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@electrictime.com w: www.electrictime.com Tower & Street Clocks Since 1928

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@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@electrictime.com > w: www.electrictime.com > Tower & Street Clocks Since 1928 > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com >

I don't think the clockwork backup idea died with that product. I've seen common timeswitches (the type used to control streetlights, where it wasn't done centrally) with a clockwork mechanism would by a motor, though I don't think it was such an exotic mechanism as the one you describe. You can imagine the effort needed to reset streetlight clocks if a power cut put them all a few hours out of sync. These were made by Sangamo-Weston so presumably a descendant of the one you describe. On Mon, Mar 25, 2024 at 11:42 AM Mahlon Haunschild via time-nuts < time-nuts@lists.febo.com> wrote: > 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@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@electrictime.com > > w: www.electrictime.com > > Tower & Street Clocks Since 1928 > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe send an email to time-nuts-leave@lists.febo.com > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com

An electrically-wound mechanical clock was common in automobiles up until recent times. Jeremy