How to variable control the speed of your 110v AC power tools the safe and correct way..

In this tutorial we will look at how to control the speed of your 110V AC power tools the correct and safe way...
Sorry i did forget to mention the AC Rheostat, It works but I still prefer the variac.. FYI the dimmer controllers for your house lights and fans use these, you need a heavy duty one to use power tools with...