[time-nuts] Frequency referenced temperature regulator

Bob Camp lists at rtty.us
Mon Nov 8 23:51:25 UTC 2010


Hi

You can do very much the same thing by getting an SC to run on both the B and C modes at the same time.

Bob

On Nov 8, 2010, at 6:04 PM, Magnus Danielson wrote:

> Poul-Henning,
> 
> On 11/08/2010 04:04 PM, Poul-Henning Kamp wrote:
>> 
>> I'm contemplating building a small temperature control enclosure for
>> testing various electronics.
>> 
>> I have a handful of peltiers suitable for the purpose, and was
>> pondering the right control mechanism.
>> 
>> Most people would reach for a NTC, put it in a wien-brige etc etc.
>> 
>> But since I happen to have access to much more stable frequencies
>> than voltages, I thought of a different way:
>> 
>> 1. Mount a X-tal-osc with really lousy tempco inside the enclosure.
>> 
>> 2. Compare its output to a stable reference frequency.
>> 
>> 3. Use the output of the phase comparator to drive the Peltier.
>> 
>> It is basically a PLL where temperature is used as EFC...
>> 
>> Has anybody tried that ?
>> 
> 
> Have a look at "microprocessor compensated crystal oscillators". It runs the oscillator in both basic and third overtone at the same time. By measuring the beat frequency between the modes, the temperature can be measured.
> 
> See the John Vig presentation
> http://www.am1.us/Papers/U11625 VIG-TUTORIAL.PDF
> starting at page 43.
> 
> I see no reason why it could not be used to stabilize the temperature.
> 
> Cheers,
> Magnus
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.




More information about the time-nuts mailing list