8X Diode Murder fund

[Tech_Junkie]

Hey they both would scare me. I'm nervous just pointing my GGW around.

You're up early/late Dave.

 

[Krutz]

..but 500mw is any better? *giggles*

manuel

 

[Crazy Jay]

Ha lasers scare you Tech? Shame shame :tsk:
I would love a portable gigawatt laser in my hands. Now that is something to fear!

 

[IgorT]

..or a reliable 500mw..?

500mW is much more reasonable than 700mW, but we'd still have to pretend that the first 12x's use the 450mW Pulsed Sanyo diode...
Unfortunatelly the ratings we have available seem to indicate otherwise... :undecided:

Thing is, the open can diode is big for a reason. And it's rated for 150mW CW / 300mW Pulsed if i recall correctly (just like the first 12x's are supposed to be)...
EDIT: Sorry, the Open Can is rated for 150mW CW / 400mW Pulsed...

But we're already reaching powers an open can can't even imagine with 8x's!
However there are at least two reports of 8x's developing kinks at ~400mW.. Luckily, one of the two is on their way to me... :yh:


In any case, i'm hoping that by comparing overdriven diodes of known (or at least guesstimated) ratings, we could find some kind of pattern, like how long they live when set to 2x their CW ratings or 3x their CW ratings, and that it might be approximatelly correct for future diodes as well (varying from diode to diode of course, depending on efficiency most likelly)..

Luckily i've been saving some high efficiency 6x diodes (with a broken window), just for an experiment like this... :angel:

 

[HIMNL9]

Uhm, about the rated powers ..... we have also to keep in mind that the rated powers that manufacturers say on their specs, are the ones for a normal 50.000 hours continuous working life ..... never seen peoples here that plan to have their BR continuously operating for 50.000 hours .....

But at the same time, also need to keep in mind that degradation on overpower is an exponential curve, not a linear one ..... and also usually the graphs are referred to overpower a LD in CW mode, referred to its pulsed power as comparison ..... IF (with a lot of uncertainity) a diode is rated for 250mW CW, what can be expected at 500 mW CW ? ..... 1500 hours ? .... 2000 ? ..... and at 750 mW ? ..... a pair of hours with a lot of luck, probably ?

Personally, also if a 12X can be pushed to 700mW with no ideas about the life expectance, i may be happy to use it at 500 / 550 mW, well heatsinked, for have a possibility of some more hours of life (especially considering their cost )

 

[suiraM]

i am sure that germany went further than almost all other countries, in all aspects. but then again, mankinds phantasy is almost unlimited..

I didn't start the thread jack, but I may as well finish it...

Japan went further than Germany by a ridiculously wide margin, and neither can stand up to the creativity of historical figures that are widely revered today, at least in terms of actual cruelty. For the most part, Germany was looking to do legitimate research. Unfortunately on people who did not volunteer. The same was mostly the case for the United States in the modern Tuguskee experiments and the Scandinavian research on adrenalin use in EMT practice. Not so much for Japan, although much of it had legitimate wartime uses.

From this, the world took a great leap forward in intensive care medicine and triage.

Such knowledge always comes at a price, and it is rarely paid by volunteers. In Iraq, during the First Gulf War, a doctor from my country (which was occupied by the Nazi during WW2) was working at a field hospital that treated civilians. They had to use napalm in a bathtub to dispose of all the body parts and corpses. At one point, he realized how to improve the survival rates after massive crushing injuries and explosive damages, knowledge which he then disseminated. You will benefit from that knowledge if you ever have a limb smashed, for instance. But who do you have to thank for that knowledge? Who paid the price?

A young boy paid the price.

He was collecting mines to support his family, because there was a bounty on mines that were turned in undetonated, since there was great difficulty in clearing out the minefields that threatened civilian and military both. The family was dirt poor, and the bounty was a substantial amount. Maybe something like the cost of a PHR diode. Unlike the Jews, these kids weren't being rounded up and put in a camp. He was sent out by his parents, in order that the family might not die from starvation. He was not the first kid that family lost that way, nor was he the last.

But he was the one who bought you better medical care at the price of his life.

Doctors need to keep a clinical detachment to their research subjects.

Many need to keep the same detachment to their patients.

