Zwo Peltier cooler

[John78]

On 10/27/2017 at 15:18, cjdawson said:

I can see this being a very interesting project and I can see myself making a V1 and then modifying several times.     For my first test, I'm still going to stick with the 12706.   It'll work well enough for a proof of concept, and I'll be able to get an idea of how good/bad it is.   Once V1 is working, and if it works well enough, I can see going for dual stacked peltier is an option and achieveable too.   At that point, going for good 5v jobs should do the trick nicely.     Would be great to be able to make my uncooled camera work at -10 or -20.

To echo @Gina, I spent 3 or 4 weeks experimenting with 12706's in single and stacked configurations using both variable DC supplies and a FET PWM controller, I 3d printed a case for the camera which I neoprene lined and then I wrote a temperature control algorithm in python/sharpcap which reads the sensor temp and an arduino PWM controller.

The conclusion I reached was a 12706 is completely unsuitable for the application.  You can achieve 8-9c below ambient in a single configuration and nearly 20c below with them stacked and PWM control - it was drawing like 10 amps in the stack configuration so 120w of heat to deal from just the TEC's and useless for me as a battery powered imager.

I've ummmed an arrred about the expense of a cooled camera for months with them being ~£300 more than the un-cooled model and that I could make the cooler myself - but - at the end of the day a suitable stacked TEC is £100+, controller and faff £100+ and then it will get covered in condensation inside and out and you don't have a warranty. 

£300 isn't really bad value for what they are providing, but by all means keep experimenting

[Gina]

That was the conclusion I came to between doing my own cooling and spending the extra on a professionally designed and tested cooling system built in.  Furthermore the drivers for the cameras cover all the controls for the cooler as well as capturing images.  Getting 45 degrees cooling below ambient is very difficult indeed.  I never achieved anything like it in my experiments.

[cjdawson]

I think that's where our goals will be differing.   I'm not looking to get 45 degrees below ambiant.   The working temp is

working Temperature

-5°C—45°C

 

So, I'm looking to get my Camera to a stable -4.   The idea isn't to get perfection, it's to get better than uncooled.

[Gina]

Ah yes, you should be able to accomplish that were a single decently efficient Peltier TEC.

[1CM69]

On 10/26/2017 at 12:51, Dr_Ju_ju said:

If you've not seen it, there is an Instructable write up here: https://www.instructables.com/id/Peltier-Cooling-for-ZWO-Astro-Camera/

Thanks for sharing my instructable, hope it helps 

[cjdawson]

4 hours ago, 1CM69 said:

Thanks for sharing my instructable, hope it helps 

Yep, it was useful.   I'm going to use the neoprene insulation coat idea for sure.   Might also extend it so that the cold plate that I make is also wrapped to help it be a little bit more efficient.

[cjdawson]

definatly some good progress here.  Maybe s little more dialling in to get lower.   I’m thinking about adding another epdm gasket