Author Topic: Peltier Cooler  (Read 9322 times)

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MarkS

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Peltier Cooler
« on: May 02, 2009, 15:27:56 »

Inside this 12v drinks cooler from Maplin (on special offer at £20): http://www.maplin.co.uk/Module.aspx?ModuleNo=226811
there is an easily removable Peltier cooler which draws 2.5A

I bought mine today (plenty still in stock at Eltham) because I can think of a few uses for a Peltier Cooler and a Canon  ;)

Thanks to John for drawing my attention to this interesting thread: http://ukastroimaging.co.uk/forums/index.php?topic=44675.0 and Gary Honis' mod: http://ghonis2.ho8.com/rebelmod450d16c.html

Denise spotted me taking it apart:  "What's that?", she asked. 
"Oh it's a drinks cooler - it's got a really useful Peltier inside".
"You're not taking it to bits are you?".
"Well - yes".
"But it would be really useful to use it as a drinks cooler in the Summer!".

Mark

Daniel

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Re: Peltier Cooler
« Reply #1 on: May 02, 2009, 15:40:53 »
Ooh, I Like the sound of this, Peltier cooling that doesn't require me taking my camera apart :)

Think I might make a trip to eltham myself!

Daniel
:O)

Ian

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Re: Peltier Cooler
« Reply #2 on: May 02, 2009, 15:55:40 »
if you've got a DSLR, isn't the done thing is to cut a hole in the door for the lens and encase the whole camera in the fridge?

Then you can still use it cool drinks. Or a least half of one poked through the hole :)

MarkS

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Re: Peltier Cooler
« Reply #3 on: May 03, 2009, 17:49:30 »

I've been busy ...

Total cost £20 all in - everything built from a Maplin drinks cooler.










Ian

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Re: Peltier Cooler
« Reply #4 on: May 03, 2009, 18:50:43 »
cool
 
hehe :D

RobertM

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Re: Peltier Cooler
« Reply #5 on: May 03, 2009, 19:31:31 »
That's really neat Mark.  Was everything you used to make it recovered from that drinks cooler ?

MarkS

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Re: Peltier Cooler
« Reply #6 on: May 03, 2009, 19:31:39 »
I've now done some testing.

At first I didn't install the external fan either but the heatsink became very hot.  The cooling was far more effective with the fan.

Specifications of finished result:
Weight:  0.6kg (coincidentally the same as the 350D) - most of this is the heavy heatsink
Temperature drop from an ambient 22deg (with camera inside and exposed T adaptor) :
8degC after 30min. 
13degC after 60min. 
15degC after 90min.
16degC after 120min.
Power consumption:  3.2A at 12V (including fan)

Observations:
Probably, an internal fan (to distribute cold air) would help increase the temperature drop. 
The exposed T adaptor gets very cold and it may be responsible for a lot of wasted cold.
My main complaint is that the supplied fan is very noisy - I must replace this with a silent one!

Overall, I'm pretty pleased.  An ambient temperatiure of 22C is a very warm Summer's evening - it means I can cool the camera to 6C on such an evening.  ;)

Mark


RobertM

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Re: Peltier Cooler
« Reply #7 on: May 03, 2009, 19:42:37 »
What does the weight work out to be ?

MarkS

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Re: Peltier Cooler
« Reply #8 on: May 03, 2009, 19:44:53 »
Quote from: RobertM
That's really neat Mark.  Was everything you used to make it recovered from that drinks cooler ?

Everything!  Well, everything except the duck tape to hold the salvaged polystyrene together.

Here's the finished result with the fan on top (again salvaged from the cooler).



Mark

MarkS

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Re: Peltier Cooler
« Reply #9 on: May 03, 2009, 19:48:20 »
Quote from: RobertM
What does the weight work out to be ?

0.6kg - a lot of this weight is the heavy heatsink from the cooler.
Strangely enough, 0.6kg is the same weight as the EOS350D body.

Mark

MarkS

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Re: Peltier Cooler
« Reply #10 on: May 05, 2009, 05:35:28 »
In practice, i.e. with the camera switched on and taking long exposures, the temperature reduction is only 12C from ambient and not the 16C I originally got.  This is probably due to the heat given off by the camera - it's not as efficient as the 450D or the 1000D.

It still makes a big difference - reducing the CCD dark current by a factor of 4 but it's not as good as I hoped for.

I think some modifications will be required ...

Mark
« Last Edit: May 05, 2009, 05:43:25 by MarkS »

RobertM

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Re: Peltier Cooler
« Reply #11 on: May 05, 2009, 08:26:40 »
Mark, Just a few thoughts...

You should add the small internal fan, that would help with removing heat.  I would also suggest an internal heatsink the other side of the Peltier with that fan.  Something like a motherboard chipset cooler would increase the heat gradient and allow it to cool down quicker.  The air movement would also give a very slight cooling effect which would help.  You really want the fan to run slowish to reduce heat generated by the motor otherwise you won't see as large an improvement.

Insulate the inside of the box if it's metal.
Put PTFE tape around the T-thread at the camera end (if the thread allows that)
Insulate any part of the T-thread adaptor that shows on the inside.

Watchout for condensation!!!!!

Keep going till you end up with a cooled astro camera ;)