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FrozenGate by Avery

LPC-840 discussion thread

Well I have an adjustable bench psu shipping to me now and a lab sytle heatsink from Mrcrouse so as soon as they both arrive ill post some power numbers on what my diode does.

Although with the above results im not exactly hopeful, honestly seems like a waste of time but ill do it anyways :)
 





techood sent me a replacement diode. this one is supposed to be the real thing. did anyone else contact them? they did seem eager to make things right and when i pop it into my groove i'll report back.
 
cheech226 said:
techood sent me a replacement diode. this one is supposed to be the real thing. did anyone else contact them? they did seem eager to make things right and when i pop it into my groove i'll report back.
Click to expand...

It will be a few weeks before I can test mine, if mine is a fake like most of you have posted I'll be contacting them for sure at that time.
 
I haven't even pulled the trigger on these yet. I won't buy them unless I can
be reasonably certain I will actually be getting what is advertised. We
eagerly await the the test results of these "real" LPC-840s.
 
I've ordered several red diodes or complete lasers from China and without fail, every single one of them was over rated by
50 percent or more.
 
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Well this is one of those good news bad news posts. I got the stuff to do the testing and my diode performed almost identical to the others above except it doed earlier, right as it was finishing up 30 seconds at 250ma it died, peak output 151mw@250ma.

here is pic of it at 200ma, was just about to take the 250ma pic when it died.


Seems like a fake/lower rated diode to me.
 
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Techhood is RETARDED.

I sent them a message about how crappy these diodes are and sent them the above pic. There response to this was that 2.3V is to high and I need to use a voltage limiting driver??????

Do these guys even have a clue what they are doing? I find this odd because I have had good luck purchasing from them in the past.

Correct me if im wrong here but lasers do require CURRENT limiting drivers correct? Not voltage.

EDIT TO ADD:

There own for sale page lists specs for these at 2.2v - 3v..... but 2.3v is to high? what a bunch of idiots.

EDIT # 2:

Apparently I was talking to the idiot CS rep I got a reply from another customer service person and they are sending me a new diode. Im not even sure if that's a good thing or not though lol.
 
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So finally got my replacement diode from techood! yay!

Its definitely a different diode the weird thing is it DOES NOT have the Mitsubishi Logo on it like in the pics on their sale page and like the first fake diode they shipped me did. I find this rather strange.

It is however a open can diode and from the power im going to post below does seem to be at least a LPC-826 or better diode, it scores a little higher than my Survival lasers LPC-826 at the same power with the same lens.

Now onto the good stuff, i was actually able to test this one to its fullest :)





















As you can see it falls off very sharp from 500ma to 550ma with only a 10mw gain, seems to act just like a LPC-826 with best power set to 500ma or so.

Any thoughts on this? sure doesnt look like we will see a 500mw single mode red with this one........

In text format:

100ma = 32mw
150ma = 90mw
200ma = 132mw
250ma = 182mw
300ma = 226mw
350ma = 266mw
400ma = 305mw
450ma = 328mw
500ma = 354mw
550ma = 364mw
 
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Just one last question before I unsubscribe from this thread: What lens was used in the tests? Have we tried Acrylic or Single Element?
 
IsaacT said:
Just one last question before I unsubscribe from this thread: What lens was used in the tests? Have we tried Acrylic or Single Element?
Click to expand...

I agree we are done with these particular diodes from this seller but I am not convinced this is an authentic lpc 840 diode, as I said it lacks the logo.

As for the lens I have only tested it with my g2 knock off, it's the one from Paul's original source for the group buy before the joker took over. As this lens has tested 7% better than my authentic g2 in the red spectrum. So as far as I know those numbers should be best case scenario.

I do have a red coated 3 element and a handful of acrylic lens I can test with as well but I doubt that they would be higher power, I'll try it with my authentic g2 as well I guess then all bases will be covered.

If anyone has a source for an authentic lpc 840 please let me know :)
 
So I tested with a acrylic and G-2 and 3 element. As I suspected none beat the above posted powers. So those numbers above are indeed best case scenario.

If anyone finds a real source for a LPC-840 please let me know.
 
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I'm interested in this diode for a project but so far am unable to find data sheets. Does anyone have the spec sheet for the LPM-826, 836 or 840 so I can compare the divergence figures with other diodes? If you can point me the way, or post a link, much appreciated.
 
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Thanks much, from that datasheet the minimum possible divergence is 7 and 14 degrees for the two planes which isn't too bad at all, if you can get one that tight, not likely. More likely to get the average at 10.5/16 degrees, still better than a lot of laser diodes and far better than the high power 1 watt+ diodes out there that I have found so far.

I'm interested in this diode but fear getting fake ones now and I can't find a for sure data sheet to know the manufacturers stated divergence of the LPC-840. I've been collecting a few datasheets for somewhat low divergence laser diodes, they can be viewed here: http://imageevent.com/qdf_files/tec...gencelaserdiodedatasheets?rotp=7347&rotp=7670
 
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