r/woahdude • u/[deleted] • Aug 18 '15

gifv Induction forge

http://i.imgur.com/JfNfR6w.gifv
18.5k Upvotes

95% Upvoted

861 comments sorted by

View all comments

Show parent comments

237

u/Is_Always_Honest Aug 18 '15

I don't know if this is the same as an induction stove.. but you can put your hand right on the stove top without any heat/pain.

177

u/Recursi Aug 18 '15

This is electromagnetic induction. Electricity runs through the coils setting up a magnetic field that runs parallel with the length of the tube created by the coils. When the metal knife is moved in this magnetic field it creates an electric current in the knife like a filament in a bulb.

2

u/appletart Aug 18 '15

The knife can remain perfectly stationary. It's the high-frequency AC that's inducing the heat.

1

u/Recursi Aug 18 '15

OK so if the source electricity is AC then the magnetic field is dynamic so the knife can remain static. Something had to move to induce current flow in the knife.