[time-nuts] Thunderbolt mounting

[Eric Garner]

Mike:

Lady Heather implements a PID temp control feature using the  "TT" command.

from lady heather's heather.cpp file:

//                      - Added ability to actively stabilize the device
//                        temperature. (/TT=degrees or TT command line option).
//                        Uses the serial port RTS and DTR lines.  RTS is the
//                        temperature controller enable (+12=off, -12=on)
//                        DTR is the heat (-12V) / cool (+12V) line.  Simple
//                        implementation:  Isolate tbolt in a box,  set control
//                        temperature below typical unit operating temp and
//                        above normal room temp,  when unit signals COOL turn
//                        on fan to move room air into the box.  You want the
//                        fan to move enough air to cool the unit,  but not so
//                        much air that the temperature drops by more than 0.01C
//                        per second.  The indicator of too much airflow is a
//                        temperature curve that spikes down around 0.1C several
//                        times per minute.  Too little airflow shows up as a
//                        curve that oscillates around 0.25C about set
point over
//                        a couple of minutes.  Good airflow should show a
//                        temperature curve stable to with 0.01C with
a period of
//                        between 1 and 3 minutes.   Generally you do not want
//                        the fan to blow directly on the unit (mine
is surrounded
//                        by foam).  You want to gently move air through the
//                        box.  It can help to include a large thermal mass in
//                        the box (I use a 2kg scale weight).


-Eric


On Wed, Jul 11, 2012 at 7:00 PM, Mike S <mikes at flatsurface.com> wrote:
> On 7/11/2012 8:15 PM, Chris Wilson wrote:
>>
>> Does anyone know if there's a means to log max and min temps for these
>> things? I was going to make a crude box for mine out of 2 inch cavity wall
>> insulation hard foam,
>
>
> The TB reports it's own temperature. Lady Heather will track it.
>
> I'm surprised no one has mounted one to a Peltier cooler, and stabilized the
> temp with PID control, based on the self-reported temp. Why not run it
> cooler than ambient? I'd assume a simple microcontroller could handle the
> task, but don't have any deep PID control knowledge myself.
>
>
>
>
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-- 
--Eric
_________________________________________
Eric Garner