445nm diode MURDER thread

[HumanSymphony]

With a small TEC one has been run up to 1W for 45 minutes inputting around 1A and was steady. Pushing it higher though started to see output drop away to 925mW.

Hope that helps. Not the answer to a simple heatsink output but gives clues.

M

Spyderfire has 2 in regular heatsinked hosts. One at 900mA and one at 1.05A

 

[Morgan]

Spyderfire has 2 in regular heatsinked hosts. One at 900mA and one at 1.05A

Do you know what the mW outputs are for Spyderfire's? With TEC the output may be higher, it just dropped away as the heat increased in the other test and I don't recall if it stabilised at the lower level. I think 75 degrees f at the 1W mark, (Can't remember the conversion to Celsius). I don't think the diode was harmed in any way at that point but wouldn't output any more.

I reserve judgement on how reflective this info is though. This is what I meant about collation of all this, "testing".

M


[EDIT: Just seen Spyderfire's post - Quote, "2nd Build - Labby - AMC7135 driver @ 1.050A - putting out ~1W

3rd Build - Jayrob 18650 - Microboost set to 900mA - putting out ~980mw", End quote.

Wonder if he stopped a 1A for the same reasons?]

 

[HumanSymphony]

Do you know what the mW outputs are for Spyderfire's? With TEC the output may be higher, it just dropped away as the heat increased in the other test and I don't recall if it stabilised at the lower level. I think 75 degrees f at the 1W mark, (Can't remember the conversion to Celsius). I don't think the diode was harmed in any way at that point but wouldn't output any more.

I reserve judgement on how reflective this info is though. This is what I meant about collation of all this, "testing".

M


[EDIT: Just seen Spyderfire's post - Quote, "2nd Build - Labby - AMC7135 driver @ 1.050A - putting out ~1W

3rd Build - Jayrob 18650 - Microboost set to 900mA - putting out ~980mw", End quote.

Wonder if he stopped a 1A for the same reasons?]

I don't think it's a heat issue The diode is getting maxed out. Once it reaches a certain point the efficiency goes WAY down causing it take much more current to make those mW.

 

[ElektroFreak]

We need IgorT. He's about the only proper guy for this if we're going to do it.

 

[daguin]

We need IgorT. He's about the only proper guy for this if we're going to do it.

His expertise and attention to detail has spoiled us. He "disappears" from time to time. Right now looks like one of those times.

I think that he is an international spy. I wonder if he has a "double 0" designation? :eg:

Peace,
dave

 

[ElektroFreak]

Yeah.. and you know he'd be beside himself if he were here. Maybe he still lurks even though he's not posting.

 

[Benm]

Guys -- If you want to contribute, buy a $50 diode and contribute data. That's what we're about. Sooooo many posts only fog the incoming data.
BUY AND BUILD......
HMike

I tend to agree on this - some people will push these diodes to their limit in any case, and likely share data about what happened. At $50 or so a pop, there is little need for a group-funded murder experiment, people will blow these up on their own just fine, and report at what point things turned bad.

Its similar to the earlier sony, phr and loc tests - diodes are cheap enough for individuals to play with and produce data, there is little need to set up any collective action here.

 

[lasersbee]

You missed my main point. You will NEVER get the kind of "confident" knowledge you are requiring, from only two or even four diodes. This is the "false" sense of confidence I talked about. Diodes are too inconsistent for that to work.

The following is going to be a MAJOR over-simplification

To discover where they will run a certain diode, manufacturers/researchers run MANY diodes at the same current. They look for the point where 50% of the diodes fail after the desired lifetime. When they reach that point (50% fail) they record it. Since the diodes in the projector were running at ~650mW and the projector is "rated" for 10,000 hours, it is probable that at 650mW about half of the diodes will be dead at 10,000 hours of use.

Understanding the way diodes are rated and the sometimes exgtreme variability in them, how can seeing that two diodes ran at any length of time at any current will assure you that any other diode will run for that time at that current. What if yours were ones that would run longer than "rated"? What if they were ones that would run shorter than "rated"? What if you got one of each?

Even IgorT's 12X experiment exposes the problems inherent in this kind of "research." Before IgorT got a 12X to run at the desired current, TWO OF THEM FAILED AT LOWER CURRENTS! However, instead of accepting this limit, we and he kept trying. We finally got one that acted the way we wanted and all breathed a sigh of relief that we had finally gotten a diode that was not defective. People now jumped on the higher "safe" current as proven by IgorT's testing. This despite the "fact" that 2/3 of the diodes tested failed well below the succesful one.

