Heatsink/Collimator for 5W C-mount

[millirad]

Wags, I like what you've done. I wonder how well a cpu coolant circulating system would work, like the hotrodded PC's use.

 

[sbdwag]

Wags, I like what you've done. I wonder how well a cpu coolant circulating system would work, like the hotrodded PC's use.

You know Ive been there done that. I had a overclocked cpu on a 40cm2 pelter that was running at -16C at about twice clocked speed. The front side buss was the weak point and I could not cool it. I mounted two 120mm fans on a motorcycle radiator to cool the water jacket.

This is probably something I will do but Im worried about frost and shorts. And is it possible to get the cpu too cold. How many watts of cooling do I need.
Chris at Heruursciences said that If I seat the diode on Indium foil it will help with the heat transfer and I would be possible to run the 5W at stock power but not to push it to the 7W max it is rated for unless I add active cooling.

Ill need both intake and return water lines, 12V into the pelter, and I will probably also add a thermostat into the block.

Many ideas running thru my mind.

Regards
sbdwag

 

[ElektroFreak]

You won't have to worry about condesationa since you won't be usign the TEC in the same fashion as you did with your CPU. You want the TEC to keep the diode around 20C at all times, so you won't need to get too cold..

 

[sbdwag]

You won't have to worry about condesationa since you won't be usign the TEC in the same fashion as you did with your CPU. You want the TEC to keep the diode around 20C at all times, so you won't need to get too cold..

20C thats almost room temperature. Even at 2800ma's for 20 minutes the sink is barely getting warm to the touch. Im not sure that I should be worried about active cooling.

regards
sbdwag

 

[HIMNL9]

Anyway, having done all the things yourself, must be easy to put a thermal probe on this block (maybe in a hole, dipped in thermal grease), and connect it to the PSU circuit as safety shutdown ..... just for avoid any risk

 

[ElektroFreak]

20C thats almost room temperature. Even at 2800ma's for 20 minutes the sink is barely getting warm to the touch. Im not sure that I should be worried about active cooling.

regards
sbdwag

The issue tends to be the fact that these (and almost all other) diode's lifetime is shortened drastically starting at 25C and above.. Just a few degrees can make all the difference. With IR diodes, if you can feel even the slightest warmth the temperature is most likely too high. Cool to the touch is ideal. Too cold, and the output will drop drastically. Typically, the acceptable temperature window is from -10-25C, but your diode could be different. Best to err on the side of caution IMO..

Really it all boils down to duty cycle. If you want truly unlimited burn time (days if you want) a TEC is essential. If you just want a few minutes at a time, passive cooling with a temp limiter (like HIMNL9 suggested) will do..

 

[sbdwag]

Elektrofreak

Thanks for the info. Sounds like I do not need a heck of a lot of tec. May be a small 40 watt with only a fan and a sink on the hot side. Im thinking about ways to regulate it. If I take a 14v pelter and put it on 5V's should drastically reduce the cooling capability. Perhaps just what I need to stay in that temperature range. Would be some trial and error to get it just right.

Thanks again for the info.


regards
sbdwag

 

[Krutz]

if you come up with a peltier-regulator (temperature feedback), that would be really great news! had no luck with extensive googlesearch, and never saw a hobbyists-version.. TECs themselves are quite cheap now!

manuel

 

[ElektroFreak]

^go to die4laser.com and send an email to the address at the top of the page regarding "die4chill". It's exactly what you are asking for..

A 4Ow tec attached to an LM317 adjustable driver will work great in a pinch, but there is no control over the temp other than the pot on the 317 driver.

 

[Krutz]

haha true, thanks!
in fact I have his die4thing lpm ;-)

manuel

 

[HIMNL9]

A 4Ow tec attached to an LM317 adjustable driver will work great in a pinch, but there is no control over the temp other than the pot on the 317 driver.

Not a professional solution, but you can improvvisate a negative feedback, using a NTC in the regulation network of the LM317, and putting it on the heatsink ..... when temp increase, resistance decrease, so voltage increase, TEC cool more, when temp decrease, resistance increase, Vout decrease and TEC cool less