I am an American who just moved to Europe. Back in the States I accrued a plethora of power tools related to blacksmithing and carpentry. My question is, is it safe to use a 220-240v to 110-120v step down converter for power tools. I am aware that American tools are designed for 60hertz and that Europe uses 50hertz, and I am concerned that I might damage the tools or the home I am renting. Any thoughts?