Drop in diode quality?

[Kenom]

Has anyone noticed a considerable drop in the power that everyone is able to achieve from the SenKat diodes? I used to be able to get consisitently 150mw stable from gregs diodes and now I'm burnin out within weeks. Not to mention the first diodes that we used to get from him didn't have any lableling on the diodes and now the newest batches all have labels on them. anyone care to speculate or share a similair finding?

 

[jayrob]

Hmmm...That's interesting. I don't think I have seen the 'new' ones yet. The last one I used, I have set at 294mA with a DDL driver using a 4.3 ohm resistor. It puts out over 200mW at this current. I never checked to see if it had any labeling on it...
Jay

 

[knimrod]

Has anyone noticed a considerable drop in the power that everyone is able to achieve from the SenKat diodes?  I used to be able to get consisitently 150mw stable from gregs diodes and now I'm burnin out within weeks.  Not to mention the first diodes that we used to get from him didn't have any lableling on the diodes and now the newest batches all have labels on them.  anyone care to speculate or share a similair finding?

Labeling? I haven't gotten any new ones from Greg recently but this is a picture of one from a batch I received from him in November. These have been typical of what everyone else has reported..

 

[Kenneth_v]

Is SenKat's site stonetek.org?

 

[chido]

http://sales.stonetek.org/

 

[Kenneth_v]

I hope I dont have an inferior diode on the way!!

 

[Gazoo]

Kenom,
Take a look at this thread:

http://www.laserpointerforums.com/forums/YaBB.pl?num=1199990106

I can't comment because the last batch of diodes I received from SenKat all end JL and I have not tried them yet.

 

[Kenom]

well, I've had to replace 8 diodes in the last 2 weeks. Those were all in my dorcy's with a 5 ohm resistor making the current around 250ma. 150mw+- some were 145 some were 167. but each and every one of them has come back dead. the ONLY thing i've changed is I'm using plastic on the base of my diodes instead of the metal backings on the modules. I'm still using my heatsinks, and the existing driver inside the flashlight so it just doesn't make any sense to me.

 

[D3StRoY]

Strange, have one here.. just in a aixiz housing.. have been using it at 3.8ohms sometimes and 5ohms, still working very good for 2 weeks now.

Maybe the preinstalled diodes are still the old batch ?! :-?

Still waiting for the wonderfull kenom lpm, will see how much mW it is by that time.

 

[desslok]

Hmm, I have one in the mail. I'll let you know how it pans out. I am also getting some of the same ones from Australia, I'll be curious to see how they compare.

 

[flogged]

well, I've had to replace 8 diodes in the last 2 weeks. Those were all in my dorcy's with a 5 ohm resistor making the current around 250ma. 150mw+- some were 145 some were 167. but each and every one of them has come back dead. the ONLY thing i've changed is I'm using plastic on the base of my diodes instead of the metal backings on the modules. I'm still using my heatsinks, and the existing driver inside the flashlight so it just doesn't make any sense to me.

One thing you could do is compare the labeling on the old/new diodes.

There's just so much we don't know about these diodes other than they are Sony's. It's possible the first batch were different.

Then again considering how far overspec we are driving these diodes you've got to assume some failures.

The first two pointers I made were with diodes from the first GB in August. I didn't bother to look at the labeling. I recently ordered two more, but since I haven't used them in anything I can't comment on their reliability.

 

[drlava]

I'm performing some long-duration tests on them in my rig and so far the results don't look too good.
see the other thread
http://www.laserpointerforums.com/forums/YaBB.pl?num=1199990106

 

[desslok]

Got mine yesterday. I'm going to run it at 240mA, because that's what the driver happened to be set at and it looked good to me. Mine has a line stretched through the center of the dot. It almost looks like I could use it to make a fake UFO on the wall. I can't really take a pic, because it seems to blind my camera. i can focus it down just fine, and it burns like crazy at this current. I wouldn't be able to make any controlled comparisons, but I'll let you know if it dies right away or anything like that. I could probably turn down the current a bit and still have it burn, but for only $20, i'm not really that worried about it.

 

[cmendoza]

I've burned out 2 in the last few weeks in the River Rock 2AAA host which should be delivering ~150 mA. I ran them up to 1min at a time. It could easily be my poor electrical work but I've used thermal epoxy on the leads after soldering them and also epoxied three 10gm copper cpu heatsinks to the Aixiz housing. I'm hoping the GB diodes from Dave at photonlexicon will hold up better.
They sure were fun while they lasted!

 

[toked323]

yea my diodes in the dorcy mini died at 225ma thats never happened to me before with senkats diodes

 

[Kenom]

it's been verified with extensive tests by Dr. lava that the stonetek diodes are indeed lower power than we're thinking. Based on his findings, 130mw is pushing this diode to it's limits. That's about 180ma!!

I do NOT think that this is intentional or something that SenKat is even aware that the diodes he got is different quality or even different diodes. I've talked with him and as far as he knows he's been getting the same diodes all along, so it's probably the seller sending him either a different diode entirely or it's a bad batch. One thing that has been found if the batch code (the bottom 4 numbers) is 0155 or 0158. don't push it over 130mw.