On 12/21/20 5:59 PM, Gerhard Hoffmann wrote:
Both agree that ripple > 1 KHz is harmless. But then the current
delivered
to the TEC is quite large usually - and It's a different question if
you want such
large and dirty currents on your table or in your device.
Yes.. we were testing a
A properly-tuned PID system does not cycle!
Dana
On Mon, Dec 21, 2020 at 6:49 PM Bob kb8tq wrote:
> Hi
>
> Finding a data sheet on a TEC that goes past *very* basic stuff is
> essentially
> impossible. The bottom line is that the people who make them very much
> want to sell them to you.
Hi Bob,
Sure, but I think some of these requirements will be met for fairly
cheap devices soon enough. Another aspect we also discussed is that
while a module on its own may not do all the things needed to meet a
level, if it has sufficient of capabilities to support additional checks
and then
Am 22.12.20 um 00:43 schrieb Hal Murray:
[Old mail, context is TECs] bruce.griffi...@xtra.co.nz said:
If the drive current ripple is too high fatigue failure from cyclic
thermomechanical stress can be significant.
Do good data sheets say anything about that? Is there a frequency term
in
Hi
Well, we’re not talking about $9 parts here. Typical prices in the $500 to
$2,000 in
quantity would be a better description. That said, the OEM’s normally saw the
field
upgrade process as a bigger risk than not getting involved in it …..
Bob
> On Dec 21, 2020, at 7:51 PM, Magnus Danielson
Hi Bob,
Yes, there is even receivers with no know way of upgrade in the field.
But this framework was not meant to make all receivers meet the
requirements, rather the opposite, the unofficial class of level 0 is
most of those receivers. If level 1 or higher is needed for critical
infrastructure
Original source about TEC lifetime reduction when the TEC ripple cureent is
high:
https://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1991-02.pdf
Page 74
I suspect that someone there may have been bitten by the short TEC life
experienced without the LC filter.
Although they used relatively small
Hi
Finding a data sheet on a TEC that goes past *very* basic stuff is essentially
impossible. The bottom line is that the people who make them very much
want to sell them to you. Finding information in those data sheets that suggest
problems … not so much.
The problem is (mainly) physical.
[Old mail, context is TECs]
bruce.griffi...@xtra.co.nz said:
> If the drive current ripple is too high fatigue failure from cyclic
> thermomechanical stress can be significant.
Do good data sheets say anything about that?
Is there a frequency term in there? Can I use PWM, which is as much
Hi
I would guess that out of say 100 OEM’s using a GPSDO, at least 99 of them had
*major* concerns about field upgrades. Their take was that supporting them had
always turned into a disaster. No matter how clear the instructions, a
significant
number of systems went down / stayed down while
Hello;
I have a TD-1251/U USAF version of the FE-5440A Master clock. I have a
photocopy of the manual however there are four errors:
- Page 8-7 Fig 8-2 Sheet 2 of 2
- Page 8-31 Fig 8-10 3 of 3
- Page 8-69 Fig 8-22
- Page 8-75 Fig 8-24 Sheet 2 of 3
At a bare minimum I'd like even photos of page
Hi,
On 2020-12-21 09:02, Poul-Henning Kamp wrote:
>
> Bob kb8tq writes:
>
>> I have seen cases of “goes away until power cycled”. I have not seen any
>> cases of
>> “goes away forever” other than the obvious ( = feed it an insane almanac
>> that prevents
>> if from ever locking up ).
Bob kb8tq writes:
> I have seen cases of “goes away until power cycled”. I have not seen any
> cases of
> “goes away forever” other than the obvious ( = feed it an insane almanac
> that prevents
> if from ever locking up ). Even with that said, I have not seen an example ot
> that
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