[bomelia]

Well, Wes, that was very informative. I am following a thread at Sawmill Creek (woodworking forum) that is discussing this very issue. Nobody can agree on anything. It sounds like you are saying that "typical" shop induction motors (table saw, grinders, etc) can be controlled electronically (speed wise). Now, from what I have been able to discern is that it is true for three phase motors, but not single phase. Also, the single phase motors in our shops have those capacitors for starting. If the motor slows, then there is an electro-mechanical system that will engage the starting capacitors (vary the phase so the the motor speeds back up).

So what would you say to this? And do you know of a device that can be bought reasonably) to control induction motor speed?

Also, I have read that the induction motor cooling design is optimal at the design speed, thus, external cooling should be supplied when slowing them down (mostly talking about 3 phase motors).

Mike