26 Jul
2018
26 Jul
'18
9:17 a.m.
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:
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
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).