Dear members, I've been troubleshooting a problem with my camera for a while. The camera no longer wants to cool. at first I thought it would be up to the controller. but have now found out that it does not matter what type of control I connect the peltier module because the problem remains. now i also emailed Bill Lynch but he had no answer for me at that time. that's why I throw it here in the group. I am looking for the technical information of the Peltier unit, so that I can look for a replacement. I hope there is someone here who can help me with that. thank you in advance! Regards Simon
The problem could be in the TEC or the circuitry that runs it. What model of camera do you have? Serial number?
Hi Doug i tested the electronic circuit. and that is good. But when I test the peltier it cools down and heats up again and it smells funny... I performed this test using a separate power supply. there is also a strange smell from the peltier I have the STL 11000M SN:110594418
Sounds like you are cooking the TEC. Getting cold and hot again sounds like there's nowhere for the heat to go. Is it properly seated to the heat sink? Is the fan running? This should really go to @Bill for service.
I am looking for the technical information of the Peltier unit so that I can look for a replacement that is the only thing I need to know. I am sure the Peltier unit is done. and neet to be replaced "Sounds like you are cooking the TEC. Getting cold and hot again sounds like there's nowhere for the heat to go. Is it properly seated to the heat sink? Is the fan running?" Yes it is properly installed
I strongly recommend sending the camera in to Bill for service, rather than trying to fix this yourself. You won't be able to use the same supplier we do, as we have to order them in large quantities. A similar part is DigiKey.com part number 1487-1151-ND. We can take no responsibility whatsoever if your attempt at repair fails.
Hi Doug, It is an easy to replace part. and very accessible. and if it doesn't work, that's not a big deal. sending the camera in and having it repaired is too expensive for how old the camera is. if there was still a warranty on it, I would definitely send it back for repair. but thank you very much! now i can finally order the part. I will keep you informed if it was successful.
an update from my side. I received the tec cooler last week and installed it yesterday. and it works great. if i cool to minus 20 it uses +/- 60% power is this kind of what the camera should do? Thanks again for the help through the forum
Power applied and curent consumption depends on the ambient temperature. -20 is a reasonable target for the STL. It may run at 100% until it gets there, and then start to back off.
Hi Simon, there's no way for us to provide any further insight into this, or to know if there is further damage to the camera electronics that are impacting the results.
Thnx Bill, Do you also know if there is an overview of what the sweet spot of this camera is. Duration of subs and at what temperature. or is that something I do by trial and error?
Sorry, I don't know. I don't do astrophotography and don't have the practical experience to comment on exposure lengths. Although, I would think -20 would be sufficient temperature wise.
The QE curve for your chip is nearly identical to my KAI 2020 chip in my ST-2000 as both are part of the Kodak series at the time with 2 improvement in the series history. Your chip temperature setting varies with the ambient temperature. There is no real sweet spot as these chips change with age. I do master darks and bias frames seasonal along with the flats. I do -7C (20F) and -18C (0F) spring through fall. -18C, 25C and -35C in the colder months. I do and median combine 4-8 exposures at 1, 2, 3, 5 and 10 minutes for the masters on an non-observable cold night. There are many tutorials out there on CCD imaging. As with Ansel Adams, It is all in the processing! Joe
I usually operate mine at -20C. There's a diminishing return below -30C, additional cooling really doesnt substantially improve the dark current.
