Quote:
Originally Posted by gregbradley
....
Jase I would be going for lower temps with your D09. It has powerful cooling. The only thing that may get in your road is the firmware. It is designed to work out its own setpoint. So you could tell it to go to -40C and it should but the firmware may kick in if the % power is beyond its programmed setting (80%?? - ask Apogee what they set it to).
My U16M would do that occassionally which can upset an imaging run if you are not expecting it. I suppose though it will happen in the first 35 minutes. That's when I asked it to achieve too high a cooling number but my one was the standard cooling package not the D09. I never saw a voltage warning either. But then the D09 no doubt draws a lot more power. Perhaps it is a firmware issue rather than an actual voltage issue.
....
Greg.
|
You're right Greg, I should be pushing the camera harder. A set point of -40c all year round is certainly achievable with the D9F cooling, undoubtedly lower in winter. The voltage problem isn't firmware related. Apogee would have advised if it were given the camera came back from a routine service a few months ago. I suspect it is power related. The power supply I have is not Apogee certified, but a third party of similar output. The original fried a while ago. I think I'll place an order for another original to see if this alters the situation.
===
Richard,
Thanks a lot for your comprehensive input and opinion on the CCD chamber seals. Not doubted your knowledge as I know you work with these CCD's all day long, but there are a lot of hypothetical and probabilities as one could expect. Its so darn hard to get a clear statement from any manufacture on the topic...and I guess...who cares when they offer lifetime warranty on the chamber seal anyway. I think you nailed it in your opening two sentences, though I'm still intrigued to the logic and reasoning of others. I agree with your statement regarding a camera powered up will age faster. Though you can apply the same logic to owning a car. A car you leave in the garage will last longer than the one your drive around. I've had to replace a few fans, no different to tires on a car.
Quote:
Originally Posted by ptc
It is certainly possible to design a camera that can be cooled separately from powering up the electronics, so in theory it should be possible to leave one cooled down but not under bias, so as to minimize the risk, but none of the amateur Astrocams I have seen work that way.
|
What is the reasoning manufacturers haven't done this? Manufacturers make the assumption that ALL users cool and turn off their camera each session?
Quote:
Originally Posted by ptc
One thing is certain; the fans aren't arranged in such a way to efficiently shed heat from the heatsink in the Uxxx designs: the fans' airflow stagnates at the bottom of the heatsink in the one I examined.
|
Yes, I can understand that. You are obviously referring to the non-D9F configuration of the Uxxx designs. At least I hope you are, as you would also be implying the FLI PL isn't efficient. The Apogee D9F configuration is near identical as the FLI PL with the three fans blowing air through the heat sink. The only difference being the Apogee D9 has a larger heat sink than the FLI PL in both depth and width, but the heat sink/air flow design is fundamentally the same.
Quote:
Originally Posted by ptc
sounds like you have a problem with the design of the camera or power supply.
there's no good reason that a properly designed camera and or power supply cannot run at full load and behave properly.
what are you using Jase?
|
Power supply. See note above to Greg's response. I'll order an "official" replacement power supply from Apogee. What I've got works, but there is no way I could operate at 95% cooling power with the current supply. I pushed the camera last night and achieved 48C below ambient but MaximDL was reporting 10.9V UNDERVOLTAGE. I've got a lab report for the camera that indicates it was tested out as 62C below ambient so I'm assured its not the camera...time to get ordering.