8X Diode Murder fund

[Tmar]

Yup, kill it

 

[Slipstream]

it may take a while to kill it..

I accidentaly left my pocket mini 8x @ 605mw ON for about 30-35 minutes..

I noticed it after it burnedmy skin through my jeans made me jump..

It still works and still @605mw

 

[jayrob]

Man dude! What's the current setting on your FlexDrive to get that much power?

Igor, please look for my PM and/or e-mail...

 

[Slipstream]

440mA flex v4

http://laserpointerforums.com/f38/12x-br-diodes-46798-4.html#post638932

 

[IgorT]

it may take a while to kill it..

I accidentaly left my pocket mini 8x @ 605mw ON for about 30-35 minutes..

I noticed it after it burnedmy skin through my jeans made me jump..

It still works and still @605mw

Fascinating. 605mW and no degradation after 30 minutes + your normal use?

These diodes apparently vary more from one to another than we thought.
Especially since the low efficiency 12x never reached 605mW.


This is also the reason i badly want to test another 12x, only at a safer current - simply to proove that they are better than 8x's, cos there is one thing that worries me. The higher Vf.... :undecided:



Jay: Checking now. Checked.

 

[HIMNL9]

Speaking about LG BH08, i was searching an 8X (for a repair), and i've found this on ebay:

Brand New LG Blu Ray 8x Burner / Writer BH08 ls20 OEM - eBay (item 140372653826 end time Feb-06-10 13:04:17 PST)

Do you know if this is the better price (considering that they sell "free shipping", or if there's some better ones ?

I'm asking cause here in Italy, the better price that you can find for BH08 burners, actually, is around 240$, plus shipping, and was wondering about international sellers (also cause the ones that i find posted occasionally here on the forum, don't ship outside USA, normally)

 

[daguin]

Man dude! What's the current setting on your FlexDrive to get that much power?

Igor, please look for my PM and/or e-mail...

440mA flex v4

http://laserpointerforums.com/f38/12x-br-diodes-46798-4.html#post638932

Did you disassemble the laser or build a new one for this reading, Slip?

IIRC Slipstream simply turned up the pot on an existing laser after Yobresal reported high current. If that is the case, then I believe that the current reading is probably invalid.

If you read the current on the battery side of a laser with a flexdrive (boost driver), the current is incorrect. As I understand it, the current would have to be measured between the driver and the diode.

Speaking about LG BH08, i was searching an 8X (for a repair), and i've found this on ebay:

Brand New LG Blu Ray 8x Burner / Writer BH08 ls20 OEM - eBay (item 140372653826 end time Feb-06-10 13:04:17 PST)

Do you know if this is the better price (considering that they sell "free shipping", or if there's some better ones ?

I'm asking cause here in Italy, the better price that you can find for BH08 burners, actually, is around 240$, plus shipping, and was wondering about international sellers (also cause the ones that i find posted occasionally here on the forum, don't ship outside USA, normally)

Sometimes, you can get them for less, but that is a "normal" price for these on ebay.

Peace,
dave

 

[jayrob]

If you read the current on the battery side of a laser with a flexdrive (boost driver), the current is incorrect. As I understand it, the current would have to be measured between the driver and the diode.

Peace,
dave

That's right Dave...

With a boost circuit, you will measure battery current draw obviously from the battery to host, but it will be much more current in a single battery/blu-ray build from the battery.

Because the driver is using current to boost the voltage that the diode is asking for. For instance, in my Key Chain 10280 6X, my current setting for the FlexDrive is 183mA's, but the battery current draw to boost voltage needed by the diode at that current with a fully charged 10280, is 288mA's.

And the battery current draw will continue to have more and more demand as the battery drains, because the voltage will be getting lower, and the driver will be using more and more current to boost...

 

[HIMNL9]

Sometimes, you can get them for less, but that is a "normal" price for these on ebay.

Peace,
dave

Thanks, then this time i will go with this one (this time, i don't need it for laser, just for repair the PC of a client, so i need it integer and working).

 

[Slipstream]

Hi Daguin

I dissasembled my laser and changed the current on the flex with a dummy load.

