Peltier Chip for handheld cooling

[upaa27]

Hello all!

So for awhile now I have been working on and designing a triple diode NDB7A75 and was thinking about cooling(obviously) that would work in a handheld. I was looking for something that wouldn't break easily and didn't move(aka a water pump) and began learning about the Peltier chip.

Basically a Peltier chip works by using current to move heat to an already hot spot.

The only problem is finding a Peltier chip for our needs. Or is it? https://tetech.com/Peltier-Thermoel...Temp=400&coldSideTemp=20&potted=0&emailsent=0

Don't forget that the hot end needs to be heatsinked!

What do you guys think of this method? Would you use it?

 

[ARG]

I wouldn't use it, not in a handheld anyway. A finned heatsink with a fan would do a lot more good.

 

[upaa27]

How handheld would that be though?

Another option would be to mill out our aixiz modules into multiple fins about 2mm+ deep (wouldn't do more) and thread very thin tubing around the grooves created by the fins and install a very small water pump and reservoir in the handheld.

 

[Bionic-Badger]

I think you misunderstand Peltiers. They're just electronic heat pumps, but a heat pump won't function if you don't have some means of disposing of your heat at the destination. Typically the Peltier is useful only when a material's conduction alone is not sufficient to cool your target.

I would definitely work on the heatsinking portion of your design, and only after you have a workable solution, start thinking about Peltiers. Peltiers also generate their own heat; you'll need to dissipate that as well.

Overall, your three diodes really aren't generating that much heat, especially compared to computer chips. You can probably get away with just adding more surface area to the exterior of your host. If you really want to spread it out, maybe insert some heatpipes into the host. They're not that hard to purchase and can fit into a host easily if you're designing it yourself.

 

[upaa27]

Ok thanks for the reply!

The biggest thing I was looking for was a duty cycle of at least 5min in relatively small host.

Heat pipes would probably be the best option.

 

[CDBEAM777]

Well....The Tridentis is a triple 9mm 445 Diode Combiner See:

laserpointerforums.com/f65/tridentis-6-7w-blue-beauty-83781.html

....RU going to combine or have three (3) side by side beams ? I assume you are going to combine.

And....in combining....there goes the "small" HH !!!....
Maybe medium....but, not small !

AND...these 7A75 's are " Wide Body" as compared to the 9mm 445. I would say you will likely want to run the three(3) beams thru a set of Anamorphic prism's.....like the Tridentis.

If I had to do a triple combiner over, I think I would either do everything and not use a host, but if I did use a host, I would consider two(2) 26650 vs four (4) 18650. Maybe even the " Big Boy " host ?? Dunno ? And, I would still use knife edging, for a triple arrangement. That will give you your least optical loss, and when you plop down almost 1K for diodes...well, might as well get the most photonic bang for your buck !

Peltier use in a HH ?? Doable...BUT S U C K 'S power....and just is most inefficient !! I would just have a good mass of Aluminum or borrow from the computer guys ! Heat pipe arrangement...and maybe a very,very small fan ??

Five (5) minutes continuous PO ??? That is a long time....but OK. If that is the case, maybe some heat pipe arrangement ....pull something outa a junk laptop. That might be inexpensive and may be what the doctor ordered ??

Post your design. I am interested to see what you have in mind ! Good luck !

 

[upaa27]

Well....The Tridentis is a triple 9mm 445 Diode Combiner See:

laserpointerforums.com/f65/tridentis-6-7w-blue-beauty-83781.html

....RU going to combine or have three (3) side by side beams ? I assume you are going to combine.

And....in combining....there goes the "small" HH !!!....
Maybe medium....but, not small !

AND...these 7A75 's are " Wide Body" as compared to the 9mm 445. I would say you will likely want to run the three(3) beams thru a set of Anamorphic prism's.....like the Tridentis.

If I had to do a triple combiner over, I think I would either do everything and not use a host, but if I did use a host, I would consider two(2) 26650 vs four (4) 18650. Maybe even the " Big Boy " host ?? Dunno ? And, I would still use knife edging, for a triple arrangement. That will give you your least optical loss, and when you plop down almost 1K for diodes...well, might as well get the most photonic bang for your buck !

Peltier use in a HH ?? Doable...BUT S U C K 'S power....and just is most inefficient !! I would just have a good mass of Aluminum or borrow from the computer guys ! Heat pipe arrangement...and maybe a very,very small fan ??

Five (5) minutes continuous PO ??? That is a long time....but OK. If that is the case, maybe some heat pipe arrangement ....pull something outa a junk laptop. That might be inexpensive and may be what the doctor ordered ??

Post your design. I am interested to see what you have in mind ! Good luck !

This host has and is being machined by a very good member on the forum *cough*sinner*cough*

It is nearing completion and all my materials are pretty much set minus 1 NDB7A75.

The batteries used are two 32650s

I would post all the diagrams and stuff, just my handwriting is sht and it is pretty messy looking in general(thats why I designed the host in sketchup).

I am going to pbs 2 and knife edge 1.

If I do need to add anything to the host design I do have the equipment to.

For beam correction I was thinking about using a cylindrical lense as the optics tray is 50mm out so a nice amount of space to squeeze a corrective optic in.


IF you want to look at my host in a 3d view with the measurements you can pm me and I can send you a .stl of it.

:thanks:

 

[CDBEAM777]

NICE !!!!! Very nice, Sinner does great work !

Got any sketches of you optical lay-out ? Cylindericals will correct great...but anamorphic's are less demanding to set up !

Perfect on the power source !! RU going to use the new Lazereer Super X-Drivers ?? They kick out 5A, IIRC ??

Thanx for sharing ! :eg:

 

[Bionic-Badger]

Anamorphics are okay but assume that your beam is already collimated in both axises. Gotta have them coated for your wavelength too.

You'll probably want more mass and more fins. Some heat-pipes to the end might help you out. You can get those thin rod-type ones on ebay. Then you can just put them co-axial with your laser diodes to help distribute the heat to your finned areas.

I'd actually worry more about having enough mass on either side of the diodes and ways to dissipate the heat from all sides. Maybe the handle can be made more "grippy" with additional fins that would also serve as the hand-grip.

 

[starlight]

I recently used a fan/heatsink from a laptop computer. It worked fine just wanted better duty cycle so changed to finned heatsink with larger fan. I'll use it on another project soon.

 

[Bionic-Badger]

That's not exactly a handheld-sized fan, y'know.

 

[upaa27]

NICE !!!!! Very nice, Sinner does great work !

Got any sketches of you optical lay-out ? Cylindericals will correct great...but anamorphic's are less demanding to set up !

Perfect on the power source !! RU going to use the new Lazereer Super X-Drivers ?? They kick out 5A, IIRC ??

Thanx for sharing ! :eg:

Using 3.5a with the sxb but hoping to turn em up to 3.8 once I see how well it preforms.

I will try to get some pictures up later today.

Thanks!

 

[starlight]

That's not exactly a handheld-sized fan, y'know.

No it probably isn't. I posted because computer cooling was mentioned in another thread I was reading recently and they mentioned laptop cooling because it's small stuff.
Bionic Badger you are right the fan is to big for any handheld application but it is very small and is a heatsink.

the fan/heatsink combo make it a cool little unit

sorry if I interrupted anything here

 

[upaa27]

This is a basic diagram I quickly drew up that is much cleaner than my notes.

Each square is 5mm

Prism is not to scale but its reflector is.