So how many diodes do we need to kill? At what current should we run them? How many hours of life at a given current will be acceptable? What good is "killing them" at all? We will know at what current those particular diodes failed after a given number of hours. However, what will that tell me about MY diode?

Peace,
dave

Excellent logic Dave....IMO...

I have 4 LDs coming into the shop... 3 from EF (A130) and
1 from Dan on PL (A140)... First I want to know if the A130
LD isdifferent from the A140 LD...
Since some members have tested the 455nm LD at 1 Watt...
I would like to set up a test to see the lifespan of 1 or more
LDs at 1 Watt laser Output...


Jerry

 

[DJNY]

We need IgorT. He's about the only proper guy for this if we're going to do it.

I PMd him according the 445nm issue last week. I don´t know if he even recognized this new WL. But concerning the 12x test, I also think he is the right guy if he is interested and has the time for it.

 

[Xplorer877]

You missed my main point. You will NEVER get the kind of "confident" knowledge you are requiring, from only two or even four diodes. This is the "false" sense of confidence I talked about. Diodes are too inconsistent for that to work.

The following is going to be a MAJOR over-simplification

To discover where they will run a certain diode, manufacturers/researchers run MANY diodes at the same current. They look for the point where 50% of the diodes fail after the desired lifetime. When they reach that point (50% fail) they record it. Since the diodes in the projector were running at ~650mW and the projector is "rated" for 10,000 hours, it is probable that at 650mW about half of the diodes will be dead at 10,000 hours of use.

Understanding the way diodes are rated and the sometimes exgtreme variability in them, how can seeing that two diodes ran at any length of time at any current will assure you that any other diode will run for that time at that current. What if yours were ones that would run longer than "rated"? What if they were ones that would run shorter than "rated"? What if you got one of each?

Even IgorT's 12X experiment exposes the problems inherent in this kind of "research." Before IgorT got a 12X to run at the desired current, TWO OF THEM FAILED AT LOWER CURRENTS! However, instead of accepting this limit, we and he kept trying. We finally got one that acted the way we wanted and all breathed a sigh of relief that we had finally gotten a diode that was not defective. People now jumped on the higher "safe" current as proven by IgorT's testing. This despite the "fact" that 2/3 of the diodes tested failed well below the succesful one.

So how many diodes do we need to kill? At what current should we run them? How many hours of life at a given current will be acceptable? What good is "killing them" at all? We will know at what current those particular diodes failed after a given number of hours. However, what will that tell me about MY diode?

Peace,
dave

Agreed 100%

But we're always going to be push any diode to it's limits. If 650mW is a safe current then the next step is to find the point at which these diodes fail at a much higher rate. Even 100 hours of use is a good lifetime from a $50 diode. But I totally agree with you that we may never get a good understanding of them with just a dozen or so being tested. And seeing how diodes vary so much, a good general understanding of the average capabilities of these diodes is pointless when it comes to the individual hobbyist. But it's a safe bet to assume it's within the ballpark of any particular diode. Especially since they're so cheap.

IMO 650mW is freaking awesome. It would be the most powerful laser I've ever owned not to mention it is such a new and exotic wavelength. So that'll do it for me. Even if it was 200mW I'd be cool with it. From my experience, and many of you should agree, when you're dealing with lasers that are so close to the extreme ends of the visible spectrum the power output doesn't really matter as much. Once you're over 2-300mW another that is double the power won't seem all that much brighter. At least not twice as bright. So unless you get kicks out of fulling your house with smoke as you amuse yourself by burning stuff, I really don't see the need for these to be pushed. Like I said, even 200mW would be bitchen for me.

-Tony

 

[DJNY]

:bumpit: for this important thread!


BTW has anyone killed a 445nm diode yet?

 

[Krutz]

chris (heerursciences) was the first one I read who killed a diode here.. it was over 2 watt optical output, if I remember correctly.

manuel

 

[Grix]

Wicked lasers is donating a whole projector just so voluntary vets can kill all the diodes for data.

 

[DJNY]

Wicked lasers is donating a whole projector just so voluntary vets can kill all the diodes for data.

If this is true you should make it more public here, so that Dave, Jeff, Mike, Jay etc. can read this.

 

[Grix]

There is a thread in the vet section.

These are doing the testing:

hemlock_mike
Jayrob
Dave
Eudaimonium
Silvershot
charliebruce
brtaman
robjdixon
HIMNL9

 

[DJNY]

Should I have to spam more to reach the 1000 "vet-score" or do they make this thread public to the down-to-earth people?