John & Don, Thanks for your thoughts and ideas. Limited availability of different sizes and shapes of vacuum bottle is a problem, but I'll be keeping your ideas in mind when I make my selection. Ed On 7/30/2011 6:29 PM, J. Forster wrote:
[snip] That will give you a static match, not necessarily a dynamic match. Consider if you filled the Dewar with mercury. Certainly a thermos of mercury would have much different thermal behaviour than an oscillator, but I don't have a thermos of mercury. I think what you're getting at is whether my replacement thermal system has similar dynamic thermal characteristics to the original. Yes. You should, IMO, try to match the heat leak and the thermal inertia to keep the loop dynamics the same. Unfortunately, there's no way for me to test that since the original is smashed. Static comparison is all I can do. You can try to keep the Dewar internals as near as possible to the original. That and the leakage should roughly do it. Best, -John ============= Of course, if you go too far in reducing the current, the oven could overheat. The oscillator includes a precision thermistor to monitor the temperature of the oven to prevent this. Any comments? Ed Good luck. -John Thanks. This is turning into an interesting project. Ed _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
