5K20.40 Eddy Current Levitator
A magnet levitates over a rapidly spinning aluminum disc. As a control experiment, a brass nut may be used to demonstrate that the levitation is an eddy current effect.
-  Magnet
-  Brass nut attached to a piece of card stock
-  Magnet attached to a piece of card stock
-  Aluminum disc attached to a motor
- (Optional)  Video camera
- Plug in the motor.
- The disc spins at several thousand RPM. DO NOT TOUCH.
- Keep the magnet away from the centre and edge of the aluminum disc. If the magnet comes too close to the edge it can skip and shatter. If it comes too close to the centre, it can stick suddenly to the magnetic screws in the centre.
- The magnet is strong and brittle. Handle with care.
- Position the magnet on the aluminum disc and hold on to the end of the piece of card stock.
- Turn on the motor. The magnet will levitate.
- Turn off the motor.
- Position the brass nut on the aluminum disc and hold on to the end of the piece of card stock.
- Turn on the motor. The brass nut will not levitate.
- PIRA 5K20.40
- Demonstration Manual for 12-in-1 Apparatus; DHP El-1; DaR B-290
- T.D. Rossing and J.R. Hull, "Magnetic Levitation," TPT 29, 552 (1991)
- Don't attempt this at home!
- A Nd-B-Fe magnet (1/2" diameter, 1/4" thick) is attached to a piece of card with double sided tape. The brass nut is 1/4-20.
If you have any questions about the demos or notes you would like to add to this page, contact Ricky Chu at ricky_chu AT sfu DOT ca.