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Peltier cooled ZWO ASI 120 MC


Corpze

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Hi, just wanna share the results of my latest diy project, My recently bought ASI 120 MC camera.

I fitted a 40x40mm 60w 12v peltier bought from ebay with a old AMD cpu-cooler and fan, all connected with a DC-plug as the rest of my equipment.

A little dew on the camera but non inside the housing. Note that this mod just coos the housing but the difference in noise is satisfying for me.... you can go on step further and drill a hole in the casing and grind a little aluminum so that the cooling reaches directly to the sensor...

I let the pictures speak for them selves :)

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post-28724-0-58332000-1372242310_thumb.j

post-28724-0-48502000-1372242313_thumb.j

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The cooltime is about 5min, i got down to 3 C before i shut it off... i will try to push the cooler as far as it goes when i got some more time to it... i might even change from the 0.5mm cool pad between the peltier and the camera housing, i felt that the 3.2w/mk glue that is between the peltier and the heat sink was waaaayyyy better in conductivity. I guess that will give me some extra degrees i hope :)

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That's an excellent mod - I've certainly noticed how the CMOS chips used in the ASI cameras (and other similar cameras from other makers) are prone to 'it's full of stars' levels of noise at long exposures, but the cooling really makes a substantial difference.

If you're interested, the latest version of SharpCap now includes support for reporting the sensor temperature of the ASI120MC as well as the full range of other camera controls supported by the ASI SDK.

You can find the Sharpcap beta here : http://www.sharpcap.co.uk/sharpcap/news/newbetaversionavailable

The ASI SDK can be downloaded from here : http://www.zwoptical.com/Eng/Software/index.asp

cheers,

Robin

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Hi, just wanna share the results of my latest diy project, My recently bought ASI 120 MC camera.

I fitted a 40x40mm 60w 12v peltier bought from ebay with a old AMD cpu-cooler and fan, all connected with a DC-plug as the rest of my equipment.

A little dew on the camera but non inside the housing. Note that this mod just coos the housing but the difference in noise is satisfying for me.... you can go on step further and drill a hole in the casing and grind a little aluminum so that the cooling reaches directly to the sensor...

I let the pictures speak for them selves :)

post-28724-0-79793000-1372242311_thumb.j

post-28724-0-58332000-1372242310_thumb.j

post-28724-0-48502000-1372242313_thumb.j

Hi,

That is a very effective mod. May I ask how you secured the Peltier unit to the back of the camera?

Regards,

A.G

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Between the camera and peltier there is a thermal pad without any glue or anything so i can easily remove the cooling-package, the whole package is secured with some strong O-rings.

/Daniel

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Nice mod Corpze - might want to consider some silica gel within the camera housing to reduce the risk of condensation on the PCB. You will also find that you get a much lower temprature if you can insulate the body of the camera to keep the cool in. This also helps to keep the condensation/ice of the body of the camera. I'd expect to see noise reduction of 85-90%, perhaps a little more if you can get the cmos temp down below -5C.

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Yes i am looking for some kind of insulation, that may work even better! I am also looking for a one sided thermal tape but just cant find anything besides doublesided thermal tape :-(

I have a screenshot i can upload of some wide photos later :)

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Yes that is the one... i have thougts of buying a circular heatsink also, so it fits the desing better...

Here is the screenshot from firecapture running in "meteor mode" but i think its called moving mode or something in the new beta....

post-28724-0-39891600-1372674978_thumb.j

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I had an idea similar to this a while back. If you look at where the central 1/4" socket is positioned inside the camera it would make an easy way to channel the cooling direct to the CMOS. You could simply create a threaded "cold finger" that screws into the camera housing.

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That's an excellent mod - I've certainly noticed how the CMOS chips used in the ASI cameras (and other similar cameras from other makers) are prone to 'it's full of stars' levels of noise at long exposures, but the cooling really makes a substantial difference.

If you're interested, the latest version of SharpCap now includes support for reporting the sensor temperature of the ASI120MC as well as the full range of other camera controls supported by the ASI SDK.

You can find the Sharpcap beta here : http://www.sharpcap....ersionavailable

The ASI SDK can be downloaded from here : http://www.zwoptical...tware/index.asp

Robin - can you read CMOS temperature output from the QHY5l-II mono (Aptina MT9M034). This would be really useful for dark frame comparison/validation!

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Yes i am looking for some kind of insulation, that may work even better! I am also looking for a one sided thermal tape but just cant find anything besides doublesided thermal tape :-(

I have a screenshot i can upload of some wide photos later :)

If you can source some compressed neoprene sheet 6-8mm thick is excellent - old wetsuit material is good and its easy to cut, glue and tape to make a nice snug jacket for the ASI. Otherwise a low density foam packaging built up in layers and then wrapped in electrical insultating tape works quite well.

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Robin - can you read CMOS temperature output from the QHY5l-II mono (Aptina MT9M034). This would be really useful for dark frame comparison/validation!

Hi Jake,

right now the QHY SDK doesn't provide temperature data for this camera (or the colour version). As far as I can see the chip does have a temperature readout function, so I will ask the guys at QHY to see if they can add support for this.

cheers,

Robin

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Between the camera and peltier there is a thermal pad without any glue or anything so i can easily remove the cooling-package, the whole package is secured with some strong O-rings.

/Daniel

Hi Daniel,

Many thanks for your reply. I was thinking of using thermal paste between the peltier unit and the camera housing. Do you think that this would work?

A.G

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Hi Daniel,

Many thanks for your reply. I was thinking of using thermal paste between the peltier unit and the camera housing. Do you think that this would work?

A.G

Butting in again, sorry. Thermal paste (arctic silver 5) is good @ 8.9W/mK, but quite messy - most thermal pads are much slower to transfer heat, but the Phobya XT 120 x 20 x 0.5mm Self Adhesive Thermal Pad available from http://www.specialte...-pid-14140.html - these give about 7W/mK which is not quite as good as AS5, but certainly comparable with most thermal pastes and not messy. You can peek these off and clean up the residue with some IPA, though it might react a bit and discolour the red anodised aluminium, so would recommend a test first.

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That thermal pad sounds good, the one i have now is from ebay and has somewhat crappy condictivity... 7w/mk sounds really good!

I would really avoid paste on the camera housing because that stuff goes everywhere!

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cool project! :grin:

yes thermal insulation will give you further ~5°C

also as above stated hot glue or similar on the pcb will prevent condensation!

it will also lower the "volume" of remaining air inside the camera which can condensate.

as insulation i used scraps of styrodur :rolleyes:

have this all tried on my QHY5II

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