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Dim 445 diode

drummerdimitri

drummerdimitri

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Oct 15, 2007
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510
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Hello guys,

I was busy re-building my 445 laser from scratch today, and everything was fine until the diode started acting funny. When i connected it to a battery a while ago, I had a strong blue line hitting the wall, but now with the same battery i get a very dim light that is in circular form. Even when connected to my flexdrive, it draws amps from the battery but retains its low output in a circular shape (even). Any ideas about where to start here? I've been working for hours straight and this has just really pissed me off!

Thanks!
 





DTR

DTR

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Jun 24, 2010
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Man sorry to hear that.:cryyy: That circular output is what we call a zombie. Most common way I have seen it happen is if the diode gets spiked from a capacitor. When you reconnected it to your flexdrive did you remember to short the output wires before connecting the diode? Also are you saying you ran it directly from a battery with no driver?
 
drummerdimitri

drummerdimitri

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No, i never heard of shorting the output wires before connecting the diode. Yes, I did run it directly from a battery at first to make sure the diode is working fine. Any ideas on what to do next?
 
LaZeRz

LaZeRz

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Feb 19, 2011
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Yeh. sorry man but the diode is pretty much dead now :(

Before connecting your diode be sure to short the 2 + and - pins from the driver...

If you want any more help etc. Just PM me :)
 
drummerdimitri

drummerdimitri

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Oh man, that really sucks! I guess I will have to give it another try some other time. How should i short them? While the laser is operational or not? Thanks!
 
C

carulli2

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Jun 27, 2011
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before you attach the laser diode use a metal object to touch both the negative and the positive outputs from the driver. do this with no power applied to the driver. solder the laser diode to the driver BEFORE attaching the power supply.

here is why: most driver have a capacitor across the output because while in operation this smooths the output of the driver. if you power the driver without a load attached the capacitor becomes fully charged, when you attach the diode to the output the capacitor discharges fully into the diode (normally killing it).

hope this helped :)
 
Xtrm2Rick

Xtrm2Rick

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drummerdimitri said:
No, i never heard of shorting the output wires before connecting the diode. Yes, I did run it directly from a battery at first to make sure the diode is working fine. Any ideas on what to do next?
Click to expand...

Tech_Junkie said:
...oh yeah...NEVER hook up a diode directly to a battery.
Click to expand...

What he said.

The battery most likely have given it to much mAh and/or voltage ( batteries give spikes in its output, look it up on the internet) and since laser diodes are pretty sensitive to these spikes they would most likely die everytime you do it this way.

you probobly have damaged your diode the first time and where lucky it didnt die in the first second.

also if you test your diode you still need to use a driver, and if you didnt even put it in a module/heatsink yet dont drive it to high yet! you might overheat the diode and also kill it.....these things can get prettty hot!
 
Last edited:
drummerdimitri

drummerdimitri

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What if the driver has been damaged during the process as well? How can i check if it is working properly. These things are tiny and are a huge pain in the ass to work with. I accidentally got some solder stuck to some parts on the driver but de-soldered them back but I have no clue if I did it correctly. I think my safest bet is to purchase a flexdrive connected to the diode with the current set so that I don't screw up again.
 
mark-in-dallas

mark-in-dallas

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Apr 22, 2009
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Don't feel to bad Dimitri, I did the same thing on my first build, then bought a diode/driver combo to finish it.

You'll need a test load to test the driver, which you'll also need for setting the current. If you try powering the driver without a load attached you will fry it.
 
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