Re: Magnetic vs gravity impulsing

Andy Young

So do I!


-----Original Message-----
From: <> On Behalf Of Mike Isaacs
Sent: 13 January 2020 18:56
Subject: Re: [synchronomeelectricclock] Magnetic vs gravity impulsing


I have the same problem as Ian Richardson, i.e. receiving multiple copies of your messages. Six copies of the last, as well.

Mike I

In message <>, Ian Richardson via Groups.Io <> writes

I don't know why, but every time you post it comes at least 3 times!
This last one came 6 times!!

Ian R

-----Original Message-----
From: Bepi <>
To: synchronome1 <>
Sent: Mon, 13 Jan 2020 14:07
Subject: [synchronomeelectricclock] Magnetic vs gravity impulsing

The old dear synchronome seems to be much better at measuring time than
I was expecting.
When I say measuring time here I mean intrinsically, with reference to
its own internally produced noise. Then there are all those nasty
explicitly time dependent potentials like temperature, pressure,
celestial body attraction, etc, we'll take care of them later, here I
am only concerned with the internally manufactured noise. The noise
which would look statistically the same whenever you conduct the experiment. Correct me if I am wrong.
The ones who have looked at my previous post might have noticed that I
added to the clock a magnetic impulsing system (MagImp) which seems to
be working really well, if there is interest I can describe it in
detail in another post.
It works well in the sense that I can reduce the impulse irregular
period to the level of any other free fall period by carefully
centering it in the sense of Airy's tangent rule. With MagImp the
average power is somewhat reduced too, I got rid of the clock losses
linked to the timing wheel operation, and I am always referring to
stationary states at constant amplitude of when the clock ticks
normally, I should say ticked. And with those losses we do without the associated noise too.
In the following I will show circular error free data where the
amplitude stays the same for hours, within a few thousands of a degree,
corresponding to a fraction of a microsecond of circular error.
With the following graphs I'll compare two runs, one with magnetic
impulsing and the other with the old gravity escapement of a classic
synchronome. The clock is always the same other than the missing
drawing arm, I can switch from one impulsing scheme to the other in a
matter of minutes on the same clock, the one I purchased a few months ago on Ebay for 280 pounds.
First set of plots refer to the classic escapement:

the second set of plots refer to the magnetic impulsing case:

Compare the second graph of both set first: the average period over the
impulsing cycle vs time in hours. The average is different because the
data were taken months apart and the calibration had been changed in
the meantime, but we are not interested in the average, we are
interested in the regularity of the clock. The y scale to contain all
the measurements is roughly twice as big for the MagImp data, in fact
over the experimental run the SD (standard deviation) of the MagImp
data is 4.14 μs while for the gravity arm case the SD is 1.82 μs. The
impulsing cycles are different, the MagImp cycle consists of 5 clock
periods, the synchronome of 15, but the MagImp data have been averaged
over the same number of periods, 15, before taking the SD, so the SD comparison is fair.
The circular error variation calculated from the amplitude (green
points third
graph) is shown in the red trace. In both cases the circular error
contribution to the SD is negligible, a small fraction of 1 μs.
The real surprise is in the period within the cycle, first trace. The
data show typical individual period amplitudes during the run. Those
specific ones occurred at the end of the blue trace just below the
second graph, in hours from the beginning of the run but they all look statistically the same.
Pay attention to the y scale in those graphs, always in s, the
mechanical escapement induces ms size fluctuations around the power
impulse, plus a mess after it, while the magnetic impulse induces a
variation in the order of tens of μs, if any. The MagImp impulse was
not optimized as well as it could but its amplitude deviations are
nevertheless not bigger than the following free pendulum ones. You
couldn't tell when the impulse occurred and it was only 60 to 70 ms long.
The regularity of a clock, even this fast scale regularity, is not just
a matter of size of the fluctuations but also of their correlation
properties, I'll test the autocorrelation function when I have time,
but the fluctuations themselves are a prerequisite for errors and in
the mechanical case they are almost 2 orders of magnitude larger. Did
you ever look at the output of a clock timer like a Microset with a
quartz clock as an input? It's frozen on the same period reading to the
0.1 μs figure. I don't have a Microset, I use what Luke Mester gives away for free and an Arduino based one, but the result is the same.
Since the SD we are talking about is the one of the averages over the
whole cycle, 15 periods, what just said means that those large
deviations of impulse duration occurring at and around impulsing are
just as regular and reproducible as all the others.
I find this surprising and I would like to share it with all those
people that fell speechless in front of these data too.

Disclaimer: In this document words importing the masculine gender shall
be deemed and taken to include the feminine gender and the singular to
include the plural and the plural the singular unless the contrary as
to gender or number is expressly provided or unless the same is
inconsistent with the context and where covenants are to be entered
into by more than one person the same shall be entered into jointly.....

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[ A MIME image / jpeg part was included here. ]
Mike Isaacs

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