You don't go into the cancer ward expecting that it will be a pleasant experience, or that you will feel good about it at the end of the day. You go in there knowing that people will die under your care today, that there will be crying and screaming and despair, but mostly just grim resignation and polite, forced smiles from desperate and disillusioned people who are just trying to pull through yet another day in hell. Go home at the end of the day. The patients will be there when you come back in the morning, just like every day you see them. Not neighbours, not friends, not people. Patients. They come, they go. Usually, they come back. Eventually, they go. Can't hold on to them all.

You don't come into the forensics lab expecting to be greeted by lots of hundred year olds who look like they're just sleeping. You know you will see kids missing half their face, bags with dead babies in them, women with their purse still fused to their melted skin, and that there will be the inevitable sample glass with some small quantity of an unidentifiable but distinctly biological mass that constitutes the earthly remains of what used to be some unkown person. Then you get to figure out what to tell the families of those you do manage to identify, while meticulously moving the last few maggots from a corpse into a sample container... wouldn't want to get sloppy just because lunch is coming up, after all. That's the last of'em, now you can eat. For a moment think about... nah... best not. Best leave the subject behind, think about the game on sunday instead.

When enough propaganda is poured into a country to make its people, doctors included, see a segment of the population as rats, or as a disease, then there is nothing unusual, or even inhuman, about going on about the business of cutting them, burning them, liquefying them, injecting them with poisons and diseases, and so forth. It's business as usual, except it just so happens that it will give you more accurate data (yay!) than the guinea pig you did the same thing to last week. A moments pause to consider if... no, that would be disturbing. Not like it's people. That would be hard to face. Subjects. Much better. That's it. Subjects. Lights out. Come back tomorrow. Maybe get the wife something nice when the paycheck comes in.

You will perhaps note that the gas used to kill jews is the same as the United States uses in gas chamber executions, which means that either it is humane, or the executions carried out with it in the US were illegal under the section of the law which regulates the humane aspect of executions. There were two exceptions, and in those cases, carbon monoxide was used instead, which is hardly the worst way to go (that's what people die from when they put a hose to the car window from the exhaust and leave the motor on).

Germany circa 1930~45 deserved a lot of flak.

However, they were also demonized in hindsight, with people preferring to believe that the German people were evil, or directed by out-and-out evil people, rather than believing that the road to hell begins with one small step, then another small step, then another small step... until you're half way there. Humans are not the kind, gentle souls one might want to believe. Nor are we all that good at keeping track of what's happening around us. Else, the US population would have been at the White House with guns years ago, after GWB gave himself the exact same privileges that Hitler conferred on himself, in exactly the same way, with exactly the same justification. All you needed was another plane through a building, and you'd be back in the 30's, except it would be Muslims this time, not Jews.

Antisemitism wasn't a bad word back then, just like racism wasn't a word in the Old South. It was just the way people saw things. The way people have always seen things. In every language of the world, there's been a word for people (effectively, "us," as opposed to who ever "them" might be), and one or more words for those who either look differently (The Red Man (colonials about native americans), Aswadim (middle easterners about nubians)), those who speak differently (barbarian is from the graeco-roman way of saying "blah blah"), those who believe differently ("heretic", "communist", "infidel", "fascist", "undemocratic", etc.) and so forth. It is hard wired into the reptilian part of our brain, but we have the ability to shift where we draw the line, and it pretty much comes down to "familiar" vs "different" if you don't apply propaganda to it. One day, there's going to be a word for what went on at Gitmo, you betcha.

No doubt Germany did a lot of things that are reprehensible.

They were not the first to do any one of those things.

They were not the last to do any one of those things, except the systematic approach in constructing detention centres for the demonized enemy du jour, unless you count Silvia Berlusconi (Italy) and George W. Bush (USA). That would be a tenuous comparison, though, since their respective detention centres did not get so full that the problem needed a Final Solution, and their respective cultures were not yet so convinced as to buy into one. All it would take to change that, though, would be another airplane for the US. Not sure about Italy.

And, at the end of the day, World War 2 put an end to public acceptance of antisemitism, cemented democracy as the gold standard of government, changed eugenics from a bright idea into something to be safeguarded against at all cost, led to great insight into how a human being acts under pressure from authority figures, established standards for ethical research, entrenched the notion of war crimes, significantly advanced women's liberation, and so forth.

Pretty much everything we value in the modern, western lifestyle is a response to WW2.

It's a mixed legacy. A great price was paid. But something good came out of it.

History is written by the victorious, all else is covered by vae victus.

