I recently started photographing again after a long break. I bought a new telescope and set everything up. I also had to reinstall my computer. After installing all the necessary software, I encountered a problem: my camera was not being recognized. After much troubleshooting, I discovered that the SBIG software had changed from what it used to be, and I needed to ensure I was using the correct version. Now the camera works, but I'm facing a new issue where it shows the CCD temperature as -153.7, which is obviously incorrect. I hope someone can help me with this. It seems like it might be a software / driver problem?? I have the same result whit Maxim_DL and CCDOps
Thnx Bill, Do you have a diagram where I can find the contact points so that I can measure it? I have measured the one at the back, which is for ambient temperature, and it seems to be working. Do you also have a part number that I could potentially replace it with?" Simon
The thermistor is physically located underneath the ccd, underneath the thermal tape that the ccd sits atop of. Although I know that there is one, I can't think of another spot to measure it off the top of my head. Considering that you'll have to remove the ccd in order to change it, you may as well measure it there. My guess is that it is probably corroded and there will be no need for any measurement, you'll be able to see it.
Hi Bill, Sorry for the late response, but I was in the hospital for my shoulder. Everything is much better now. I have removed the sensor. It was a delicate job, but I managed it. However, I can't see what type it is. I want to order one for testing. Could you tell me which one I need to order? I currently measure 2.4 K Ohm at room temperature. When I heat it, the value decreases. But when I connect the camera now, it shows +99°C instead of -159°C. I once had it show the correct value when I shook the sensor. regards Simon
If memory serves, 3K ohms at room temperature is what we used. I don't know what the part number was. -Bill
I looked up the part number, but it isn't very helpful because the part is long obsolete and there's no information available on it.
3k sounds right. If I connect 3 x 500 ohm resistors in series, I get to 67°C, but it would be nice if I could get the exact value. Also, maybe the type, for example, thermocouples, resistance thermometers, and thermistors.
If you can find out if it is a positive or negative coefficient thermistor then any thermistor that physically will fit and works off the supplied voltage would probably work even if it isn't reading an accurate temperature. While knowing the accurate temperature is nice the main thing is keeping the temperature constant and being able to replicate that temperature for dark frames is what is important. If its 50 degrees off so what as long as it is consistent.
It is a Quality Thermistor Inc. part number QT1206-T-302F. That is all the information I have available. I think you'll find Google is not very helpful.
I thought the same myself. Against my better judgment, I ordered the following NTC resistor: the NJ28MA0302F. I've been experimenting with resistors, and 3K should come very close. It only costs €1.50, and from there I can continue testing. Thank you for your valuable information; it is very helpful. We need to help each other to keep those old cameras running!
After some Google searches, I managed to find something. I hope someone else can also benefit from this
Okay so you need a negative temperature coefficient, Curve T, 3000 ohms at 25C. I'm sure you can find a suitable substitute out there. Check out DigiKey.com as a good starting point. This thermistor was used for the ST-7 series as well as the STL series.
