A self-starting swinging apparatus including a free-running oscillation circuit comprising two transistors which are a PNP transistor and an NPN transistor, the bases of both transistors being connected respectively to the collector of one transistor directly and to the collector of the other transistor through a capacitor for setting a time constant; a driving coil connected to the collector of the transistor with the capacitor connected thereto, as a load on the transistor; and a permanent magnet having a relatively repulsive magnetic pole arrangement of the same polarity as, or having a relatively attractive magnetic pole arrangement of a different polarity from, that of a magnetic pole in a magnetic field which ought to be generated in the driving coil when an electric current is fed to the driving coil from the oscillation circuit, the permanent magnet being relatively movable with respect to the driving coil and capable of performing a relative swing motion under the action of an arbitrary restoring force, one of the permanent magnet and the driving coil being fixed to a swinging side and the other fixed to a stationary side in a position near or deviated from a neutral point of a swing motion of the swinging side.
An intriguing and educational display structure (1) appears to be spinning upon itself without any apparent drive mechanism, power supply or bearing. The structure comprises two concentric hollow spheres (3, 5) spaced apart by a transparent fluid (6). The outer sphere is totally transparent, immobile and may rest on a tripod (2) or other type of support. The inner sphere may be partially transparent or translucent and carries over its surface, a design such as a map of the world (7). The inner sphere rotates within, and independently from the first outer one. The internal, that is self-contained drive mechanism is referenced to either a compass, a light angle detector, or a gravity sensor, and uses either a conventional electrical motor with its own internal field winding and communitator, or one made of a rotor comprising a cross-array of electromagnets (AC, BD) that interact with the earth magnetic field.