 

[IgorT]

So, i did a 10h replot and i got some fascinating results...

Diode Stats:
- Ith = 33mA
- Slope Efficiency = 1.331mW / mA
- Absolute Efficiency = 21.07%
- Po @ 348mA = 420.3mW (92.69% of initial)


With this diode the Ith IS actually climbing. I did a very careful Ith measurement and it went from 31mA to 33mA. I noticed this at 6h, but i thought it was a small error.

But the more interesting part is, that the slope efficiency barelly changed in the last four ON hours. There is a small measurable difference, but barelly noticable. As i did the re-plot, many numbers simply overlapped until i got higher up, same can be seen in the PI plot.


So it seems this diode, while it degraded rapidly at first, isn't quite ready to give up yet, and intends to go quite a bit further....


This also gives me some hope for my personal 8x, since we've seen the same pattern twice now - fastest degradation at the very beginning and a drastic slowing down later on.


If i'm lucky, i may just be noticing this rapid early degradation, and it will slow down almost to a halt in a little while, and my laser may very well live a long and happy life. :yh:





P.S. My personal 8x is currently at 429mW. I definitelly measured it at 440mW once (on a VERY VERY cold night), and i remember it being stable at 436-437mW at warmer temperatures.

For a while i was hoping it's all due to temperature, but by now it's more than clear that some degradation is taking place. So far it dropped to 98.2% of it's initial power if initial was 437mW.



EDIT: Reinserting the original 8x murder candidate for a side by side Double Murder... :evil:

Thanks to everyone for your consent.

 

[daguin]

Hi Daguin

I dissasembled my laser and changed the current on the flex with a dummy load.

Let me make sure I have all the info correct then:

8X diode (LG or Pioneer?)
flexdrive set at 440mA (per dummy load)
605mW (with no degradation after <30 minutes "on")

Did you test the VF?

Peace,
dave

 

[IgorT]

Let me make sure I have all the info correct then:

8X diode (LG or Pioneer?)
flexdrive set at 440mA (per dummy load)
605mW (with no degradation after <30 minutes "on")

Did you test the VF?

Peace,
dave

440mA on an 8x? So it's not even a freak?
EDIT: I just checked, and it must be a high efficiency diode, i've only seen one higher. And i've seen some 8x's have very low Vfs.... I guess it's possible the Vf would end up around 6V or a tiny bit more allowing the FlexDrive to work. But it's definitelly something i would check first.


I don't understand how no one is noticing any power drops anyway. I've been seeing it on every laser since PHRs. Am i still abusing my main laser 10 times more than everyone else? :undecided:

 

[Slipstream]

Let me make sure I have all the info correct then:

8X diode (LG or Pioneer?)
flexdrive set at 440mA (per dummy load)
605mW (with no degradation after <30 minutes "on")

Did you test the VF?

Peace,
dave

From a Lg drive the Bh08

No i didnt test VF . . when it comes to testing those things i seem to be the "dummy load"

This one started @ 350ma then I set it to 410ma and lastly its been at 440ma. I may try to to take it to 460ma either today or tomorrow.

It may have degraded somwhere in there , but because i didnt have it at a specific ma between reading i may have missed it.

there definitely arent any visual differences in the actual spot ( like black spots , lines etc..)


I have 3 8x's , and this one was the one that had the lowest output @ 350ma

 

[IgorT]

8x's don't seem to degrade in that way, at worst i'm expecting a kink to develope, but they seem to wanna degrade quite a bit further....



Anyway, the 12x driver was reset to 300mA, tested and placed on the old 8x diode.

The first 8x is now blasting against the second counter setup meant for the 12x, so i was able to set it to the value from the experiment "end" (9013 cycles) with it's control panel. :yh:


Time to take some pics....

 

[IgorT]

I let the diodes run all day yesterday and through the night, and they reached 160h on Murder Candidate #1 (LG 8x #3) and....

20h on Murder Candidate #2 (LG 8x #1)! :yh:


20h explains how they can be set to 360mA and then last a while...