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Cooled Lumenera ??


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I'd like people to share their thoughts with me please.

I'm considering making modifications to my Lu070m cam so as to cool it.

the two options are :-

a)to indirectly tec cool the chip via the ally case.

b)to add only a fan at the back of the case to blow air into the circuitry( bare in mind the chip face is isolated so would not be in danger of having motes blown onto it.

How difficult would it be to add the TEC to the rear of the case to cool the chip via conduction and what are the possible implications ? eg frost on the chip ??

Is it worth it ??

All and any ideas /thoughts etc would be greatly rec'd !

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I have a modded toucam with a fan blowing into the circuitry, presumably just as you describe it. I'm not sure if it makes much difference for just taking videos, but it's a simple mod and maybe worth trying? I've yet to make my case for my LU070, so I might just do this from the outset!

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What I've been thinking of last night was, basically putting a small TEC on the outside of the back plate then a heat sink and a small fan and then on the inside stick a row of RAM heatsink ( acting as a cold sink)

Ram Chip Heat Sinks : Chipset Cooling : Maplin

There ought to be enough space between the legs inside the case. I'm thinking all controls could be boxed and be separate to the cam- weight is something I'm watching !

Adam I'm more than happy to sit back and watch someone with more experience try it out first, especially if it might be incorporated from scratch :)

Generally wotdya fink ??:)

ps apart from the TEC , can be bought cheaply via evilbay there's this

Akasa AKVCX01 universal cooling kit : Chipset Cooling : Maplin

Oooh the bottom line is IS it worth it ? Would it be a benefit to gain etc and reduced noise ?

Edited by beamish
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  • 4 months later...

Hi,

I hope my first post can be useful, even if I'm replying to an old thread :(

Back in my high school years I completely modified a Philips 675K for long exposure and cooled it with a TEC. It was a fun little project - and with youthful enthusiasm I turned an alloy cold chamber for the CCD which was subsequently sealed and purged with nitrogen. The webcam design (little daughter board for the CCD) allowed for taking the chip off and cooling it "directly" with a cold finger inside the chamber without too much fuss.

However, I decided to use one of the standard TEC's you can buy from eBay.

I'll learn from experience I guess, but the wattage rating on a TEC works both ways. The 30mmx30mm or 40mmx40mm are a minimum of 50W. You've got to get rid of that energy in the form of a heatsink and probably a fan. The maximum DeltaT is fixed, so if the hot side gets "too" hot the cold side will not be effectively cooling the CCD.

I think the TEC I got was an even higher wattage than this so the heatsink and fan I needed added considerably to the weight. The end result was quite a heavy camera which took brilliant dark frames on the bench and had the CCD down to around -15 on a nights imaging but it was a pig to use because of the weight. It was fun to build, but as a practical camera not really too successful.

I'll see if I can dig some pictures out both of the build and images through the camera.

Anyway - in a rambling sort of way, the point I'm making is get the correct TEC for the job. A CCD generates very little heat of its own so you don't need a great old TEC to cool it. If you look at the specs of the TEC's you will see their DeltaT's are pretty much the same. The smaller TEC you can get away with the less your cooling needs. Look at Starlight Xpress cameras, they use the body of the camera to passively dissipate the heat generated by the TEC - they're using the "correct" size TEC.

BUT - cameras designed to be cooled from the ground up usually have the PCB designed to help with cold fingers and whatnot, which with the lumenera is not the case. The easy option would then be to ignore the above, get a big TEC and blow the cold air into the housing. It means you put a lot more strain on your imaging equipment, mount, focuser etc and you run the risk of turning a nice practical light little camera into something a bit more troublesome to use.

Using a fan on its own to blow air into the case kind of relies on the temperature of the air that is being blown around. I may be wrong but the CCD doesn't generate much heat of its own, in use, you don't get noisy images because leaving the shutter open heats it up, its the temperature of the CCD itself that is important rather than stopping it heating up, if that makes sense. So, you are only ever going to be able to keep the CCD at ambient which is not always low enough.

I have something similar to a lumenera with a 1/3" 1024x768 sensor being delivered soon which I will be attacking with the aim of working out how to cool the thing. I have a 9mmx14mm TEC rated at something like 9W so I'll be getting my heart racing again soon when I inevitably start trying to desolder the CCD.

Going with a small TEC does mean taking the CCD off and trying to in some way isolate it when cooling - you certainly will need to worry about due and ice if going down that route too. A small TEC will cool a CCD just fine, however it won't do well at having to cool an entire case heated by all the other components as well.

I'm yet to start thinking on how to tackle the design yet as I want the camera here first to have a little look and play. However if anyone is listening and is at all interested I'll let people know of any progress I make.

Thanks all, and sorry for the ramble.

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I added a tec to a DSI IIC its only a tiny little one and made thermal contact with the CCD using a cold finger the hot side was the metal finned case and a fan was used to get a bit of flow over the fins... A Guy in the US used to sell kits...

I did get moisture problems so in the end I put a few small packs of dessicant inside the case...

Billy...

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Well if that was a ramble then I say ramble on ( wasn't that a title of a Zep song BTW ?) !!

I must admit to having shelved the cooling plans for the time being, initially thinking of cooling passively by putting a TEC and sink/fan on the back of the ally case and letting nature and radiation do the rest. I found what you say interesting and will give it some thought if I return to the idea.

But as you pointed out, one of the arguments against doing it is that you add a fair bit of weight to what already weighs in at 320g plus the addition of cable sand separate power source. The other reason I began to look into it was to perhaps use it for longer exp, but the Lu070 is limited ( unlike the SKYnyx) to 179secs and so far they're have been no replies to my SOS regards a firmware mod to change it.

Also......the cam can't be modded to take an ICX 618ALA chip ;).

however my SPC can :):(

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