5K40.49b - Space Circles - Space Balls

Code Number:
Demo Title:
Space Circles - Space Balls
Motors, Elec. & Mag.
Area of Study:
Perpetual Motion
Space Circles Demo, Space Balls Demo, Fresh 9 volt Batteries.

See also 5K40.49b in Electricity and Magnetism

These demos are specially designed brushless DC electric motors.  The moving parts have magnets in them and correspond to the rotor and flywheel of the motor.  The base of the demo contains a battery, coil, steel core, and a transistor.  The moving rotor induces an electric current in the coil.  This current is amplified and fed into an electromagnet which applies a torque to the magnetic rotor.

  • H. Richard Crane, "A Spinning Top, Lenz's Law and Electric Watches", TPT, Vol. 22, # 2, Feb. 1984, p. 113.
  • C.L. Stong,  "An Electrometer, a Temperature Control Apparatus, and a Simple Electric Motor",  The Amateur Scientist,  October, 1965.

Disclaimer: These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist.  The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose.  The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources.  Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks.  These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage.  Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.