[time-nuts] Electronically Disciplined Mechanical

Alexander Pummer alexpcs at ieee.org
Tue Jun 9 17:46:05 EDT 2015

Hi Bert
at the Neu Tecknicumbuchs, /Buchs/, Switzerland somebody made a "diplom 
work" a quite-few years ego very similar clock, the pendulum was 
synchronized to the 75kHz accurate time transmitter, you may could find 
out more about it at  the Neu Tecknicumbuchs, /Buchs/, Switzerland

On 6/9/2015 7:26 AM, Bert, VE2ZAZ wrote:
> Hi Tom,
> Thanks a lot for your feedback and for having been an inspiration for this project.
> With a temperature-stabilized setup, it is now concievable to run the system at a constant impulse duration. This would not have been possible without temperature control, as the pendulum arm length varied too much to maintain an oscillation using a constant impulse width. I tried this overnight at a couple of occasions with an aluminium arm, only to find the pendulum dead in the morning...  :-o
> So in order to achieve this, I will add a serial command to keep the last impulse duration. That command would be sent once the system is fully stabilized.
> Thanks,
> Bert, VE2ZAZ
> Message: 8
> Date: Mon, 8 Jun 2015 14:46:50 -0700
> From: "Tom Van Baak" <tvb at LeapSecond.com>
> To: "Discussion of precise time and frequency measurement"
>      <time-nuts at febo.com>
> Subject: Re: [time-nuts] Electronically Disciplined Mechanical
>      Pendulum
> Message-ID: <ED4D31631FC440A19A71631386F46143 at pc52>
> Content-Type: text/plain;    charset="utf-8"
> Hi Bert,
> Thanks for posting that project. What a wonderful combination of electronic and mechanical timing, of design and measurement, of hardware and software, of PICs and Python.
> One side experiment that would be interesting is to collect a couple of days of data using a fixed drive and then compare that with the same number of days using your adaptive FLL drive. The resulting phase or rate or ADEV plots would be amazing.
> /tvb
> ----- Original Message -----
> From: "Bert, VE2ZAZ" <ve2zaz at yahoo.ca>
> To: <time-nuts at febo.com>
> Sent: Monday, June 08, 2015 10:11 AM
> Subject: [time-nuts] Electronically Disciplined Mechanical Pendulum
>> Greetings,
>> I just want to let those who are curious about disciplining a mechanical pendulum that I have pretty much wrapped up playing with a 1m-long pendulum, which I control with PIC micro firmware and try to mainain at a constant temperature. Accuracy for 20-second averaging is typically better than 1 ppm. I have documented my work here:
>> On my website ( http://ve2zaz.net/Pendulum_Ctl/Pendulum_Ctl.htm ),
>> On Youtube ( https://www.youtube.com/watch?v=7NdGX4A8W88 )
>> Thanks,
>> Bert, VE2ZAZ
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