[GreenKeys] Teletype Motors

[WB6BLV (DM06)]

synchronous motors CAN turn at or near 3450 rpm...   synchronous speed depends on line frequency AND the number of pairs of poles in the motor... I have worked on many synchronous motors in Orgatron amplified reed organs that turn at or near 3500 rpm and are TWO POLE motors..   of course four pole synchronous motors turn at or near 1750 rpm when excited from a 60 Hz source...

also, just because a motor turns at or near some multiple or sub-multiple of a common synchronous speed does not necessarily indicate it is indeed a synchronous motor...

interestingly, for  many years the speed and torque of railroad locomotives was controlled, to some extent, by switching the pole configuration of the wheel motors...   a large number of poles would provide tremendous starting or low-speed pulling torque while switching to a configuration of fewer poles would provide increased speed once accelerating the load had been accomplished and  therefore less torque was required...  more interestlingly consider the task of the railroad engineer, who, before the era of automation, had to manually throw all those high-amperage switches to alter the pole configuration of the locomotive's wheel motors...   talk bout the need for speed and dexterity....

i think i still have coupla 16/8/4/2 pole pair  motors behind the shop and i know i still have one of the old manual locomotive switch panels out there somewhere...  geez, now my interest has again been peaked so i gotta go find the thing and again admire it...  it's raining, thanks a lot!

YOMV

John
WB6BLV at inreach.com