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Benm

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All crazyness aside, i do wonder how well these things would perform if cooled to extremes. Dunking one in liquid N2 just to see what happens would be fun, though i think it might just crack due to rapid thermal compression.

If you graph the LD current vs Po, you will see a knee (leveling curve) in the graph showing that the diode is at it's limit. Back-off !!!
I think i'll have a go a finding that knee point once i get some proper cooling for the module. The little heatsink star that i have around it now isnt all that effective.

I saw an interesting piece of alu intended to mount a hinge on a wall (or pole) in the dyi shop. I hope they have one where i can fit the module in and mount it on a larger heatsink (think CPU sized).

As for monitoring voltage: I've taken some measurements at currents between 40 an 160 mA, the relation seems similar to that of LEDs so far. Guess i'll find a cheap extra meter somewhere so i can watch both simulatnously though i don't expect any exciting results.
 



philguy

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By the way, there is a very easy (yet dangerous) way to cool a LD, lighter gas (butane).
If you turn the cartridge upside down, the liquid gas will shoot out, starting to evaporate and cooling its surroundings well below freezing.
I killed my first LD (2$ pointer, long time ago) in a puddle of butane, driving it up to 12V (no resistors), watching it get brighter and brighter, then dimmer and dimmer... :)
Very good ventilation needed!!! Ever heard of "explosion" or "suffocate"? Yet good for a short cooling "shot".

Think I might use that sometimes outdoors, if I have to decide heat vs. duty cycle.
 

Benm

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I've used lighter gas as a short-term coolant for other electronics projects, just to test for buggy soldering (thermal contraction and expansion reveals such defects well).

I would advice any sane person against doing this though, since messing with electronics often involves sparks, which is asking for trouble really.

The safer alternative is to use CO2, the spray from a liquid CO2 container rapidly cools to -70C or so at which point it'll snow dry ice. Massive condensation usually results though, so be careful.
 

Things

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kwinchee said:
lol i bet he wasent using  a circuit lol and just using AA battrys
nope i was using a circuit, but i guess i had the pot up to far or some stupid mistake like that?
 

Daedal

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philguy said:
By the way, there is a very easy (yet dangerous) way to cool a LD, lighter gas (butane).
If you turn the cartridge upside down, the liquid gas will shoot out, starting to evaporate and cooling its surroundings well below freezing.
I killed my first LD (2$ pointer, long time ago) in a puddle of butane, driving it up to 12V (no resistors), watching it get brighter and brighter, then dimmer and dimmer... :)
Very good ventilation needed!!! Ever heard of "explosion" or "suffocate"? Yet good for a short cooling "shot".

Think I might use that sometimes outdoors, if I have to decide heat vs. duty cycle.
There are canisters that are a much better substitute than butane, and less 'explosive'. As a matter of fact... I think they're harmless and not even flammable ;)

--DDL
 

Things

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oh hey daedal, in my sig on spectraforum, i put your a link to your GB for blu ray diodes ;)
 

Things

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oh yeah, i love freezing things with spray-on deodorant, i froze a little chip to -60C, and it had smoke stuff coming off it all over the place! ;D
 




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