IgorT
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I'm sorry for not posting about this sooner, but it really depressed me. I needed some time to figure out what to do... :undecided:
In any case, i have some BAD news and some "good" news.
That, and some weird observations about the bad news part....
I prepared everything so carefully this time, with all the safeties already in place from the start, and the addition of the optical "LPM" in the 12x sensor, that i was sure i could extract useful data out of the second 12x diode no matter what.
I was so sure, that i freed up an entire day, just so i could focus on the diode alone, monitor it closelly during the early hours of the experiment (by checking the optical LPM every 10 minutes) and do as many re-plots as required (and some more, just to be on the safe side).
I hooked everything up, set an alarm to go off every 10 minutes, and flipped the Cycler switch.
Immediatelly, the 12x counter registered the light, as did the 8x counter, i could see the light, everything seemed to be working fine.
Then i looked at the optical "LPM" and it showed nothing. So i start checking the connections (the "LPM" is completelly independent from everything else in the Torture Chamber, and hooked up to a DMM through alligator clips, so something could have disconnected), but everything seemed fine.
So i took a closer look at the two diodes that just started their first cycle, and i notice that the light is only coming out of the 8x!
It took a few moments for my brain to comprehend what just happened, and by the time it did, i felt like i got kicked in my stomach. I was trying to figure out other possibilities, like the driver dying, but...
The BAD news is, that the 12x is dead! Dead, after only a single plotting up to 440mA and a single power-up at 440mA. :cryyy:
I was slightly paranoid before, due to what happened with the first diode - that was the reason for all the careful preparations... I always check everything at least three times before powering it up, here i was even more careful.
But while i was "slightly" worried before, i got really freaked out when i saw this happen - again!
What the hell is the deal with these 12x's?!?
You may be wondering what could possibly be the good news after this!
Well, it's not really good, it's "good". It depends on the point of view. It's not good for me (or rather my PP account), but it IS very important to me. And it's good for our collective knowledge of these weird diodes, which are slowly starting to gnaw at my nerves....
The "good" news is, that at that point i became completelly obsessed with finding out if 12x's are any better than 8x's at all..
This was the main point for me with the second diode, since the first one got me worried, now it's even more so.
I had one 12x diode left over, so i started testing that one, because i simply HAVE to figure it out!
That's the "good" news - there will be a 12x Murder Experiment, but with a third diode...
The third Murder Candidate is a very high efficiency 12x diode, in absolute efficiency practically identical to the Plextor.
BUT, i am taking a different approach to testing this one. I'll explain more about it tomorrow when i post a report, but it's a test, which starts at a lower power for a certain amount of time and then (if everything is OK) continues at a higher power for the same amount of time, and so on.
It's similar to what DrLava suggested as a possibility, except that it starts higher, in this case at the level of the second 8x Murder Candidate, to compare degradation to 8x's first and make 100% sure the 12x is degrading slower than an 8x at the same power would, before going any further.
The weird news is, that if i was asked to identify the second (now "dead") 12x by it's electro-optical characteristics, i would say it is a low efficiency 8x diode, and not a 12x!
- It's Ith was a whole 7mA higher than with all the other 12x's - 34mA instead of 27mA.
- It's slope efficiency was that of a very low efficiency 8x. Almost too low to make sense for a 12x.
- It's Vf was lower than with other 12x's, again much closer to 8x's which have a lower Vf than 12x's on average.
It's as if i received an 8x sled along with two 12x sleds. Everything about it screamed of an 8x (the Ith was the loudest, all three together are almost definitive).
This had me confused before i started testing, but i thought, how could an 8x diode be in a 12x drive?!? Now i don't know what to think.
But there is even weirder news about it.
It IS dead. Well kinda. But at the same time, i can still bring it to lase! :thinking:
After i noticed that it's not producing light in the Torture Chamber, i immediatelly turned the Torture Chamber OFF, and put the 12x on the Diode Analyzer.
As i slowly increased the current, a normal looking spot appeared next to the spontaneous emissions! At that point i thought "oh thanks god, it's not the diode, the driver must have died for some reason or perhaps the PSU is not powerful enough to power everything!"
But as i increased the current further, the lasing stopped!
If i reduced it, it didn't come back at a specific current. But it would come back if i raised it again, and again it would stop as the current was increased further.
I repeated this a couple of times, then i tried not increasing the current past the point where it started lasing, but it would still go off within moments. After a while i could not bring it to lase anymore, as if a minor increase in temperature stopped it.
If i let it cool off it would repeat all this again. It lases, but only up to a certain current, and if left at the current where it lases, it drops in power rapidly as if minute temperature differences are affecting it dramatically.
So it's dead alright, but like the first one, it became undead, only in a different fashion.
Anyway, this is it for now. Perhaps we should all start praying for the third 12x Murder Candidate.