How we view Nazi Germany today tells us everything we need to know about how it could happen in the first place, if we just pause to reflect carefully on it. To dismiss everything with superficial, knee-jerk reactions and conditioned responses is to dismiss every lesson we could possibly hope to learn from the millions slain. That would do no credit to their memory, I think. Nor would it do justice, one way or the other, to history.

Education is reflecting on cause and effect, not memorizing popular conclusions.

"A great many people think they are thinking when they are merely rearranging their prejudices." - William James.

 

[Krutz]

now thats some hard stuff here..
you sound quite cynical, not? still, you sum up what i more and more come to realize. you have much more knowledge on history than me, but i think our conclusions would sound similar. for me, i pretty much gave up on humanity and future (both in general). could go so far to say humanity makes me sick. still, i love the *individual* human. just dont let them form too large communities, things go downhill from there on.. ;-)

enough threadjack from me.

thanks for your well reflected and argumented thoughts, suiram.

manuel

 

[IgorT]

Uhm, about the rated powers ..... we have also to keep in mind that the rated powers that manufacturers say on their specs, are the ones for a normal 50.000 hours continuous working life ..... never seen peoples here that plan to have their BR continuously operating for 50.000 hours .....

But at the same time, also need to keep in mind that degradation on overpower is an exponential curve, not a linear one ..... and also usually the graphs are referred to overpower a LD in CW mode, referred to its pulsed power as comparison ..... IF (with a lot of uncertainity) a diode is rated for 250mW CW, what can be expected at 500 mW CW ? ..... 1500 hours ? .... 2000 ? ..... and at 750 mW ? ..... a pair of hours with a lot of luck, probably ?

Personally, also if a 12X can be pushed to 700mW with no ideas about the life expectance, i may be happy to use it at 500 / 550 mW, well heatsinked, for have a possibility of some more hours of life (especially considering their cost )

I understand that, but it's not 50.000, it's 1000h or 6000h, depending on manufacturer.
1000h is their lower limit for reliability in a drive... You have one zero too many in your explanation...

I know we are trading their lifetime for more power, i try to explain that to anyone who asks for a laser, so they can make an informed decision about the power...

And i know that many people have an 8x at 400mW or more which are seemingly doing fine. But keep in mind that many of them are completelly new, and while they are being set to amazing powers, we don't really know how many hours they'll make it.
Especially, since i now also know that 8x's at 400mW are developing kinks, which were not previously there (we used to think diodes from 100mW CW and up have no kinks)..

One of these 8x's is in the hands of Hemlock Mike, who was among the first to set them there... I don't know HOW old it is, or how many hours it has on it, so it doesn't tell me much.

But itw3ak has an 8x he got only 3 months ago, and it started doing the same thing (developed a kink) with not too much use.. That diode is on it's way to me for testing.

You're saying 1500h or more from a 250mW Pulsed rated diode (that's an 8x) pushed to 500mW CW.
If that were true, i'd push them MUCH higher, maybe even to 1W!

But in reality, i fear we won't get 100-150h from an 8x at 400mW...

100h+ is what i'm hoping to get from diodes, for "reliability" in hobby laser pointers...
The 1500h at 500mW you are mentioning would allow drive manufacturers to make 16x BluRay writers right now using an 8x diode!



I know i am often too cautious, but that's because i don't want to end up with 1-15h (20h max) lasers, which is what happened, when i tried setting PHRs to 150-200mW..

Fact is, these diodes allow us setting them to powers we should expect from diodes two higher power ratings away!
If someone is willing to risk losing them in a matter of hours, i'm not saying they shouldn't do so, just to see a very high power beam, if they want to... I might do it myself as well!

The only thing i want is that people would understand that this results in a dramatically shortened life. And with experimentation, we can figure out how much life we can expect at these high powers..




EDIT: Otherwise, since high efficiency 8x's can clearly be set to 500mW at least for a while, i would be willing to set my first personal 12x there!
While i have no clue about the number of hours it'll survive, it will surelly be quite a bit more than an 8x would...

 

[scopeguy20]

EDIT: Otherwise, since high efficiency 8x's can clearly be set to 500mW at least for a while, i would be willing to set my first personal 12x there!
While i have no clue about the number of hours it'll survive, it will surelly be quite a bit more than an 8x would...

Igor do you already have a 12X burner on order for yourself? -Glenn

 

[HIMNL9]

@IgorT, sorry, don't know what happened ..... maybe i confused life expectance of LD and leds, perhaps ..... my guilty (i still remember to have seen some similar numbers, 25.000 to 50.000 hours MTBF related to LDs, but maybe they was related to reading units, not burners, that uses only 5mW diodes).

