Perpetual Motion toy
Perpetual Motion toy
Illustration of a circuit
Explanation of mystery top with two figures of the device

 

Code Number: 5K40.49b

Demo Title: Space Circles - Space Balls

Condition: Excellent

Principle: Motors, Electricity and Magnetism

Area of Study: Perpetual Motion

Equipment: 

Space Circles Demo, Space Balls Demo, Fresh 9-volt Batteries.

Procedure: 

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.

References:

  • 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.