Magnetic positioning mechanism for fluid-supported self-rotating displays

A self-rotating device comprises:

• a container carrying a fluid;
• a self-powered rotating body buoyantly supported by said fluid;
• wherein said body comprises:
• an axis of rotation;
• an electric motor contained inside said body, said electric motor comprising:
• a counter-torque element rotationally responsive to an ambient magnetic field;
• and,
• wherein said device further comprises:
• a magnetic lateral positioning structure apart from said body and apart from said electric motor, wherein said magnetic lateral positioning structure is fixed in a non-rotating manner to said container;
• and,
• wherein said magnetic lateral positioning structure is located an effective distance from said counter-torque element so as to laterally bias said body toward a position of magnetic equilibrium between said magnetic lateral positioning structure and said counter-torque element.