So it does seem like this is the issue. I’ll contact QHY to see if they can address this behavior. Even with a cool down of 0 it still takes FOREVER for the temp to actually cool. SGP does not control the power. We only set the temperature. So setting a temp of -20 on my QHY11 I would expect it to eventually hit that temperature no matter how often I check that temperature. Apparently though, the QHY driver will only increase the power when we poll for the temperature. So if we never ask for the temperature the driver will never increase the TEC power to make the camera cooler. And likewise I guess it will only increase it a certain amount per poll.
We’ll decrease the poll period and I’ll also contact QHY about addressing this in a manner that doesn’t rely on the client asking for the temperature to make the TEC functional.