Nikola Tesla is my hero!

[kandrathe]

I'm not sure what you mean by "return to". Induction motors are used all over the place. Most stationary woodworking tools run on them ("benchtop" tools mostly use universal motors). Most industrial electric motors are induction (big machines driven by 3-phase motors). Even the whirling disc in your electric meter is an induction motor.

The trend towards permanent magnet motors has been primarily because they are smaller and lighter. The main reason benchtop woodworking tools don't use induction motors is because they're heavy.

In fact, I contemplated installing a 3-phase converter into my garage rather than re-wire some industrial equipment I have. But, alas, another day.

Mostly I meant the increased popularity of variable frequency regulating speed 3-phase asynchronous induction motors beyond the industrial, now that we can adjust speed more precisely with circuitry.

http://www.torquenews.com/119/toyota-and...ric-motors

It is interesting that the US and Canada got out of rare earth production due to ecological pressures and being undercut by China's low labor costs, and now due to increases in demand, and production limitations on supply China is causing the world to innovate it's way out of part of the demand rather than cause them to re-open domestic mining operations.