Hi
One of the bigger unknowns in all this is how tight your control point needs
to be held
in order that your crystal only sees 0.1C. So far we have sort of assumed that
the
control point and the crystal see the same thing. That’s never the case.
If the outside temperature goes from -30 to +
albertson.ch...@gmail.com said:
> I say "effective" because we can dither the low order bits to gain maybe 6
> effective bits form 4 real bits (we can filter the switching noise from a
> low frequency dither)
It's hard to filter low frequencies and the more bits you gain by dithering
the lower
I am looking for a spare Alubos ABP 800 series enclosure (115mm length),
mounting flanges are not required.
Some time-nuts readers noted in April, they had "extra" Alubos 800 enclosures
(Bopla).
The TAPR GPS Experimenters kit (Synergy SynPaQ/E) used a custom Alubos case --
115mm in length with mo
FCT Electronics catalog pages.
http://www.mouser.com/ds/2/276/Zubehoer_DSub_Steckverbinder-472747.pdf
NOTE: European mfg. (like FCT) sell both 4-40 (English) and M3 (metric
hardware).
Purchase correct size.
In addition to Sliding latch, you will also find plastic and metal dust caps.
That may be
Jerry -
I noted that no one answered your query from April.
D-subminiature connectors were introduced by Cannon in 1952.
https://en.m.wikipedia.org/wiki/D-subminiature
That "sliding lock" (or latch) method for attachment was common with AUI
connections (15-pin size) for the original Ethernet (1
Hi
> On Jun 10, 2017, at 5:15 PM, Poul-Henning Kamp wrote:
>
>
> In message , Bob kb8tq writes:
>
>> If you want the controller noise to *not* be the limiting factor at an ADEV
>> floor of 1x10^-12,
>> that drives you to a noise floor of < 0.1 mK. You can then work through the
>> va
In message , Bob kb8tq writes:
>If you want the controller noise to *not* be the limiting factor at an ADEV
>floor of 1x10^-12,
>that drives you to a noise floor of < 0.1 mK. You can then work through the
>various thermal
>gains to come up with a level of DAC bits that you need. You c
Hi
> On Jun 10, 2017, at 4:10 PM, Chris Albertson
> wrote:
>
> On Sat, Jun 10, 2017 at 12:59 PM, Poul-Henning Kamp
> wrote:
>
>>
>>
>> Delta-Sigma strategies for spreading the noise-spectrum are
>> interesting, but will not save you if the required heater power
>> ends up being a sm
In message <73a71ef4-eb76-4965-b3d5-53f9dd5bf...@n1k.org>, Bob kb8tq writes:
>If we want to hold the oven at some temperature +/- 0.1 C, the control loop
>needs to go from full on to full off over that range.
...ehhh, what ?
>You will map (somehow) the full range of the output into a 0
Hi,
As a side comment. I've seen an OCXO misbehave such that it was
bang-bang regulating. For a short while it was heating up and then the
crystal was cooling down slowly until the heater was turned on again,
shortly. The effect being that the temperature of the crystal was
essentially a saw-
Hi
The next issue is that “noise” has a pretty broad definition in this case.
If you are looking at set point, it also would include temperature drift and
aging. Neither one seem to show up on the standard MCU ADC data sheets :)
It can even be a bit difficult to find them on some (but certainly n
Hi,
On 06/10/2017 09:59 PM, Poul-Henning Kamp wrote:
In message <017ac7d5-751b-4084-a3b3-e5132509c...@n1k.org>, Bob kb8tq writes:
You may well use a custom set of control parameters for the warmup phase.
The easiest way to avoid overshoot is to use a properly damped PI(D),
which is
On Sat, Jun 10, 2017 at 12:59 PM, Poul-Henning Kamp
wrote:
>
>
> Delta-Sigma strategies for spreading the noise-spectrum are
> interesting, but will not save you if the required heater power
> ends up being a small rational fraction (1/2, 1/3, 1/4 ...) of the
> full scale.
>
How many ou
In message <017ac7d5-751b-4084-a3b3-e5132509c...@n1k.org>, Bob kb8tq writes:
>You may well use a custom set of control parameters for the warmup phase.
The easiest way to avoid overshoot is to use a properly damped PI(D),
which is _exactly_ the same thing you want once you are out of the
On Sat, Jun 10, 2017 at 11:33 AM, Magnus Danielson <
mag...@rubidium.dyndns.org> wrote:
> Hi,
>
> I was about to make this very point myself. The resolution of the ADC
> needs to be higher than the limit you try to achieve. There is several ways
> to reason about it, but one is that the system is
Hi
At least in my experience, a properly functioning OCXO will rarely (if ever) be
outside +/- 1 degree of the
set point when in full PID (integrator enabled) mode. You may well use a custom
set of control parameters
for the warmup phase. You might even use a non-PID based control (shut off all
Hi,
Very good point Poul-Henning, very good point.
The mux is there, we don't need the resolution far out, and with only a
little though code-wise and hardware wise we get the best of resolution
and range where we need it.
Cheers,
Magnus
On 06/10/2017 09:06 PM, Poul-Henning Kamp wrote:
In message <3897c09a-d76c-474c-8907-9ea25f8c3...@n1k.org>, Bob kb8tq writes:
>The “limited range” part of it is why the op-amp makes so much
>sense. If the ADC can “see” +/-10C that’s way more than will ever be useful.
Most uC's have a pile of mux'ed ADC inputs, so do all of the above:
Hi,
Indeed. I prefer to have margins and dynamics, as it makes it easier.
Cutting in on that will require more work to ensure it works, hence you
have to work more to save money in order to maintain stable operations.
Cheers,
Magnus
On 06/10/2017 08:50 PM, Bob kb8tq wrote:
Hi
The “limited
Hi
The “limited range” part of it is why the op-amp makes so much sense. If the
ADC can “see” +/-10C that’s
way more than will ever be useful. You could make a pretty good case for -5/ +1
C as being way more than
you will ever use. The only real issue with the +1 is ok argument is when you
off
Hi,
I was about to make this very point myself. The resolution of the ADC
needs to be higher than the limit you try to achieve. There is several
ways to reason about it, but one is that the system is a bit slugish you
want to have higher resolution in order to react of changes before they
ove
Of all the GPS devices that Lady Heather supports, only three send the time
code before the 1PPS. The last byte of the time code message arrives the
indicated number of milliseconds from the PPS pulse:
Z38xx and related devices (including Lucent KS): -965 ms
Lucent RFTG-m: -663 ms
Trimble SV6
Hi,
Many modern counters use this trick too, but much more gift-wrapped, in
that they themselves shift their oscillator to measure the shift and
hence figure out which overtone is being used and hence derive the
correct frequency. With HP5245 etc you had to do a little work on your
own for po
Hi
You do work pretty hard to turn the metal can into a getter. The other issue is
that
the adsorption and desorption rates are quite different. Once you get the
“stuff”
into a layer state, it takes a long time to get it back out. Much better to not
have it
there in the first place.
If the
24 matches
Mail list logo
