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oh my god, my m140 diode worked for 40 mn

djLscatt

djLscatt

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when I took it from my bag yesterday, it was on and the batteries were fully decharged. It was in a holster and the tailcap was on the lens. this m140 diode runs with a 1.8A driver, the copper heatsink is from survival laser, and two 18350 batteries .
the calculation I made is: 1200mah/1800ma=0.66 which is 40mn with the decrease of the current.
I'm afraid the diode didn't like it:(
what do you think?
the lifetime must be now less than before.
 





Wolfman29

Wolfman29

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Well, what type of batteries were they? If they weren't quality batteries, then you probably don't actually have a 1.2Ah capacity. Secondly, what type of driver is it? Because they could easily run out of juice enough to power the laser but still have some juice left over for lower voltage applications.
 
djLscatt

djLscatt

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the batteries are some crappies ultrafire and the driver is a mohgasm lineare driver.
The tailcap which is on the lens to protect it was burnt.
 
scumbagatheist

scumbagatheist

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So, I don't understand...Did you try freshly charged batteries yet w/ no luck? Is it LED'd? Haven't even tried anything yet?

I was just reading about someone who accidently left their 445 on in their pocket w/ a lens cap on. It cooked the inside of the cap and overheated the diode, aka LED'd.

Good luck to you.
 
Zeebit

Zeebit

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I had enountered the same situation several times with my 532nm. It was in my pocket and it was so frigging hot when I pulled it out :eek: It happened thrice I think and I am just lucky it didn't burn out.
 
trussmonkey25

trussmonkey25

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lol. I had my spartan roll off the seat. turn its self on and start melting int door panel befor i realized what that burning smell was...I couldnt pull over to get it :-0. Fifteen minuts later i found an exit to shut it off. now it stays at home..I use the one with key lock off
 
BowtieGuy

BowtieGuy

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You might want to be sure that there aren't any pieces, or residue from the melted lens protector on the lens before you try it out.
I had a similar accident happen. I got lucky, no apparent damage, but a lot of crap on the lens.

Good luck!
 
djLscatt

djLscatt

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hey
done: batteries fully charged and lens cleaned ,it works fine.
I was lucky the crappy ultrafire batteries were not fully charged and the cap on is " blue glow in the dark".
the life of the diode must be shorter now.
 
ApexProxy

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With any luck your driver may have protected your diode. Good buck drivers will limit current when they overheat so its possible that your diode was running at a much lower current after some time. Since you are estimating the runtime based on the capacity of the cells its possible the laser ran for far longer but at a reduced current.

I actually plan to do a test similar to this situation with one of my drivers. I will hook it up to my bench power supply and then to a 3A test load(actively cooled) and run the thing for a half hour or more and monitor the current output by the driver as it heats up. I may very well blow the driver but it may provide a good idea on how well it can protect my lasers. I would like to set the test up so that I can take pictures at intervals to record the input and output currents.
 
scumbagatheist

scumbagatheist

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I'm glad to hear your diode lived through this experience. It's fortunately not one I've gone through yet. I imagine with the way we all play with (semi-abuse) our diodes, you or I wouldn't notice the difference in lifespan....one can hope anyway.
 
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