[time-nuts] GPSDO simulation tool

Magnus Danielson magnus at rubidium.dyndns.org
Wed Mar 26 15:58:05 EDT 2014

On 24/03/14 07:12, Hal Murray wrote:
> magnus at rubidium.dyndns.org said:
>> I did a temporary hack on the PID code to convert the D-term into I^2  term,
>> by integrating the integrator output. First attempt was indeed  quite
>> resonant just to show that I was in the unsafe region. Backing  down on the
>> strength of the component sure did remove much of the  resonance, but I did
>> not see any appreciable improvement in filtering  performance, so quick and
>> dirty hacking isn't sufficient, darn.
> Maybe it isn't sufficient to make a great GPSDO, but it's more than
> sufficient to point out the advantages of Tom's simulation setup.
> Thanks Tom.

Did some home-work on third-degree PLL parameters, so now I know why I 
failed, as I never tried to do it right.

One thing that Tom's simulator isn't doing is calculating the parameters 
for the PID for you, or backwards what characteristics you will get.


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