[time-nuts] Re: Power line timing

[Mahlon Haunschild]

Tangent alert:  this brings to mind a recent find at an antique store; a
variety of clock I had never heard of before.

One hundred years ago the idea of power line frequency control wasn't very
important.  In many cases, people were lucky to have electric power at
all.  But there was still a demand for a clock that one didn't have to wind
in some way but, nevertheless, kept accurate time.

The relatively-new Sangamo Electric Co. (run by Jacob Bunn Jr.) had a
synchronous shaded-pole motor that was used as part of their
demand-measuring watthour meter products, but they also had at that time
the idea of an electric clock powered by that same synchronous motor.  To
solve the problem of power frequency / quality / availability Jake Jr.
apparently rang up his dad, Jacob Bunn Sr., who of course ran the Illinois
Watch Co., looking for a solution.  The answer they came up with was a
clock movement that used an Illinois 16s pocket watch escapement built into
a platform,  with a mainspring that was continuously wound by the Sangamo
motor through a reduction gear train.  When the mainspring reached a
certain degree of winding strength, a small brake would act on the motor's
gear train to stall it, preventing overwinding.  The mainspring had
sufficient power to operate through a 24 hour power failure.

The below clock is a model 5106 and is in my collection, awaiting cleaning
and other restoration.  Along with the "Sangamo" logo on the dial you can
also see the "Illinois" brand on the 11-jewel platform escapement, proudly
displayed through a small (quarter-sized) round window in the dial.
Internally it is of the highest quality, with gold-plated gears, damascened
plates, etc. even though these details were never seen by the owners.  The
clocks were only made for roughly six years or so, and were as accurate as
a railroad pocket watch (more so, since they didn't move around and were
under constant winding tension).  They were also expensive.  My clock was
$60 in 1926, which would be $1050.00 today.

https://photos.app.goo.gl/ev5KmUbrrcsTAfCv7

Best regards

Mahlon - N4ZK

On Sun, Mar 24, 2024, 6:04 AM Thomas D. Erb via time-nuts <
time-nuts at lists.febo.com> wrote:

> Some old Warren Master Clocks from our collection.
>
> https://electricclock.omeka.net/exhibits/show/warren-master-clocks/warren-master-clocks
>
> BTW - in the 1970's and 1980's we used to make a faux version of one of
> these for some small power grids - it consisted of a small quartz (I think
> GE) wall clock and a AC mains clock - the power grid operator would just
> synch them up.
>
>
>
>
> Thomas D. Erb
> p:        508-359-4396
> f:        508-359-4482
> a:        97 West Street, Medfield, MA 02052 USA
> e:         tde at electrictime.com
> w:        www.electrictime.com
> Tower & Street Clocks Since 1928
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at lists.febo.com
> To unsubscribe send an email to time-nuts-leave at lists.febo.com
>