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Laser Diode cooled with TEC (finished)

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SenKat

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Andy - considering these guys are pushing these diodes to the limits and back again, TEC is not too OTT I think...okay...MAYBE a little bit, but if it prolongs the life, and develops into even more of an electronics hobby - I say go for it :)  We can not have too many circuit-heads running around on here :) hehehehehehe !



P.S. It looks GREAT, Death Angel ! Where did you get the LED/LCD readout for the temperature - same PC shop ? How much was it, thermister and all ? I could use one of those, I am certain :)
 

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I was looking around for some thermometers and switches for heating control at about 300 degrees celsius, it turns out with a little searching there are lotsa places that can supply you with permanently mountable, and unpluggable, thermocouples, probably a K type for this, and a device for monitoring that could theoretically log the data, and can turn it off if it overheats!

But yeh a cheapo thermometer would do... :p they sell them losta places around here, pc shops, cheap shops, outdoor places, the sorta places that carry geographical stuff have good ones (i mean like telescopes drink bottles, weather stations, nice torches, kinda like camping shop but different)
look around greg you're sure to find something!
 
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SenKat

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Bluefusion - I don;t really get out of the house too much, I HATE trying to drive with just my left foot :p There IS a big old PC warehouse type of thing down the street though - maybe I can putter over there, and see if they have one of the CPU sensors or something hooked to an LCD array.....Hmmmmmmmmmmm
 

Benm

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You could get an indoor/outdoor thermometer, even just from DX or something. Just mount the outdoor sensor in/against the module and you'll have a good readout. Range of those things is usually at least -20 to +50 C, should be sufficient.

Or get one with 2 external sensors, one for the heatsink and one for the module ;)
 
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SenKat

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EXCELLENT !!!! sniff....sniff....sniff..... I love you guys....you are all so helpful ! [smiley=thumbsup.gif]
 

andy_con

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SenKat said:
Andy - considering these guys are pushing these diodes to the limits and back again, TEC is not too OTT I think...okay...MAYBE a little bit, but if it prolongs the life, and develops into even more of an electronics hobby - I say go for it :)  We can not have too many circuit-heads running around on here :) hehehehehehe !



P.S.  It looks GREAT, Death Angel !  Where did you get the LED/LCD readout for the temperature - same PC shop ?  How much was it, thermister and all ?  I could use one of those, I am certain :)
im not saying that playing isnt good LOL

but the diodes in my 200mw red modules are running high, there rated at 120mw. but a simple heat sink works great. the housing never gets hot on mine.

was justa thought
 
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Yeah Greg, the one I have was $24 and it is a thermal controller. It has 3 thermal sensors on it and 3 fan controllers. Not bad though. I like it. ;)
 

Gazoo

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andy_con said:
isnt tec a diode a bit OTT???

just heat sinking a diode is enough
Actually you have brought up a good point. Heatsinking is enough for portables running short duty cycles, but as hard as we push these diodes in our DIY labbys, TEC or fan cooling is almost a must. Personally I like the TEC route much better.

I received a new set of peltiers today and recently received my LPM-1. I have always been very curious as to what effect a TEC has, and I found out as soon as the glue dried.. ;D

I am running an open can diode with ~400ma's. I normally was able to get ~230mw's out of it running it with some cooling. The reason I say some is because I did not have my previous peltier glued perfectly flat.

Anyway, I constructed a new TEC and was able to get an additional 15mw's out of the diode. I might have been able to get a little more had I applied more current to the peltier, but I did not want to risk it on account of condensation.

Out of curiosity, I shut off the TEC, and the power of the diode dropped as it heated up. I let it get quite warm and the power had dropped to 170mw's. TEC cooling is a huge plus.... ;)
 

Hemlock_Mike

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As SenKat says -- Some of us are pushing LD's to the limits :eek:

Go look at the post about burned out LD's !! I'm loosing my ranking here as we "push" on....

Mike
 

andy_con

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i run my 120mw diodes in my scanner at 200-230ma which gives me 200mw. heat sink is more than enough
 

Gazoo

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That must be a very efficient diode. 230ma's is giving you an output of 200mw's????

Regardless, if your diode is rated at 120mw's cw and you are running 230ma's, you really are not pushing it that hard. Some have gone as high as 300mw's with the GB diode and it is rated at 80mw's cw.

Per my post above, with the amount of current I am pushing my open can with, a TEC is a plus. A heat sink might be adequate but it would have to be big and at least cooled with a fan.
 

Benm

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Gazoo said:
Actually you have brought up a good point. Heatsinking is enough for portables running short duty cycles, but as hard as we push these diodes in our DIY labbys, TEC or fan cooling is almost a must. Personally I like the TEC route much better.
Passive heatsinking is enough to run them a decent power permanently too, really.

But one thing with these LD's is that they become more efficient when they get colder. Even at equal current, they generate more power at 10 celcius than for example at 30 (which requires a decent heatsink already).

I'm not sure how far this goes on, they probably work even better when freezing - but then condensation and ice formation will ruin things without special precautions.
 




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