Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

Buy Site Supporter Role (remove some ads) | LPF Donations

Links below open in new window

FrozenGate by Avery

The Micro Driver Module (MDM) concept (picture)

Toaster said:
Also some of yours are using copper fins. Aluminum is better for fins and copper for solids!! :)
Click to expand...

Incorrect, Copper moves heat faster than Aluminum. Aluminum holds more heat than Copper.

Look up heat capacity and thermal conductivity.
 





Pontiacg5 said:
Incorrect, Copper moves heat faster than Aluminum. Aluminum holds more heat than Copper.

Look up heat capacity and thermal conductivity.
Click to expand...

Well copper does both faster now that I look it up....

My bad

"He already said, it's somewhere on the first page." is 41 characters longer than "Fyerender"
 
Last edited:
Its all good. I was just really bored so I had to see lol

Nothing meant to be rude :)
 
Toaster said:
Well copper does both faster now that I look it up....

My bad
Click to expand...

Copper does not "do both faster" copper sheds heat to surrounding air faster. Aluminum is less dense than copper so it can hold more heat.

That is the reason why the diode mount is copper and the driver heatsink is aluminum. The copper sucks the heat away from the diode then sheds it off to the aluminum. There is more copper/aluminum contact than diode/copper contact to compensate for aluminum's poor thermal conductivity.
At least that is how it all works in theory, it will be interesting to see if it works in practice.

Kryczeck, I did get your e-mail but I haven't had a chance to look at that file yet. Hopefully I'll get some stuff finished tonight so I can take a look. Thanks!

Edit: Could you take the fins on these here (http://laserpointerforums.com/f48/micro-driver-module-mdm-concept-picture-55699-2.html#post786867) and turn them so they follow the length of the module? That would be possible to machine and would let you run a fan too.
 
Last edited:
No, aluminum would take .897 joules to change the temperature 1 degree Kelvin per gram. Copper would take .385 joules to change the same temperature. Therefore aluminum can absorb more heat (energy) per degree than copper.

That is why massive copper blocks with no fins are really ineffective and unnecessary. In those situations aluminum would likely allow longer runtimes.

Copper can move 401 Watts per meter per degree of temperature gradient, aluminum can only do 120-180. Calculating either one of these to the T would be incredibly difficult because you need to know surface areas and masses and all that. Luckily solidworks has a way to simulate heat dispersion. I need to figure out how to use that, thermally engineered laser hosts :D
 
Last edited:
Thats for weight. Volume I am talking about, for weight, aluminum is better though.
 
Toaster said:
Thats for weight. Volume I am talking about, for weight, aluminum is better though.
Click to expand...

Yeah, that is true. I missed that, you could fit more copper in the same space as aluminum. I thought this through at some point and it made sense, I need to rack my brain for a while. It's been too long since I designed these things and taken Physics classes!
 
Cool, I am glad we came to a consensus:)

On the down side, copper will hold it longer
 
Not sure if this thread is dead or not...but the last few comments from Pontiac and Toaster got me thinking again... As well as ideas from Toke...

Let's say I've got this host:
SFL2.png


And I've designed a new head for it that's more of a heatsink like this:
Note: I'm not sure if something like this can be manufactured with the blind threads and all...but assuming it can...
Heads.png


Then my new host looks something like this:
NewHost.png


So my question is, which one of these configurations would be most optimal given the copper vs. aluminum discussions above?

I mean, now that I have a heatsink that can house the entire module, would it still benefit having the module head exposed and finned?

Here are the different configs:

Module entirely embedded within the heatsink:
Embedded1.png


Module head exposed (two different models):
RoundFins1.png

SquareFins1.png


Or would it even matter?
 
I would say the first option is best, the two others are barely making use of the new head.
 
You must log in or register to reply here.


Back
Top