Remote control of a tower clock

[fdew]

I have a nice old tower clock that I get to service once in a while. Sadly it was converted to run on AC quite a few years ago by gearing a small AC motor to the escape wheel shaft (The "Surplus" parts have been lost)

The customer is asking for remote control. This would be easy to do with some sort of a two speed motor, or by turning the clock into a waiting train (Start a faster AC motor once a minute and let it run until a cam on the escape wheel shaft drops off one minute later) and run the whole thing with a master clock.

I won't drill any new holes in the clock or do any other damage, but do you have any suggestions on how best to do this?

Thank You

Frank

[gvasale]

once upon a time, Bodine made a 2 speed gearmotor. Verdin used them in their installations. I think they were really motors with dual windings. They would have a fast run switch on the controller, but you could reset one faster by hand, but then there are issues between the actual time and the time on the controller. The fast mode really was only a little faster. Anything else and you're going to get away from a regular synchronous motor.

None of these contol units or motors are considered to be servicable units by their makers today. Independent motor shops can do the motors. Unknown about details of the contoller.
more in formation

[flynwill]

If you're going to replace the motor I'd suggest a modern stepper or servo motor driven by an off-the-shelf controller. You also might be able to get an off-the-shelf motor and controller from one of the commercial tower-clock makers that would be suitable. Or perhaps Le Arsi will sell you a custom one from the Philippines.

Alternately you could buy or build a variable frequency AC drive for the existing (I presume 60 Hz) motor. You probably won't be able to drive it any faster than about 20% fast, but maybe that is enough if it's just a matter of resetting if from power failures or Daylight savings time.

Most Bodine gearmotors are not synchronous and would not be suitable for timekeeping. (At least not without some sort of feedback mechanism).

[ElectricTime]

Variable speed AC drive controls will not work with most motors used on clocks.

On permanent magnet motors - the higher frequency screws up the phase shift created by the capacitor.

My firm make two options;

We have a control they will turn the clock off after a power failure or after the daylight savings time change - this is a modified version of our
99B control as shown at;

http://www.electrictime.com/controls_and_chimes/99b_mi_standard_control


You can also use the same drive unit with a motor box with an internal vane.

Please feel free to contact me directly at tde@electrictime.com or 508.359.4396 x 117

[sam]

Is there a Company out there that has a Stepper Motor/Controller package for Tower Clocks?

Thanks,

Sam

[ElectricTime]

Yes, we do on special order.

http://www.electrictime.com