Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: vidam on June 03, 2008, 01:21:55 PM

Title: # of magnetic poles
Post by: vidam on June 03, 2008, 01:21:55 PM
The DC brushless motor by Scorpion has 14 magnetic poles:
http://www.rcdude.com/servlet/the-710/Scorpion-4020-dsh-16-Brushless-Motor/Detail
What does this mean exactly and how does it affect the type of speed controller I use?

Title: Re: # of magnetic poles
Post by: AndrewM on June 03, 2008, 02:13:00 PM
The number of magnetic poles is just the number of times the circumference of the armature or can flip-flop from north to south.  Up to a point, the more poles, the more efficient.  After you get past a given number (based on size, and magnetic strength and other things) you start loosing efficiency.  In this case, there are 14 physical magnetic poles, and 14 electromagnets.  At any given time, 7 of the electromagnets are north facing, and 7 south facing.  The ESC just flip-flops the electromagnets to match where it is rotationally in such a way that it continues to rotate.

So now to the answer you want to hear...  It does not effect the type of speed controller you use, provided it is a BRUSHLESS speed controller, and is rated for the correct number of amps.