[time-nuts] Is a crystal likely to change frequency by 3% ?

Alexander Pummer alexpcs at ieee.org
Sat Sep 13 08:44:18 EDT 2014



there is only one magnet, which drives the fastest moving arm -- the 
pointer for the seconds -- the other arms are connected via gears, by 
the way that case with the weak periodically recovering battery is an 
observed one, I connected a paper chart recorder to the clock  and 
recorded the battery voltage change and the driver pulses of the magnet 
-- the recorder was not able to follow the individual pulses, but the 
envelope
73
Alex


  On 9/13/2014 5:08 AM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:
> On 13 Sep 2014 01:23, "Alexander Pummer" <alexpcs at ieee.org> wrote:
>> just open the box, look for the wires which going to the magnet which
> drives the minute hand and measure the period time -- not the frequency, it
> is to low
>> yes analog quarz clock slows down as the battery get old,  you will be
> surprised, that the driver pulse's period time dos not change, but
> sometimes the divider chain or the mechanic skips a pulse, as the battery
> voltage drops further suddenly the clock mechanic or the electronic will
> stop working, takes less current so the battery recovers a bit, because the
> magnet did not used power for a while, and will run again for a while, the
> pause between two run time will be larger and larger so the clock looks
> like going slower
>> 73
>> Alex
> So if it the mechanics skips a pulse,  one really needs some method of
> measuring the position of the hands and recording that.
>
> In any case, the explanation you give is different to Dave McGuire.
>
> Maybe the second hand is more likely to slip if trying to fight gravity
> (between 30 and 0 seconds) and less likely when gravity helps (between 0
> and 30 seconds)
>
> It would be interesting to see a detailed study of this.
>
> Dave
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.



More information about the time-nuts mailing list