Tuesday, November 3, 2009

SMMA Fall Technical Conference - Day 1

Today was the pre-conference workshops day, and that meant a four-hour course on "Fundamentals of Brushless Motor Control" for me.

Oh boy.

Despite the 8AM-ness of it, I got a lot out of it. It was just the right level for me...stuff I had seen before but don't full understand yet. Hence the reading material. That's the kind of thing that will keep me entertained for quite a while.

For one, I learned that there are more ways than I knew of to drive a PWM signal in an h-bridge or 3-phase bridge. I don't really understand some of the more clever ways yet, or the differences in performance, but it's something to look into in the controllers I build.

Other than that, today was Essex Active plant tour day. I learned what a slot wedge is:

A slot wedge.

It's a wedge that goes in slots. (Motor slots, of course.) It can be made of many things, including Nomex. The windings presumably go inside the wedge. And presumably the wedge is a tad longer than the slot. So the windings never touch steel. Genius. I wish I had some when we were winding the scooter motors. Oh well.

My table-top demo is ready and I will be manning the post early tomorrow morning. Then in the afternoon I present, right before AC Propulsion... Moderately frightening. More pictures tomorrow when that's all over with and I can relax a bit.

1 comment:

  1. i harvested slot wedges from a crufted AC motor for one of the motors I randomly built. Generally if you revamp old AC motors you can chisel out the windings but leave the slot liners intact. violin, no windings on steel.