Copper Brakes on an Electric Seth Thomas?

[Keith Doster]

I've been wrestling with this movement for several days, repairing "repairs" made by others. Not being very familiar with electric clocks, and not at all with this one, can someone explain what's going on with what appears to be copper disks that spin past mounted permanent magnets? Do these somehow serve as governors? I've never seen this before. Thanks!

 

[Keith Doster]

I found this weirdness regarding copper and magnets on YouTube. Wow. So I'm certain this is the braking/governor for the chime and strike trains. The magnets are adjustable to regulate their effect on the copper discs. At least that is my assumption. Haven't tried it yet.

 

[Karl Thies]

They are magnetic governors, by adjusting how deep or how shallow they cover the disc will change the speed that the chimes play.

 

[Keith Doster]

They are magnetic governors, by adjusting how deep or how shallow they cover the disc will change the speed that the chimes play.

Hey Karl, thanks for the response. Have you ever seen this kind of magnetic setup on any other clocks, or was this only a Seth Thomas thing?

 

[Karl Thies]

I have not seen this on any other clock Seth Thomas or otherwise, and in later versions of this movement they went back to the regular fan governor. i did not particularly like this innovation and found it troublesome at times with the chime speed being somewhat erratic.

 

[Keith Doster]

I have not seen this on any other clock Seth Thomas or otherwise, and in later versions of this movement they went back to the regular fan governor. i did not particularly like this innovation and found it troublesome at times with the chime speed being somewhat erratic.

Thanks again, for responding, Karl. Is there a secret to adjusting the depth of the magnets or is it just trial and error?

 

[Karl Thies]

It is basically trial and error . The deeper the wheel is in the magnetic field, the slower it will spin and further out will spin faster. Remember too that magnets get stronger with the cold and weaker with the heat. I think this innovation was solely for the sake of innovation and they realized the original fan governor was far more reliable. But, that is my opinion.

 

[sophiebear0_0]

That's a very interesting clock and a nice video clip. Thanks for posting them.

In a slightly different application, ATO did use small copper pipes/hoops to prevent overswing on their magnetic pendulums. The concepts was that this would retain a uniform pendulum swing as the battery ran down. The method works well in this application. It is factory set and cannot be adjusted.

Regards,

Peter

 

[Armando Alcaraz]

I've been wrestling with this movement for several days, repairing "repairs" made by others. Not being very familiar with electric clocks, and not at all with this one, can someone explain what's going on with what appears to be copper disks that spin past mounted permanent magnets? Do these somehow serve as governors? I've never seen this before. Thanks!

View attachment 755794

Same movement on my Seth Thomas. My breaks are are very dirty but the copper disc rotate freely.

 

[Wimberleytech]

Yes, I have serviced several of these. As soon as I saw the copper disks, I knew--I am an electrical engineer.
In simple terms, as the disk spins a current is induced that creates a magnetic field opposing the one that induced the current. So, it adds "resistance" to the rotation of the disk. Seth Thomas was clever by half. The magnets lose their strength over time. What I have done is attach small neodymium disk magnets to the plate and adjust them to achieve the performance I want.
A conventional fly works better, but I do think it is cute.