Torque...

[jmcall10]

Hi,

First of all this is my first post so hello to all.

Ok my question is regarding ac/dc electrical motors and the machine torque equation.

Basically I have been asked what would happen to the motion of the motor if the polarity of the field supply would be reversed, taking into account the machine torque equation.

Now I have looked in many books etc and I cant fathom out how the "torque equation" comes into it? I understand that the motor will rotate the other direction. But I dont see where the torque equation helps prove this?

Any help would be greatly appreciated.

Jmcall10

 

[rryles]

What happens if you put a negative number into the torque equation for the field supply?

 

[jmcall10]

I understand where you are going with that, however am I right in saying you cant get a negative torque?

Are you saying that in a positive dc supply it goes one way and with a negative dc supply it goes the other?

I understand that but not how the torque equation proves this

Jmcall10

 

[rryles]

A negative torque is a torque in the opposite direction.