[time-nuts] Frequency referenced temperature regulator
Bob Camp
lists at rtty.us
Mon Nov 8 15:26:08 UTC 2010
Hi
Actually the biggest issue is hysteresis. That's what killed the 2804.
Bob
-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of John Ackermann N8UR
Sent: Monday, November 08, 2010 10:14 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Frequency referenced temperature regulator
Sounds like the way the HP 2804 quartz thermometer works. HP came up with a
special crystal cut that was very linear with temp, and I suspect the
hardest part of your idea might be the linearity of the tempco of your
crystal. But you could characterize that and store in a correction table.
John
On Nov 8, 2010, at 10:04 AM, "Poul-Henning Kamp" <phk at phk.freebsd.dk> 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 ?
>
> --
> Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
> phk at FreeBSD.ORG | TCP/IP since RFC 956
> FreeBSD committer | BSD since 4.3-tahoe
> Never attribute to malice what can adequately be explained by
incompetence.
>
> _______________________________________________
> 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.
_______________________________________________
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