From: Dave Goodyear <dave@kb2networks.com>

Date: August 2, 2012 7:44:18 PM MDT

To: "Astro_IIDC@yahoogroups.com" <Astro_IIDC@yahoogroups.com>

Subject: RE: [Astro_IIDC] Cooling Fins

Hi Guys.  Seeing Milton’s cooler made me cool my GrassHopper Express 2.8mp.  During solar my camera would easily hit 135-140F.  With the dual cooler my camera now shows through AstroIIDC as around 74.2F.  I just finished this mod yesterday.  Just like Milton, different voltages and amps vary the cooling.  I have found that 8v is the ideal voltage for the dual coolers.  @12v it pulls 5 amps  @14 it pulls 6amps.  At 8volts its pulls around 2.5/3 amps.  One amp for the fans.

Now I do know that the coolers are cooling the case way below ambient temp and the dew point.  I live next to the ocean in southern California and my humidity is always very high.  Especially at night.  The case will start to form a lot of water.  My plan is to either wrap the camera more, add a timing circuit, or seal the camera in a box except for the nosepiece and fill with Scuba air (Scuba air’s dew point is -56F)  Scuba air works very well when the front glass of a camera dews up.  I can use a ccd chamber sealer and seal the front of the CCD with scuba air and the ccd sealer.

I was able to pick up ten 30mm x 30mm peltier coolers with heat sinks on ebay for $20 and six maglev 40mm x 40mm x 28mm fans for $15. I use Anderson Powerpoles exclusively with my tele power as well as other areas so I have extra “poles”.

The Reflective insulation was something I added a little bit ago without testing.

Here are a few links to pics.  The second one is not in focus all that well:

http://ns1.kb2networks.com/GHXPeltier1.jpg

http://ns1.kb2networks.com/GHXPeltier2.jpg  

Dave Goodyear

KB2 Networks Inc.

214 Main St. #318                            

El Segundo, CA  90245

310-933-2436

From: Astro_IIDC@yahoogroups.com [mailto:Astro_IIDC@yahoogroups.com] On Behalf Of Milton Aupperle
Sent: Thursday, August 02, 2012 3:26 PM
To: Astro_IIDC@yahoogroups.com
Subject: Re: [Astro_IIDC] Cooling Fins

Hi Ray;

On 2-Aug-12, at 3:08 PM, Ray Byrne wrote:

>
>
> Hi Milton,
>
> I was under the impression that cooling a camera was a necessary
> thing to do only for DSO imaging. Both my DMK and PGR camera get
> quite hot but I'm using them for Solar/Lunar/Planetary only. Is it a
> noise issue and would cooling help reduce noise in planetary imaging?

It doesn't make much difference for noise that I have been able to
determine. I have measured the intra frame noise levels for high speed
(30+ fps) at cool (+5°C) and high 40°C+ and their is no appreciable
difference.

For long exposure it sure does make a difference and greatly reduces
the number of Hot Pixels too.

The main reason for cooling electronics is it prolongs the life span
of the camera - especially when operating in the sun shine.

HTH..

Milton Aupperle