And yes, if life expectance of a LD in working conditions is 5000 / 6000 hours, then at our levels can be 100 / 150 hours with luck and short duty cycles ..... but this give the idea that pushing that diode to 700mW, it last just minutes

..... setting PHRs to 150-200mW .....

LOL, i know what you mean, i made the same for error ..... set a driver to 190mA thinking to attach it to an AW210 diode, then used a PHR for error ..... oh, it worked very good ..... for 10 minutes

 

[IgorT]

Igor do you already have a 12X burner on order for yourself? -Glenn

No, i think only Dave has so far... :yh:

I was talking about when i finally have one.
No idea when that will be yet...

 

[IgorT]

A thought occured....

Since i'll be cycling the two lowest efficiency diodes to test their lifetime, what do i set them to?

A certain current, or a certain power?


The reason i'm wondering is, that these two diodes will produce quite a bit less power than others at the same currents.
If i set them to a certain power, say 400mW, this will require more current than with the good or very good ones.

But this extra current would finish them off faster, and the result would not be how many hours 8x diodes can survive 400mW, but rather how many hours the lowest efficiency diodes can survive the increased current required to reach 400mW.

If instead we test the diodes at a certain current, like for instance the current where 8x's reach 400mW on average, the result could be more meaningful.


I already said i expect the lowest efficiency diodes not to live as long as high efficiency ones.
If a low efficiency diode is set to the same power, it will need more current than a high efficiency one. This extra current will shorten it's life.
But even if a low efficiency diode is set to the same current, where it will produce less power, chances are it will again die sooner than the high efficiency one, IF efficiency really is an indicator of diode "health"..

Regardless of what the two murder candidates are tested for - specific current or specific power - the result will (most likelly) represent the minimum number of hours 8x's can survive that current or power.

I'm just trying to figure out which of the two would make more sense to test for.


I took a look at the graph showing the first two 8x diodes. The lower efficiency one needs 35mA more to reach 400mW, the high efficiency diode reaches it at 280mA. Seems like the average current required to reach 400mW could be 300mA.


So do i test 300mA to see the minimum lifetime at the average current required for 400mW, or do i actually set the lowest efficiency diode to 400mW?

The same question will become even more important, if the results should be so good that the next power we want to test is higher!

Sure, we'd all love to know how long an 8x can survive 500mW, right? But fact is, only the very high efficiency 8x's are reaching 500mW+ at 360mA. Others may need a little more current, but the lowest efficiency diode could require 410mA if not more, to reach that kind of power! And i don't think any 8x, regardless of efficiency, would last long at 410mA...

So IF we go and test for a higher power with the second murder candidate, i think we should test for a specific current again - in fact, we might not have a choice, since the diode could pop instantly at 410mA.
In this case i'd cycle the second one 360mA, where high efficiency 8x's go above 500mW (while the murder candidate will be producing 460mW or less)...


Since we are looking for some averages here, i think testing specific currents instead of specific powers, would give much more useful results, especially if we want to apply them to other 8x diodes...



In an ideal world, i'd also cycle a high efficiency 8x diode for a comparison, but in this case, it would be a waste of a good diode.

Even with a GGW it feels like a waste, but "luckily" i broke a window or two on those, so it's easier... :angel:

 

[jayrob]

I would like to see 300mA testing personally, but I know that no matter what is decided, that we are going to learn a lot from your testing Igor...

So that said, I would think that we can just put our trust in your gut feeling as to how they should be tested.

 

[Krutz]

totally agree, these details are up to you, igor!
i said test the first diode at 400mW output, but your point is true. so lets see how much off the two lowest are, compared to the others?

manuel

 

[daguin]

totally agree, these details are up to you, igor!
i said test the first diode at 400mW output, but your point is true. so lets see how much off the two lowest are, compared to the others?

manuel

Test current specific. The output will vary, but most of us set by current rather than output.

Peace,
dave

 

[Tech_Junkie]

Ha lasers scare you Tech? Shame shame :tsk:

My house is basically 3 12'X12' rooms with 7 foot ceilings. So reflective surfaces are abound. My goggles are small, so I'm always worrying getting a reflection bounced. Obviously the higher the power, the more power in the reflections.

I didn't start the thread jack, but I may as well finish it...

suiraM you didn't jack this thread, you raped it. The thread is a testing and info thread. A lot of money and time is being spent here. Its not your personal soap box. Try PM next time please.