Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 14, 2014 0:18:34 GMT
I ran an experiment today with an off the shelf 40 MM Peltier Cooler with Fan. I mounted on the bottom side of the Mallin Cam Jr Pro (EXHad CCD). This was not a life or death issue, just wanted to see what would happen. I used ty wrap's to mount without thermal pad or thermal compound (I will some order some today). Surprise both Perceived Quality and Hot Pix Count (using Miloslick Hot Pix Removal Tool) were improved. The data... Test 1 Cooler On, AGC 3, 30 Sec Exposure for 15 minutes Garage Temp 81.1 F, Cam Temp 60.4 F, Peltier Heat Sink Temp 92.0 F Hot Pix Count 91 Test 2 Cooler Off, AGC 3, 30 Sec Exposure for 15 minutes Garage Temp 81.3 F, Cam Temp 92.0 F, Peltier Heat Sink Temp 83.0 F Hot Pix Count 133 Test 3 ... Repeat Test 1 Same results 91 hot Pix...amazing... Overall Results....Less Hot Pics (about 33%) and Many Fewer Warm Pics (Background is Darker). I will continue to experiment, much more room for improvement on mounting and thermal transfer into the Cam. Pics at www.flickr.com/photos/skywatch_utah/sets/72157644830405922/
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 14, 2014 2:22:37 GMT
interesting thread. Suscribed
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 14, 2014 7:03:55 GMT
That sounds like a worthwhile simple mod Pat, and presumably will be better when the thermal pad and paste is added. I will look into this for my Pro.
|
|
|
Post by Dragon Man on Jun 14, 2014 11:24:34 GMT
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 14, 2014 12:04:07 GMT
Pat can you post what TEC you are using? As in controller. Thanks
Hemmi
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 15, 2014 16:52:45 GMT
I ran an experiment today with an off the shelf 40 MM Peltier Cooler with Fan. I mounted on the bottom side of the Mallin Cam Jr Pro (EXHad CCD). This was not a life or death issue, just wanted to see what would happen. I used ty wrap's to mount without thermal pad or thermal compound (I will some order some today). Surprise both Perceived Quality and Hot Pix Count (using Miloslick Hot Pix Removal Tool) were improved. The data... Test 1 Cooler On, AGC 3, 30 Sec Exposure for 15 minutes Garage Temp 81.1 F, Cam Temp 60.4 F, Peltier Heat Sink Temp 92.0 F Hot Pix Count 91 Test 2 Cooler Off, AGC 3, 30 Sec Exposure for 15 minutes Garage Temp 81.3 F, Cam Temp 92.0 F, Peltier Heat Sink Temp 83.0 F Hot Pix Count 133 Test 3 ... Repeat Test 1 Same results 91 hot Pix...amazing... Overall Results....Less Hot Pics (about 33%) and Many Fewer Warm Pics (Background is Darker). I will continue to experiment, much more room for improvement on mounting and thermal transfer into the Cam. Pics at www.flickr.com/photos/skywatch_utah/sets/72157644830405922/AN IMPORTANT UPDATE I believe I have DAMAGED my Jr Pro Cam with the cooling experiment. I had Star Smear last night while making some Alignment runs. I rechecked this AM in a Dark Frame Cooling On and Off and have verified something has happened. DO NOT TRY THIS WITH YOUR JR PRO!!! Thanks Patrick...New Pics #4 and #5 www.flickr.com/photos/skywatch_utah/sets/72157644830405922/
|
|
|
Post by johnno on Jun 15, 2014 21:09:03 GMT
Pat it's strange on how this could of happened as you was only cooling the casing, have you checked inside the camera to see if any dew on any of the components.
Looking at your cam temp its not if you went down into the minus's, it's was well above freezing temperature.
Did you use a probe in the camera or just took a reading of the casing with the laser gun
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 15, 2014 21:52:10 GMT
All I'm seeing is diagonal interferance all over the images. Are all the power cables out of the way?
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 15, 2014 21:53:17 GMT
Just LASER, but NO frost visible on anything (still was warm here). Possible condensation on CCA's. Reset Cam from Buttons per Chris A (photo #6). A bit better. Will not know for sure till I get a star field to look at.
Clouds for a few days, so I will continue to look at dark frames to see it it get back to normal and continue heating cycles to make sure it is dried out. Temp was about 60 F and Humidity was about 45% (which is high for this location). Could be just a bit of water on the inside, but no sign of water on the outside of the case (which is the coldest part of the cam). Thanks for the info. Patrick
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 15, 2014 21:55:52 GMT
All I'm seeing is diagonal interferance all over the images. Are all the power cables out of the way? Running on Battery, got a bit better when I reset the cam. That has been a problem for some time (dating back 8 months). Normally goes away when I have an object in view. Do not know for sure, but another issue to look at. Will continue to trouble shoot. Zig Zag may be from the video converter. I have a 7" LCD here in a day or two, so I can look at the cam output directly (not thru the converter, computer display. May open the cam after I check everything else. Thanks Patrick
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 15, 2014 22:24:25 GMT
Maybe you could try mounting the cooler on a substutute camera, or a small cam sized tin. run the cooler for a while, then open the tin and see if there is anything going on inside, like frost or moisture gathering.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 15, 2014 22:35:45 GMT
Maybe you could try mounting the cooler on a substutute camera, or a small cam sized tin. run the cooler for a while, then open the tin and see if there is anything going on inside, like frost or moisture gathering. Excellent thought, I will give that a try. Thanks Patrick
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 15, 2014 23:22:40 GMT
All I'm seeing is diagonal interferance all over the images. Are all the power cables out of the way? Running on Battery, got a bit better when I reset the cam. That has been a problem for some time (dating back 8 months). Normally goes away when I have an object in view. Do not know for sure, but another issue to look at. Will continue to trouble shoot. Zig Zag may be from the video converter. I have a 7" LCD here in a day or two, so I can look at the cam output directly (not thru the converter, computer display. May open the cam after I check everything else. Thanks Patrick UPDATE: Ran Composite from the cam to my 22" LCD display and Milo and Converter on the 26" LCD Display. Composite has NO ZIG ZAG, Milo / Converter HAS ZIG ZAG. Not a Cam issue. Patrick
|
|
|
Post by johnno on Jun 16, 2014 0:10:45 GMT
That's a good result, cheaper to replace the other items,
|
|
|
Post by Dragon Man on Jun 16, 2014 5:24:25 GMT
Converter? Pat, do you mean your Video Grabber?
Video Grabbers are well known to cause all sorts of defects and artifacts. Using a good quality Video Grabber usually fixes the problem.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 17, 2014 2:32:13 GMT
Update....Dried Cam but running for a few hours. Took new Dark Frames. Looks like all back to Normal before cooling. Suspect Dew on Circuit Card/ Cards. Need to Conformal Coat before I try cooling again. Updated Pics 7, 8, 9. Thanks Patrick www.flickr.com/photos/skywatch_utah/sets/72157644830405922/
|
|
|
Post by Dragon Man on Jun 17, 2014 5:21:54 GMT
Good News Pat.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 17, 2014 5:50:16 GMT
Phew, bet you are relieved Pat. Thats good news.
|
|
|
Post by johnno on Jun 17, 2014 9:42:22 GMT
Good news Pat, just shows that there is a bit more to it than just fitting a peltier, I wonder if you had put a non conductive coating over the circuitry it might of helped
|
|