Chris I am not sure if you want to measure temperature or control a fan. To measure there are many options depending on how much money you want to spend. To control I suggest either a LM 335 or a NTC resistor. I have worked extensively with both and for measuring I have now downsized to a YSI. Used to have a HP XTAL thermometer. Spend a lot of time and money on temperature control on Rb's and OCXO's all part of GPSDO's and have come to the conclusion on OCXO's a combination of thermal Isolation and thermal mass is the best solution and on Rb's fans. Spend a year playing with concepts on the FE5680 with all kind of fans and heat sinks and aluminum shapes till it hit me the answer was right in front of me. In my opinion a fan/heat pipe out of an old laptop is the cheapest and best solution, low cost, low noise, no special assemblies and easy to control. Use an aluminum plate as the interface or use the bottom plate directly and use one of the bottom screws to hold your sensor it is internally directly tied to the spine of the Rb. Wide variety available on ebay under CPU fan. Bert Kehren In a message dated 4/23/2014 10:38:11 P.M. Eastern Daylight Time, [email protected] writes:
I have both an OCXO and an FE-5680 Rb oscillator and I'd like to track their temperatures. What is the best why to measure? Maybe each has a different best method The OCXO is just a small steel can. Is measuring the steel can temperature the best why to go. Epoxy some kind of sensor to it? The Rb is mounded to a large heat sink and there is a fan. I want to control the fan so as to keep the Rb temperature constant. In both cases I tried using TMP36 three terminal sensors and just got noise. The reported temperature was up and down more than 2C. The fan controller just chases noise. BTW the fan based temperature control is effective. The FE5680 gets very warm in it's box but if I give the 12V fan even 8 volts the heat sink quickly cools. I want to throttle the fan to keep the Rb at constant temperature but the temperature data I'm getting is not very good. The problem I think is that any sensor I have is on the outside of the oscillator and is effected by cooling air What are others doing? What's the best kind of sensor. -- Chris Albertson Redondo Beach, California _______________________________________________ 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. _______________________________________________ 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.
