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ArcticMyst Security by Avery

A few questions and lots of pics.

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Apr 13, 2008
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I had working PHR-803T. I now have a nonworking PHR-803T.

I was running it at 120ma, as it seemed to be the most commonly used current. I had built the laser on a piece of wood, but I wanted to put it in something safer, but while I was working on it, I dropped the heatsink(heavy copper core from a CPU heatsink) which contained the module and diode. It fell about 4 inches and was caught by the diode wires. The wires and solder did not break on either the diode or the driver.

I didn't think anything of it, and put everything into a 2D maglite(yeah, I know it's huge and heavy, but it was the only thing handy.) Only problem is that when I turned it on it was WAY dimmer, and I noticed the spot looked odd. I took the lens off and took this picture:
http://jake.tscsupport.com/images/Laser/Blu-Ray/Blu-ray_damaged.JPG

The only image I have of how it looked before is in this video:
http://www.youtube.com/watch?v=J_CEU0rcIVw

Image of the driver(LM317T):
http://jake.tscsupport.com/images/Laser/Blu-Ray/Driver.JPG

Image of the module in its heatsink:
http://jake.tscsupport.com/images/Laser/Blu-Ray/DSC08165_2560x1920.JPG

More random images of it:
http://jake.tscsupport.com/images/Laser/Blu-Ray/

It was working fine until I started working on it, the current is still the same, and I never disconnected the diode when I was working on it. Neither of the diode pins are connected to the case. I suspect static killed it. But I asked in the chat room and some said it was from me running it too long, but it never even became warm.

I am about to buy another diode, and I would like to know how to avoid killing it. Should I use a lower current? If so, what current? I want it to last a reasonably long time(Longer then the 12 hours the last one did.)

Man, this board has a lot of info on it, almost did not need to post(this might have been answered already, but all the answers I could find were different, some said 150ma was fine, others to said keep it lower then 100ma.)
 
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Joined
May 7, 2008
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couple things here. 120mA is on the slightly high end for a long life duration. 110mA is more nominal for a good life expectancy, although these pointers can be pushed way higher with more consequence.

In regard to your diode becoming dim... when a diode becomes dim like that it is referred to as "LED" or the diode LED'd. It can happen from a cap releasing its energy, shock or vibration, or from over powering the diode. In your case I am willing to say it was caused by that 2-3 pound copper lug falling 4-5 inches, meaning about a 25 lb force was exerted on the diode pins. This could easily destroy a diode.

Good thing with the group buys going around you can replace your 803T for about $8!!!

good luck! and always remember to short your caps too!

EDIT::::

and with the size heat sink you're using, I imagine that running at 100-110mA for 12 hours will be just fine. maybe drill a few holes or machine some fins to increase the surface area on the heat sink.
 
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That's what I thought caused it.

The resister on the driver is rated at 11ohms +/- 1%, this should give 114ma. my meter's ma setting does not work because I accidentally blew its fuse... So I used the amps setting, giving me 0.12 amps, or 120ma, I suspect that the meter is not very accurate(I got it from DX,) especially in that setting.

I think I will just leave the driver as it is and and limit the run times. I built an identical laser for my friend, and his still works fine. I just have no idea how I'm gonna get the focusing module out of the heatsink, I needed a vice to get it in...

Edit: I lost the test load I made, and I can't find my 1ohm resisters to make another...
 
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is the heat sink open on the other side of the module? you may be able to hammer it out with a nail punch of soft metal rod. Since the diode is already dead it wont do any damage other to maybe just the module. Dont hammer a screw driver though because it will likely damage the screw driver.
 
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I doubt it will damage it as bad as high voltage will. I once melted the end of a screwdriver off.

I am just worried about damaging the module, but I should be able to figure something out. I don't want to bend the back of it, because I will need that to press the new diode in. If all else fails, I could order a new module and put the diode in it. Then use it to push the old one out and the new one in all in one step.
 
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haha wow, melting a screw driver sounds pretty intense. sounds like you got a good plan though. good luck!
 
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<offtopic>
I also melted a hard drive today because I was bored: http://www.youtube.com/watch?v=Nub4Z0uHoV4 </offtopic>

I hope I don't kill this one. Now, to convince dad to order stuff for me... It's embarrassing, I'm 17 and I can't buy stuff for myself, and the bank won't let me have a debit card until I'm 18.
 




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