I need to rename this thread into 12x Murder Experiment Take 3 now. :undecided:
In any case, i have some BAD news and some "good" news.
That, and some weird observations about the bad news part....
I prepared everything so carefully this time, with all the safeties already in place from the start, and the addition of the optical "LPM" in the 12x sensor, that i was sure i could extract useful data out of the second 12x diode no matter what.
I was so sure, that i freed up an entire day, just so i could focus on the diode alone, monitor it closelly during the early hours of the experiment (by checking the optical LPM every 10 minutes) and do as many re-plots as required (and some more, just to be on the safe side).
I hooked everything up, set an alarm to go off every 10 minutes, and flipped the Cycler switch.
Immediatelly, the 12x counter registered the light, as did the 8x counter, i could see the light, everything seemed to be working fine.
Then i looked at the optical "LPM" and it showed nothing. So i start checking the connections (the "LPM" is completelly independent from everything else in the Torture Chamber, and hooked up to a DMM through alligator clips, so something could have disconnected), but everything seemed fine.
So i took a closer look at the two diodes that just started their first cycle, and i notice that the light is only coming out of the 8x!
It took a few moments for my brain to comprehend what just happened, and by the time it did, i felt like i got kicked in my stomach. I was trying to figure out other possibilities, like the driver dying, but...
The BAD news is, that the 12x is dead! Dead, after only a single plotting up to 440mA and a single power-up at 440mA. :cryyy:
I was slightly paranoid before, due to what happened with the first diode - that was the reason for all the careful preparations... I always check everything at least three times before powering it up, here i was even more careful.
But while i was "slightly" worried before, i got really freaked out when i saw this happen - again!
What the hell is the deal with these 12x's?!?
You may be wondering what could possibly be the good news after this!
Well, it's not really good, it's "good". It depends on the point of view. It's not good for me (or rather my PP account), but it IS very important to me. And it's good for our collective knowledge of these weird diodes, which are slowly starting to gnaw at my nerves....
The "good" news is, that at that point i became completelly obsessed with finding out if 12x's are any better than 8x's at all..
This was the main point for me with the second diode, since the first one got me worried, now it's even more so.
I had one 12x diode left over, so i started testing that one, because i simply HAVE to figure it out!
That's the "good" news - there will be a 12x Murder Experiment, but with a third diode...
The third Murder Candidate is a very high efficiency 12x diode, in absolute efficiency practically identical to the Plextor.
BUT, i am taking a different approach to testing this one. I'll explain more about it tomorrow when i post a report, but it's a test, which starts at a lower power for a certain amount of time and then (if everything is OK) continues at a higher power for the same amount of time, and so on.
It's similar to what DrLava suggested as a possibility, except that it starts higher, in this case at the level of the second 8x Murder Candidate, to compare degradation to 8x's first and make 100% sure the 12x is degrading slower than an 8x at the same power would, before going any further.
The weird news is, that if i was asked to identify the second (now "dead") 12x by it's electro-optical characteristics, i would say it is a low efficiency 8x diode, and not a 12x!
- It's Ith was a whole 7mA higher than with all the other 12x's - 34mA instead of 27mA.
- It's slope efficiency was that of a very low efficiency 8x. Almost too low to make sense for a 12x.
- It's Vf was lower than with other 12x's, again much closer to 8x's which have a lower Vf than 12x's on average.
It's as if i received an 8x sled along with two 12x sleds. Everything about it screamed of an 8x (the Ith was the loudest, all three together are almost definitive).
This had me confused before i started testing, but i thought, how could an 8x diode be in a 12x drive?!? Now i don't know what to think.
But there is even weirder news about it.
It IS dead. Well kinda. But at the same time, i can still bring it to lase! :thinking:
After i noticed that it's not producing light in the Torture Chamber, i immediatelly turned the Torture Chamber OFF, and put the 12x on the Diode Analyzer.
As i slowly increased the current, a normal looking spot appeared next to the spontaneous emissions! At that point i thought "oh thanks god, it's not the diode, the driver must have died for some reason or perhaps the PSU is not powerful enough to power everything!"
But as i increased the current further, the lasing stopped!
If i reduced it, it didn't come back at a specific current. But it would come back if i raised it again, and again it would stop as the current was increased further.
I repeated this a couple of times, then i tried not increasing the current past the point where it started lasing, but it would still go off within moments. After a while i could not bring it to lase anymore, as if a minor increase in temperature stopped it.
If i let it cool off it would repeat all this again. It lases, but only up to a certain current, and if left at the current where it lases, it drops in power rapidly as if minute temperature differences are affecting it dramatically.
So it's dead alright, but like the first one, it became undead, only in a different fashion.
Anyway, this is it for now. Perhaps we should all start praying for the third 12x Murder Candidate.
I need to rename this thread into 12x Murder Experiment Take 3 now. :undecided:
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