RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Paul Koning]

> On Jul 26, 2018, at 11:26 AM, Tony Duell via cctalk <cctalk at classiccmp.org> wrote:
> 
> On Thu, Jul 26, 2018 at 4:14 PM, Chuck Guzis via cctalk
> <cctalk at classiccmp.org> wrote:
> 
>> Such MG setups were very common in industry before modern
>> semiconductors.  When I had a summer job showing movies at a drive-in
>> theater (a long time ago), the supply for the carbon-arc lamps was a
>> 40hp motor powered by 3-phase 60Hz, driving a DC generator.  In WWII
>> radio equipment, MGs in a unitzed form called "dynamotors" were used to
>> supply the high-voltage anode voltage for the tubes.  Electroplating
>> shops similarly used large DC generator setups to supply plating current.
> 
> I believe if you want to be pedantic that a motor-generator set is a motor
> (with an armature/rotor and a field/stator) mechanically coupled to a
> generator (with its own armature/rotor and field/stator) whereas a
> dynamotor has a common field/stator (and possibly both armature
> windings have to be wound on the same core).

Yes, so Wikipedia is wrong to describe a dynamotor as a motor-generator and show it in the m-g article rather than the rotary transformer article.

I remember the dynamotors shown in that photo, my father had that exact unit and several other "Command Set" radios.  The dynamotors clearly had a single armature, with input brushes at one side and output brushes at the other.

	paul