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

Dr. David Kirkby (Kirkby Microwave Ltd) drkirkby at kirkbymicrowave.co.uk
Sat Sep 13 08:08:02 EDT 2014

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.


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