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ArcticMyst Security by Avery

Hothead 445 :(

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I was setting up a 445 today and realized it was getting very hot, very fast. I was testing it on my bench supply at 1A using a hotlight HS and the heatsink was warm after 10 seconds, and at 25 secods it was hot! I didn't understand it but the output looked normal. Has anyone else ever had this problem?
 





joeyss

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Sounds like there could be a short in the wires or something is stealing excess current.


more current= more heat
 
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Zombie.

750zombie2.jpg
 
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Once a standard 445nm LD suffers damage.. it takes a
LOT more current to get it to lase at the undamaged
output level... If you can even get close to that original
undamaged output level.. (but highly unlikely)..


Jerry
 
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Yep, degraded junction means more power required, but didn't he say that he was limiting the Amps with his supply to 1A? Shure sounds like a short through the sink, but then there wouldn't be much optical output, would there?
 

Helios

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It sounds like a short to me. Even if your power supply was inaccurate and sending it 2 amps it still shouldn't hot that fast. Any more current than that and it wouldnt lase. So my guess is you have a short in your wiring or maybe an internal short in the diode?
 
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Zombie = Damaged diode that generates large amounts of heat, but low power.

Keep reading sunshine.

@Ben. Do you have a LPM? Measure the output. If its lower than original its damaged. If its the same then you have a short.
 

Helios

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Zombie = Damaged diode that generates large amounts of heat, but low power.

Keep reading sunshine.

@Ben. Do you have a LPM? Measure the output. If its lower than original its damaged. If its the same then you have a short.

With a short he would get a low reading as well though. In reality the chance that you would have a short and still get enough current through the diode for it to lase is low. I'm going with tj on this. You have a very hot blue LED.
 
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With a short he would get a low reading as well though. In reality the chance that you would have a short and still get enough current through the diode for it to lase is low. I'm going with tj on this. You have a very hot blue LED.

??? :thinking:

You're going with me, but said almost the opposite. :whistle:

Anywho, wouldn't a short pop a fuse or something?
 
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Helios

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??? :thinking:

You're going with me, but said almost the opposite. :whistle:

Anywho, wouldn't a short pop a fuse or something?

I think its unlikely that he would have a short and a diode that's putting out any light so I agree that is damaged or fried.

I originally thought a short but I'm allowed to change my mind right...
 
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Guys there is NO short unless its internal, I hooked up my bench supply directly to the pins. The output looks normal, maybe even a bit better then normal. Oh and I dont have a LPM, well I do, but it doesn't work. There could be a chance that this is a freak diode and is super powerful at a lower amps. But until I can test the output on an LPM we will never no for sure.
 
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^^ If anything it would be a less powerful diode not a more efficient.

If it was efficient then the diode would run cooler and put out more power.

Can you take a Picture of your set up.

Also have you tested everything on a testload before you hooked up the diode.?
 
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Helios

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Definitely not a freak diode in a good way that's for sure. If your getting that much heat and the psu is really limiting the current to one amp then it has ti be putting out low power. That heat is energy lost.
 
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since you don't have pix, i say check your connection at the pins. you could have a bad solder job. which goes back to the whole "short" theory

michael.
 
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