); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY Dear all,
the major problem for the use of a Peltier cell with a quartz oscillator is that the cell maximum operating temperature is of the order of 80 degrees Celsius. This is due to the low melting point of the metal pairs suitable to produce the Peltier effect (reversed thermocouple). The resonator inversion temperature occurs at 70-80 degrees Celsius, depending on the cut angles. A more general problem is that a good temperature controlled oven has high thermal resistance, limited by the dissipation inside the oven. Unfortunately, the Peltier cell has low thermal resistance, which means poor isolation from the oven. This problem is made worse by the joule effect, which always go with the Peltier effect. For this reason, the temperature fluctuations of the Peltier heat sink tend to be larger than the environment fluctuations (unless you use water cooling!). Thus, the thermal fluctuations propagating through the Peltier cell tend to be an amplified version of the environment fluctuation. This phenomenon is dramatic when the Peltier cools down, and a minor problem when the Peltier cell heats up. Very best, Enrico On 13 Oct 2007, at 22:13 , Don Collie wrote: > ); SAEximRunCond expanded to false > Errors-To: [EMAIL PROTECTED] RETRY > > Has anyone concidered using a small Peltier pile to maintain the > crystal`s > temparature. I understand that these devices will heat or cool, so > it would > be possible to maintain the crystal temparature at , say, 25 degrees > celcius, over a range of ambient temparatures > [perhaps 0 to 70 degrees]. There would be several advantages in this > approach. > Cheers!,................................Don Collie jnr. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ > time-nuts > and follow the instructions there. Enrico Rubiola professor of electronics web: http://rubiola.org e-mail: [EMAIL PROTECTED] FEMTO-ST Institute 32 av. de l'Observatoire 25044 Besancon, FRANCE voice: +33(0)381.853940 (E.Rubiola) voice: +33(0)381.853999 (switchboard) fax: +33(0)381.853998 _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
