Re: GE Motor

[Lee Hart <leeahart@earthlink.net>]

stevenr@flash.net wrote:
> Actually I didn't make compensation windings, I just wanted to add
> them if I could get them from GE. I'm adding a winding for Regen use.
> I'm going to add a winding around the existing field coil using
> smaller wire that I can enerjize with a seperate regen circuit.

Sounds like Steve is making it a compound motor, instead of a pure
series motor. Be aware that when you have both series and shunt field,
the two windings will also act as a transformer. A PWM controller
applies quite a large voltage to the few-turn series winding. This will
get stepped up to some amazing voltages on the shunt winding!

Example: Motor has a 1v 10-turn series field. You add a 10v 100-turn
shunt field. Assume a 120v battery pack; when controller runs motor at
50% duty cycle, 60v appears across motor armature, and +/-60v appears
across series field (+60v when controller is on, -60v when off).
Transformer action means the shunt field has a +/-600v square wave
across it!

A true compensating winding goes into slots cut in the face of the main
poles. It would be a *lot* of work to retrofit!

Interpoles are a separate set of smaller poles and windings that go in
the space between the existing main poles. Fairly simple to add if there
is room, presuming you can find the pole pieces.
-- 
Lee A. Hart                Ring the bells that still can ring
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