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ArcticMyst Security by Avery

How did my diode die?

Benm

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If you can easily replace the whole module that would be the way to go. Getting thediode in the module also protects it well during shipping.
 





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Mar 24, 2015
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Using a 9mm diode will have some advantages, but the big disadvantage is that you need to get a new module to contain it. So i'd go for the M140 drop-in replacement in this case.

Why not just get a 7875 already pressed into a full copper 12mm module from DTR?

So, yeah, this is what I'm on the fence about now. It's either a new M140 diode only ($37) or a 7875 w/ module ($64). I'm leaning towards the 7875 right now since I'll probably use the 5.6mm module for something else in the future so it's not a total loss and not having to worry about soldering and pressing the new 9mm is nice. So it's a $27 difference for all that and hopefully a much longer life.

p.s. How do you do the hypertext link deal where you have "Heatsink" typed that goes to the link?
It's up top in the tools, right?

1. Highlight the text you want to be the link
2. Click this button in the toolbar:
This is a link to an image showing you which button to push!

I also underlined the text so you can tell it's a link. By default, you can't tell unless you mouse over it.
 
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I've built a ton of lasers and I can truly say that there's a reason they are called DIEodes

They go 'poof' on all of us once in a while, that just seems to be a fact of life, and is to be expected when pushing these things above absolute maximum ratings.

I guess what I was hoping for was for someone to point out an obvious mistake I made so I never burn out another one. It's annoying that they can just fail like that but I'm glad to know I'm not alone.
 
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If you bought your diode from ebay it could have been an old A-140 and they won't hold up to 1.45 amps for all that long even when they were new. 1.2a is about the max for a fresh A-140

A-140

Macrodiode-6.jpg


M-140

Macrodiode-5.jpg


The M-140 has the circle on the back by the code.

Macrodiode-9.jpg


This is all on DTR's page. :beer:
 
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If you bought your diode from ebay it could have been an old A-140 and they won't hold up to 1.45 amps for all that long even when they were new. 1.2a is about the max for a fresh A-140

Yes, I was aware that I bought an A140. I got it on ebay from DTR where it was clearly labeled as a 'A' type. Apparently I misunderstood the difference in max current for these diodes.

I've now found on this page the following recommendation: "The A140 runs at 1.25A for best life expectancy and the M140 runs best at 1.7A for best life expectancy. I suggest a max of 1.8A with appropriate heatsinking."

I hadn't seen this before and I instead deferred to this on the ebay page: "The A-Type M140's average about 1.8W @ 1.8A using a G-1/2 lens."
 




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