# Question for Motor experts

**URL:** <https://community.electricforum.com/t/question-for-motor-experts/984>\
**Category:** EV Small Talk\
**Created:** [September 27, 2008, 2:31pm UTC](https://community.electricforum.com/t/question-for-motor-experts/984 "2008-09-27T14:31:16Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Qmavam](https://avatars.discourse-cdn.com/v4/letter/q/9de0a6/32.png) [@Qmavam](https://community.electricforum.com/u/Qmavam)\
**Post date:** [September 27, 2008, 2:31pm UTC](https://community.electricforum.com/t/question-for-motor-experts/984/1 "2008-09-27T14:31:16Z")

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I’m looking for info on how a shunt field type motor works and some advice  
If you know of any URLs about shunt field type motors, please post them.  
I have a shunt type motor, the shunt is 40 ohms.  
I have a series type motor controller (Alltrax NPX4834).  
I know your supposed to use a different controller for shunt  
type motors, but I have what I have.

I have three thoughts about how to connect it.

Just connect the shunt to the battery voltage and leave it.

Connect the shunt to the battery voltage with a reostat  
so the current can be adjusted. (Where to have the current  
at what time would be the question)

Connect the shunt to the motor plus and let the controller  
PWM the parallel shunt/armature connection.

This is on a gokart and I’m using the contoller at about 1/3  
of max current.

Can you help?  
Thanks, Qmavam

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**Author:** ![Engineer\_Bill](https://avatars.discourse-cdn.com/v4/letter/e/b5ac83/32.png) [@Engineer\_Bill](https://community.electricforum.com/u/Engineer_Bill)\
**Post date:** [October 18, 2008, 11:28am UTC](https://community.electricforum.com/t/question-for-motor-experts/984/2 "2008-10-18T11:28:41Z")

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I would go with the reostat, you generally want to drive the shunt at a lower voltage than the armature. Best would be to buy a shunt controller. If no shunt controller and no reostat, the next best would be to drive the field coils ona a seperate supply. You would have to experiment to see what works the best. I have seen people driving a shunt motor with a PM controller so I know it can be done.