I have discovered an possible issue with my ST-8300m camera. Long story short, the shutter behaves erratically when 13.8V is applied to the camera (this is from a PowerWerx power supply). I went through a lot of testing before I isolated this cause - eliminating the USB hub, replacing cables, changing USB ports, testing with CCDOps, changing the camera attitude, changing cooling setpoint, messing with the shutter phase. But eventually, I discovered that the voltage level is directly correlated to the issue. Prior to this winter, I always used a marine battery to power my gear, but with the acquisition of a new mount, I also switched over to using a power supply, and by default it runs at 13.8V. Before this change, I have never experienced any issue with the camera performance. FWIW, it appears that the level (at least as indicated by the display of my power supply) where the shutter works reliably 100% of the time is <= 12.7 V. Higher than that and it will becomes erratic: hanging in mid-cycle, not shutting completely, generating lots of clanking. etc. This problem is very repeatable on my setup at levels of 13+V. Ideally, I would like to be able to run at 13.8V... This is pretty standard for a 12V system and AP recommends 13.8V. My question is whether there is something about my camera that is defective? A malfunctioning regulator, perhaps? Or is 13.8 volts above the design parameters of the camera and it is not surprising that this level of voltage is causing a problem? I appreciate any input that can be provided! Best regards, Craig
Hi again, I was wondering if any SBIG folks have a thought on this... Particularly, if my camera is not being operated from the AC adapter but from a 12v power supply, would you expect it to operate normally at up to 13.8v (which I don't think is terribly unusual)? I am trying to decide if there is a problem with my particular camera or if this is outside the normal parameters of operation and not surprising? Is this the correct place to ask the question? Thanks very much for any help you can provide. Best regards, Craig
Craig, I think 13.8 is at the top end of the "hairy edge". While I'm not the Engineer that designed the camera, I feel safe saying that it was intended to run at 12VDC. If the spec says 10-14, 13.8 is kinda pushing it in my opinion. I liken it to revving your engine in the red all the time. Eventually, something is going to give. Just my 2 cents. -Bill
Bill, I appreciate your response. Coming at it from the other direction, if my camera currently operates improperly at anything over 13V, it seems that I already have something that isn't performing up to specification. While its a simple matter to adjust the power supply down a bit, today, I wonder if I should take this as a sign that something may be degrading already... and perhaps should receive attention before I count on it at a star party, for example? Thanks and regards, Craig
