IgorT
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- Oct 24, 2007
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Thanks to everyone on this forum, there is a second 12x ready for the Torture Chamber. :bowdown:
I will use this thread to post the results of the testing (degradation plots).
I will also use this opportunity to show a comparison of all the 12x diodes i tested so far (one of them a Plextor drive).
First, here is the diode that will be tortured:
I plotted it up to 440mA, where it produced 564mW. It is of a lower efficiency than the first 12x Murder Candidate, but observing the degradation of three 8x's of different efficiencies convinced me this shouldn't matter much - the determining factor for it's lifetime should be it's power setting, not the current required.
Compared to other 12x diodes, it looks like this:
12x #1 (white) is the first murder candidate, 12x #2 (dark blue) is a diode from a Plextor drive.
As you can see, four of the five 12x's start at practically the same Ith (27mA - noticably lower than with 8x's), and form an evenly spread out group in terms of slope efficiency.
The Murder Candidate is slightly different and starts at an Ith of 34mA, with a lower slope efficiency, and stands a little appart from the group, just like the first 8x Murder Candidate did (still alive at over 450h).
Even tho the 12x diode from the Plextor drive has the highest efficiency of the group, the group looks no different than any other group of identical diodes would. I don't see any reason to believe the Plextor diode would be any different from the Pioneer 12x's.
One thing i noticed was, that the second murder candidate 12x has a much lower forward voltage than other tested diodes in the group, so in terms of absolute efficiency it is not as much of an outsider and comes closer to the rest of the group.
This can be seen here, in the Po/Pe plot, where the optical output power is plotted against the electrical power going into the diode (= current multiplied by voltage):
One interesting thing in this plot is, that once the forward voltages are taken into account, three of the diodes huddle together almost into one tightly packed fat line.
The Plextor diode is still on the top, but due to it's higher forward voltage, two of the Pioneer diodes almost completelly overlap it, even tho they need a higher current to reach the same power - their absolute efficiency is practically the same.
Yet another reason i don't believe that the Plextor diodes are any different from the ones found in the Pioneer drive.
Their Ith is identical, the slope efficiencies show no unusual differences (LG 8x's formed the same picture only at a lower average efficiency), and in absolute efficiency, two of the tested Pioneer diodes are nearly identical as the Plextor.
In any case, that's enough of comparing (until i test more diodes).
I rebuilt the Torture Chamber for the second 12x Murder Experiment, in a way that will allow me to keep an eye on the diode's power (to make sure it's not dropping too fast) during cycling, without having to interrupt it for a re-plot.
I turned one of the sensors into a simple optical power meter, by including a tiny solar panel in the back (thanks, HIMNL, for the idea):
Measuring the current the solar panel produces will warn me of any unusual behavior. It's not an accurate power meter, but good enough to warn me if a re-plot is required.
Everything is prepared, but before i begin, i would like to make sure everyone (or rather the majority) can agree on what current / power to test.
In the "Current for 12x Murder Experiment" thread, i read a couple of suggestions for 430mA (=550mW+), while the poll results indicate a desire to test 440mA (= 564mW in this case), but were mostly meant for the previous diode i believe.
Once i get more confirmations (or different suggestions?) i can start the testing.
When i thought i would pay for the diode myself, i said i would decide on the setting myself as well, but after so many members donated again, i would prefer if we shared the responsibility for the decision, and make sure everyone is happy with it.
I will use this thread to post the results of the testing (degradation plots).
I will also use this opportunity to show a comparison of all the 12x diodes i tested so far (one of them a Plextor drive).
First, here is the diode that will be tortured:
I plotted it up to 440mA, where it produced 564mW. It is of a lower efficiency than the first 12x Murder Candidate, but observing the degradation of three 8x's of different efficiencies convinced me this shouldn't matter much - the determining factor for it's lifetime should be it's power setting, not the current required.
Compared to other 12x diodes, it looks like this:
12x #1 (white) is the first murder candidate, 12x #2 (dark blue) is a diode from a Plextor drive.
As you can see, four of the five 12x's start at practically the same Ith (27mA - noticably lower than with 8x's), and form an evenly spread out group in terms of slope efficiency.
The Murder Candidate is slightly different and starts at an Ith of 34mA, with a lower slope efficiency, and stands a little appart from the group, just like the first 8x Murder Candidate did (still alive at over 450h).
Even tho the 12x diode from the Plextor drive has the highest efficiency of the group, the group looks no different than any other group of identical diodes would. I don't see any reason to believe the Plextor diode would be any different from the Pioneer 12x's.
One thing i noticed was, that the second murder candidate 12x has a much lower forward voltage than other tested diodes in the group, so in terms of absolute efficiency it is not as much of an outsider and comes closer to the rest of the group.
This can be seen here, in the Po/Pe plot, where the optical output power is plotted against the electrical power going into the diode (= current multiplied by voltage):
One interesting thing in this plot is, that once the forward voltages are taken into account, three of the diodes huddle together almost into one tightly packed fat line.
The Plextor diode is still on the top, but due to it's higher forward voltage, two of the Pioneer diodes almost completelly overlap it, even tho they need a higher current to reach the same power - their absolute efficiency is practically the same.
Yet another reason i don't believe that the Plextor diodes are any different from the ones found in the Pioneer drive.
Their Ith is identical, the slope efficiencies show no unusual differences (LG 8x's formed the same picture only at a lower average efficiency), and in absolute efficiency, two of the tested Pioneer diodes are nearly identical as the Plextor.
In any case, that's enough of comparing (until i test more diodes).
I rebuilt the Torture Chamber for the second 12x Murder Experiment, in a way that will allow me to keep an eye on the diode's power (to make sure it's not dropping too fast) during cycling, without having to interrupt it for a re-plot.
I turned one of the sensors into a simple optical power meter, by including a tiny solar panel in the back (thanks, HIMNL, for the idea):
Measuring the current the solar panel produces will warn me of any unusual behavior. It's not an accurate power meter, but good enough to warn me if a re-plot is required.
Everything is prepared, but before i begin, i would like to make sure everyone (or rather the majority) can agree on what current / power to test.
In the "Current for 12x Murder Experiment" thread, i read a couple of suggestions for 430mA (=550mW+), while the poll results indicate a desire to test 440mA (= 564mW in this case), but were mostly meant for the previous diode i believe.
Once i get more confirmations (or different suggestions?) i can start the testing.
When i thought i would pay for the diode myself, i said i would decide on the setting myself as well, but after so many members donated again, i would prefer if we shared the responsibility for the decision, and make sure everyone is happy with it.
but I cannot help myself!
