, or are they different somehow and not as "flexible" when it comes to extreeme overdriving?

One thing is almost certain - it won't be as huge a step as it was from 6x's to 8x's....
I remember reading somewhere that the newer 405nm diodes have been optimized to be tougher (something about a layer of something added :confused: memory sucks, sorry) which could account for how long these (8X) diodes are lasting at ~300% CW power ratings.

Exerd is testing one 12X to very high powers (over 700mW) and has about 7 minutes on this diode. Already he is noticing RAPID degradation.

What I am getting from this is that these new diodes are too tough, physically, to "LED" (like a 6X or LOC would at this percentage of CW overdrive) so instead of instant death we are getting rapid degradation.

I have not heard any updated reports on others' 12X power levels after X amount of use, but my personal 12X has accumulated around 45 minutes of use over the past 3 days and I am noticing no degradation at all. I am getting the same power reading as I was with the first light at 300mA (+/-1mW depending on lens adjustment).
I would assume (safely, methinks) that <300mA or 450mW is "safe" for a 12X, and >350mA is pushing the limits.
For those running their diodes >400mA or >600mW, I think lifetimes may be fairly short.

We all want to see an immense amount of power from these diodes, but I think that realistically (pessimistically?) that the only reason these diodes are surviving as long as they are is because they are structurally too tough to break right off the bat AND that this does not go without consequence. They most likely will degrade rapidly. Even 100 hours of life (which may be ok for pointer use) is a VERY short lifetime compared to the >1000 hours they are rated at while fulfilling their intended life in disc writers.

Of course, this is purely speculation...

I would love it if someone (like pullbangdead) would chime in and help me out regarding the developments with the structure of the die in these 405's. :bowdown: I do not know enough about this stuff to make a very educated comment.

I am not yet comfortable with pushing my personal diode to the edge, but I will continue to check the output and will report anything unusual.

For now, though, I think we should not over estimate these diodes until further testing/more detailed info. clears some fog.
Doing so could end up being another expensive mistake.
 
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Traveller

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...i initially set the test 12x to 550mW, since it's at a current, where the high efficiency ones would actually reach 600mW+ ... Basically, the idea is (or was), to test a CURRENT, where good 12x's reach 600mW and less good ones 550mW (or anything in between)... In any case, right now the 12x's driver is set to 420mA, where it will produce approx 590mW, and i'm just waiting for confirmation, to flip the Torture Switch.
Sounds good to me, "me" being nothing more than a humble future 12x build(s) "buyer". Why? Because the next BR I buy should be able to do half a watt for most of it's life span. Having [attempted to] analyze all these graphs, it sounds like a diode will lose 10% of it's initial efficiency during it's nominal lifespan and thus I would like to have 500mW throughout it's lifespan. When I buy a 12x, I will ask for 550mW. If it's 580, great, but I'm really not all that excited about some extra 30mW at this already high level of output... .

A SOLID 500mW is a magical number, 600 less so... (imho) :beer:


EDIT: The next target number (for me) would be ah... 666mW, muhahaha... :evil:

(but in which case I'd prefer something in the 660nm range :eg:)
 
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